Re: ShopTalk: NBP-COG
Hi Guys, At the risk of raising the spine issue for the umpteenth time I thought I might mention one lttle alignment technique I tried which worked pretty well. There seem to be some concern as to just how closely a particlar point (sorry, plane) on the shaft could be aligned. I'm and NBP at 3:00/9:00 or 9:00/3:00 sort of guy. Admittedly it is difficult to get the alignment down to the couple of degrees but 5 degrees is a whole lot better than 45 dgerees. To see how close I could get it I took a 1" square plastic block about a half inch thick and cut a .56" notch in it. I installed a set screw to hold the block onto the shaft. I drilled a small hole in the side of the block and stuck a 10" long shis ka bob stick in it. I then secured it to the shaft about where the grip would end. I did my twanging and when I found the minimum frequency plane while twanging vertically I slid the block around 'til the stick pointed directly vertical. When I glued the head in place I simply addressed the "ball" and rotated the shaft until the pointer was pointed at my target, or directly away from it if the logo looked better. I haven't messed with this approach lately. I find it much easier to use shafts with one cpm variation or less. Cheers, John K
Re: ShopTalk: NBP-COG
Dave T. First, thanks much for taking the time and expending the energy to respond so completely to my sophomoric question! There clearly appears to be some strongly held divergent opinions and theories, regarding residual bends, placement of spines, COG, etc! Thanks to you and all that entered the fray, I now know more about these things than I care to know, but still don't know enough! Like the scholar that returned from a 2 year sabbatical when asked what he had learned said: "The only thing I can say with certainty is that I am absolutely, totally confused, but at a significantly higher level!! Again thanks all; I will eventually figure it out; hope ya'll do too!!! - Original Message - From: "Dave Tutelman" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Thursday, October 09, 2003 4:23 PM Subject: Re: ShopTalk: NBP-COG > At 12:48 PM 10/9/03 -0500, Bill Douglas wrote: > >Gentlepersons, > > I have been lurking on this NBP-COG "Fest" and lacing the level of > >technical acumen the protagonists and antagonists possess have become > >totally confused! However, its too juicy to not dive in; so here's at it! > > > > I read some time ago that Golfsmith did some experimenting/testing with > >the Spine/Cog alignment and found there was no appreciable/discernable > >difference in shaft performance vs. Spine at one of the 4 cardinal > >positions. Also if I'm not mistaken, John Kaufman got confirming results > >when he did similar experimenting/testing. Is this the same thing that's > >being discussed in this case? Please advise. Thanks in advance!! > > Bill, > You're right, it is confusing. In fact, lots of the people in the > discussion are confused, because we can't all be right when we're saying > such different things. Anyway, let me give you my take on it. If I'm wrong > (of course I doubt that, but there are others who are SURE I am -- who > knows?), then this will be further confusing. > > First of all, we are talking about spine alignment or NBP alignment. Leave > COG out of it for a while, until we understand spine and NBP. > > SPINE is the stiffest plane of a shaft in bending. NBP is the most flexible > plane. The concept of plane is the first area of disagreement among the > protagonists. Some say that it is possible for the stiff side to be 180* > opposite the flexy side. But the engineers in the group say that is not so; > it is an artifact of an imperfect instrument used to find the spine. In > fact, spines will be 180* apart every time, hence I talk about "plane". > Similarly NBPs will be 180* apart from one another every time. BTW, that is > what John Kaufman proved. He proved nothing about how to align the spine or > NBP when you make a club, just that the order of things as you go around > the shaft is spine-NBP-spine-NBP at about 90* intervals. This also agrees with: > * Theory that every mechanical and structural engineer learns in school. > * Tests that others have done, including one I've witnessed involving a > FlexMaster. > > There is another issue here: the residual bend in the shaft. That is, no > shaft is perfectly straight. Some are straighter than others. Any lack of > straightness will "fool" the simple spine finder. There are more accurate > ways of finding/measuring the spine that are not fooled by lack of > straightness. Dan Neubecker (inventor of the NeuFinder, which is fooled) > takes the position that you should orient what you find in the NeuFinder, > because bend affects performance in the same way that spine does. I don't > believe any such thing. Oh, it might coincidentally be true, though I doubt > it. But there is no evidence to support it -- and two of the three theories > of spine alignment (the two credible ones, IMHO) say that's not even close. > > OK, now we have talked about characterizing the shaft. Let's talk about how > we align shafts in clubs. I'll assume the shafts are straight, so that > spine is the only alignment issue. There are three competing assertions > about how to orient the spine: > > (1) Spine in the target line, NBP in the heel-toe plane. That is > essentially what Weiss advocates. (He talks about the FLO. But if you find > the REAL spine, then the higher-frequency FLO is exactly the spine.) > > (2) NBP in the target line, spine in the heel-toe plane. Most members of > this forum believe in this orientation. It seems to make the most sense to > me; no quarrel with the forum here. It also happens to be what Talamonti > advocates. > > (3) NBP oriented toward the center of gravity (COG in the forum, CG > traditionally). T
RE: ShopTalk: NBP-COG
I can honestly say that this is the first time I have ever seen a noticeable difference in performance from a change in shaft. I'm a swinger, not a hitter, with a swing speed of about 105-mph with a 45-inch driver. I had previous good luck with the YS-6 and Purple Ice and was a bit hesitant about using the more tip-stiff NV. I inserted an NV 65-S 1.25-inches (minimum insertion recommended by Aldila) in my 983K and the ungripped frequency came out to 248-CPM at 45-inches (5-inch butt clamp). The NV feels really solid without any "boardiness". My trajectory tends to be low but, with the ball teed up high, the trajectory is great with a flat apex. I have used the shaft for about three months now and I have yet to hit a slice or hook with it. When my swing is "on" I get the longest, straightest drives I have ever hit. When the swing is "off" the NV keeps me on or near the fairway. This is the best graphite shaft I have ever used. -Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]Sent: October 11, 2003 12:54 AMTo: [EMAIL PROTECTED]Subject: Re: ShopTalk: NBP-COGIn a message dated 10/8/2003 1:14:12 PM Pacific Daylight Time, [EMAIL PROTECTED] writes: I have reshafted my three drivers using the NBP-COG alignment (975J/GraphiteDesign YS-6; 975J-VS/Graphite Design Purple Ice; 983K/Aldila NV) and wasvery pleased with the results of all three. I reshafted one of my Titleist962 sets with the new Balistik shaft using the S1-COG alignment and reallylike these as well. Anecdotal info for what it's worthHi,What did you think of the Aldila NV ?David
Re: ShopTalk: NBP-COG and Testing
On Fri, October 10, 2003 at 7:35 pm, Dave Tutelman sent the following > > * Charlie has taken a fair number of shafts that show up as Type 1 in > a spine finder (he has three different bearing-based spine finders) > and found the TRUE spine and NBP using a FlexMaster and a procedure > we designed together. The true spine and NBP were not nearly the same > as what the spine finder said. And, once he had found them by > measuring actual stiffness, he did find FLO in the NBP and spine > planes. But yes, they wobbled all over the place in the fake N-S > plane that the spine finder found. Now I have to pick up a freqency meter and re-align all the shafts in my clubs. All my steel shafted clubs are aligned according to the residual bend detected by my spine finder, it's probably as good as random alignment. Doh! ;-) Thanks for all the info, Dave. -Dave
Re: ShopTalk: NBP-COG
At 01:51 AM 10/10/03 -0700, David Rees wrote: On Thu, October 9, 2003 at 6:34 pm, Dave Tutelman sent the following > (1) You don't need 2-d measurements but they would be interesting, > and for EXACTLY the reason you suggest. The spine and NBP planes will > show all the force in the direction of the bending, and no > perpendicular component. Other planes will show a perpendicular > force, which is why FLO works to find spines and NBPs. Yep. I'm getting the hang of it now. You are indeed. > (2) You need to be careful to measure the DEFLECTION of the shaft, > not the POSITION. That is, you need to measure the DIFFERENCE in > position between zero load and full known load Isn't that what I said? ;-) I don't know; you didn't say enough for me to be sure. If you say so, then fine. ;-) I googled FlexMaster and found some information on it. Seemed like their proponents were intent on bashing frequency analyzers as "old technology", but then go on to say that they double check all their work with one. Seems to me now that you would be able to use either tool effectively, though the only benefit of the FlexMaster is being able to measure how bent the shaft is. But it seems that the bend of the shaft doesn't matter unless it's REALLY bent! Actually, the major benefit of the FlexMaster is that it can flex-match a set of clubs MUCH faster than a frequency meter. It is probably faster (and easier, no math) than a NeuFinder, but I haven't used a NeuFinder yet for that so I can't be sure. It is neither better nor worse than a frequency meter in the quality of the match -- no matter what they say. Their big advantage is productivity. If you're a high-volume shop, the productivity can pay for the high initial price of the machine. > BTW, the difference-deflection measurement is essentially what John > Kaufman did in his testing to show that all shafts are really Type 2. I'll have to go read up on that again.The more I read the more I convince myself that the tried and true method of aligning the N-plane along the target line is the way to go. I suspect that is correct, though I haven't seen comparative data to prove it. But be sure to use the REAL N-plane. If you measure an N-S plane, you probably don't have the right plane. If you have an S-S plane and an N-N plane at right angle to one another, then you almost certainly have the right plane. Good luck! DaveT
Re: ShopTalk: NBP-COG
In a message dated 10/8/2003 1:14:12 PM Pacific Daylight Time, [EMAIL PROTECTED] writes: I have reshafted my three drivers using the NBP-COG alignment (975J/Graphite Design YS-6; 975J-VS/Graphite Design Purple Ice; 983K/Aldila NV) and was very pleased with the results of all three. I reshafted one of my Titleist 962 sets with the new Balistik shaft using the S1-COG alignment and really like these as well. Anecdotal info for what it's worth Hi, What did you think of the Aldila NV ? David
Re: ShopTalk: NBP-COG and Testing
At 01:29 AM 10/11/03 +, golf54com wrote:
Hi DaveT
Allow me to provide some background info. to the question:
Harry,
Thanks for the explanation. I was hesitant to answer the question as first
posed because it sounded like a trick question, like there was some sort of
"catch". Now that I fully understand the question, I know how to deal with it.
Earlier this year, I bought some of the new Apollo steel shafts.
I found and marked N. Majority, not all were type 1 per bearing
spinefinder. I understand in theory that all shafts are type 2 and
not type 1 vs. type 2. I evaluated a dozen and they seemed pretty
bad. Most rolled ok on a flat table, so not severely bent. Almost
every shaft I tested had a severe wobbler on the N-S plane, to the
point my GS freq. analyzer wanted to error out. I've never had the
freq. analyzer error out from testing a steel shaft before ... why?
Turned it 90 degrees and up to 6 cpm difference between N-S and 90
deg. rotation. These steel shafts resembled the graphite shaft demo
that is a severe supershaft. Now I have another 'show and tell'
shaft, to share with potential customers. Why wobble on N-S plane?
Why wobble on the N-S plane? Because we disagree on the definitions of N and S.
* Your definition of N and S is whatever your spine-finder tells you.
* My definition is the direction of minimum ("N") and maximum ("S")
stiffness.
Those two need not be the same. And if you EVER find an "N-S plane" in your
spine finder (that is, N and S separated by 180*), the two definitions are
very different for that shaft.
John Kaufman and Charlie Badami have both done experiments, with different
instruments, that show what the engineers on ShopTalk have been saying for
years: all shafts are Type 2 if you measure the actual stiffness.
* John has measured a bunch of shafts using both a frequency meter (hey,
he makes them for a living) and an "inverted flex board". Both showed that:
- Maximum stiffness occurs at 180* intervals, and corresponds to
the plane of maximum frequency.
- Minimum stiffness occurs at 180* intervals (90* away from the
maximum), and corresponds to the plane of minimum frequency.
* Charlie has taken a fair number of shafts that show up as Type 1 in a
spine finder (he has three different bearing-based spine finders) and found
the TRUE spine and NBP using a FlexMaster and a procedure we designed
together. The true spine and NBP were not nearly the same as what the spine
finder said. And, once he had found them by measuring actual stiffness, he
did find FLO in the NBP and spine planes. But yes, they wobbled all over
the place in the fake N-S plane that the spine finder found.
Hope this addresses your question.
DaveT
RE: ShopTalk: NBP-COG
Dave, You can account for bend in the shaft in the NF2, it just takes a little more work and a different tip bearing arm design. You do it by differential deflection. That is deflect the shaft a given amount and take a measurement. Then deflect the shaft an additional common distance, say 1" and take a second reading. The difference between these two readings will be the true shaft stiffness, with the bend effect neutralized. Compare that number to other readings taken around the shaft and you can determine if where the stiffest and softest plane of the shaft is, without regard to shaft geometric anomalies. Dave T. deserves the credit for pointing out this process to me and then I came up with a simple tip bearing design alternative to make it work. Dan Neubecker [EMAIL PROTECTED] >-Original Message- >From: David Rees [mailto:[EMAIL PROTECTED] >Sent: Thursday, October 09, 2003 6:41 PM >To: [EMAIL PROTECTED] >Subject: Re: ShopTalk: NBP-COG > > >On Thu, October 9, 2003 at 2:23 pm, Dave Tutelman sent the following >> >> SPINE is the stiffest plane of a shaft in bending. NBP is the most >> flexible plane. The concept of plane is the first area of >> disagreement among the protagonists. Some say that it is possible for >> the stiff side to be 180* opposite the flexy side. But the engineers >> in the group say that is not so; it is an artifact of an imperfect >> instrument used to find the spine. In fact, spines will be 180* apart >> every time, hence I talk about "plane". Similarly NBPs will be 180* >> apart from one another every time. BTW, that is what John Kaufman >> proved. He proved nothing about how to align the spine or NBP when >> you make a club, just that the order of things as you go around the >> shaft is spine-NBP-spine-NBP at about 90* intervals. This also agrees >> with: * Theory that every mechanical and structural engineer learns >> in school. * Tests that others have done, including one I've >> witnessed involving a FlexMaster. > >Not being a mechanical or structural engine who is familiar with the >tensile properties of the materials used in golf shafts, I may >be way off >base here, but here goes: > >Isn't it possible for a material to have different compression >and tensile >strengths? > >For example, we'll use some poor ascii art below depicting a >side view of >a shaft where one side of the shaft is significantly thicker than the >other: > > > > > >The top side drawn with the - is the thin side, the bottom >side drawn with >the = is the thick side. > >Assume (which is probably a bad assumption but will get the >point across) >that the material does not compress at all, but does stretch linearly >depending on the thickness of the material. > >If you pull down on the shaft the club will deflect some >amount. But if >you push up on the shaft the club will only deflect 1/2 the >amount as it >deflected down. Measured in a frequency meter you will only get one >reading as a frequency meter can only measure stiffness in >planes, but in >a deflection meter you will find the shaft bends different >amounts in each >direction obviously affecting the position you might want to orient the >shaft. It also seems that if the shaft started off bent in >one direction >or the other, it would affect the stiffness of the shaft in each >direction. How much? I don't know, you guys who know materials better >than can will probably tell me what I've described isn't >possible. ;-) >Please do if I'm totally off base. > >So from what I can tell, the main drawback of a frequency meter is that >you can only measure stiffness in planes, when a shaft may >actually have a >different stiffness in each direction. > >The main drawback of your typical spine finder (don't know if >this applies >to the NF2 or not) is that you don't take into account any bend of the >shaft. It seems to me that a method which could be used to measure the >stiffness of a shaft would be done as follows: > >Clamp one end of the shaft in a bearing device with no load on >the other >end. Take 2-d deflection measurements at multiple points around the >shaft, making sure that each measurement is made using a >constant force. >An easy way would be to use a weight free hanging to prevent >side-forces >from affecting measurements. 2-d measurements may not be necessary if >shafts always bend in the vertical plane, but I think if they did, you >would always get FLO no matter which way you aligned a shaft. > >Once you've got this data, you will be able to predi
RE: ShopTalk: NBP-COG
Tom, Ok, I see that you did ask about the hard spot. I was thinking NBP-COG wince that is the subject line :-) In that case I agree with you. The hard spot, being the most unstable spot on the shaft, can't be precisely oriented and many of us don't care where the hard spot is, since it is not the plane that the shaft most wants to naturally bend in. Many of us are orienting shafts based on NBP for that reason. The NBP can often be precisely found and oriented, if you believe in what a spine finder tells you. In the case of NBP to any related clubface alignment, it can be done quite precisely. Dan [EMAIL PROTECTED] >-Original Message- >From: tflan [mailto:[EMAIL PROTECTED] >Sent: Thursday, October 09, 2003 4:13 PM >To: [EMAIL PROTECTED] >Subject: Re: ShopTalk: NBP-COG > > >Uh; > >I didn't mention anything about NBP-GOG. What I said was its virtually >impossible to assemble a club with the "hard spot" in a >precise position. I >have a spinefinder and a freq machine. I find hard spots - >spines, and soft >spots - NBP's easily. No problema. I don't deny the existence >of spines, >NBP's, or COG's. My argument is about marking and assembling. > >TFlan > >- Original Message - >From: "Dan Neubecker" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Sent: Thursday, October 09, 2003 6:44 AM >Subject: RE: ShopTalk: NBP-COG > > >> Hi Tom, >> >> It depends on what theory you believe in. If you believe >that a spine >> finder can find the correct NBP location as I do, then you >absolutely can >> get the NBP exactly at the COG. >> >> Bernie's post on NBP to COG alignment contained a quote from an >experimental >> set I made up. I did not have any high expectations for >that set when I >> made it up. Let me tell you that I was shocked by the >difference in the >> results. The results continue today after months with this set. I >continue >> to hit the best irons of my life. Now this set was a >combination of new >> things for me. First, I used a new shaft, PC Mach 22's, >with R+, S- and S >> shafts in the set. I used my NF2 to tip trim them to a >matching profile >of >> .010" deflection between clubs, never having to trim more >than 1/2" tip to >> do so, and the find the NBP locations. Then I made up the >clubs with a >3/8" >> change between lengths, for a poor man's MOI match. Finally >I assembled >> them using the NBP (N1) to COG alignment. >> >> It could have any of those factors, or all of them that led to these >> results, but I was literally shocked by how much better they >played than >any >> set I've used. It was the most difference I have seen in at least 10 >years >> of experimenting with clubs, different lengths, different >shafts, flexes, >> torques, components, you name it, I've tried it. >> >> I can't ignore results like that, regardless of how tenuous >the theory. >> >> Dan Neubecker >> [EMAIL PROTECTED] >> >> >> >-Original Message- >> >From: tflan [mailto:[EMAIL PROTECTED] >> >Sent: Wednesday, October 08, 2003 12:04 PM >> >To: [EMAIL PROTECTED] >> >Subject: Re: ShopTalk: NBP-COG >> > >> > >> >Dr Tutelman: >> > >> >A question, por favor. When this subject was broached several >> >months ago, >> >and the thread unwound for about 3 weeks, I asked a question >> >that got no >> >universally agreed upon answer. The question was; is the spine >> >found at the >> >top of the shaft or at the bottom of the shaft when testing in >> >Dick's spine >> >finder? Responses were equally, and passionately, divided. >> > >> >I then asked another question; if when one finds the spine, >> >the "hard spot" >> >via the use of our arguably primitive methods, how can one >> >accurately mark >> >and then place the hard spot in a specific position? As I >recall, you >> >responded, correctly, that we'd be lucky to get the spine >> >situated to within >> >3 to 4 degrees. You mentioned the circumference of the >.335" tip, when >> >reduced to 360 degrees, would be virtually impossible to set >> >accurately. I >> >agree. An assembler would need to identify the spine at the >> >shaft tip by >> >marking it with a needle, then mark the hosel in the >precise finished >> >position. Then he'd need to mark the ferrule so the enti
RE: ShopTalk: NBP-COG
There hasn't been any difference in the mean or average impact position on my driver from NBP@ 9 / 3 o'clock to NBP-COG, I just seem to hit it there more often with the NBP-COG alignment. Unfortunately (from a scientific point of view, but fortunately from a scoring point of view) my switch to the NBP-COG alignment occurred while my handicap was coming down from 12 to 8. If I had to take an educated guess, I'd say the more consistent impact pattern had more to do with the Indian learning to shoot better than any improvement in the arrow. -Original Message- From: Bernie Baymiller [mailto:[EMAIL PROTECTED] Sent: October 9, 2003 2:28 PM To: [EMAIL PROTECTED] Subject: Re: ShopTalk: NBP-COG Jim, > My 983K with the Aldila NV is getting a wear spot high in the middle of the face. Interesting in that I also thought the impacts on my woods with NBP-COG were slightly higher on the face, though centered. Didn't notice it on irons as much. Maybe toe droop because NBP more in the vertical plane? Might be something to watch for. Notice any changes in impact area on your S1-COG alignment? Dan, any change in your impact locations? Bernie Writeto: [EMAIL PROTECTED]
Re: ShopTalk: NBP-COG
On Thu, October 9, 2003 at 6:34 pm, Dave Tutelman sent the following > At 04:41 PM 10/9/03 -0700, David Rees wrote: >> >> Isn't it possible for a material to have different compression and >> tensile strengths? > > Possible, yes. Does it actually happen? Worth discussing. Summary - steel has the same elasticicity in tensile and compressive modulus, graphite is very close to the same Thanks for validating what I assumed was true, but wasn't sure of. > A few comments: > > (1) You don't need 2-d measurements but they would be interesting, > and for EXACTLY the reason you suggest. The spine and NBP planes will > show all the force in the direction of the bending, and no > perpendicular component. Other planes will show a perpendicular > force, which is why FLO works to find spines and NBPs. Yep. I'm getting the hang of it now. > (2) You need to be careful to measure the DEFLECTION of the shaft, > not the POSITION. That is, you need to measure the DIFFERENCE in > position between zero load and full known load. Even more accurate is > to measure the difference between a small load and a bigger load, > where the load difference is known precisely. If you just measure the > POSITION of the shaft under load, you will still be fooled by shaft > bend, because the starting (no-load) position is different for > different orientations. Isn't that what I said? ;-) > The NF2 does not do difference measurement, so it is fooled by bend. > Dan has designed a way to solve this problem -- a reversible front > bearing -- and I think it is on the NF2 web site. But nobody except > Dan has built one of these. It also involves arithmetic (subtracting > two deflection readings for each shaft position), which has turned > off at least one clubmaker to whom I proposed the solution. (That is, > the solution of an NF2 for difference-deflection measurement to find > the true spine.) He is now using the FlexMaster, which can do the > arithmetic internally. I googled FlexMaster and found some information on it. Seemed like their proponents were intent on bashing frequency analyzers as "old technology", but then go on to say that they double check all their work with one. Seems to me now that you would be able to use either tool effectively, though the only benefit of the FlexMaster is being able to measure how bent the shaft is. But it seems that the bend of the shaft doesn't matter unless it's REALLY bent! > BTW, the difference-deflection measurement is essentially what John > Kaufman did in his testing to show that all shafts are really Type 2. I'll have to go read up on that again.The more I read the more I convince myself that the tried and true method of aligning the N-plane along the target line is the way to go. NBP-CG has still piqued my interest, though. There's a good pic showing the stiffness of your typcial shaft around it's cross-section on John K's site here: http://www.csfa.com/tech35.htm Really helps to visuallize the problem at hand. I wonder if NBP-CG seems to work well because the typical angle of attack of a solid swing is a few degrees in-out and aligning the CG of the head tends to align the NBP very close to this angle (at least in the irons). Thinking about it a bit more, has anyone tried aligning the stiff-plane with the CG? Thanks, -Dave
Re: ShopTalk: NBP-COG
Dave Tutelman <[EMAIL PROTECTED]> wrote: -- snip -- >Bill, >You're right, it is confusing. In fact, lots of the people in the >discussion are confused, because we can't all be right when we're saying >such different things. Anyway, let me give you my take on it. -- snip -- This summary is IMHO as good as it could possibly be. Thanks, DaveT. Ciao, Marcello __ McAfee VirusScan Online from the Netscape Network. Comprehensive protection for your entire computer. Get your free trial today! http://channels.netscape.com/ns/computing/mcafee/index.jsp?promo=393397 Get AOL Instant Messenger 5.1 free of charge. Download Now! http://aim.aol.com/aimnew/Aim/register.adp?promo=380455
Re: ShopTalk: NBP-COG
Hi Dave, I'm going to take a swing at describing bending and the concept of neutral bending axis. I may simply confuse the issue, but it's already well confused so here goes. Imagine a perfectly symmetrical shaft clamped rigidly and horizontal on one end and an imaginary vertical plane aligned to the axis of the shaft. If you look down the shaft you are looking at the vertical plane edge on. If we apply an axial load (a load in the direction of the axis of the shaft) to the end of the shaft it will create a stress in the shaft material that is the same all the way around the shaft, because the shaft is perfectly symmetrical. This stress will be tensile or compressive depending on the direction we load the shaft, and the magnitude of this uniform stress times the cross sectional area of the shaft wall (we'll assume the shaft is hollow) will equal the load applied (the force) because the shaft is not moving. A static situation requires that the forces all be in balance. Now let's remove the axial force and hang a weight on the tip of the shaft, so that it bows downward, but still in the vertical plane. Pick a point on the shaft and imagine an axis that is perpendicular to the vertical plane and passes through the center of the shaft. Now because the shaft is being bent down, the material on the top of the shaft is in tension and the material on the bottom of the shaft is in compression, with the greatest stresses in the material at the very top of the shaft and the very bottom of the shaft (tension and compressive stresses, respectively). The stress levels transition from maximum tension at the very top of the shaft to maximum compression at the very bottom of the shaft, passing through zero at the location of the axis we have imagined perpendicular to the plane of bending and passing through the center of our symmetrical shaft. This is the neutral bending axis and is characterized by being the location of zero stress in the walls of the shaft and the axis about which the moments created by the tensile forces in the upper half of the shaft and the moments created by the compressive forces in the lower half of the shaft equal each other (in bending the moments have to sum to zero for static equilibrium). Remember that a moment is a force times the distance away from the axis you are calculating it about. In the wall of the shaft each little element of the shaft wall has a stress on it and that stress times the area of the element (which is a force) times the distance that element is from the neutral axis defines that elements contribution to the total moment about the neutral axis. (this is really tough without being able to draw figures) If instead of pulling down on the tip of the shaft we pull up the geometry of the shaft cross section has not changed so the neutral axis remains in the middle of the shaft, the moments from the stresses in the top half of the shaft still equal the moments in the bottom half (with the signs reversed) and the shaft shows the same stiffness when being bent up as it did when it was being bent down. Now let's suppose that the material in the top of the shaft is thicker than in the bottom half of the shaft, the shaft is now asymmetric (a 'strong' side and a 'weak' side if you apply an axial load, but not, as we will see, with a bending load). But the shaft is still in static equilibrium so the moments created by the stresses above the neutral axis still have to equal those below the neutral axis. What happens is that the stress distribution changes and the neutral axis moves closer to the upper (the thicker) wall of the shaft. The shaft stiffness remains the same whether the shaft is being bent up or being bent down (within the assumed bending plane) because the geometry of the shaft does not change (at least not appreciably with the amount of bending in a golf club) and the neutral axis remains in the same location regardless of the direction of bending. The stiffness of a shaft depends on it's geometry and the plane of bending you are talking about, but within that plane of bending the shaft is equally stiff in both directions. When engineers talk about bending stiffness we aren't talking about direction we are talking about the plane in which the bending occurs. Dave T. understands this very well and when he talks about NBP being 180* apart he is trying to put this concept into words someone without the mechanics background who thinks of shafts as having a strong side and a weak side in bending (as they can when loaded with an axial force) can relate to. NBP's (or directions of minimum bending stiffness) are 180* apart because that puts them in the same plane and the bending stiffness of a shaft in any given plane of bending is the same in both directions. The same is true of 'spines'. Consider a shaft with an elliptical cross section. The plane of maximum stiffness will be that through th
RE: ShopTalk: NBP-COG
Good reply Dave, and similar to a question I posed a few years ago. John K made me a believer. Mark A Patton [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of David Rees Sent: Thursday, October 09, 2003 7:41 PM To: [EMAIL PROTECTED] Subject: Re: ShopTalk: NBP-COG On Thu, October 9, 2003 at 2:23 pm, Dave Tutelman sent the following > > SPINE is the stiffest plane of a shaft in bending. NBP is the most > flexible plane. The concept of plane is the first area of > disagreement among the protagonists. Some say that it is possible for > the stiff side to be 180* opposite the flexy side. But the engineers > in the group say that is not so; it is an artifact of an imperfect > instrument used to find the spine. In fact, spines will be 180* apart > every time, hence I talk about "plane". Similarly NBPs will be 180* > apart from one another every time. BTW, that is what John Kaufman > proved. He proved nothing about how to align the spine or NBP when > you make a club, just that the order of things as you go around the > shaft is spine-NBP-spine-NBP at about 90* intervals. This also agrees > with: * Theory that every mechanical and structural engineer learns > in school. * Tests that others have done, including one I've > witnessed involving a FlexMaster. Not being a mechanical or structural engine who is familiar with the tensile properties of the materials used in golf shafts, I may be way off base here, but here goes: Isn't it possible for a material to have different compression and tensile strengths? For example, we'll use some poor ascii art below depicting a side view of a shaft where one side of the shaft is significantly thicker than the other: The top side drawn with the - is the thin side, the bottom side drawn with the = is the thick side. Assume (which is probably a bad assumption but will get the point across) that the material does not compress at all, but does stretch linearly depending on the thickness of the material. If you pull down on the shaft the club will deflect some amount. But if you push up on the shaft the club will only deflect 1/2 the amount as it deflected down. Measured in a frequency meter you will only get one reading as a frequency meter can only measure stiffness in planes, but in a deflection meter you will find the shaft bends different amounts in each direction obviously affecting the position you might want to orient the shaft. It also seems that if the shaft started off bent in one direction or the other, it would affect the stiffness of the shaft in each direction. How much? I don't know, you guys who know materials better than can will probably tell me what I've described isn't possible. ;-) Please do if I'm totally off base. So from what I can tell, the main drawback of a frequency meter is that you can only measure stiffness in planes, when a shaft may actually have a different stiffness in each direction. The main drawback of your typical spine finder (don't know if this applies to the NF2 or not) is that you don't take into account any bend of the shaft. It seems to me that a method which could be used to measure the stiffness of a shaft would be done as follows: Clamp one end of the shaft in a bearing device with no load on the other end. Take 2-d deflection measurements at multiple points around the shaft, making sure that each measurement is made using a constant force. An easy way would be to use a weight free hanging to prevent side-forces from affecting measurements. 2-d measurements may not be necessary if shafts always bend in the vertical plane, but I think if they did, you would always get FLO no matter which way you aligned a shaft. Once you've got this data, you will be able to predict what direction the shaft will flex and how much based on the weight used. The tricky part will then to use that data to align the shaft in the position which most consistently returns the clubhead to the spot the golfer expects it to. I think Dan's NF2 can do all these types of measurements but the 2-d measurements, maybe it can be easily adapted to make 2-d deflection measurements as well. -Dave --- Incoming mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.520 / Virus Database: 318 - Release Date: 9/18/2003 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.520 / Virus Database: 318 - Release Date: 9/18/2003
Re: ShopTalk: NBP-COG
At 04:41 PM 10/9/03 -0700, David Rees wrote: On Thu, October 9, 2003 at 2:23 pm, Dave Tutelman sent the following > > SPINE is the stiffest plane of a shaft in bending. NBP is the most > flexible plane. The concept of plane is the first area of > disagreement among the protagonists. Some say that it is possible for > the stiff side to be 180* opposite the flexy side. But the engineers > in the group say that is not so; it is an artifact of an imperfect > instrument used to find the spine. In fact, spines will be 180* apart > every time, hence I talk about "plane". Similarly NBPs will be 180* > apart from one another every time. BTW, that is what John Kaufman > proved. He proved nothing about how to align the spine or NBP when > you make a club, just that the order of things as you go around the > shaft is spine-NBP-spine-NBP at about 90* intervals. This also agrees > with: * Theory that every mechanical and structural engineer learns > in school. * Tests that others have done, including one I've > witnessed involving a FlexMaster. Not being a mechanical or structural engine who is familiar with the tensile properties of the materials used in golf shafts, I may be way off base here, but here goes: Isn't it possible for a material to have different compression and tensile strengths? Possible, yes. Does it actually happen? Worth discussing. First of all, you don't mean "strength", which is how much stress the material can take before it fails. You mean elasticity, in particular the "elastic modulus" or "Young's modulus", which is how much stress the material can take to elongate or compress a particular amount. But that's just the words you should use to talk about it; your concept is right on. OK, so we find that lots of steel shafts are "Type 1"; that is, a spine finder shows an NBP 180* away from a spine. We find almost all graphite shafts are "Type 2"; that is, a spine finder shows two spines separated by 180* and two NBPs separated by 180*. So, if your theory has any validity, it should be particularly prevalent in steel, right? Wrong! Steel (and all structural metals I'm aware of) have the same modulus in compression and tension. Therefore, steel Type 1 shafts reflect bend, not a "strong side" and "weak side". Composites (like epoxy/carbon-fiber) may have a slightly different tensile and compressive modulus. But they are close enough that the geometric asymmetries that cause spines are way more important than the modulus differences -- so graphite shafts are Type 2 shafts. For example... Your example would have been valid if your premise were. Unfortunately, for all practical purposes, the compressive modulus is the same as the tensile modulus for shaft materials. BTW, I'd like to comment on the measurement scheme you propose: The main drawback of your typical spine finder (don't know if this applies to the NF2 or not) is that you don't take into account any bend of the shaft. It seems to me that a method which could be used to measure the stiffness of a shaft would be done as follows: Clamp one end of the shaft in a bearing device with no load on the other end. Take 2-d deflection measurements at multiple points around the shaft, making sure that each measurement is made using a constant force. An easy way would be to use a weight free hanging to prevent side-forces from affecting measurements. 2-d measurements may not be necessary if shafts always bend in the vertical plane, but I think if they did, you would always get FLO no matter which way you aligned a shaft. A few comments: (1) You don't need 2-d measurements but they would be interesting, and for EXACTLY the reason you suggest. The spine and NBP planes will show all the force in the direction of the bending, and no perpendicular component. Other planes will show a perpendicular force, which is why FLO works to find spines and NBPs. (2) You need to be careful to measure the DEFLECTION of the shaft, not the POSITION. That is, you need to measure the DIFFERENCE in position between zero load and full known load. Even more accurate is to measure the difference between a small load and a bigger load, where the load difference is known precisely. If you just measure the POSITION of the shaft under load, you will still be fooled by shaft bend, because the starting (no-load) position is different for different orientations. The NF2 does not do difference measurement, so it is fooled by bend. Dan has designed a way to solve this problem -- a reversible front bearing -- and I think it is on the NF2 web site. But nobody except Dan has built one of these. It also involves arithmetic (subtracting two deflection readings for each shaft position), which has turned off at least one clubmaker to whom I proposed the solution. (That is, the solution of an NF2 for difference-deflection measurement to find the true spine.) He is now using the FlexMaster, which can do the arithmetic internally. BTW, the difference
Re: ShopTalk: NBP-COG
On Thu, October 9, 2003 at 2:23 pm, Dave Tutelman sent the following > > SPINE is the stiffest plane of a shaft in bending. NBP is the most > flexible plane. The concept of plane is the first area of > disagreement among the protagonists. Some say that it is possible for > the stiff side to be 180* opposite the flexy side. But the engineers > in the group say that is not so; it is an artifact of an imperfect > instrument used to find the spine. In fact, spines will be 180* apart > every time, hence I talk about "plane". Similarly NBPs will be 180* > apart from one another every time. BTW, that is what John Kaufman > proved. He proved nothing about how to align the spine or NBP when > you make a club, just that the order of things as you go around the > shaft is spine-NBP-spine-NBP at about 90* intervals. This also agrees > with: * Theory that every mechanical and structural engineer learns > in school. * Tests that others have done, including one I've > witnessed involving a FlexMaster. Not being a mechanical or structural engine who is familiar with the tensile properties of the materials used in golf shafts, I may be way off base here, but here goes: Isn't it possible for a material to have different compression and tensile strengths? For example, we'll use some poor ascii art below depicting a side view of a shaft where one side of the shaft is significantly thicker than the other: The top side drawn with the - is the thin side, the bottom side drawn with the = is the thick side. Assume (which is probably a bad assumption but will get the point across) that the material does not compress at all, but does stretch linearly depending on the thickness of the material. If you pull down on the shaft the club will deflect some amount. But if you push up on the shaft the club will only deflect 1/2 the amount as it deflected down. Measured in a frequency meter you will only get one reading as a frequency meter can only measure stiffness in planes, but in a deflection meter you will find the shaft bends different amounts in each direction obviously affecting the position you might want to orient the shaft. It also seems that if the shaft started off bent in one direction or the other, it would affect the stiffness of the shaft in each direction. How much? I don't know, you guys who know materials better than can will probably tell me what I've described isn't possible. ;-) Please do if I'm totally off base. So from what I can tell, the main drawback of a frequency meter is that you can only measure stiffness in planes, when a shaft may actually have a different stiffness in each direction. The main drawback of your typical spine finder (don't know if this applies to the NF2 or not) is that you don't take into account any bend of the shaft. It seems to me that a method which could be used to measure the stiffness of a shaft would be done as follows: Clamp one end of the shaft in a bearing device with no load on the other end. Take 2-d deflection measurements at multiple points around the shaft, making sure that each measurement is made using a constant force. An easy way would be to use a weight free hanging to prevent side-forces from affecting measurements. 2-d measurements may not be necessary if shafts always bend in the vertical plane, but I think if they did, you would always get FLO no matter which way you aligned a shaft. Once you've got this data, you will be able to predict what direction the shaft will flex and how much based on the weight used. The tricky part will then to use that data to align the shaft in the position which most consistently returns the clubhead to the spot the golfer expects it to. I think Dan's NF2 can do all these types of measurements but the 2-d measurements, maybe it can be easily adapted to make 2-d deflection measurements as well. -Dave
Re: ShopTalk: NBP-COG
- Original Message - From: "tflan" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, October 09, 2003 4:05 PM Subject: Re: ShopTalk: NBP-COG > Well, we can agree to disagree on this point. All I'm saying is that its > virtually impossible, given our assembly practices, to set a head on a shaft > at a precise spot. Its simple to visualize. Imagine 360 degrees marked > around a shaft tip that's .335" in circumference. The lines would be atop > one another. You simply cannot do it accurately. You may be able to locate > the "hard spot" with whatever device you're using but getting it precisely > located at say 2:00 is nigh to impossible. I am not sure I agree. How close can you get a grip to being in the right spot? I frequently use ribbed grips so it's important to get the top alignment mark right at 12:00. And same with the flat spot of a putter. It's a pain in the butt, pun intended, but I usually can get it right. And a head is a lot easier to fiddle with during gluing than a grip that's a little off. On irons I use the score lines as a starting point. On woods, I find the graphics on the sole usually run due east-west. So with those I hold the club out in front of me, sole closest to me, face skyward, and shaft pointing away. I do my best to hold the head with the graphics dead plumb, then sight down the line and gingerly rotate the shaft till my 9:00 mark is straight up. Then extra-gingerly try to set the club down for drying. Then do it 3 or 4 more times cause it felt like it moved when I was handling it. LOL. I use shafting beads because they make it easier to handle the club at that point without it so easily rotating off the mark. 5 degrees is a lot of rotation. I would bet I get my mark glued up within +/- 2 degrees, and maybe 1. If I really am that good, :), then the next question is how accurately can I get the shaft marked. I think I get the mark made accurately too. BUT... The most vague part of the whole operation for me is deciding where to put the mark. Steel shafts with bends are easy in my program. But graphites usually have a pretty wide NBP in my bearing finder. I can see why the NF would improve that. SO, I think I can draw the line and glue to the line pretty well. Not so confident about finding the damn spot to mark in the first place though. Doug Clark
Re: ShopTalk: NBP-COG plus Golf around Joplin
Hi Dave et al I keep seeing my name pop up in these endless emails every now and then. I agree with everything Dave has written. My own very limited testing indicates alignment of the bend has little effect. Alignment of a true spine does have an effect. I like the N plane in the target planes. Makes the most sense to me. I try to use shafts with very little spine but I recently picked up some shafts with up to 13cpm differential frequencies. I'm going to see just how bad a club I can build! Now to something really important. I'll be driving to Tucson in a few weeks and would like to play golf somewhere around Joplin, MO. Preferably a little west and close to the freeway. Any suggestions? Cheers, John K - Original Message - From: Dave Tutelman <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Thursday, October 09, 2003 4:23 PM Subject: Re: ShopTalk: NBP-COG > At 12:48 PM 10/9/03 -0500, Bill Douglas wrote: > >Gentlepersons, > > I have been lurking on this NBP-COG "Fest" and lacing the level of > >technical acumen the protagonists and antagonists possess have become > >totally confused! However, its too juicy to not dive in; so here's at it! > > > > I read some time ago that Golfsmith did some experimenting/testing with > >the Spine/Cog alignment and found there was no appreciable/discernable > >difference in shaft performance vs. Spine at one of the 4 cardinal > >positions. Also if I'm not mistaken, John Kaufman got confirming results > >when he did similar experimenting/testing. Is this the same thing that's > >being discussed in this case? Please advise. Thanks in advance!! > > Bill, > You're right, it is confusing. In fact, lots of the people in the > discussion are confused, because we can't all be right when we're saying > such different things. Anyway, let me give you my take on it. If I'm wrong > (of course I doubt that, but there are others who are SURE I am -- who > knows?), then this will be further confusing. > > First of all, we are talking about spine alignment or NBP alignment. Leave > COG out of it for a while, until we understand spine and NBP. > > SPINE is the stiffest plane of a shaft in bending. NBP is the most flexible > plane. The concept of plane is the first area of disagreement among the > protagonists. Some say that it is possible for the stiff side to be 180* > opposite the flexy side. But the engineers in the group say that is not so; > it is an artifact of an imperfect instrument used to find the spine. In > fact, spines will be 180* apart every time, hence I talk about "plane". > Similarly NBPs will be 180* apart from one another every time. BTW, that is > what John Kaufman proved. He proved nothing about how to align the spine or > NBP when you make a club, just that the order of things as you go around > the shaft is spine-NBP-spine-NBP at about 90* intervals. This also agrees with: > * Theory that every mechanical and structural engineer learns in school. > * Tests that others have done, including one I've witnessed involving a > FlexMaster. > > There is another issue here: the residual bend in the shaft. That is, no > shaft is perfectly straight. Some are straighter than others. Any lack of > straightness will "fool" the simple spine finder. There are more accurate > ways of finding/measuring the spine that are not fooled by lack of > straightness. Dan Neubecker (inventor of the NeuFinder, which is fooled) > takes the position that you should orient what you find in the NeuFinder, > because bend affects performance in the same way that spine does. I don't > believe any such thing. Oh, it might coincidentally be true, though I doubt > it. But there is no evidence to support it -- and two of the three theories > of spine alignment (the two credible ones, IMHO) say that's not even close. > > OK, now we have talked about characterizing the shaft. Let's talk about how > we align shafts in clubs. I'll assume the shafts are straight, so that > spine is the only alignment issue. There are three competing assertions > about how to orient the spine: > > (1) Spine in the target line, NBP in the heel-toe plane. That is > essentially what Weiss advocates. (He talks about the FLO. But if you find > the REAL spine, then the higher-frequency FLO is exactly the spine.) > > (2) NBP in the target line, spine in the heel-toe plane. Most members of > this forum believe in this orientation. It seems to make the most sense to > me; no quarrel with the forum here. It also happens to be what Talamonti > advocates. > > (3) NBP oriented toward the center of gravity (COG in the forum, CG > traditionally). This i
Re: ShopTalk: NBP-COG
Uh; I didn't mention anything about NBP-GOG. What I said was its virtually impossible to assemble a club with the "hard spot" in a precise position. I have a spinefinder and a freq machine. I find hard spots - spines, and soft spots - NBP's easily. No problema. I don't deny the existence of spines, NBP's, or COG's. My argument is about marking and assembling. TFlan - Original Message - From: "Dan Neubecker" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, October 09, 2003 6:44 AM Subject: RE: ShopTalk: NBP-COG > Hi Tom, > > It depends on what theory you believe in. If you believe that a spine > finder can find the correct NBP location as I do, then you absolutely can > get the NBP exactly at the COG. > > Bernie's post on NBP to COG alignment contained a quote from an experimental > set I made up. I did not have any high expectations for that set when I > made it up. Let me tell you that I was shocked by the difference in the > results. The results continue today after months with this set. I continue > to hit the best irons of my life. Now this set was a combination of new > things for me. First, I used a new shaft, PC Mach 22's, with R+, S- and S > shafts in the set. I used my NF2 to tip trim them to a matching profile of > .010" deflection between clubs, never having to trim more than 1/2" tip to > do so, and the find the NBP locations. Then I made up the clubs with a 3/8" > change between lengths, for a poor man's MOI match. Finally I assembled > them using the NBP (N1) to COG alignment. > > It could have any of those factors, or all of them that led to these > results, but I was literally shocked by how much better they played than any > set I've used. It was the most difference I have seen in at least 10 years > of experimenting with clubs, different lengths, different shafts, flexes, > torques, components, you name it, I've tried it. > > I can't ignore results like that, regardless of how tenuous the theory. > > Dan Neubecker > [EMAIL PROTECTED] > > > >-Original Message- > >From: tflan [mailto:[EMAIL PROTECTED] > >Sent: Wednesday, October 08, 2003 12:04 PM > >To: [EMAIL PROTECTED] > >Subject: Re: ShopTalk: NBP-COG > > > > > >Dr Tutelman: > > > >A question, por favor. When this subject was broached several > >months ago, > >and the thread unwound for about 3 weeks, I asked a question > >that got no > >universally agreed upon answer. The question was; is the spine > >found at the > >top of the shaft or at the bottom of the shaft when testing in > >Dick's spine > >finder? Responses were equally, and passionately, divided. > > > >I then asked another question; if when one finds the spine, > >the "hard spot" > >via the use of our arguably primitive methods, how can one > >accurately mark > >and then place the hard spot in a specific position? As I recall, you > >responded, correctly, that we'd be lucky to get the spine > >situated to within > >3 to 4 degrees. You mentioned the circumference of the .335" tip, when > >reduced to 360 degrees, would be virtually impossible to set > >accurately. I > >agree. An assembler would need to identify the spine at the > >shaft tip by > >marking it with a needle, then mark the hosel in the precise finished > >position. Then he'd need to mark the ferrule so the entire > >assembly could be > >stuck together in one operation. That's nearly impossible given the > >workplaces of most assemblers. > > > >So, this thread re; placing cog/spine in some specific location with > >accuracy is theoretically interesting but in practice its pretty much > >useless. I'm not knocking anyone, just making a point that's been made > >several times in the past. > > > >TFlan > > > >- Original Message - > >From: "Dave Tutelman" <[EMAIL PROTECTED]> > >To: <[EMAIL PROTECTED]> > >Sent: Tuesday, October 07, 2003 10:49 AM > >Subject: Re: ShopTalk: NBP-COG > > > > > >> A few points I'd like to make concerning things that were > >brought up in > >> this thread: > >> > >> (1) As Alan Brooks and John Kaufman and I have said in the > >past, every > >> shaft will have the stiffest directions (that is, spines) at 180* > >> intervals. Similarly with the most flexible directions (that > >is, NBP). If > >> you measure anything else, there is something wrong with > >your measuring > >> equipment. (Others
Re: ShopTalk: NBP-COG
At 12:48 PM 10/9/03 -0500, Bill Douglas wrote: Gentlepersons, I have been lurking on this NBP-COG "Fest" and lacing the level of technical acumen the protagonists and antagonists possess have become totally confused! However, its too juicy to not dive in; so here's at it! I read some time ago that Golfsmith did some experimenting/testing with the Spine/Cog alignment and found there was no appreciable/discernable difference in shaft performance vs. Spine at one of the 4 cardinal positions. Also if I'm not mistaken, John Kaufman got confirming results when he did similar experimenting/testing. Is this the same thing that's being discussed in this case? Please advise. Thanks in advance!! Bill, You're right, it is confusing. In fact, lots of the people in the discussion are confused, because we can't all be right when we're saying such different things. Anyway, let me give you my take on it. If I'm wrong (of course I doubt that, but there are others who are SURE I am -- who knows?), then this will be further confusing. First of all, we are talking about spine alignment or NBP alignment. Leave COG out of it for a while, until we understand spine and NBP. SPINE is the stiffest plane of a shaft in bending. NBP is the most flexible plane. The concept of plane is the first area of disagreement among the protagonists. Some say that it is possible for the stiff side to be 180* opposite the flexy side. But the engineers in the group say that is not so; it is an artifact of an imperfect instrument used to find the spine. In fact, spines will be 180* apart every time, hence I talk about "plane". Similarly NBPs will be 180* apart from one another every time. BTW, that is what John Kaufman proved. He proved nothing about how to align the spine or NBP when you make a club, just that the order of things as you go around the shaft is spine-NBP-spine-NBP at about 90* intervals. This also agrees with: * Theory that every mechanical and structural engineer learns in school. * Tests that others have done, including one I've witnessed involving a FlexMaster. There is another issue here: the residual bend in the shaft. That is, no shaft is perfectly straight. Some are straighter than others. Any lack of straightness will "fool" the simple spine finder. There are more accurate ways of finding/measuring the spine that are not fooled by lack of straightness. Dan Neubecker (inventor of the NeuFinder, which is fooled) takes the position that you should orient what you find in the NeuFinder, because bend affects performance in the same way that spine does. I don't believe any such thing. Oh, it might coincidentally be true, though I doubt it. But there is no evidence to support it -- and two of the three theories of spine alignment (the two credible ones, IMHO) say that's not even close. OK, now we have talked about characterizing the shaft. Let's talk about how we align shafts in clubs. I'll assume the shafts are straight, so that spine is the only alignment issue. There are three competing assertions about how to orient the spine: (1) Spine in the target line, NBP in the heel-toe plane. That is essentially what Weiss advocates. (He talks about the FLO. But if you find the REAL spine, then the higher-frequency FLO is exactly the spine.) (2) NBP in the target line, spine in the heel-toe plane. Most members of this forum believe in this orientation. It seems to make the most sense to me; no quarrel with the forum here. It also happens to be what Talamonti advocates. (3) NBP oriented toward the center of gravity (COG in the forum, CG traditionally). This is a brand new proposal from Tom Wishon. I've already posted my explanation of the theory behind it. Is this a more important effect than #1 and #2? I don't know. I don't think Tom does either yet. But people are trying it out. None of the tests I've seen were controlled experiments, just "I built a set of irons this way and they work well." So far, returns are favorable. I don't know if that means much, given that most of the reports I've seen so far involve shafts with very little spine -- so orienting them any way at all might give fairly similar results. Let's get back to your statement, "there was no appreciable/discernable difference in shaft performance vs. Spine at one of the 4 cardinal positions". That says that orientations #1 and #2 are both good enough that it's hard to tell the difference between them. I'm quite prepared to believe this. I hope to find out soon. Anyway, there are lots of interesting questions about spine alignment where people are taking positions but there is either no data or no strong-enough data to either support or refute those positions. Here are a few: * Obviously, which orientation is "best": #1, #2, or #3 above, or maybe a different one altogether. * How much difference does it make? There are tests that have been done to determine this, but the results are commercial secrets
Re: ShopTalk: NBP-COG
Well, we can agree to disagree on this point. All I'm saying is that its virtually impossible, given our assembly practices, to set a head on a shaft at a precise spot. Its simple to visualize. Imagine 360 degrees marked around a shaft tip that's .335" in circumference. The lines would be atop one another. You simply cannot do it accurately. You may be able to locate the "hard spot" with whatever device you're using but getting it precisely located at say 2:00 is nigh to impossible. How am I playing? Handicap went from 7 to 10 in a month. I'll shoot 74, then 87, then 79, then 84. Its maddening. Yesterday it was 36/44. Today it was 43/37. No one thing is consistently bad. Sometimes its the putter, sometimes its the irons, sometimes its the driver. I never know when the lurch is going to lunge. I've been playing a 975J for a while. I've had 7 shafts in it so far. The latest one, a Fujikura gold 4565 (oem) seems to be working pretty well. I put a "perfect" set of irons together. Rifle Tour Flighted 5.0's in Ping heads. Heads all weighted to 7 gram increments. Lofts and lies adjusted to my peculiar style of attack, lengths and swingweights right where I want them. Can't hit them for beans. Went back to my old Mach 22 shafted Dynacraft Tour Forged. Ah golf. Sometimes it sucks, sometimes not. TFlan > > How've you been playing lately? Is your lurch still lurching down the > fairway? I was just getting consistently back into the mid-high 70s when I > tore up my left shoulder (probably rolled over in bed the wrong way) about a > week ago and might not be able to play for at least a couple of weeks. Then, > it'll be back to trying to break 80 again. There is always another challenge > for us senior players. :-) > > Bernie > Writeto: [EMAIL PROTECTED] >
Re: ShopTalk: NBP-COG
- Original Message - From: "Dave Tutelman" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 2:19 PM Subject: Re: ShopTalk: NBP-COG The question(s) were in the first paragraph and in the last paragraph. First question was "is the spine at the top or bottom of the shaft?" Second was "how can one accurately mark and place the shaft in position?" The answer to the first is still debatable. The answer to the second is, presumably, that you can't. I agree with you that until there's some empirical evidence to prove the point, spine location is essentially meaningful as a selling tool. Theoretically its a fascination subject. In practice its hit or miss if you're trying to hit a precise spot from butt end to tip to hosel. TFlan > I'm having trouble finding the promised question. I found a concluding > statement that I might agree with. But if the spine is big enough, and > alignment is sufficiently non-critical, then maybe it isn't useless in > practice. > > Cheers! > DaveT >
Re: ShopTalk: NBP-COG
Corey and Ray, Looks to me like you are describing FLOing a shaft. Dave T seems to feel FLO could be important for spine location, Phil Talamonti of Advanced Shaft Dynamics feels FLO is unimportant and has no use in aligning a shaft properly. Guess it's up to us non-engineers to try it and see. :-) Bernie Writeto: [EMAIL PROTECTED] - Original Message - From: "Corey Bailey" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, October 09, 2003 2:15 PM Subject: Re: ShopTalk: NBP-COG > Ray, > You just described the process that I use for assembling every club. What > it tells me is that when the club is brought in line at the bottom of the > swing, it will flex in a linear planeI think. > > :-) > > CB > > At 10:53 PM 10/8/2003 -0400, you wrote: > >anyone ever dry install the head on a shaft , clamp it in a freq. meter with > >the toe up ,face pointing to an imaginary target [right handed club] and > >twang it to see if you could the head to "run flat" or flat line ? if you > >rotate the head on the shaft , then reset it toe up until you you can get a > >flat line run , what does that tell you about a shaft/clubhead assembly? > >Ray > > > >
Re: ShopTalk: NBP-COG
Jim, > My 983K with the Aldila NV is getting a wear spot high in the middle of the face. Interesting in that I also thought the impacts on my woods with NBP-COG were slightly higher on the face, though centered. Didn't notice it on irons as much. Maybe toe droop because NBP more in the vertical plane? Might be something to watch for. Notice any changes in impact area on your S1-COG alignment? Dan, any change in your impact locations? Bernie Writeto: [EMAIL PROTECTED]
Re: ShopTalk: NBP-COG
Ray, You just described the process that I use for assembling every club. What it tells me is that when the club is brought in line at the bottom of the swing, it will flex in a linear planeI think. :-) CB At 10:53 PM 10/8/2003 -0400, you wrote: anyone ever dry install the head on a shaft , clamp it in a freq. meter with the toe up ,face pointing to an imaginary target [right handed club] and twang it to see if you could the head to "run flat" or flat line ? if you rotate the head on the shaft , then reset it toe up until you you can get a flat line run , what does that tell you about a shaft/clubhead assembly? Ray
Re: ShopTalk: NBP-COG
Hi Alan, If you suspend those graphite shafts on two points (V-blocks, etc.) you will note some run-out but usually less than observed in steel shafts. Obviously (not trying to preach to the choir here) the differences in materials and manufacturing processes will produce different results in the rudimentary equipment that we are trying to be scientific with. I have to say however that I have found curiosities with sheet wrapped graphite shafts that I have not come across in steel shafts (and likewise). For example: In the last 5 years or so that I have been examining shafts I have come across the occasional sheet wrapped shaft with three hard sides that are not symmetrical. Thus, all of our agreed upon alignments get redefined for those special situations. Of course, it always pops up on the ocassion where the customer wants his or her 3 wood the next day and there is no turn-around time for the parts. Some of the other questions you invited me to jump in on: "Besides curvature (or residual bend) what other anomalies are we talking about here?" I just gave an example above - CB "How do they affect the behavior of a golf club when it is swung?" The $64,000.00 question. Hopefully, Dave T's Iron Byron results will provide some answers. There already has been some robot testing done in the orient by an Australian clubmaker named Danny Seng. His results suggest that different orientations produce different shot patterns. - CB "And how is it that a 'spine finder' identifies them?" I'm not sure what you are asking here. Bearing finders will identify both differences in wall thickness and curvature as a spine so it often comes down to feel and experience to make the judgement. The bottom line is "how can I build the best product for the customer". - CB Hope I helped, Best, CB At 06:28 AM 10/9/2003 -0700, you wrote: Thanks, Corey, I did a quick check on several of the graphite shafts I have in the garage and they all appeared to have some runout when I rolled them in my spine finder (I didn't try and isolate whether it was shaft curvature or out-of-round butts). It was less than some of the steel shafts (particularly the stepped ones) I have checked but still noticeable. Please jump in with my query to Dan about what other 'anomalies' we are talking about here. Thanks, Alan At 10:26 PM 10/8/2003 -0700, you wrote: Alan: Don't toss out your bearing finder just yet. Graphite shafts don't have the residual bend that steel shafts do and a bearing finder is useful for identifying the anomalies associated with them. Best, CB
Re: ShopTalk: NBP-COG
Gentlepersons, I have been lurking on this NBP-COG "Fest" and lacing the level of technical acumen the protagonists and antagonists possess have become totally confused! However, its too juicy to not dive in; so here's at it! I read some time ago that Golfsmith did some experimenting/testing with the Spine/Cog alignment and found there was no appreciable/discernable difference in shaft performance vs. Spine at one of the 4 cardinal positions. Also if I'm not mistaken, John Kaufman got confirming results when he did similar experimenting/testing. Is this the same thing that's being discussed in this case? Please advise. Thanks in advance!! - Original Message - From: "MPRUITT" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 9:48 PM Subject: Re: ShopTalk: NBP-COG > Jim , what kind of procedure did you use given the fitting of a shaft in a > titleist 975 series head ? > Ray > - Original Message - > From: "Thomson, Jim" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Wednesday, October 08, 2003 4:12 PM > Subject: RE: ShopTalk: NBP-COG > > > > I have reshafted my three drivers using the NBP-COG alignment > (975J/Graphite > > Design YS-6; 975J-VS/Graphite Design Purple Ice; 983K/Aldila NV) and was > > very pleased with the results of all three. I reshafted one of my Titleist > > 962 sets with the new Balistik shaft using the S1-COG alignment and really > > like these as well. Anecdotal info for what it's worth. > > > > -Original Message- > > From: Letourneau, Henry J AM1(AW) (VAW120) > > [mailto:[EMAIL PROTECTED] > > Sent: October 8, 2003 2:23 PM > > To: '[EMAIL PROTECTED]' > > Subject: RE: ShopTalk: NBP-COG > > > > > > Richard, there seems do be as many different views on spine allignment as > > there are positions to allign to! In the end I will have to do some > testing > > to see for myself, I will mention however that when i started spine > > alligning about a year ago i was doing all of the clubs spined to the 1200 > > position because it felt better. My question to you is have you tried the > > nbp-cog allignment and what were your results. Would S1-COG make more > sense > > than simply alligning a set of irons to 1200? My experience is limited to > > building 10 to 12 sets a year over the past three years and am always > > looking for the best possible method af set matching available for my > > customers as well as myself. Thanks - Jim Letourneau > > > > -Original Message- > > From: Richard Kennedy [mailto:[EMAIL PROTECTED] > > Sent: Wednesday, October 08, 2003 10:46 AM > > To: [EMAIL PROTECTED]; [EMAIL PROTECTED] > > Subject: Re: ShopTalk: NBP-COG > > > > > > > > Scott, to put it very simply , ALIEN THE HARD SPINE AT 12:00. 12:00 > keeps > > the clubhead toe from drooping.Forget what ever anybody else says, > > especially Mr. David T.whom is not a clubmaker per se & who knows very > > little about making/fitting of golfclubs. By his own admission he only > > makes , at the very most, one set of clubs per year and those are strictly > > for his own personal use, Mr. David T. made that statement not I. In > fact > > Mr. David T. fought us "SPINER'S" tooth and nail that the position off the > > spine had no effect on the playability or the flex of the golfclub. It > was > > not until several People outside of ShopTalk or SpineTalk got into the > fray, > > with lots of money backing them,that he got into the discussion.I'm > not > > to sure but I think that Ed J., the host of SplineTalk, asked, I feel is a > > better word to use then lets say kicked off of SpileTalk, because of his > > disruptive and know it all air that he tried to use in his posts. I do > not > > subscribe to SpineTalk not because I do not believe in their views, which > > by the way I helped to put into use, but because I'm am presently engaged > in > > other web sites that will have some, I hope, effecting with my health. I > > am not the clubmaker that has been spining the longest but i have been > > "SPINEING" golfclubs since 1984 long before it became popular. > > > > RK > > > > KENNEDY > >golf equipment > > manufacturer's of world class golfclub repair equipment > > ---Original Message--- > > > > From: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > > Date: Wednesday, October 08, 2003 1:02:35 AM > > To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
RE: ShopTalk: NBP-COG
Dave, >That manifests itself as a difference in flexibility, or pure >spine. It >will show up in a Neufinder, but will also show as FLO, and >will show from >differential deflection measurement. Have you tested concentricity problems to verify how they manifest themselves in FLO, on a FM or a spine finder? How about when combined with a bend in the shaft or an out of round section. You seem to be saying these things aren't important, yet don't account for how you have determined that they are not or at what magnitude they are not and under what combinations they are not. Same thing for the out of round area. Just how big does an out of round area have to be before it can affect shaft performance? Is it usually the case that the out of round section is just local or is it more often extending down a good amount of the shaft, say the whole butt section, for example? If the whole butt section is out of round, do you still think it will not affect performance? Obviously, if the whole shaft out of round would effect performance. At what point would a section of out of round shaft effect the reading of a FM or flo? I have yet to see any study that answers these types of questions, nor a thorough study that indicates that these anomalies are not important and have no effect on shaft bending properties. > >What I was talking about when I said "out of round" -- and >what, I assume, >Alan meant as well -- was small out-of-round places on the outside >diameter, in the vicinity where the bearings rest on a >Neufinder (or other >bearing-based spine finder). That will affect the position at >which the >shaft "wants" to rest, but will have no effect on the >performance of the >shaft during a swing. How do you know it has no effect and how big does a "local" out of round have to be before it does? Have you tested your frequency meter theory for finding spines and flo out completely? For example, might the FM be reacting to the nature of a differential stiffness in the butt area only, or even and out of round in the butt section? If you find FLO when clamped at the butt end, are you sure it will have the same flo when clamped in the middle or by the tip? I've seen no studies of this. Under what amount of pressure on the clamp end, does the clamp cause a local out of round in the shaft and possibly effect flo results? These types of question could be endless. Because there are unanswered questions does that mean the theory is invalid? > >You have this interesting belief that flex asymmetry and shaft >bend have >the same effect on performance. I'm not sure where the belief >comes from, >but I know of no organized evidence to support it. The few >tests I've seen >to determine the effect of small bend on an otherwise >symmetric shaft have >not given the performance differences that folks have observed >from spines. I can't quote studies, but that does not make it invalid. There's just lots of guys anecdotal results and a few companies making money from the concept. What scientific studies of the effects that spines, NBP's, concentricity, out of roundness, shaft bend, or of flex asymmetry, for that matter, in a golf shaft can you quote? I'd like to read them. You and Alan make it sound as if your theory is the only one and has fully tested and found to be valid. I certainly don't see a preponderance of evidence on your side of the scale either. Dan
Re: ShopTalk: NBP-COG
anyone ever dry install the head on a shaft , clamp it in a freq. meter with the toe up ,face pointing to an imaginary target [right handed club] and twang it to see if you could the head to "run flat" or flat line ? if you rotate the head on the shaft , then reset it toe up until you you can get a flat line run , what does that tell you about a shaft/clubhead assembly? Ray - Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 5:36 PM Subject: Re: ShopTalk: NBP-COG > Tom, > > You need to build yourself an NF2. If I rotate to the spine on my NF2 with a > dial indicator and can read the deflection in thousandths, as well as see > the deflection go up as I go toward the spine, and see the resistance > direction of the shaft and its affect on the dial indicator's probe, then it > is obvious to me that the point of least stability is a spine, or stiffer > point on the circumference of the shaft. If there are two, I can measure > them both in thousandths and know which is the S1 and which is the S2, as > well as their magnitude from the NBP deflections. > > I think that if I mark the location of the NBP, a dead stable point, with > the accurate marking guide (dead center over the shaft on an NF2) on the > wider section of the shaft just below the grip, that I can get closer than > 4° in an NBP-COG alignment. In fact, since gravity pulls the head to the COG > (I hope), my only alignment variables are my NBP marking accuracy and my > ability to put the NBP exactly at 6 o'clock. Since the marking guide is very > close to the flexed shaft, I think that I can mark it within 2°...but > whether I can get the NBP exactly at 6 repeatably, I'm not sure yet. I made > a small jig from a section of graphite shaft that is exactly 1/2 the > circumference of the shaft at the point I mark the NBP. This allows me to > put a mark 180° from the NBP, which I will be able to orient at 12 on a > table top. Of course, this assumes I'm using a similar-diameter shaft at the > marking point. > > Another way that I've tried marking the 12 o'clock point is to put the > NBP-marked shaft in my Workmate slot and close it up to the point that I can > just rotate the shaft. Looking up from underneath, I can center the NBP mark > in the small slot, then mark the top dead center. There are probably some > other ways that might work better. > > How've you been playing lately? Is your lurch still lurching down the > fairway? I was just getting consistently back into the mid-high 70s when I > tore up my left shoulder (probably rolled over in bed the wrong way) about a > week ago and might not be able to play for at least a couple of weeks. Then, > it'll be back to trying to break 80 again. There is always another challenge > for us senior players. :-) > > Bernie > Writeto: [EMAIL PROTECTED] > > > - Original Message - > From: "tflan" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Wednesday, October 08, 2003 1:03 PM > Subject: Re: ShopTalk: NBP-COG > > > > Dr Tutelman: > > > > A question, por favor. When this subject was broached several months ago, > > and the thread unwound for about 3 weeks, I asked a question that got no > > universally agreed upon answer. The question was; is the spine found at > the > > top of the shaft or at the bottom of the shaft when testing in Dick's > spine > > finder? Responses were equally, and passionately, divided. > > > > I then asked another question; if when one finds the spine, the "hard > spot" > > via the use of our arguably primitive methods, how can one accurately mark > > and then place the hard spot in a specific position? As I recall, you > > responded, correctly, that we'd be lucky to get the spine situated to > within > > 3 to 4 degrees. You mentioned the circumference of the .335" tip, when > > reduced to 360 degrees, would be virtually impossible to set accurately. I > > agree. An assembler would need to identify the spine at the shaft tip by > > marking it with a needle, then mark the hosel in the precise finished > > position. Then he'd need to mark the ferrule so the entire assembly could > be > > stuck together in one operation. That's nearly impossible given the > > workplaces of most assemblers. > > > > So, this thread re; placing cog/spine in some specific location with > > accuracy is theoretically interesting but in practice its pretty much > > useless. I'm not knocking anyone, just making a point that's been made > > several times in the past. > > > >
Re: ShopTalk: NBP-COG
Jim , what kind of procedure did you use given the fitting of a shaft in a titleist 975 series head ? Ray - Original Message - From: "Thomson, Jim" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 4:12 PM Subject: RE: ShopTalk: NBP-COG > I have reshafted my three drivers using the NBP-COG alignment (975J/Graphite > Design YS-6; 975J-VS/Graphite Design Purple Ice; 983K/Aldila NV) and was > very pleased with the results of all three. I reshafted one of my Titleist > 962 sets with the new Balistik shaft using the S1-COG alignment and really > like these as well. Anecdotal info for what it's worth. > > -Original Message- > From: Letourneau, Henry J AM1(AW) (VAW120) > [mailto:[EMAIL PROTECTED] > Sent: October 8, 2003 2:23 PM > To: '[EMAIL PROTECTED]' > Subject: RE: ShopTalk: NBP-COG > > > Richard, there seems do be as many different views on spine allignment as > there are positions to allign to! In the end I will have to do some testing > to see for myself, I will mention however that when i started spine > alligning about a year ago i was doing all of the clubs spined to the 1200 > position because it felt better. My question to you is have you tried the > nbp-cog allignment and what were your results. Would S1-COG make more sense > than simply alligning a set of irons to 1200? My experience is limited to > building 10 to 12 sets a year over the past three years and am always > looking for the best possible method af set matching available for my > customers as well as myself. Thanks - Jim Letourneau > > -Original Message- > From: Richard Kennedy [mailto:[EMAIL PROTECTED] > Sent: Wednesday, October 08, 2003 10:46 AM > To: [EMAIL PROTECTED]; [EMAIL PROTECTED] > Subject: Re: ShopTalk: NBP-COG > > > > Scott, to put it very simply , ALIEN THE HARD SPINE AT 12:00. 12:00 keeps > the clubhead toe from drooping.Forget what ever anybody else says, > especially Mr. David T.whom is not a clubmaker per se & who knows very > little about making/fitting of golfclubs. By his own admission he only > makes , at the very most, one set of clubs per year and those are strictly > for his own personal use, Mr. David T. made that statement not I. In fact > Mr. David T. fought us "SPINER'S" tooth and nail that the position off the > spine had no effect on the playability or the flex of the golfclub. It was > not until several People outside of ShopTalk or SpineTalk got into the fray, > with lots of money backing them,that he got into the discussion.I'm not > to sure but I think that Ed J., the host of SplineTalk, asked, I feel is a > better word to use then lets say kicked off of SpileTalk, because of his > disruptive and know it all air that he tried to use in his posts. I do not > subscribe to SpineTalk not because I do not believe in their views, which > by the way I helped to put into use, but because I'm am presently engaged in > other web sites that will have some, I hope, effecting with my health. I > am not the clubmaker that has been spining the longest but i have been > "SPINEING" golfclubs since 1984 long before it became popular. > > RK > > KENNEDY >golf equipment > manufacturer's of world class golfclub repair equipment > ---Original Message--- > > From: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > Date: Wednesday, October 08, 2003 1:02:35 AM > To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > Subject: Re: ShopTalk: NBP-COG > > Let me preface this by saying my introduction to this subject is at most > a week old, and if my statements seem out to lunch, they very well may > be. I'm trying to think this through with my own limited understanding. > I'm certainly not trying to pass this off as if I know something that > the rest of you don't. > > If I remember my physics correctly (and I probably don't), I expect any > system like this to have some natural vibration; the twang you induce > for FLO would cause this particular system to vibrate at its natural > frequency. If the system is FLO aligned correctly this vibration is > along the target line at impact, i.e 3-9 o'clock. Otherwise this > vibration has a 12-6 o'clock component to it, which would help take the > clubface out of the line with the ball. Please note that I have no idea > how large this component would be. Are we talking fractions of > millimeters here? If the NBP is aligned to COG, the local minima for > shaft rigidity, then the vibration should be at a minimum because this > is the most inherently stable shaft orientation for the force applied (I > used the term damping to describe this ... I should
RE: ShopTalk: NBP-COG
At 09:04 AM 10/9/03 -0500, Dan Neubecker wrote: How about shaft concentricity problems where the hole in the center of the shaft is offset a bit from center, resulting in different shaft wall thickness around the shaft. I'm sure you are aware that they can be slightly out of round, even if only for a portion of the shaft... Dan, That manifests itself as a difference in flexibility, or pure spine. It will show up in a Neufinder, but will also show as FLO, and will show from differential deflection measurement. What I was talking about when I said "out of round" -- and what, I assume, Alan meant as well -- was small out-of-round places on the outside diameter, in the vicinity where the bearings rest on a Neufinder (or other bearing-based spine finder). That will affect the position at which the shaft "wants" to rest, but will have no effect on the performance of the shaft during a swing. You have this interesting belief that flex asymmetry and shaft bend have the same effect on performance. I'm not sure where the belief comes from, but I know of no organized evidence to support it. The few tests I've seen to determine the effect of small bend on an otherwise symmetric shaft have not given the performance differences that folks have observed from spines. Hope this clarifies things, DaveT
Re: ShopTalk: NBP-COG
In a message dated 10/9/03 9:50:24 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: My 983K with the Aldila NV is getting a wear spot high in the middle of the face. Now let's see if this wear spot is in the right place. You will need a simple tool: A golf ball drilled part way through and mounted on a tip section of shaft about 6 inches long. Hold the club aloft, lightly about 1-2" below the grip. Tap the bottom edge of the face with the ball end of the "tool". Tapping from toe to heel. Mark the spot where the head stops twisting. Tap the mark to confirm that you have marked it correctly. Tap across the mid section of the clubface. Mark and confirm as above. Tap across the top edge of the face. Mark and confirm as above. Connect the three marks with your marker. Is the ball wear mark touching the line you marked? I'd bet not. Your wear spot would (I believe) be toward the toe from the marked line. To identify the real sweet spot of any club, wood or iron you tap on the line and listen to the sound. When you hear a sharp "click" you have found the actual sweet spot. Are your ball wear marks there? If not, it's back to the drawing board. Check your stance/ball position, tee height, lie angle (irons), length,shaft choice, etc.
Re: ShopTalk: NBP-COG
Hey, Dan, I like that.:>) df - Original Message - From: "Dan Neubecker" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, October 09, 2003 8:23 AM Subject: RE: ShopTalk: NBP-COG > Alan, > > I appreciate that you are an engineer. I work with several daily, who > happen to be my business partners. However, your position here is somewhat > elitist in nature. Most in this forum are not engineers, do not have the > ability to formulate an analytical model, and must come to our own > conclusions through our own empirical testing. You aren't suggesting that > we just believe whatever the engineers tell use are you? I know engineers > often make mistakes, as I said, I work with them daily. They often rely on > an accepted body of work done by others before them. There is the > possibility that some of that work is flawed. > > Many of us have a lot of years of clubmaking experience and are very aware > of the placebo effect and have actually grown wary of any new "theory". > Usually when we test new things it is with some skepticism. So when > something we are skeptical about going in, shows a startling difference, > then we cannot just ignore it and wait for the engineers to confirm that it > is real. We are attempting to assemble the best performing clubs we can, so > why ignore something we have found to be beneficial in our own > experimentation and has shown repeatedly positive results with our > customers? > > Perhaps you should have a more open mind and try some of these things for > yourself, rather than just relying on theory. If all the inventors out > their in our history waited for the engineers to put their stamp of approval > on what they were doing, do you suppose we'd be as advanced as we are now > technologically? > > Respectfully, > > Dan Neubecker > [EMAIL PROTECTED] > >
RE: ShopTalk: NBP-COG
Alan, How about shaft concentricity problems where the hole in the center of the shaft is offset a bit from center, resulting in different shaft wall thickness around the shaft. I'm sure you are aware that they can be slightly out of round, even if only for a portion of the shaft. Perhaps it is just a problem with inconsistencies in the sheet wrap. And of course there is the curvature issue that is very common. I assume it would not be unexpected to find several of these anomalies to occurring in one shaft. I've certainly seen my share of shafts without a curve in them that demonstrated something other than the standard type 2 shaft behavior. For example where the NBP's are 180º and equal in strength under flex, or where the spine plane is not 90º to the NBP plane. These shafts certainly have other anomalies than curve or flex differential in order to demonstrate these odd bending properties. I guess if we could ask the engineers or manufacturing experts at SKFiber or one of the other companies that seemed to have solved the shaft spine/anomaly problem, we'd be able to find out what all the problems were they had to solve, and why most other manufacturers have not. The problems must be difficult ones to solve or we'd have many more shaft demonstrating limited consistency problems. Dan Neubecker [EMAIL PROTECTED] >-Original Message- >From: Alan Brooks [mailto:[EMAIL PROTECTED] >Sent: Thursday, October 09, 2003 8:20 AM >To: [EMAIL PROTECTED] >Subject: RE: ShopTalk: NBP-COG > > >Corey Bailey also referred to "other anomalies" in a shaft. Besides >curvature (or residual bend) what other anomalies are we talking about >here? How do they affect the behavior of a golf club when it is >swung? And how is it that a 'spine finder' identifies them? >The articles >I have read only refer to identifying stiffness variations >with a spine finder. > >Thanks, > >Alan Brooks > > > >At 07:55 AM 10/9/2003 -0500, you wrote: >>Dave, >> >>Well, that depends on how you define NBP. We've had this >discussion before. >>You choose to define NBP as the softest flex plane in a shaft >and the spine >>as the stiffest plane, excluding shaft geometric anomalies from >>consideration. >> >>A number of us disagree with that assumption and believe that >geometric >>anomalies might be just as important in shaft alignment as >stiffness. We >>feel a combination of differential stiffness and shaft >geometric anomalies >>in a shaft should be combined to determine the best >alignment, which is >>exactly what a spine finder does. >> >>Dan Neubecker >>[EMAIL PROTECTED] >> >> >> >-Original Message- >> >From: Dave Tutelman [mailto:[EMAIL PROTECTED] >> >Sent: Wednesday, October 08, 2003 5:35 PM >> >To: [EMAIL PROTECTED]; [EMAIL PROTECTED] >> >Subject: Re: ShopTalk: NBP-COG >> > >> > >> >At 04:49 PM 10/8/03 -0500, Don Flatgard wrote: >> >>NBP-COG alignment. >> >>I posted this the other day and received no response so I'll >> >do it again. >> >>I agree with you on the difficulty of aligning the NBP and >COG to the >> >>degree. >> >>My method is to prepare the shaft, install the ferrule, find >> >the NBP with >> >>the NF. Take the DI off, turn the NF up-side down on the >> >bench and install >> >>the head and let it seek it own COG, let the epoxy set up >> >with the club in >> >>the NF. >> >>In my small mind I don't see how you could get any closerdf >> > >> >Don, >> >That will indeed get as close as you can measure it. (It's a >> >variant of an >> >approach I originally suggested.) Two flies in the >ointment, however: >> > >> >(1) The NF2 only finds the true NBP if the shaft is straight >> >and round. >> >Otherwise, there is an error (frequently a significant error) in the >> >position you find. >> > >> >(2) This approach only works for NBP-COG alignment. That's a >> >new theory, >> >and most of the anecdotal data (and all of the organized >> >published data) >> >use either NBP-target or spine-target alignment. >> > >> >Cheers! >> >DaveT >> > >> > >
Re: ShopTalk: NBP-COG
Dan, I also believe you are right because it works for me. I only had a chance to do it for a couple of people and they say the same thing. If it's not, then the "shaft puring" process GS is using is wrong too. I have a "pured" shaft from GS that I use as a demo, my NF shows the same shaft orientation. Which means a whole lot of other people think so too. Don - Original Message - From: "Dan Neubecker" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, October 09, 2003 8:29 AM Subject: RE: ShopTalk: NBP-COG > Don, > > Yes this will do the job as accurately as any method I'm aware of. > > BTW, some of us do believe that a spine finder does find the correct NBP, > that it should be a combination of flex differential and shaft geometric > anomalies that determines this location. > > Dan Neubecker > [EMAIL PROTECTED] > > > >-Original Message- > >From: Don Flatgard [mailto:[EMAIL PROTECTED] > >Sent: Wednesday, October 08, 2003 4:49 PM > >To: [EMAIL PROTECTED] > >Subject: Re: ShopTalk: NBP-COG > > > > > >NBP-COG alignment. > >I posted this the other day and received no response so I'll > >do it again. > >I agree with you on the difficulty of aligning the NBP and COG to the > >degree. > >My method is to prepare the shaft, install the ferrule, find > >the NBP with > >the NF. Take the DI off, turn the NF up-side down on the bench > >and install > >the head and let it seek it own COG, let the epoxy set up with > >the club in > >the NF. > >In my small mind I don't see how you could get any closerdf > > > > > > > >- Original Message - > >From: "tflan" <[EMAIL PROTECTED]> > >To: <[EMAIL PROTECTED]> > >Sent: Wednesday, October 08, 2003 12:03 PM > >Subject: Re: ShopTalk: NBP-COG > > > > > >> Dr Tutelman: > >> > >> A question, por favor. When this subject was broached > >several months ago, > >> and the thread unwound for about 3 weeks, I asked a question > >that got no > >> universally agreed upon answer. The question was; is the > >spine found at > >the > >> top of the shaft or at the bottom of the shaft when testing in Dick's > >spine > >> finder? Responses were equally, and passionately, divided. > >> > >> I then asked another question; if when one finds the spine, the "hard > >spot" > >> via the use of our arguably primitive methods, how can one > >accurately mark > >> and then place the hard spot in a specific position? As I recall, you > >> responded, correctly, that we'd be lucky to get the spine situated to > >within > >> 3 to 4 degrees. You mentioned the circumference of the .335" > >tip, when > >> reduced to 360 degrees, would be virtually impossible to set > >accurately. I > >> agree. An assembler would need to identify the spine at the > >shaft tip by > >> marking it with a needle, then mark the hosel in the precise finished > >> position. Then he'd need to mark the ferrule so the entire > >assembly could > >be > >> stuck together in one operation. That's nearly impossible given the > >> workplaces of most assemblers. > >> > >> So, this thread re; placing cog/spine in some specific location with > >> accuracy is theoretically interesting but in practice its > >pretty much > >> useless. I'm not knocking anyone, just making a point that's > >been made > >> several times in the past. > >> > >> TFlan > >> > >> - Original Message - > >> From: "Dave Tutelman" <[EMAIL PROTECTED]> > >> To: <[EMAIL PROTECTED]> > >> Sent: Tuesday, October 07, 2003 10:49 AM > >> Subject: Re: ShopTalk: NBP-COG > >> > >> > >> > A few points I'd like to make concerning things that were > >brought up in > >> > this thread: > >> > > >> > (1) As Alan Brooks and John Kaufman and I have said in the > >past, every > >> > shaft will have the stiffest directions (that is, spines) at 180* > >> > intervals. Similarly with the most flexible directions > >(that is, NBP). > >If > >> > you measure anything else, there is something wrong with > >your measuring > >> > equipment. (Others have already noted that residual bend > >affects a spine > >> > finder's reading. That is probably the most common
RE: ShopTalk: NBP-COG
Hi Tom, It depends on what theory you believe in. If you believe that a spine finder can find the correct NBP location as I do, then you absolutely can get the NBP exactly at the COG. Bernie's post on NBP to COG alignment contained a quote from an experimental set I made up. I did not have any high expectations for that set when I made it up. Let me tell you that I was shocked by the difference in the results. The results continue today after months with this set. I continue to hit the best irons of my life. Now this set was a combination of new things for me. First, I used a new shaft, PC Mach 22's, with R+, S- and S shafts in the set. I used my NF2 to tip trim them to a matching profile of .010" deflection between clubs, never having to trim more than 1/2" tip to do so, and the find the NBP locations. Then I made up the clubs with a 3/8" change between lengths, for a poor man's MOI match. Finally I assembled them using the NBP (N1) to COG alignment. It could have any of those factors, or all of them that led to these results, but I was literally shocked by how much better they played than any set I've used. It was the most difference I have seen in at least 10 years of experimenting with clubs, different lengths, different shafts, flexes, torques, components, you name it, I've tried it. I can't ignore results like that, regardless of how tenuous the theory. Dan Neubecker [EMAIL PROTECTED] >-Original Message- >From: tflan [mailto:[EMAIL PROTECTED] >Sent: Wednesday, October 08, 2003 12:04 PM >To: [EMAIL PROTECTED] >Subject: Re: ShopTalk: NBP-COG > > >Dr Tutelman: > >A question, por favor. When this subject was broached several >months ago, >and the thread unwound for about 3 weeks, I asked a question >that got no >universally agreed upon answer. The question was; is the spine >found at the >top of the shaft or at the bottom of the shaft when testing in >Dick's spine >finder? Responses were equally, and passionately, divided. > >I then asked another question; if when one finds the spine, >the "hard spot" >via the use of our arguably primitive methods, how can one >accurately mark >and then place the hard spot in a specific position? As I recall, you >responded, correctly, that we'd be lucky to get the spine >situated to within >3 to 4 degrees. You mentioned the circumference of the .335" tip, when >reduced to 360 degrees, would be virtually impossible to set >accurately. I >agree. An assembler would need to identify the spine at the >shaft tip by >marking it with a needle, then mark the hosel in the precise finished >position. Then he'd need to mark the ferrule so the entire >assembly could be >stuck together in one operation. That's nearly impossible given the >workplaces of most assemblers. > >So, this thread re; placing cog/spine in some specific location with >accuracy is theoretically interesting but in practice its pretty much >useless. I'm not knocking anyone, just making a point that's been made >several times in the past. > >TFlan > >- Original Message - >From: "Dave Tutelman" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Sent: Tuesday, October 07, 2003 10:49 AM >Subject: Re: ShopTalk: NBP-COG > > >> A few points I'd like to make concerning things that were >brought up in >> this thread: >> >> (1) As Alan Brooks and John Kaufman and I have said in the >past, every >> shaft will have the stiffest directions (that is, spines) at 180* >> intervals. Similarly with the most flexible directions (that >is, NBP). If >> you measure anything else, there is something wrong with >your measuring >> equipment. (Others have already noted that residual bend >affects a spine >> finder's reading. That is probably the most common thing >that is wrong >with >> your measuring equipment.) >> >> (2) FLO is important!!! It is not important because of >anything the shaft >> may be doing during the swing (unlike a fishing rod), but it >is one of the >> more reliable ways to find the REAL spine, untarnished by things like >> residual bend. In other words, FLO is a more reliable >spine-finder than >> Colin's or Dan's. Slower perhaps, but it finds the real spine. >> >> (3) There are three theories that I have seen about why >spine alignment >> matters. NBP-COG is one of them. Here's the reasoning behind it: >> * At the moment of impact, the major force bending the shaft is >> centrifugal force. (That is probably true, but not >universally accepted. >> But let's proceed on the assumption that it is true.) >>
RE: ShopTalk: NBP-COG
Bernie, The irons play better than before but my handicap has come down from 12 to 8 this year. I'm playing more and striking the ball better so it's difficult to say if the S1-COG alignment has helped. It certainly hasn't hurt. Every club that I have aligned with the COG, i.e., S1-COG with the steel-shafted irons and NBP-COG with the graphite-shafted woods has felt really solid. My 983K with the Aldila NV is getting a wear spot high in the middle of the face. Jim -Original Message- From: Bernie Baymiller [mailto:[EMAIL PROTECTED] Sent: October 8, 2003 5:45 PM To: [EMAIL PROTECTED] Subject: Re: ShopTalk: NBP-COG Jim, Anecdotal info, as was mine, but did you notice any differences in the way the irons played? I haven't tried the S1-COG alignment yet, but with NBP-COG, as I noted in my previous post, found the short irons in particular to be much more in the direction I aimed them. Bernie Writeto: [EMAIL PROTECTED] - Original Message - From: "Thomson, Jim" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 4:12 PM Subject: RE: ShopTalk: NBP-COG > I have reshafted my three drivers using the NBP-COG alignment (975J/Graphite > Design YS-6; 975J-VS/Graphite Design Purple Ice; 983K/Aldila NV) and was > very pleased with the results of all three. I reshafted one of my Titleist > 962 sets with the new Balistik shaft using the S1-COG alignment and really > like these as well. Anecdotal info for what it's worth. > > -Original Message- > From: Letourneau, Henry J AM1(AW) (VAW120) > [mailto:[EMAIL PROTECTED] > Sent: October 8, 2003 2:23 PM > To: '[EMAIL PROTECTED]' > Subject: RE: ShopTalk: NBP-COG > > > Richard, there seems do be as many different views on spine allignment as > there are positions to allign to! In the end I will have to do some testing > to see for myself, I will mention however that when i started spine > alligning about a year ago i was doing all of the clubs spined to the 1200 > position because it felt better. My question to you is have you tried the > nbp-cog allignment and what were your results. Would S1-COG make more sense > than simply alligning a set of irons to 1200? My experience is limited to > building 10 to 12 sets a year over the past three years and am always > looking for the best possible method af set matching available for my > customers as well as myself. Thanks - Jim Letourneau > > -Original Message- > From: Richard Kennedy [mailto:[EMAIL PROTECTED] > Sent: Wednesday, October 08, 2003 10:46 AM > To: [EMAIL PROTECTED]; [EMAIL PROTECTED] > Subject: Re: ShopTalk: NBP-COG > > > > Scott, to put it very simply , ALIEN THE HARD SPINE AT 12:00. 12:00 keeps > the clubhead toe from drooping.Forget what ever anybody else says, > especially Mr. David T.whom is not a clubmaker per se & who knows very > little about making/fitting of golfclubs. By his own admission he only > makes , at the very most, one set of clubs per year and those are strictly > for his own personal use, Mr. David T. made that statement not I. In fact > Mr. David T. fought us "SPINER'S" tooth and nail that the position off the > spine had no effect on the playability or the flex of the golfclub. It was > not until several People outside of ShopTalk or SpineTalk got into the fray, > with lots of money backing them,that he got into the discussion.I'm not > to sure but I think that Ed J., the host of SplineTalk, asked, I feel is a > better word to use then lets say kicked off of SpileTalk, because of his > disruptive and know it all air that he tried to use in his posts. I do not > subscribe to SpineTalk not because I do not believe in their views, which > by the way I helped to put into use, but because I'm am presently engaged in > other web sites that will have some, I hope, effecting with my health. I > am not the clubmaker that has been spining the longest but i have been > "SPINEING" golfclubs since 1984 long before it became popular. > > RK > > KENNEDY >golf equipment > manufacturer's of world class golfclub repair equipment > ---Original Message--- > > From: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > Date: Wednesday, October 08, 2003 1:02:35 AM > To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > Subject: Re: ShopTalk: NBP-COG > > Let me preface this by saying my introduction to this subject is at most > a week old, and if my statements seem out to lunch, they very well may > be. I'm trying to think this through with my own limited understanding. > I'm certainly not trying to pass this off as if I know something that > the rest of you don't. > > If I remember my physics cor
RE: ShopTalk: NBP-COG
Alan, I appreciate that you are an engineer. I work with several daily, who happen to be my business partners. However, your position here is somewhat elitist in nature. Most in this forum are not engineers, do not have the ability to formulate an analytical model, and must come to our own conclusions through our own empirical testing. You aren't suggesting that we just believe whatever the engineers tell use are you? I know engineers often make mistakes, as I said, I work with them daily. They often rely on an accepted body of work done by others before them. There is the possibility that some of that work is flawed. Many of us have a lot of years of clubmaking experience and are very aware of the placebo effect and have actually grown wary of any new "theory". Usually when we test new things it is with some skepticism. So when something we are skeptical about going in, shows a startling difference, then we cannot just ignore it and wait for the engineers to confirm that it is real. We are attempting to assemble the best performing clubs we can, so why ignore something we have found to be beneficial in our own experimentation and has shown repeatedly positive results with our customers? Perhaps you should have a more open mind and try some of these things for yourself, rather than just relying on theory. If all the inventors out their in our history waited for the engineers to put their stamp of approval on what they were doing, do you suppose we'd be as advanced as we are now technologically? Respectfully, Dan Neubecker [EMAIL PROTECTED] >-Original Message- >From: Alan Brooks [mailto:[EMAIL PROTECTED] >Sent: Wednesday, October 08, 2003 8:44 PM >To: [EMAIL PROTECTED] >Subject: Re: ShopTalk: NBP-COG > > >A couple more thoughts on Dave's statement here (which I agree >with). If >the effects were pronounced, we wouldn't be having this >discussion. We're >arguing about it because they aren't pronounced. At most, they are >marginally detectable. In the scientific community, experimentally >determined results are not accepted until they have been independently >replicated by other researchers. This is done in the hope >that errors by >one researcher will be caught before they are accepted >(remember cold fusion?) > >The other problem we are dealing with here is that all of the >anecdotal >testimony about this or that is the result of testing by us >humans. As Dr. >Phil put it when discussing weight loss, we subconsciously >work to meet our >expectations. If we are handed a golf club that we believe is >better, it >will be, at least for a while, EVEN IF THE CLUB HAS NOT >CHANGED PHYSICALLY >AT ALL. As Dave said, until we have a working analytical >model that we can >use to investigate the effect of spines and have >experimentally validated >it there is insufficient quality testing from which to draw meaningful >conclusions. > >If spines of modern magnitude (less than 5 cpm) do have a measurable >effect, it is going to take some very careful analysis and >experimental >work to quantify, and I am very confident that it will be below the >threshold of human recognition (probably even the pro's). > >Grind away folks, > >Alan Brooks > > > >At 05:19 PM 10/8/2003 -0400, you (Dave T.) wrote: >>Until we have a working analytical model for why spine >alignment helps, we >>won't know how accurate the alignment has to be. I have to >guess it isn't >>very critical. If it were -- and given the truth about how >hard it is to >>align to better than 5 degrees -- the data from hitting >actual clubs would >>be even more random than it is. >
RE: ShopTalk: NBP-COG
Don, Yes this will do the job as accurately as any method I'm aware of. BTW, some of us do believe that a spine finder does find the correct NBP, that it should be a combination of flex differential and shaft geometric anomalies that determines this location. Dan Neubecker [EMAIL PROTECTED] >-Original Message- >From: Don Flatgard [mailto:[EMAIL PROTECTED] >Sent: Wednesday, October 08, 2003 4:49 PM >To: [EMAIL PROTECTED] >Subject: Re: ShopTalk: NBP-COG > > >NBP-COG alignment. >I posted this the other day and received no response so I'll >do it again. >I agree with you on the difficulty of aligning the NBP and COG to the >degree. >My method is to prepare the shaft, install the ferrule, find >the NBP with >the NF. Take the DI off, turn the NF up-side down on the bench >and install >the head and let it seek it own COG, let the epoxy set up with >the club in >the NF. >In my small mind I don't see how you could get any closerdf > > > >- Original Message - >From: "tflan" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Sent: Wednesday, October 08, 2003 12:03 PM >Subject: Re: ShopTalk: NBP-COG > > >> Dr Tutelman: >> >> A question, por favor. When this subject was broached >several months ago, >> and the thread unwound for about 3 weeks, I asked a question >that got no >> universally agreed upon answer. The question was; is the >spine found at >the >> top of the shaft or at the bottom of the shaft when testing in Dick's >spine >> finder? Responses were equally, and passionately, divided. >> >> I then asked another question; if when one finds the spine, the "hard >spot" >> via the use of our arguably primitive methods, how can one >accurately mark >> and then place the hard spot in a specific position? As I recall, you >> responded, correctly, that we'd be lucky to get the spine situated to >within >> 3 to 4 degrees. You mentioned the circumference of the .335" >tip, when >> reduced to 360 degrees, would be virtually impossible to set >accurately. I >> agree. An assembler would need to identify the spine at the >shaft tip by >> marking it with a needle, then mark the hosel in the precise finished >> position. Then he'd need to mark the ferrule so the entire >assembly could >be >> stuck together in one operation. That's nearly impossible given the >> workplaces of most assemblers. >> >> So, this thread re; placing cog/spine in some specific location with >> accuracy is theoretically interesting but in practice its >pretty much >> useless. I'm not knocking anyone, just making a point that's >been made >> several times in the past. >> >> TFlan >> >> - Original Message - >> From: "Dave Tutelman" <[EMAIL PROTECTED]> >> To: <[EMAIL PROTECTED]> >> Sent: Tuesday, October 07, 2003 10:49 AM >> Subject: Re: ShopTalk: NBP-COG >> >> >> > A few points I'd like to make concerning things that were >brought up in >> > this thread: >> > >> > (1) As Alan Brooks and John Kaufman and I have said in the >past, every >> > shaft will have the stiffest directions (that is, spines) at 180* >> > intervals. Similarly with the most flexible directions >(that is, NBP). >If >> > you measure anything else, there is something wrong with >your measuring >> > equipment. (Others have already noted that residual bend >affects a spine >> > finder's reading. That is probably the most common thing >that is wrong >> with >> > your measuring equipment.) >> > >> > (2) FLO is important!!! It is not important because of anything the >shaft >> > may be doing during the swing (unlike a fishing rod), but >it is one of >the >> > more reliable ways to find the REAL spine, untarnished by >things like >> > residual bend. In other words, FLO is a more reliable >spine-finder than >> > Colin's or Dan's. Slower perhaps, but it finds the real spine. >> > >> > (3) There are three theories that I have seen about why >spine alignment >> > matters. NBP-COG is one of them. Here's the reasoning behind it: >> > * At the moment of impact, the major force bending the shaft is >> > centrifugal force. (That is probably true, but not >universally accepted. >> > But let's proceed on the assumption that it is true.) >> > * That force will bend the shaft in the plane of the CG of the >clubhead, >
Re: ShopTalk: NBP-COG
Thanks, Corey, I did a quick check on several of the graphite shafts I have in the garage and they all appeared to have some runout when I rolled them in my spine finder (I didn't try and isolate whether it was shaft curvature or out-of-round butts). It was less than some of the steel shafts (particularly the stepped ones) I have checked but still noticeable. Please jump in with my query to Dan about what other 'anomalies' we are talking about here. Thanks, Alan At 10:26 PM 10/8/2003 -0700, you wrote: Alan: Don't toss out your bearing finder just yet. Graphite shafts don't have the residual bend that steel shafts do and a bearing finder is useful for identifying the anomalies associated with them. Best, CB At 05:46 PM 10/8/2003 -0700, you wrote: Doug, spring for the frequency meter. Or if you want I have a three-bearing 'spine finder' hanging off a cupboard in the garage you can have for the cost of shipping. I built it when I first started building clubs (about a year and a half ago) and quit using it when I realized that all I was finding was the residual bend in the shaft. If a shaft is perfectly round (and they aren't, take a micrometer to one some time) your can take the effect of bend out by taking deflections readings 180-degrees apart (hold the shaft in a particular orientation, measure the deflection, rotate the shaft 180-degrees, and measure the deflection again) and averaging the readings, repeating this in, say, 10-degree increments around the shaft, and plotting the results and basing your conclusions on stiffness variations on that. I have a master's degree in mechanical engineering and a career of experimental testing and I wouldn't put money on the results even then. Measuring frequency is the best way to identify the variations in stiffness in various planes through the axis of the shaft. Even this has the potential for error because of the interaction of the clamp (usually 'V' blocks) and an out of round or tapered shaft. But this (as Dave T. has said) is your best bet. Regards, Alan Brooks At 05:11 PM 10/8/2003 -0500, you wrote: - Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 4:36 PM Subject: Re: ShopTalk: NBP-COG > Tom, > > You need to build yourself an NF2. I hope you will excuse all my posts and my ignorance of the NF2. I know what it is in principle. I could identify it out of a pile of tools, at least. Bernie, I got the impression a few days ago that you feel it eliminates the need for a frequency meter. Did I get that right? I have been too cheap to buy a frequency meter up till now. I've been a careful spine, cut, glue, and swingweight (or v.v.) guy. I have finally decided I better get a meter, but now you have me wondering. Doug Clark
RE: ShopTalk: NBP-COG
Corey Bailey also referred to "other anomalies" in a shaft. Besides curvature (or residual bend) what other anomalies are we talking about here? How do they affect the behavior of a golf club when it is swung? And how is it that a 'spine finder' identifies them? The articles I have read only refer to identifying stiffness variations with a spine finder. Thanks, Alan Brooks At 07:55 AM 10/9/2003 -0500, you wrote: Dave, Well, that depends on how you define NBP. We've had this discussion before. You choose to define NBP as the softest flex plane in a shaft and the spine as the stiffest plane, excluding shaft geometric anomalies from consideration. A number of us disagree with that assumption and believe that geometric anomalies might be just as important in shaft alignment as stiffness. We feel a combination of differential stiffness and shaft geometric anomalies in a shaft should be combined to determine the best alignment, which is exactly what a spine finder does. Dan Neubecker [EMAIL PROTECTED] >-Original Message- >From: Dave Tutelman [mailto:[EMAIL PROTECTED] >Sent: Wednesday, October 08, 2003 5:35 PM >To: [EMAIL PROTECTED]; [EMAIL PROTECTED] >Subject: Re: ShopTalk: NBP-COG > > >At 04:49 PM 10/8/03 -0500, Don Flatgard wrote: >>NBP-COG alignment. >>I posted this the other day and received no response so I'll >do it again. >>I agree with you on the difficulty of aligning the NBP and COG to the >>degree. >>My method is to prepare the shaft, install the ferrule, find >the NBP with >>the NF. Take the DI off, turn the NF up-side down on the >bench and install >>the head and let it seek it own COG, let the epoxy set up >with the club in >>the NF. >>In my small mind I don't see how you could get any closerdf > >Don, >That will indeed get as close as you can measure it. (It's a >variant of an >approach I originally suggested.) Two flies in the ointment, however: > >(1) The NF2 only finds the true NBP if the shaft is straight >and round. >Otherwise, there is an error (frequently a significant error) in the >position you find. > >(2) This approach only works for NBP-COG alignment. That's a >new theory, >and most of the anecdotal data (and all of the organized >published data) >use either NBP-target or spine-target alignment. > >Cheers! >DaveT > >
RE: ShopTalk: NBP-COG
Dave, Well, that depends on how you define NBP. We've had this discussion before. You choose to define NBP as the softest flex plane in a shaft and the spine as the stiffest plane, excluding shaft geometric anomalies from consideration. A number of us disagree with that assumption and believe that geometric anomalies might be just as important in shaft alignment as stiffness. We feel a combination of differential stiffness and shaft geometric anomalies in a shaft should be combined to determine the best alignment, which is exactly what a spine finder does. Dan Neubecker [EMAIL PROTECTED] >-Original Message- >From: Dave Tutelman [mailto:[EMAIL PROTECTED] >Sent: Wednesday, October 08, 2003 5:35 PM >To: [EMAIL PROTECTED]; [EMAIL PROTECTED] >Subject: Re: ShopTalk: NBP-COG > > >At 04:49 PM 10/8/03 -0500, Don Flatgard wrote: >>NBP-COG alignment. >>I posted this the other day and received no response so I'll >do it again. >>I agree with you on the difficulty of aligning the NBP and COG to the >>degree. >>My method is to prepare the shaft, install the ferrule, find >the NBP with >>the NF. Take the DI off, turn the NF up-side down on the >bench and install >>the head and let it seek it own COG, let the epoxy set up >with the club in >>the NF. >>In my small mind I don't see how you could get any closerdf > >Don, >That will indeed get as close as you can measure it. (It's a >variant of an >approach I originally suggested.) Two flies in the ointment, however: > >(1) The NF2 only finds the true NBP if the shaft is straight >and round. >Otherwise, there is an error (frequently a significant error) in the >position you find. > >(2) This approach only works for NBP-COG alignment. That's a >new theory, >and most of the anecdotal data (and all of the organized >published data) >use either NBP-target or spine-target alignment. > >Cheers! >DaveT > >
Re: ShopTalk: NBP-COG
Alan: Don't toss out your bearing finder just yet. Graphite shafts don't have the residual bend that steel shafts do and a bearing finder is useful for identifying the anomalies associated with them. Best, CB At 05:46 PM 10/8/2003 -0700, you wrote: Doug, spring for the frequency meter. Or if you want I have a three-bearing 'spine finder' hanging off a cupboard in the garage you can have for the cost of shipping. I built it when I first started building clubs (about a year and a half ago) and quit using it when I realized that all I was finding was the residual bend in the shaft. If a shaft is perfectly round (and they aren't, take a micrometer to one some time) your can take the effect of bend out by taking deflections readings 180-degrees apart (hold the shaft in a particular orientation, measure the deflection, rotate the shaft 180-degrees, and measure the deflection again) and averaging the readings, repeating this in, say, 10-degree increments around the shaft, and plotting the results and basing your conclusions on stiffness variations on that. I have a master's degree in mechanical engineering and a career of experimental testing and I wouldn't put money on the results even then. Measuring frequency is the best way to identify the variations in stiffness in various planes through the axis of the shaft. Even this has the potential for error because of the interaction of the clamp (usually 'V' blocks) and an out of round or tapered shaft. But this (as Dave T. has said) is your best bet. Regards, Alan Brooks At 05:11 PM 10/8/2003 -0500, you wrote: - Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 4:36 PM Subject: Re: ShopTalk: NBP-COG > Tom, > > You need to build yourself an NF2. I hope you will excuse all my posts and my ignorance of the NF2. I know what it is in principle. I could identify it out of a pile of tools, at least. Bernie, I got the impression a few days ago that you feel it eliminates the need for a frequency meter. Did I get that right? I have been too cheap to buy a frequency meter up till now. I've been a careful spine, cut, glue, and swingweight (or v.v.) guy. I have finally decided I better get a meter, but now you have me wondering. Doug Clark
Re: ShopTalk: NBP-COG
[EMAIL PROTECTED] wrote: Plenty of good shafts are currently available now. For those of us that spine shafts it's tough enough to explain to the consumer why the graphics don't line up perfectly! Penley seems to have solved this problem. I would also point out that MFS Apache shafts are marked with the spine indicated on the butt (a white line). Coincidently, the graphics are placed at 90-degrees to this alignment mark. It saves explaining to the customer! Regards, Ron
Re: ShopTalk: NBP-COG
A couple more thoughts on Dave's statement here (which I agree with). If the effects were pronounced, we wouldn't be having this discussion. We're arguing about it because they aren't pronounced. At most, they are marginally detectable. In the scientific community, experimentally determined results are not accepted until they have been independently replicated by other researchers. This is done in the hope that errors by one researcher will be caught before they are accepted (remember cold fusion?) The other problem we are dealing with here is that all of the anecdotal testimony about this or that is the result of testing by us humans. As Dr. Phil put it when discussing weight loss, we subconsciously work to meet our expectations. If we are handed a golf club that we believe is better, it will be, at least for a while, EVEN IF THE CLUB HAS NOT CHANGED PHYSICALLY AT ALL. As Dave said, until we have a working analytical model that we can use to investigate the effect of spines and have experimentally validated it there is insufficient quality testing from which to draw meaningful conclusions. If spines of modern magnitude (less than 5 cpm) do have a measurable effect, it is going to take some very careful analysis and experimental work to quantify, and I am very confident that it will be below the threshold of human recognition (probably even the pro's). Grind away folks, Alan Brooks At 05:19 PM 10/8/2003 -0400, you (Dave T.) wrote: Until we have a working analytical model for why spine alignment helps, we won't know how accurate the alignment has to be. I have to guess it isn't very critical. If it were -- and given the truth about how hard it is to align to better than 5 degrees -- the data from hitting actual clubs would be even more random than it is.
Re: ShopTalk: NBP-COG
I've got some Harrison Pro steel shafts in my irons that showed less than 1-cpm frequency deviation even after repeated measurements. I've got some UST PF/fairway shafts that have right at 1-cpm frequency deviation. The Grafalloy Blue shaft in my driver was under 2-cpm variation. Theoretically you're right, perfection is only a goal, but I'm an engineer and we can get close enough for all practical purposes. Alan Brooks At 09:30 PM 10/8/2003 -0400, you wrote: In a message dated 10/8/2003 6:21:34 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: spine-free shafts, now that it >has been shown that they can be produced. Excuse my ignorance, but I haven't found one.
Re: ShopTalk: NBP-COG
In a message dated 10/8/2003 6:21:34 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: spine-free shafts, now that it>has been shown that they can be produced. Excuse my ignorance, but I haven't found one.
Re: ShopTalk: NBP-COG
Doug, spring for the frequency meter. Or if you want I have a three-bearing 'spine finder' hanging off a cupboard in the garage you can have for the cost of shipping. I built it when I first started building clubs (about a year and a half ago) and quit using it when I realized that all I was finding was the residual bend in the shaft. If a shaft is perfectly round (and they aren't, take a micrometer to one some time) your can take the effect of bend out by taking deflections readings 180-degrees apart (hold the shaft in a particular orientation, measure the deflection, rotate the shaft 180-degrees, and measure the deflection again) and averaging the readings, repeating this in, say, 10-degree increments around the shaft, and plotting the results and basing your conclusions on stiffness variations on that. I have a master's degree in mechanical engineering and a career of experimental testing and I wouldn't put money on the results even then. Measuring frequency is the best way to identify the variations in stiffness in various planes through the axis of the shaft. Even this has the potential for error because of the interaction of the clamp (usually 'V' blocks) and an out of round or tapered shaft. But this (as Dave T. has said) is your best bet. Regards, Alan Brooks At 05:11 PM 10/8/2003 -0500, you wrote: - Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 4:36 PM Subject: Re: ShopTalk: NBP-COG > Tom, > > You need to build yourself an NF2. I hope you will excuse all my posts and my ignorance of the NF2. I know what it is in principle. I could identify it out of a pile of tools, at least. Bernie, I got the impression a few days ago that you feel it eliminates the need for a frequency meter. Did I get that right? I have been too cheap to buy a frequency meter up till now. I've been a careful spine, cut, glue, and swingweight (or v.v.) guy. I have finally decided I better get a meter, but now you have me wondering. Doug Clark
Re: ShopTalk: NBP-COG
Doug, Both methods seem to have their advantages and disadvantages. For a hobbyist like me, the NF2 seems to do an accurate job of shaft matching...so I haven't bought a frequency meter yet, either. As a bonus, the NF2 seems to give me a good idea whether a shaft has been manufactured well or not. It tells me the raw deflection and location of the soft and stiff sides of a shaft, the size of a spine, and consistency shaft-to-shaft in a set. It can check the alignment of an assembled club. It's fast and easy to use, portable, needs no power and is a great demo which customers (mostly senior friends and players on our three courses) can understand hands-on. It does most of what a frequency meter can do, but not all...like matching the flex of an assembled club without taking it apart. (Maybe an NF2 can do that, but it requires a very short beam length.) Nor are there any "records" and charts to match your work against with an NF2 (until you make them)...frequency charts are available to tell you where a club of a certain length falls within a frequency range. PCS has an Equalizer system to compare frequencies with other machines. If I were a pro clubmaker, a frequency meter would be a necessity, I think. An NF2 would cost you about $100 to build, John Kaufman has a Club Scout Jr. that requires a little "building" on your part...the clamp, I believe... for about the same price. A top-of-the-line Club Scout is considerably more, but if I was buying a frequency meter, that's the one I would get. Quite a few NF2 builders have both and would be better at answering your question than me. Bernie Writeto: [EMAIL PROTECTED] - Original Message - From: "Doug Clark" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 6:11 PM Subject: Re: ShopTalk: NBP-COG > > - Original Message - > From: "Bernie Baymiller" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Wednesday, October 08, 2003 4:36 PM > Subject: Re: ShopTalk: NBP-COG > > > > Tom, > > > > You need to build yourself an NF2. > > I hope you will excuse all my posts and my ignorance of the NF2. I know > what it is in principle. I could identify it out of a pile of tools, at > least. Bernie, I got the impression a few days ago that you feel it > eliminates the need for a frequency meter. Did I get that right? > > I have been too cheap to buy a frequency meter up till now. I've been a > careful spine, cut, glue, and swingweight (or v.v.) guy. I have finally > decided I better get a meter, but now you have me wondering. > > Doug Clark > > >
Re: ShopTalk: NBP-COG
In a message dated 10/8/03 6:21:34 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: , Doug Clark wrote: >Spines are fascinating but annoying in my book. I really expect the >clubmaker market to vote with its dollars for spine-free shafts, now that it >has been shown that they can be produced. COME THE REVOLUTION! The catch phrase for spine-free shaft manufacturers is "virtually spine-free". That means that out of the 8 or 9 shafts you are planning on buying, a small number (7is a small number:-) ) "may have a very small spine". I don't think that in this case the shafts would be acceptable! Here's how to do itorder 200 shafts, test each one and select those that meet with your approval, then send back all the shafts that you "reject", pay the freight both ways, pay a restocking fee and build "the perfect set of irons"! With all the money a club builder will spend with a manufacturer this way, the shaft manufacturer will surely go out of business and we won't have to be "bothered" with another shaft supplier! "Boutique" shafts will become the leaders and their prices will approach $70 each. Club builders will glow about their quality but "Boutique" won't have the money to get their shafts on the Tour. THEIR "REJECTS" WILL BE AVAILABLE FOR $6-10 EACH, after repainting of course. Consumers will require hours of "selling" on the part or the club builder to convince them of "the perfection" built into "Boutique" shafts. Once sold they won't see any improvement in their scores and will be back to see you "FOR A REFUND". You will soon have a shop full of "slightly experienced clubs" at terrific prices! You will test these clubs, regrip them, adjust the lofts and lies for the next customer (at no charge). You better get ready for your place in a cardboard box under an interstate overpass! Plenty of good shafts are currently available now. For those of us that spine shafts it's tough enough to explain to the consumer why the graphics don't line up perfectly! Penley seems to have solved this problem. No sir, I didn't have anything to drink when I built your clubs! If you don't take ten strokes off your game, just bring 'em back! And we'll talk "bout it. O.K., now get your whips. Arnie
Re: ShopTalk: NBP-COG
At 04:49 PM 10/8/03 -0500, Don Flatgard wrote: NBP-COG alignment. I posted this the other day and received no response so I'll do it again. I agree with you on the difficulty of aligning the NBP and COG to the degree. My method is to prepare the shaft, install the ferrule, find the NBP with the NF. Take the DI off, turn the NF up-side down on the bench and install the head and let it seek it own COG, let the epoxy set up with the club in the NF. In my small mind I don't see how you could get any closerdf Don, That will indeed get as close as you can measure it. (It's a variant of an approach I originally suggested.) Two flies in the ointment, however: (1) The NF2 only finds the true NBP if the shaft is straight and round. Otherwise, there is an error (frequently a significant error) in the position you find. (2) This approach only works for NBP-COG alignment. That's a new theory, and most of the anecdotal data (and all of the organized published data) use either NBP-target or spine-target alignment. Cheers! DaveT
Re: ShopTalk: NBP-COG
A man after my own heart. Right on, Doug! Cheers! DaveT At 04:33 PM 10/8/03 -0500, Doug Clark wrote: Spines are fascinating but annoying in my book. I really expect the clubmaker market to vote with its dollars for spine-free shafts, now that it has been shown that they can be produced. --- deleted two more paragraphs elaborating on this obviously good idea --
Re: ShopTalk: NBP-COG
- Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 4:36 PM Subject: Re: ShopTalk: NBP-COG > Tom, > > You need to build yourself an NF2. I hope you will excuse all my posts and my ignorance of the NF2. I know what it is in principle. I could identify it out of a pile of tools, at least. Bernie, I got the impression a few days ago that you feel it eliminates the need for a frequency meter. Did I get that right? I have been too cheap to buy a frequency meter up till now. I've been a careful spine, cut, glue, and swingweight (or v.v.) guy. I have finally decided I better get a meter, but now you have me wondering. Doug Clark
Re: ShopTalk: NBP-COG
Tom, You need to build yourself an NF2. If I rotate to the spine on my NF2 with a dial indicator and can read the deflection in thousandths, as well as see the deflection go up as I go toward the spine, and see the resistance direction of the shaft and its affect on the dial indicator's probe, then it is obvious to me that the point of least stability is a spine, or stiffer point on the circumference of the shaft. If there are two, I can measure them both in thousandths and know which is the S1 and which is the S2, as well as their magnitude from the NBP deflections. I think that if I mark the location of the NBP, a dead stable point, with the accurate marking guide (dead center over the shaft on an NF2) on the wider section of the shaft just below the grip, that I can get closer than 4° in an NBP-COG alignment. In fact, since gravity pulls the head to the COG (I hope), my only alignment variables are my NBP marking accuracy and my ability to put the NBP exactly at 6 o'clock. Since the marking guide is very close to the flexed shaft, I think that I can mark it within 2°...but whether I can get the NBP exactly at 6 repeatably, I'm not sure yet. I made a small jig from a section of graphite shaft that is exactly 1/2 the circumference of the shaft at the point I mark the NBP. This allows me to put a mark 180° from the NBP, which I will be able to orient at 12 on a table top. Of course, this assumes I'm using a similar-diameter shaft at the marking point. Another way that I've tried marking the 12 o'clock point is to put the NBP-marked shaft in my Workmate slot and close it up to the point that I can just rotate the shaft. Looking up from underneath, I can center the NBP mark in the small slot, then mark the top dead center. There are probably some other ways that might work better. How've you been playing lately? Is your lurch still lurching down the fairway? I was just getting consistently back into the mid-high 70s when I tore up my left shoulder (probably rolled over in bed the wrong way) about a week ago and might not be able to play for at least a couple of weeks. Then, it'll be back to trying to break 80 again. There is always another challenge for us senior players. :-) Bernie Writeto: [EMAIL PROTECTED] - Original Message - From: "tflan" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 1:03 PM Subject: Re: ShopTalk: NBP-COG > Dr Tutelman: > > A question, por favor. When this subject was broached several months ago, > and the thread unwound for about 3 weeks, I asked a question that got no > universally agreed upon answer. The question was; is the spine found at the > top of the shaft or at the bottom of the shaft when testing in Dick's spine > finder? Responses were equally, and passionately, divided. > > I then asked another question; if when one finds the spine, the "hard spot" > via the use of our arguably primitive methods, how can one accurately mark > and then place the hard spot in a specific position? As I recall, you > responded, correctly, that we'd be lucky to get the spine situated to within > 3 to 4 degrees. You mentioned the circumference of the .335" tip, when > reduced to 360 degrees, would be virtually impossible to set accurately. I > agree. An assembler would need to identify the spine at the shaft tip by > marking it with a needle, then mark the hosel in the precise finished > position. Then he'd need to mark the ferrule so the entire assembly could be > stuck together in one operation. That's nearly impossible given the > workplaces of most assemblers. > > So, this thread re; placing cog/spine in some specific location with > accuracy is theoretically interesting but in practice its pretty much > useless. I'm not knocking anyone, just making a point that's been made > several times in the past. > > TFlan > > - Original Message - > From: "Dave Tutelman" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Tuesday, October 07, 2003 10:49 AM > Subject: Re: ShopTalk: NBP-COG > > > > A few points I'd like to make concerning things that were brought up in > > this thread: > > > > (1) As Alan Brooks and John Kaufman and I have said in the past, every > > shaft will have the stiffest directions (that is, spines) at 180* > > intervals. Similarly with the most flexible directions (that is, NBP). If > > you measure anything else, there is something wrong with your measuring > > equipment. (Others have already noted that residual bend affects a spine > > finder's reading. That is probably the most common thing that is wrong > with > > your measuring equipment.) > > > > (2) FLO is important!!! It is not important because
Re: ShopTalk: NBP-COG
Jim, Anecdotal info, as was mine, but did you notice any differences in the way the irons played? I haven't tried the S1-COG alignment yet, but with NBP-COG, as I noted in my previous post, found the short irons in particular to be much more in the direction I aimed them. Bernie Writeto: [EMAIL PROTECTED] - Original Message - From: "Thomson, Jim" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 4:12 PM Subject: RE: ShopTalk: NBP-COG > I have reshafted my three drivers using the NBP-COG alignment (975J/Graphite > Design YS-6; 975J-VS/Graphite Design Purple Ice; 983K/Aldila NV) and was > very pleased with the results of all three. I reshafted one of my Titleist > 962 sets with the new Balistik shaft using the S1-COG alignment and really > like these as well. Anecdotal info for what it's worth. > > -Original Message- > From: Letourneau, Henry J AM1(AW) (VAW120) > [mailto:[EMAIL PROTECTED] > Sent: October 8, 2003 2:23 PM > To: '[EMAIL PROTECTED]' > Subject: RE: ShopTalk: NBP-COG > > > Richard, there seems do be as many different views on spine allignment as > there are positions to allign to! In the end I will have to do some testing > to see for myself, I will mention however that when i started spine > alligning about a year ago i was doing all of the clubs spined to the 1200 > position because it felt better. My question to you is have you tried the > nbp-cog allignment and what were your results. Would S1-COG make more sense > than simply alligning a set of irons to 1200? My experience is limited to > building 10 to 12 sets a year over the past three years and am always > looking for the best possible method af set matching available for my > customers as well as myself. Thanks - Jim Letourneau > > -Original Message- > From: Richard Kennedy [mailto:[EMAIL PROTECTED] > Sent: Wednesday, October 08, 2003 10:46 AM > To: [EMAIL PROTECTED]; [EMAIL PROTECTED] > Subject: Re: ShopTalk: NBP-COG > > > > Scott, to put it very simply , ALIEN THE HARD SPINE AT 12:00. 12:00 keeps > the clubhead toe from drooping.Forget what ever anybody else says, > especially Mr. David T.whom is not a clubmaker per se & who knows very > little about making/fitting of golfclubs. By his own admission he only > makes , at the very most, one set of clubs per year and those are strictly > for his own personal use, Mr. David T. made that statement not I. In fact > Mr. David T. fought us "SPINER'S" tooth and nail that the position off the > spine had no effect on the playability or the flex of the golfclub. It was > not until several People outside of ShopTalk or SpineTalk got into the fray, > with lots of money backing them,that he got into the discussion.I'm not > to sure but I think that Ed J., the host of SplineTalk, asked, I feel is a > better word to use then lets say kicked off of SpileTalk, because of his > disruptive and know it all air that he tried to use in his posts. I do not > subscribe to SpineTalk not because I do not believe in their views, which > by the way I helped to put into use, but because I'm am presently engaged in > other web sites that will have some, I hope, effecting with my health. I > am not the clubmaker that has been spining the longest but i have been > "SPINEING" golfclubs since 1984 long before it became popular. > > RK > > KENNEDY >golf equipment > manufacturer's of world class golfclub repair equipment > ---Original Message--- > > From: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > Date: Wednesday, October 08, 2003 1:02:35 AM > To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > Subject: Re: ShopTalk: NBP-COG > > Let me preface this by saying my introduction to this subject is at most > a week old, and if my statements seem out to lunch, they very well may > be. I'm trying to think this through with my own limited understanding. > I'm certainly not trying to pass this off as if I know something that > the rest of you don't. > > If I remember my physics correctly (and I probably don't), I expect any > system like this to have some natural vibration; the twang you induce > for FLO would cause this particular system to vibrate at its natural > frequency. If the system is FLO aligned correctly this vibration is > along the target line at impact, i.e 3-9 o'clock. Otherwise this > vibration has a 12-6 o'clock component to it, which would help take the > clubface out of the line with the ball. Please note that I have no idea > how large this component would be. Are we talking fractions of > millimeters here? If the NBP is aligned to COG, the local minima f
Re: ShopTalk: NBP-COG
NBP-COG alignment. I posted this the other day and received no response so I'll do it again. I agree with you on the difficulty of aligning the NBP and COG to the degree. My method is to prepare the shaft, install the ferrule, find the NBP with the NF. Take the DI off, turn the NF up-side down on the bench and install the head and let it seek it own COG, let the epoxy set up with the club in the NF. In my small mind I don't see how you could get any closerdf - Original Message - From: "tflan" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 12:03 PM Subject: Re: ShopTalk: NBP-COG > Dr Tutelman: > > A question, por favor. When this subject was broached several months ago, > and the thread unwound for about 3 weeks, I asked a question that got no > universally agreed upon answer. The question was; is the spine found at the > top of the shaft or at the bottom of the shaft when testing in Dick's spine > finder? Responses were equally, and passionately, divided. > > I then asked another question; if when one finds the spine, the "hard spot" > via the use of our arguably primitive methods, how can one accurately mark > and then place the hard spot in a specific position? As I recall, you > responded, correctly, that we'd be lucky to get the spine situated to within > 3 to 4 degrees. You mentioned the circumference of the .335" tip, when > reduced to 360 degrees, would be virtually impossible to set accurately. I > agree. An assembler would need to identify the spine at the shaft tip by > marking it with a needle, then mark the hosel in the precise finished > position. Then he'd need to mark the ferrule so the entire assembly could be > stuck together in one operation. That's nearly impossible given the > workplaces of most assemblers. > > So, this thread re; placing cog/spine in some specific location with > accuracy is theoretically interesting but in practice its pretty much > useless. I'm not knocking anyone, just making a point that's been made > several times in the past. > > TFlan > > - Original Message - > From: "Dave Tutelman" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Tuesday, October 07, 2003 10:49 AM > Subject: Re: ShopTalk: NBP-COG > > > > A few points I'd like to make concerning things that were brought up in > > this thread: > > > > (1) As Alan Brooks and John Kaufman and I have said in the past, every > > shaft will have the stiffest directions (that is, spines) at 180* > > intervals. Similarly with the most flexible directions (that is, NBP). If > > you measure anything else, there is something wrong with your measuring > > equipment. (Others have already noted that residual bend affects a spine > > finder's reading. That is probably the most common thing that is wrong > with > > your measuring equipment.) > > > > (2) FLO is important!!! It is not important because of anything the shaft > > may be doing during the swing (unlike a fishing rod), but it is one of the > > more reliable ways to find the REAL spine, untarnished by things like > > residual bend. In other words, FLO is a more reliable spine-finder than > > Colin's or Dan's. Slower perhaps, but it finds the real spine. > > > > (3) There are three theories that I have seen about why spine alignment > > matters. NBP-COG is one of them. Here's the reasoning behind it: > > * At the moment of impact, the major force bending the shaft is > > centrifugal force. (That is probably true, but not universally accepted. > > But let's proceed on the assumption that it is true.) > > * That force will bend the shaft in the plane of the CG of the clubhead, > > because centrifugal force acts through the CG of the clubhead. (In > essence, > > it is pulling the CG of the clubhead straight away from the hands.) > > * If the shaft bends in a plane where the forces due to bending are not > > in the same plane as the bending, there will be spurious torque on the > > clubhead; you don't want that. > > * But the only planes where the force and the bending are aligned are > the > > NBP and the spine plane. In other planes, there will be some small angle > > between the bending and the force in the shaft. So you need to align one > of > > those planes (either the NBP or the spine) with the CG of the clubhhead. > > > > (4) If you build your clubs with nearly spineless shafts (like SK Fiber, > or > > the new Harrisons, or many filament-wound shafts), then it makes little > > sense to say, "I used NBP-COG alignment [or any other alignment] and it > > worked GREAT!" You were aligning an effect that probably didn't matter one > > way or another. > > > > Hope this helps, > > DaveT
Re: ShopTalk: NBP-COG
Spines are fascinating but annoying in my book. I really expect the clubmaker market to vote with its dollars for spine-free shafts, now that it has been shown that they can be produced. Recently I ordered two Penley GS-85 shafts. Each was apparently spined at the factory since it came with instructions about how to orient the graphics. One was a Type I and the other was a II, and they had the NBP pointing to the target in each case, with the graphics up. That's a lot better than nothing, but I still would prefer to have no spine to deal with. Then again, maybe "spinefree" is meaningless too. Maybe FLO is meaningless. Maybe it depends if you load the shaft once or twice during the downswing. Still, a random orientation of a strong spine does not seem to be the way to go. Give me spinefree shafts. The mind boggles. Doug Clark - Original Message - From: "tflan" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 08, 2003 12:03 PM Subject: Re: ShopTalk: NBP-COG > Dr Tutelman: > > A question, por favor. When this subject was broached several months ago, > and the thread unwound for about 3 weeks, I asked a question that got no > universally agreed upon answer. The question was; is the spine found at the > top of the shaft or at the bottom of the shaft when testing in Dick's spine > finder? Responses were equally, and passionately, divided. > > I then asked another question; if when one finds the spine, the "hard spot" > via the use of our arguably primitive methods, how can one accurately mark > and then place the hard spot in a specific position? As I recall, you > responded, correctly, that we'd be lucky to get the spine situated to within > 3 to 4 degrees. You mentioned the circumference of the .335" tip, when > reduced to 360 degrees, would be virtually impossible to set accurately. I > agree. An assembler would need to identify the spine at the shaft tip by > marking it with a needle, then mark the hosel in the precise finished > position. Then he'd need to mark the ferrule so the entire assembly could be > stuck together in one operation. That's nearly impossible given the > workplaces of most assemblers. > > So, this thread re; placing cog/spine in some specific location with > accuracy is theoretically interesting but in practice its pretty much > useless. I'm not knocking anyone, just making a point that's been made > several times in the past. > > TFlan > > ----- Original Message - > From: "Dave Tutelman" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Tuesday, October 07, 2003 10:49 AM > Subject: Re: ShopTalk: NBP-COG > > > > A few points I'd like to make concerning things that were brought up in > > this thread: > > > > (1) As Alan Brooks and John Kaufman and I have said in the past, every > > shaft will have the stiffest directions (that is, spines) at 180* > > intervals. Similarly with the most flexible directions (that is, NBP). If > > you measure anything else, there is something wrong with your measuring > > equipment. (Others have already noted that residual bend affects a spine > > finder's reading. That is probably the most common thing that is wrong > with > > your measuring equipment.) > > > > (2) FLO is important!!! It is not important because of anything the shaft > > may be doing during the swing (unlike a fishing rod), but it is one of the > > more reliable ways to find the REAL spine, untarnished by things like > > residual bend. In other words, FLO is a more reliable spine-finder than > > Colin's or Dan's. Slower perhaps, but it finds the real spine. > > > > (3) There are three theories that I have seen about why spine alignment > > matters. NBP-COG is one of them. Here's the reasoning behind it: > > * At the moment of impact, the major force bending the shaft is > > centrifugal force. (That is probably true, but not universally accepted. > > But let's proceed on the assumption that it is true.) > > * That force will bend the shaft in the plane of the CG of the clubhead, > > because centrifugal force acts through the CG of the clubhead. (In > essence, > > it is pulling the CG of the clubhead straight away from the hands.) > > * If the shaft bends in a plane where the forces due to bending are not > > in the same plane as the bending, there will be spurious torque on the > > clubhead; you don't want that. > > * But the only planes where the force and the bending are aligned are > the > > NBP and the spine plane. In other planes, there will be some small angle > > between the bending and the for
Re: ShopTalk: NBP-COG
tflan To answer your question, if the shaft is straight the hard side or the side with more thickness or more material will end up on top of the curvature when bent and free to rotate to the stable position. If the shaft is only bowed only the shaft will rotate into the stable position of bow down. If you have both a bow and a hard side the stable position will be an average of the two positions. This gives me an opportunity to expound on a new approach to spine alignment I have been thinking about and formulating over the past several months. I started out believing the spine should be a 12:00 and the only cared about Flow but have converged my thinking as follows. 1. The vibration wobble and flow are not a factor in picking a spine position as well as all of these other alignment theories that are being expounded. 2. If we look at the mechanics of the system the shaft is stable as long as the shaft is loaded away from the hard side or with the bow of the shaft or an average position if the shaft has both. This assumes the load is applied on the center line of the shaft. However if the shaft is loaded in the opposite direction as just described the shaft is unstable and would tend to move to the left or right of the straight deflection path. Adding the head and loading the shaft off the shaft center line complicates the problem but there still would be a place where we could place the spine, load the shaft at the C. G. of the system and get the shaft to deflect straight back in a stable manner. The shaft head system would still be unstable when loaded the other direction. (a method of finding this position is still under consideration) If the shaft is not in this stable condition while being loaded the shaft under load will deflect off plain and then will return to the ball off plain. 3. Since the shaft is loaded in the swing and we can have the spine located in such a position the shaft goes straight back on plain it will return to the ball on plain and we will have achieved the best performance and the solution to our spine locating problems. llhack > [Original Message] > From: tflan <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Date: 10/8/03 11:16:01 AM > Subject: Re: ShopTalk: NBP-COG > > Dr Tutelman: > > A question, por favor. When this subject was broached several months ago, > and the thread unwound for about 3 weeks, I asked a question that got no > universally agreed upon answer. The question was; is the spine found at the > top of the shaft or at the bottom of the shaft when testing in Dick's spine > finder? Responses were equally, and passionately, divided. > > I then asked another question; if when one finds the spine, the "hard spot" > via the use of our arguably primitive methods, how can one accurately mark > and then place the hard spot in a specific position? As I recall, you > responded, correctly, that we'd be lucky to get the spine situated to within > 3 to 4 degrees. You mentioned the circumference of the .335" tip, when > reduced to 360 degrees, would be virtually impossible to set accurately. I > agree. An assembler would need to identify the spine at the shaft tip by > marking it with a needle, then mark the hosel in the precise finished > position. Then he'd need to mark the ferrule so the entire assembly could be > stuck together in one operation. That's nearly impossible given the > workplaces of most assemblers. > > So, this thread re; placing cog/spine in some specific location with > accuracy is theoretically interesting but in practice its pretty much > useless. I'm not knocking anyone, just making a point that's been made > several times in the past. > > TFlan > > - Original Message - > From: "Dave Tutelman" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Tuesday, October 07, 2003 10:49 AM > Subject: Re: ShopTalk: NBP-COG > > > > A few points I'd like to make concerning things that were brought up in > > this thread: > > > > (1) As Alan Brooks and John Kaufman and I have said in the past, every > > shaft will have the stiffest directions (that is, spines) at 180* > > intervals. Similarly with the most flexible directions (that is, NBP). If > > you measure anything else, there is something wrong with your measuring > > equipment. (Others have already noted that residual bend affects a spine > > finder's reading. That is probably the most common thing that is wrong > with > > your measuring equipment.) > > > > (2) FLO is important!!! It is not important because of anything the shaft > > may be doing during the swing (unlike a fishing rod), but it is one of the > > more reliable ways to find the REAL spine, untarnished by things like > > residual b
Re: ShopTalk: NBP-COG
At 10:03 AM 10/8/03 -0700, tflan wrote: Dr Tutelman: Thank you, Tom. I guess if Al T can answer to "Admiral", then I can answer to "Doctor". A question, por favor. When this subject was broached several months ago, and the thread unwound for about 3 weeks, I asked a question that got no universally agreed upon answer. The question was; is the spine found at the top of the shaft or at the bottom of the shaft when testing in Dick's spine finder? Responses were equally, and passionately, divided. I don't think I weighed in. But if you understood my post that you tagged your question to, you can probably figure out what I think about it. If the shaft is sufficiently straight and round that the spine finder's reading actually has something to do with the spine, then the NBP is at the top AND the bottom. The spine is in a plane at about a right angle to the NBP plane. If you have to choose between the top and the bottom, then you're looking at bend or out-of-round, not spine. I then asked another question; if when one finds the spine, the "hard spot" via the use of our arguably primitive methods, how can one accurately mark and then place the hard spot in a specific position? As I recall, you responded, correctly, that we'd be lucky to get the spine situated to within 3 to 4 degrees. You mentioned the circumference of the .335" tip, when reduced to 360 degrees, would be virtually impossible to set accurately. I agree. An assembler would need to identify the spine at the shaft tip by marking it with a needle, then mark the hosel in the precise finished position. Then he'd need to mark the ferrule so the entire assembly could be stuck together in one operation. That's nearly impossible given the workplaces of most assemblers. Until we have a working analytical model for why spine alignment helps, we won't know how accurate the alignment has to be. I have to guess it isn't very critical. If it were -- and given the truth about how hard it is to align to better than 5 degrees -- the data from hitting actual clubs would be even more random than it is. So, this thread re; placing cog/spine in some specific location with accuracy is theoretically interesting but in practice its pretty much useless. I'm not knocking anyone, just making a point that's been made several times in the past. I'm having trouble finding the promised question. I found a concluding statement that I might agree with. But if the spine is big enough, and alignment is sufficiently non-critical, then maybe it isn't useless in practice. Cheers! DaveT
RE: ShopTalk: NBP-COG
I have reshafted my three drivers using the NBP-COG alignment (975J/Graphite Design YS-6; 975J-VS/Graphite Design Purple Ice; 983K/Aldila NV) and was very pleased with the results of all three. I reshafted one of my Titleist 962 sets with the new Balistik shaft using the S1-COG alignment and really like these as well. Anecdotal info for what it's worth. -Original Message- From: Letourneau, Henry J AM1(AW) (VAW120) [mailto:[EMAIL PROTECTED] Sent: October 8, 2003 2:23 PM To: '[EMAIL PROTECTED]' Subject: RE: ShopTalk: NBP-COG Richard, there seems do be as many different views on spine allignment as there are positions to allign to! In the end I will have to do some testing to see for myself, I will mention however that when i started spine alligning about a year ago i was doing all of the clubs spined to the 1200 position because it felt better. My question to you is have you tried the nbp-cog allignment and what were your results. Would S1-COG make more sense than simply alligning a set of irons to 1200? My experience is limited to building 10 to 12 sets a year over the past three years and am always looking for the best possible method af set matching available for my customers as well as myself. Thanks - Jim Letourneau -Original Message- From: Richard Kennedy [mailto:[EMAIL PROTECTED] Sent: Wednesday, October 08, 2003 10:46 AM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: Re: ShopTalk: NBP-COG Scott, to put it very simply , ALIEN THE HARD SPINE AT 12:00. 12:00 keeps the clubhead toe from drooping.Forget what ever anybody else says, especially Mr. David T.whom is not a clubmaker per se & who knows very little about making/fitting of golfclubs. By his own admission he only makes , at the very most, one set of clubs per year and those are strictly for his own personal use, Mr. David T. made that statement not I. In fact Mr. David T. fought us "SPINER'S" tooth and nail that the position off the spine had no effect on the playability or the flex of the golfclub. It was not until several People outside of ShopTalk or SpineTalk got into the fray, with lots of money backing them,that he got into the discussion.I'm not to sure but I think that Ed J., the host of SplineTalk, asked, I feel is a better word to use then lets say kicked off of SpileTalk, because of his disruptive and know it all air that he tried to use in his posts. I do not subscribe to SpineTalk not because I do not believe in their views, which by the way I helped to put into use, but because I'm am presently engaged in other web sites that will have some, I hope, effecting with my health. I am not the clubmaker that has been spining the longest but i have been "SPINEING" golfclubs since 1984 long before it became popular. RK KENNEDY golf equipment manufacturer's of world class golfclub repair equipment ---Original Message--- From: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> Date: Wednesday, October 08, 2003 1:02:35 AM To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> Subject: Re: ShopTalk: NBP-COG Let me preface this by saying my introduction to this subject is at most a week old, and if my statements seem out to lunch, they very well may be. I'm trying to think this through with my own limited understanding. I'm certainly not trying to pass this off as if I know something that the rest of you don't. If I remember my physics correctly (and I probably don't), I expect any system like this to have some natural vibration; the twang you induce for FLO would cause this particular system to vibrate at its natural frequency. If the system is FLO aligned correctly this vibration is along the target line at impact, i.e 3-9 o'clock. Otherwise this vibration has a 12-6 o'clock component to it, which would help take the clubface out of the line with the ball. Please note that I have no idea how large this component would be. Are we talking fractions of millimeters here? If the NBP is aligned to COG, the local minima for shaft rigidity, then the vibration should be at a minimum because this is the most inherently stable shaft orientation for the force applied (I used the term damping to describe this ... I shouldn't have, it isn't the correct term). If the spine were aligned at COG, then when force is applied from the downsing, the shaft wants to rotate away (as in a spine finder), because this is the most inherently unstable shaft orientation and you would get the most vibration. Again, I have no idea if the deflection due to this oscillation could cause a toe or heel hit. When I started reading up on this, I was suprised aligning the spine would have any noticable affect on your shot at all. Thank you for your patience. Scott Dave Tutelman wrote: > At 08:40 PM 10/7/03 -0600, Scott Stephens wrote: > >> It makes sense to me to align a NBP to the COG, si
RE: ShopTalk: NBP-COG
Richard, there seems do be as many different views on spine allignment as there are positions to allign to! In the end I will have to do some testing to see for myself, I will mention however that when i started spine alligning about a year ago i was doing all of the clubs spined to the 1200 position because it felt better. My question to you is have you tried the nbp-cog allignment and what were your results. Would S1-COG make more sense than simply alligning a set of irons to 1200? My experience is limited to building 10 to 12 sets a year over the past three years and am always looking for the best possible method af set matching available for my customers as well as myself. Thanks - Jim Letourneau -Original Message- From: Richard Kennedy [mailto:[EMAIL PROTECTED] Sent: Wednesday, October 08, 2003 10:46 AM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: Re: ShopTalk: NBP-COG Scott, to put it very simply , ALIEN THE HARD SPINE AT 12:00. 12:00 keeps the clubhead toe from drooping.Forget what ever anybody else says, especially Mr. David T.whom is not a clubmaker per se & who knows very little about making/fitting of golfclubs. By his own admission he only makes , at the very most, one set of clubs per year and those are strictly for his own personal use, Mr. David T. made that statement not I. In fact Mr. David T. fought us "SPINER'S" tooth and nail that the position off the spine had no effect on the playability or the flex of the golfclub. It was not until several People outside of ShopTalk or SpineTalk got into the fray, with lots of money backing them,that he got into the discussion.I'm not to sure but I think that Ed J., the host of SplineTalk, asked, I feel is a better word to use then lets say kicked off of SpileTalk, because of his disruptive and know it all air that he tried to use in his posts. I do not subscribe to SpineTalk not because I do not believe in their views, which by the way I helped to put into use, but because I'm am presently engaged in other web sites that will have some, I hope, effecting with my health. I am not the clubmaker that has been spining the longest but i have been "SPINEING" golfclubs since 1984 long before it became popular. RK KENNEDY golf equipment manufacturer's of world class golfclub repair equipment ---Original Message--- From: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> Date: Wednesday, October 08, 2003 1:02:35 AM To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> Subject: Re: ShopTalk: NBP-COG Let me preface this by saying my introduction to this subject is at most a week old, and if my statements seem out to lunch, they very well may be. I'm trying to think this through with my own limited understanding. I'm certainly not trying to pass this off as if I know something that the rest of you don't. If I remember my physics correctly (and I probably don't), I expect any system like this to have some natural vibration; the twang you induce for FLO would cause this particular system to vibrate at its natural frequency. If the system is FLO aligned correctly this vibration is along the target line at impact, i.e 3-9 o'clock. Otherwise this vibration has a 12-6 o'clock component to it, which would help take the clubface out of the line with the ball. Please note that I have no idea how large this component would be. Are we talking fractions of millimeters here? If the NBP is aligned to COG, the local minima for shaft rigidity, then the vibration should be at a minimum because this is the most inherently stable shaft orientation for the force applied (I used the term damping to describe this ... I shouldn't have, it isn't the correct term). If the spine were aligned at COG, then when force is applied from the downsing, the shaft wants to rotate away (as in a spine finder), because this is the most inherently unstable shaft orientation and you would get the most vibration. Again, I have no idea if the deflection due to this oscillation could cause a toe or heel hit. When I started reading up on this, I was suprised aligning the spine would have any noticable affect on your shot at all. Thank you for your patience. Scott Dave Tutelman wrote: > At 08:40 PM 10/7/03 -0600, Scott Stephens wrote: > >> It makes sense to me to align a NBP to the COG, since this should >> contribute the least amount of oscillation of the club head/shaft. I >> was originally thinking that the spine should be here so that the >> least amount of bending of the shaft would happen at the bottom of >> the downswing, but that would result in the most amount of oscillation. > > > Scott, > I'm sorry, but you lost me. Why would there be more oscillation with > the spine aligned with the CG than NBP-CG? Here's my take on it; > please tell me where I'm wrong: > >
Re: ShopTalk: NBP-COG
Dr Tutelman: A question, por favor. When this subject was broached several months ago, and the thread unwound for about 3 weeks, I asked a question that got no universally agreed upon answer. The question was; is the spine found at the top of the shaft or at the bottom of the shaft when testing in Dick's spine finder? Responses were equally, and passionately, divided. I then asked another question; if when one finds the spine, the "hard spot" via the use of our arguably primitive methods, how can one accurately mark and then place the hard spot in a specific position? As I recall, you responded, correctly, that we'd be lucky to get the spine situated to within 3 to 4 degrees. You mentioned the circumference of the .335" tip, when reduced to 360 degrees, would be virtually impossible to set accurately. I agree. An assembler would need to identify the spine at the shaft tip by marking it with a needle, then mark the hosel in the precise finished position. Then he'd need to mark the ferrule so the entire assembly could be stuck together in one operation. That's nearly impossible given the workplaces of most assemblers. So, this thread re; placing cog/spine in some specific location with accuracy is theoretically interesting but in practice its pretty much useless. I'm not knocking anyone, just making a point that's been made several times in the past. TFlan - Original Message - From: "Dave Tutelman" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, October 07, 2003 10:49 AM Subject: Re: ShopTalk: NBP-COG > A few points I'd like to make concerning things that were brought up in > this thread: > > (1) As Alan Brooks and John Kaufman and I have said in the past, every > shaft will have the stiffest directions (that is, spines) at 180* > intervals. Similarly with the most flexible directions (that is, NBP). If > you measure anything else, there is something wrong with your measuring > equipment. (Others have already noted that residual bend affects a spine > finder's reading. That is probably the most common thing that is wrong with > your measuring equipment.) > > (2) FLO is important!!! It is not important because of anything the shaft > may be doing during the swing (unlike a fishing rod), but it is one of the > more reliable ways to find the REAL spine, untarnished by things like > residual bend. In other words, FLO is a more reliable spine-finder than > Colin's or Dan's. Slower perhaps, but it finds the real spine. > > (3) There are three theories that I have seen about why spine alignment > matters. NBP-COG is one of them. Here's the reasoning behind it: > * At the moment of impact, the major force bending the shaft is > centrifugal force. (That is probably true, but not universally accepted. > But let's proceed on the assumption that it is true.) > * That force will bend the shaft in the plane of the CG of the clubhead, > because centrifugal force acts through the CG of the clubhead. (In essence, > it is pulling the CG of the clubhead straight away from the hands.) > * If the shaft bends in a plane where the forces due to bending are not > in the same plane as the bending, there will be spurious torque on the > clubhead; you don't want that. > * But the only planes where the force and the bending are aligned are the > NBP and the spine plane. In other planes, there will be some small angle > between the bending and the force in the shaft. So you need to align one of > those planes (either the NBP or the spine) with the CG of the clubhhead. > > (4) If you build your clubs with nearly spineless shafts (like SK Fiber, or > the new Harrisons, or many filament-wound shafts), then it makes little > sense to say, "I used NBP-COG alignment [or any other alignment] and it > worked GREAT!" You were aligning an effect that probably didn't matter one > way or another. > > Hope this helps, > DaveT
Re: ShopTalk: NBP-COG
Scott, to put it very simply , ALIEN THE HARD SPINE AT 12:00. 12:00 keeps the clubhead toe from drooping. Forget what ever anybody else says, especially Mr. David T.whom is not a clubmaker per se & who knows very little about making/fitting of golfclubs. By his own admission he only makes , at the very most, one set of clubs per year and those are strictly for his own personal use, Mr. David T. made that statement not I. In fact Mr. David T. fought us "SPINER'S" tooth and nail that the position off the spine had no effect on the playability or the flex of the golfclub. It was not until several People outside of ShopTalk or SpineTalk got into the fray, with lots of money backing them,that he got into the discussion. I'm not to sure but I think that Ed J., the host of SplineTalk, asked, I feel is a better word to use then lets say kicked off of SpileTalk, because of his disruptive and know it all air that he tried to use in his posts. I do not subscribe to SpineTalk not because I do not believe in their views, which by the way I helped to put into use, but because I'm am presently engaged in other web sites that will have some, I hope, effecting with my health. I am not the clubmaker that has been spining the longest but i have been "SPINEING" golfclubs since 1984 long before it became popular. RK KENNEDY golf equipment manufacturer's of world class golfclub repair equipment ---Original Message--- From: [EMAIL PROTECTED] Date: Wednesday, October 08, 2003 1:02:35 AM To: [EMAIL PROTECTED] Subject: Re: ShopTalk: NBP-COG Let me preface this by saying my introduction to this subject is at most a week old, and if my statements seem out to lunch, they very well may be. I'm trying to think this through with my own limited understanding. I'm certainly not trying to pass this off as if I know something that the rest of you don't. If I remember my physics correctly (and I probably don't), I expect any system like this to have some natural vibration; the twang you induce for FLO would cause this particular system to vibrate at its natural frequency. If the system is FLO aligned correctly this vibration is along the target line at impact, i.e 3-9 o'clock. Otherwise this vibration has a 12-6 o'clock component to it, which would help take the clubface out of the line with the ball. Please note that I have no idea how large this component would be. Are we talking fractions of millimeters here? If the NBP is aligned to COG, the local minima for shaft rigidity, then the vibration should be at a minimum because this is the most inherently stable shaft orientation for the force applied (I used the term damping to describe this ... I shouldn't have, it isn't the correct term). If the spine were aligned at COG, then when force is applied from the downsing, the shaft wants to rotate away (as in a spine finder), because this is the most inherently unstable shaft orientation and you would get the most vibration. Again, I have no idea if the deflection due to this oscillation could cause a toe or heel hit. When I started reading up on this, I was suprised aligning the spine would have any noticable affect on your shot at all. Thank you for your patience. Scott Dave Tutelman wrote: > At 08:40 PM 10/7/03 -0600, Scott Stephens wrote: > >> It makes sense to me to align a NBP to the COG, since this should >> contribute the least amount of oscillation of the club head/shaft. I >> was originally thinking that the spine should be here so that the >> least amount of bending of the shaft would happen at the bottom of >> the downswing, but that would result in the most amount of oscillation. > > > Scott, > I'm sorry, but you lost me. Why would there be more oscillation with > the spine aligned with the CG than NBP-CG? Here's my take on it; > please tell me where I'm wrong: > > If you align either the NBP or the spine with the CG, then any force > arising from bending at the bottom of the swing will be in the plane > of the shaft and the CG. Any other alignment will have forces outside > that plane, which could cause bending (and perhaps oscillation) in > other planes as well. > >> Then I read about FLO alignment where it is stated that alignment >> should be along the target line (see "SPINE FINDING AND WHAT TO DO >> WITH THEM AFTER YOU FIND THEM"). Am I correct that these orientations >> would be close to 90° out of phase in a 3 iron (but not nearly that >> much for a driver or sand wedge)? It seems to me that aligning the >> NBP(s) along the target line would not maximally dampen the >> oscillations, but would keep whatever oscillations are present going >> parallel to the target line (so you should hit closest to the sweet >> spot). Is that
Re: ShopTalk: NBP-COG
Let me preface this by saying my introduction to this subject is at most a week old, and if my statements seem out to lunch, they very well may be. I'm trying to think this through with my own limited understanding. I'm certainly not trying to pass this off as if I know something that the rest of you don't. If I remember my physics correctly (and I probably don't), I expect any system like this to have some natural vibration; the twang you induce for FLO would cause this particular system to vibrate at its natural frequency. If the system is FLO aligned correctly this vibration is along the target line at impact, i.e 3-9 o'clock. Otherwise this vibration has a 12-6 o'clock component to it, which would help take the clubface out of the line with the ball. Please note that I have no idea how large this component would be. Are we talking fractions of millimeters here? If the NBP is aligned to COG, the local minima for shaft rigidity, then the vibration should be at a minimum because this is the most inherently stable shaft orientation for the force applied (I used the term damping to describe this ... I shouldn't have, it isn't the correct term). If the spine were aligned at COG, then when force is applied from the downsing, the shaft wants to rotate away (as in a spine finder), because this is the most inherently unstable shaft orientation and you would get the most vibration. Again, I have no idea if the deflection due to this oscillation could cause a toe or heel hit. When I started reading up on this, I was suprised aligning the spine would have any noticable affect on your shot at all. Thank you for your patience. Scott Dave Tutelman wrote: At 08:40 PM 10/7/03 -0600, Scott Stephens wrote: It makes sense to me to align a NBP to the COG, since this should contribute the least amount of oscillation of the club head/shaft. I was originally thinking that the spine should be here so that the least amount of bending of the shaft would happen at the bottom of the downswing, but that would result in the most amount of oscillation. Scott, I'm sorry, but you lost me. Why would there be more oscillation with the spine aligned with the CG than NBP-CG? Here's my take on it; please tell me where I'm wrong: If you align either the NBP or the spine with the CG, then any force arising from bending at the bottom of the swing will be in the plane of the shaft and the CG. Any other alignment will have forces outside that plane, which could cause bending (and perhaps oscillation) in other planes as well. Then I read about FLO alignment where it is stated that alignment should be along the target line (see "SPINE FINDING AND WHAT TO DO WITH THEM AFTER YOU FIND THEM"). Am I correct that these orientations would be close to 90° out of phase in a 3 iron (but not nearly that much for a driver or sand wedge)? It seems to me that aligning the NBP(s) along the target line would not maximally dampen the oscillations, but would keep whatever oscillations are present going parallel to the target line (so you should hit closest to the sweet spot). Is that the essence of FLO alignment? Again, I'm confused by your statement. In particular, I don't have a clue what would cause damping of oscillations to be different in the different planes. I can see a difference in the creation of oscillations and their size, but I see no difference in how the oscillations would be damped. Thanks in advance, DaveT
Re: ShopTalk: NBP-COG
At 08:40 PM 10/7/03 -0600, Scott Stephens wrote: It makes sense to me to align a NBP to the COG, since this should contribute the least amount of oscillation of the club head/shaft. I was originally thinking that the spine should be here so that the least amount of bending of the shaft would happen at the bottom of the downswing, but that would result in the most amount of oscillation. Scott, I'm sorry, but you lost me. Why would there be more oscillation with the spine aligned with the CG than NBP-CG? Here's my take on it; please tell me where I'm wrong: If you align either the NBP or the spine with the CG, then any force arising from bending at the bottom of the swing will be in the plane of the shaft and the CG. Any other alignment will have forces outside that plane, which could cause bending (and perhaps oscillation) in other planes as well. Then I read about FLO alignment where it is stated that alignment should be along the target line (see "SPINE FINDING AND WHAT TO DO WITH THEM AFTER YOU FIND THEM"). Am I correct that these orientations would be close to 90° out of phase in a 3 iron (but not nearly that much for a driver or sand wedge)? It seems to me that aligning the NBP(s) along the target line would not maximally dampen the oscillations, but would keep whatever oscillations are present going parallel to the target line (so you should hit closest to the sweet spot). Is that the essence of FLO alignment? Again, I'm confused by your statement. In particular, I don't have a clue what would cause damping of oscillations to be different in the different planes. I can see a difference in the creation of oscillations and their size, but I see no difference in how the oscillations would be damped. Thanks in advance, DaveT
Re: ShopTalk: NBP-COG
I have been reading this thread with some interest. It makes sense to me to align a NBP to the COG, since this should contribute the least amount of oscillation of the club head/shaft. I was originally thinking that the spine should be here so that the least amount of bending of the shaft would happen at the bottom of the downswing, but that would result in the most amount of oscillation. Then I read about FLO alignment where it is stated that alignment should be along the target line (see "SPINE FINDING AND WHAT TO DO WITH THEM AFTER YOU FIND THEM"). Am I correct that these orientations would be close to 90° out of phase in a 3 iron (but not nearly that much for a driver or sand wedge)? It seems to me that aligning the NBP(s) along the target line would not maximally dampen the oscillations, but would keep whatever oscillations are present going parallel to the target line (so you should hit closest to the sweet spot). Is that the essence of FLO alignment? Thanks Scott Dave Tutelman wrote: A few points I'd like to make concerning things that were brought up in this thread: (1) As Alan Brooks and John Kaufman and I have said in the past, every shaft will have the stiffest directions (that is, spines) at 180* intervals. Similarly with the most flexible directions (that is, NBP). If you measure anything else, there is something wrong with your measuring equipment. (Others have already noted that residual bend affects a spine finder's reading. That is probably the most common thing that is wrong with your measuring equipment.) (2) FLO is important!!! It is not important because of anything the shaft may be doing during the swing (unlike a fishing rod), but it is one of the more reliable ways to find the REAL spine, untarnished by things like residual bend. In other words, FLO is a more reliable spine-finder than Colin's or Dan's. Slower perhaps, but it finds the real spine. (3) There are three theories that I have seen about why spine alignment matters. NBP-COG is one of them. Here's the reasoning behind it: * At the moment of impact, the major force bending the shaft is centrifugal force. (That is probably true, but not universally accepted. But let's proceed on the assumption that it is true.) * That force will bend the shaft in the plane of the CG of the clubhead, because centrifugal force acts through the CG of the clubhead. (In essence, it is pulling the CG of the clubhead straight away from the hands.) * If the shaft bends in a plane where the forces due to bending are not in the same plane as the bending, there will be spurious torque on the clubhead; you don't want that. * But the only planes where the force and the bending are aligned are the NBP and the spine plane. In other planes, there will be some small angle between the bending and the force in the shaft. So you need to align one of those planes (either the NBP or the spine) with the CG of the clubhhead. (4) If you build your clubs with nearly spineless shafts (like SK Fiber, or the new Harrisons, or many filament-wound shafts), then it makes little sense to say, "I used NBP-COG alignment [or any other alignment] and it worked GREAT!" You were aligning an effect that probably didn't matter one way or another. Hope this helps, DaveT
Re: ShopTalk: NBP-COG
In a message dated 10/7/2003 1:51:52 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: (4) If you build your clubs with nearly spineless shafts (like SK Fiber, or the new Harrison's, or many filament-wound shafts), Strange, an offer of a trial of the new Harrison's was made on this forum and it has been hanging in limbo for a long time. I know nothing about them and have no hope of ever finding out any info about them. Spineless? Maybe that describes the offer! Frank
Re: ShopTalk: NBP-COG
David, > I need to get off my butt and pull the shafts on 2/4 of my wedges and try > the NBP-COG alignment. Right now I think they are aligned spine towards > target. That's not very far off of the NBP-COG alignment, if you are using Type 2 graphite shafts. On my wedges, the NBP is aligned about 2 o'clock, which would put the spine plane about 11 o'clock instead of 9. Bernie Writeto: [EMAIL PROTECTED]
Re: ShopTalk: NBP-COG
At 05:40 PM 10/7/2003, you wrote: Are SK Fibers filament-wound? No. If not, how are they making them so uniform? Damned if I know. Next time I see Casey I'll ask him if it's a trade secret or just careful construction. Either way, they are excellent shafts. Burgess
Re: ShopTalk: NBP-COG
- Original Message - From: "Dave Tutelman" <[EMAIL PROTECTED]> > (4) If you build your clubs with nearly spineless shafts (like SK Fiber, or > the new Harrisons, or many filament-wound shafts), then it makes little > sense to say, "I used NBP-COG alignment [or any other alignment] and it > worked GREAT!" You were aligning an effect that probably didn't matter one > way or another. Which Harrisons? Are SK Fibers filament-wound? If not, how are they making them so uniform? Doug Clark
Re: ShopTalk: NBP-COG
- Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, October 06, 2003 8:32 AM Subject: Re: ShopTalk: NBP-COG > Corey, > > My question is, does residual bend affect the performance of a shaft the > same as if it were an NBP? In other words, will the assembled shaft tend to > rotate toward the residual bend point? > > Bernie Bernie, I found that the residual bend does affect the performance of the shaft. On steel shafts, I have taken apart "bad" clubs, found the spine (probably a bend), oriented the NBP to the target, put them back together, and the clubs were much improved. After all, a bend affects the bending properties of the shaft, so I think it is important to deal with it properly. Doug Clark
Re: ShopTalk: NBP-COG
On Tue, October 7, 2003 at 1:09 pm, Bernie Baymiller sent the following >> (1) As Alan Brooks and John Kaufman and I have said in the past, every >> shaft will have the stiffest directions (that is, spines) at 180* >> intervals. Similarly with the most flexible directions (that is, NBP). > > That seems to be true on many graphite shafts, but when I rotate some > graphite shafts and watch the dial indicator on my NF2, I can often find > the NBPs and spines well off 180°. Why is that? Could be that the graphite shaft has some residual bend in it? > I would agree that last statement makes sense, but again, my > observations and those of three other players suggest NBP-COG > alignment does make a difference in iron sets, whether the shafts > have an appreciable spine or not. Accuracy with my short irons is so > much improved with spines measuring no more than .006" (three shafts > in 9 measured .013", .015" and .016", about 3 cpm?) that I found it > hard to believe. After more than 10 years cussing my mis-directed > wedge shots, there was a striking difference the first round with the > new set...and after 5 rounds, they continue to be straight (sometimes > chunked, but straight). The heads are nothing unusual and shafts are > same weight and length as my other sets...all made with a 3/8" tip > trim instead of the recommended 1/2". A 90+ player, who said he > generally sprays the ball all over, phoned me after his first round > with an NBP-COG alignment to say he had never hit the ball straighter > in his one year of playing golf...took 10 shots off his normal score. > He was using Precision Superlite steel shafts. I guess time will > tell. I need to get off my butt and pull the shafts on 2/4 of my wedges and try the NBP-COG alignment. Right now I think they are aligned spine towards target. Sounds like we need to do some sort of blind test with wedges to see if there really is a difference or not. -Dave
Re: ShopTalk: NBP-COG
Dave, Thanks for the explanation of why NBP-COG works. Some comments below: > (1) As Alan Brooks and John Kaufman and I have said in the past, every > shaft will have the stiffest directions (that is, spines) at 180* > intervals. Similarly with the most flexible directions (that is, NBP). That seems to be true on many graphite shafts, but when I rotate some graphite shafts and watch the dial indicator on my NF2, I can often find the NBPs and spines well off 180°. Why is that? > If you measure anything else, there is something wrong with your measuring > equipment. (Others have already noted that residual bend affects a spine > finder's reading. That is probably the most common thing that is wrong with > your measuring equipment.) I agree, and find it quite easy to spot shafts with larger bends by their deflection drop, but have seen no evidence to suggest residual bend, which can show as an NBP on a spine finder, does not affect club performance as would an NBP. > (2) FLO is important!!! It is not important because of anything the shaft > may be doing during the swing (unlike a fishing rod), but it is one of the > more reliable ways to find the REAL spine, untarnished by things like > residual bend. In other words, FLO is a more reliable spine-finder than > Colin's or Dan's. Slower perhaps, but it finds the real spine. In my limited range testing with clubs (drivers) aligned NBP to target and with FLO (near NBP) to target, as well as spine plane to target with and without FLO, I can see no difference in performance. That includes 3 or 4 of my own drivers and observing at least a dozen made for my senior friends with handicaps from 8-18 in the past two years. But, Charlie brought up an interesting question yesterday that might change my mindset, when he asked if the NBP-COG alignment was on FLO. I've checked an assembled 2W and a 3-iron, plus a 9W I made yesterday (clamped without the grip) and all three clubs were very close to, if not on, FLO. I'll have to check a few more, as well as a Spine-COG alignment and see if that is also on FLO. Maybe NBP-COG alignment could turn out to be an easier way to FLO a shaft...no clamping and fiddling around with lasers, etc.? > (4) If you build your clubs with nearly spineless shafts (like SK Fiber, or > the new Harrisons, or many filament-wound shafts), then it makes little > sense to say, "I used NBP-COG alignment [or any other alignment] and it > worked GREAT!" You were aligning an effect that probably didn't matter one > way or another. I would agree that last statement makes sense, but again, my observations and those of three other players suggest NBP-COG alignment does make a difference in iron sets, whether the shafts have an appreciable spine or not. Accuracy with my short irons is so much improved with spines measuring no more than .006" (three shafts in 9 measured .013", .015" and .016", about 3 cpm?) that I found it hard to believe. After more than 10 years cussing my mis-directed wedge shots, there was a striking difference the first round with the new set...and after 5 rounds, they continue to be straight (sometimes chunked, but straight). The heads are nothing unusual and shafts are same weight and length as my other sets...all made with a 3/8" tip trim instead of the recommended 1/2". A 90+ player, who said he generally sprays the ball all over, phoned me after his first round with an NBP-COG alignment to say he had never hit the ball straighter in his one year of playing golf...took 10 shots off his normal score. He was using Precision Superlite steel shafts. I guess time will tell. You mention "Harrisons," using the plural. To my knowledge, only the Striper J was "virtually" spineless. Are there others? Bernie Writeto: [EMAIL PROTECTED]
Re: ShopTalk: NBP-COG
Hi Alan, As stated in my reply to Bernie, I would say yes with regards to a steel shaft, however there are always unexplainable exceptions. The steel shafts that I find exhibit the most residual bend are stepped shafts. I have a couple of rejects (both TT & Apollo) that have a measurable corkscrew bend to them. BTW, I like your reference to "Strong side" and "Weak side". The term "Spine" has always troubled me when defining the hard or strong plane of a shaft. Best, CB At 06:38 AM 10/6/2003 -0700, you wrote: Corey, you are suggesting that, in a bearing type spine finder, the response of the shaft is dominated by the residual bend in the shaft (I agree, btw, that is what my experience shows). If there is no residual bend (the shaft is perfectly straight) then the bearing type spine finder will identify azimuthal stiffness variations in the shaft, with the shaft rotating to a position with the minimum bending stiffness in the bending plane (up and down). Since there are no perfectly straight shafts, the question becomes at what amount of residual bend and what level of stiffness variation does the significance of the effects 'cross over' and one dominate over the other. I can't answer that. If you pull a shaft in tension, it can have a 'strong' side and a 'weak' side, i.e. one side of the shaft has more material than the other. When you bend a shaft, however, the neutral bending axis shifts so that the shaft is equally stiff in both directions (in the plane of bending). You will get the same deflection in both directions. No preference. We can talk about variations in stiffness planes (bending planes), but not side to side (180* apart) of the shaft variations in bending stiffness. Regards, Alan Brooks At 10:00 PM 10/5/2003 -0700, you wrote: Dear Shoptalkers, With regards to your discussions about Spines & NBP: First of all, with the shaft resting (settled, if you will) in a bent position in a bearing type spine finder, NBP is on top, spine is on the bottomPeriod. Mark the shaft in this position. If it is a steel shaft, determine the residual bend in the shaft. Roll it on a flat surface, use V-blocks and a dial indicator, but come up with a method of noting the residual bend. Note the correlation of residual bend and the location of the Spine and NBP. You will find that with the vast majority of steel shafts there is a direct correlation between the curvature of the shaft (residual band) and the location of the two planes in question. It will nearly always be the same correlation. I say nearly because I come up with some exceptions from time to time that defy explanation. Best, CB
Re: ShopTalk: NBP-COG
Hi Bernie, The short answer is "yes". NBP nearly always correlates with the outermost edge of the curvature of the residual bend of the shaft. Obviously, the more the bend, the more the possibility of it affecting the feel of the club. My whole p[oint in my last post was to get some of the forum members thinking about the relationship between the residual bend of a steel shaft and the asymmetries that they are experiencing in a bearing finder, Dan's or otherwise. NBP-COG: There was a question regarding this COG alignment and FLO From Charlie B. I've built about four woods so far using this alignment and have noted that FLO is out the window. Using this alignment hasn't produced a nasty wobbler yet but it is not the best FLO alignment either. Two of the drivers I built and aligned to COG were offset hosels and FLO was worse. I have since re-shafted one of them and went for FLO. I tried to check the alignment difference once I had marked the club for FLO but the shaft fit was a little too tight to get the head to settle off the end of the bench for a good COG mark. I personally have not been able to tell if the COG alignment feels better or not. Truth is, I don't have a refined enough swing to judge with. I haven't been able to do any experimenting with our course pro because there are major management changes afoot and I've been keeping a low profile while the dust settles. Best, CB At 09:32 AM 10/6/2003 -0400, you wrote: Corey, My question is, does residual bend affect the performance of a shaft the same as if it were an NBP? In other words, will the assembled shaft tend to rotate toward the residual bend point? Bernie Writeto: [EMAIL PROTECTED] - Original Message - From: "Corey Bailey" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, October 06, 2003 1:00 AM Subject: Re: ShopTalk: NBP-COG > Dear Shoptalkers, > > With regards to your discussions about Spines & NBP: > > First of all, with the shaft resting (settled, if you will) in a bent > position in a bearing type spine finder, NBP is on top, spine is on the > bottomPeriod. > > Mark the shaft in this position. > > If it is a steel shaft, determine the residual bend in the shaft. Roll it > on a flat surface, use V-blocks and a dial indicator, but come up with a > method of noting the residual bend. > > Note the correlation of residual bend and the location of the Spine and NBP. > > You will find that with the vast majority of steel shafts there is a direct > correlation between the curvature of the shaft (residual band) and the > location of the two planes in question. It will nearly always be the same > correlation. I say nearly because I come up with some exceptions from time > to time that defy explanation. > > Best, > > CB > > > >
Re: ShopTalk: NBP-COG
A few points I'd like to make concerning things that were brought up in this thread: (1) As Alan Brooks and John Kaufman and I have said in the past, every shaft will have the stiffest directions (that is, spines) at 180* intervals. Similarly with the most flexible directions (that is, NBP). If you measure anything else, there is something wrong with your measuring equipment. (Others have already noted that residual bend affects a spine finder's reading. That is probably the most common thing that is wrong with your measuring equipment.) (2) FLO is important!!! It is not important because of anything the shaft may be doing during the swing (unlike a fishing rod), but it is one of the more reliable ways to find the REAL spine, untarnished by things like residual bend. In other words, FLO is a more reliable spine-finder than Colin's or Dan's. Slower perhaps, but it finds the real spine. (3) There are three theories that I have seen about why spine alignment matters. NBP-COG is one of them. Here's the reasoning behind it: * At the moment of impact, the major force bending the shaft is centrifugal force. (That is probably true, but not universally accepted. But let's proceed on the assumption that it is true.) * That force will bend the shaft in the plane of the CG of the clubhead, because centrifugal force acts through the CG of the clubhead. (In essence, it is pulling the CG of the clubhead straight away from the hands.) * If the shaft bends in a plane where the forces due to bending are not in the same plane as the bending, there will be spurious torque on the clubhead; you don't want that. * But the only planes where the force and the bending are aligned are the NBP and the spine plane. In other planes, there will be some small angle between the bending and the force in the shaft. So you need to align one of those planes (either the NBP or the spine) with the CG of the clubhhead. (4) If you build your clubs with nearly spineless shafts (like SK Fiber, or the new Harrisons, or many filament-wound shafts), then it makes little sense to say, "I used NBP-COG alignment [or any other alignment] and it worked GREAT!" You were aligning an effect that probably didn't matter one way or another. Hope this helps, DaveT
Re: ShopTalk: NBP-COG
Benie Thanks for checking, like I said I will be trying today and will let you know the results. Charlie B
Re: ShopTalk: NBP-COG
Bernie Over the course of time I too have come to the conclusion that flo is not the end all but I still try to accomplish it whenever possible along with the method of alignment I use. I am going to try the NPB to CG alignment today on a couple of drivers that I am doing and will see if I get good results and feedback from the client on feel. Charlie B
Re: ShopTalk: NBP-COG
Bernie, I have used the NBP-COG method in reshafting a couple of drivers with SK pure energy shafts. Seems to be the way to go. My method rather than clamp the shaft to the bench with the NBP down was to prepare the shaft, put on the ferrule, put the shaft in the NF2 to find the NBP, then I took the DI off the NF2, turned the NF2 upside-down on the bench, installed the head and let the head turn to the COG. The epoxy sets up in a couple of hours, enough so the club can be removed...df - Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, October 05, 2003 6:41 PM Subject: Re: ShopTalk: NBP-COG > Jim, > > Generally speaking...Steel shafts are almost all Type 1, with one NBP and > one spine opposite each other. Most graphite shafts are Type 2 shafts with > two NBPs opposite each other and two spines 90° from the NBPs. The softest > NBP, call it the N1, is the NBP you want to use for the NBP-COG alignment. > When you put a flex on a shaft in free bearings, the shaft rotates to a > stable point...and the NBP is on top. But, you don't know which NBP is N1 > unless you have a way to measure the stiffness of that point. A Neufinder > with a dial indicator to measure deflection is the fastest and easiest tool > to measure N1 and N2, as well as S1 and S2, if you want to know the spine > magnatude. For this NBP-COG alignment, the location and size of the spine(s) > don't matter. You are only interested in the N1. > > > Then when you put the shaft into the housel and lay it off > > the end of the table the spine will point up and the NBP will point down > > towards the COG of the head? Does this sound right? > > If you are using a steel shaft, that is correct. I haven't used this > alignment with any steel shafts yet. Let me know how it works for you and if > you see any differences. My friend Harry used Precision Superlites with this > alignment and found them to hit the ball much straighter for him (a 90+ > player). > > Bernie > Writeto: [EMAIL PROTECTED] >
Re: ShopTalk: NBP-COG
Charlie, Just did a quick check for FLO on the 45" club length 2W I assembled NBP-COG with a Tour Golf TSEL, 54 gram R-flex which had a somewhat large spine, if I remember correctly. Even with a "sofftee-style" grip clamped in a Workmate, there is almost no ovalling. If it's not dead on the FLO point near S1, it isn't far off. Also tried a 3-iron with a filament wound Powerflex FW-501 R and it was very close, too...but, I'd expect that with almost no spine (less than .006", about 1 cpm) at all in the shaft. Will let you know how the next clubs I do with NBP-COG turn out...if I can remember to FLO 'em. BernieWriteto: [EMAIL PROTECTED] - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Sunday, October 05, 2003 11:50 PM Subject: Re: ShopTalk: NBP-COG Bernie Do you always find flow in this alignment ? Charlie B
Re: ShopTalk: NBP-COG
Corey, you are suggesting that, in a bearing type spine finder, the response of the shaft is dominated by the residual bend in the shaft (I agree, btw, that is what my experience shows). If there is no residual bend (the shaft is perfectly straight) then the bearing type spine finder will identify azimuthal stiffness variations in the shaft, with the shaft rotating to a position with the minimum bending stiffness in the bending plane (up and down). Since there are no perfectly straight shafts, the question becomes at what amount of residual bend and what level of stiffness variation does the significance of the effects 'cross over' and one dominate over the other. I can't answer that. If you pull a shaft in tension, it can have a 'strong' side and a 'weak' side, i.e. one side of the shaft has more material than the other. When you bend a shaft, however, the neutral bending axis shifts so that the shaft is equally stiff in both directions (in the plane of bending). You will get the same deflection in both directions. No preference. We can talk about variations in stiffness planes (bending planes), but not side to side (180* apart) of the shaft variations in bending stiffness. Regards, Alan Brooks At 10:00 PM 10/5/2003 -0700, you wrote: Dear Shoptalkers, With regards to your discussions about Spines & NBP: First of all, with the shaft resting (settled, if you will) in a bent position in a bearing type spine finder, NBP is on top, spine is on the bottomPeriod. Mark the shaft in this position. If it is a steel shaft, determine the residual bend in the shaft. Roll it on a flat surface, use V-blocks and a dial indicator, but come up with a method of noting the residual bend. Note the correlation of residual bend and the location of the Spine and NBP. You will find that with the vast majority of steel shafts there is a direct correlation between the curvature of the shaft (residual band) and the location of the two planes in question. It will nearly always be the same correlation. I say nearly because I come up with some exceptions from time to time that defy explanation. Best, CB
Re: ShopTalk: NBP-COG
Corey, My question is, does residual bend affect the performance of a shaft the same as if it were an NBP? In other words, will the assembled shaft tend to rotate toward the residual bend point? Bernie Writeto: [EMAIL PROTECTED] - Original Message - From: "Corey Bailey" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, October 06, 2003 1:00 AM Subject: Re: ShopTalk: NBP-COG > Dear Shoptalkers, > > With regards to your discussions about Spines & NBP: > > First of all, with the shaft resting (settled, if you will) in a bent > position in a bearing type spine finder, NBP is on top, spine is on the > bottomPeriod. > > Mark the shaft in this position. > > If it is a steel shaft, determine the residual bend in the shaft. Roll it > on a flat surface, use V-blocks and a dial indicator, but come up with a > method of noting the residual bend. > > Note the correlation of residual bend and the location of the Spine and NBP. > > You will find that with the vast majority of steel shafts there is a direct > correlation between the curvature of the shaft (residual band) and the > location of the two planes in question. It will nearly always be the same > correlation. I say nearly because I come up with some exceptions from time > to time that defy explanation. > > Best, > > CB > > > >
Re: ShopTalk: NBP-COG
Charlie, I never check for FLO any more...didn't even think of checking for it. Will have to try it and see. Before, trying the NBP-COG alignment, I had been using NBP-target because I always had good results with it...a tight impact area and solid hits. In trying the NBP-target alignment with and without FLO, I could see no difference in the results. So, I didn't see any point wasting my time clamping and twanging for no reason. Unless the shaft was really poorly built, a FLO point was relatively close to the NBP anyway. I think that I agree with Talamonti that the FLO thing is fine for fishing rods. :-) BernieWriteto: [EMAIL PROTECTED] - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Sunday, October 05, 2003 11:50 PM Subject: Re: ShopTalk: NBP-COG Bernie Do you always find flow in this alignment ? Charlie B
Re: ShopTalk: NBP-COG
Jim, > I read somewhere you pioneered this technique, No, I just happen to use an NF2 and like it a lot. Dan Neubecker invented the Neufinder 2 and continues to improve it with suggestions from many builders. >can i adapt a dial force > guage to my system? I can't imagine any way you could do it without changing everything. The only similarity is that the shaft is flexed over free bearings...and they aren't even the same kind of bearings. Bernie Writeto: [EMAIL PROTECTED]
Re: ShopTalk: NBP-COG
Dear Shoptalkers, With regards to your discussions about Spines & NBP: First of all, with the shaft resting (settled, if you will) in a bent position in a bearing type spine finder, NBP is on top, spine is on the bottomPeriod. Mark the shaft in this position. If it is a steel shaft, determine the residual bend in the shaft. Roll it on a flat surface, use V-blocks and a dial indicator, but come up with a method of noting the residual bend. Note the correlation of residual bend and the location of the Spine and NBP. You will find that with the vast majority of steel shafts there is a direct correlation between the curvature of the shaft (residual band) and the location of the two planes in question. It will nearly always be the same correlation. I say nearly because I come up with some exceptions from time to time that defy explanation. Best, CB
Re: ShopTalk: NBP-COG
Bernie Do you always find flow in this alignment ? Charlie B
Re: ShopTalk: NBP-COG
Jim, The NBP rolls to the top, not the spine. If you had a way to measure the stiffness at any point around the shaft, as on a dial indicator which measures in thousandths, you would see that the point at which the shaft wants to rotate either way is the stiffest point on the circumference of the shaft...not the point at which the shaft is stable. Bernie Writeto: [EMAIL PROTECTED] - Original Message - From: "Jim & Ivette" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, October 14, 2003 8:23 PM Subject: Re: ShopTalk: NBP-COG > all i have is a tube with two bearings in it and a third free bearing that i > use to load the shaft tip by pushing down on it. the spine rolls to the top > to find its way away from the bend which is on the bottom, by rolling the > shaft while uner a load i can feel subtle differences as i roll it. no > guage, just feel. > - Original Message - > From: "Bernie Baymiller" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Sunday, October 05, 2003 7:41 PM > Subject: Re: ShopTalk: NBP-COG > > > > Jim, > > > > Generally speaking...Steel shafts are almost all Type 1, with one NBP and > > one spine opposite each other. Most graphite shafts are Type 2 shafts > with > > two NBPs opposite each other and two spines 90° from the NBPs. The softest > > NBP, call it the N1, is the NBP you want to use for the NBP-COG alignment. > > When you put a flex on a shaft in free bearings, the shaft rotates to a > > stable point...and the NBP is on top. But, you don't know which NBP is N1 > > unless you have a way to measure the stiffness of that point. A Neufinder > > with a dial indicator to measure deflection is the fastest and easiest > tool > > to measure N1 and N2, as well as S1 and S2, if you want to know the spine > > magnatude. For this NBP-COG alignment, the location and size of the > spine(s) > > don't matter. You are only interested in the N1. > > > > > Then when you put the shaft into the housel and lay it off > > > the end of the table the spine will point up and the NBP will point down > > > towards the COG of the head? Does this sound right? > > > > If you are using a steel shaft, that is correct. I haven't used this > > alignment with any steel shafts yet. Let me know how it works for you and > if > > you see any differences. My friend Harry used Precision Superlites with > this > > alignment and found them to hit the ball much straighter for him (a 90+ > > player). > > > > Bernie > > Writeto: [EMAIL PROTECTED] > > > > > > >
Re: ShopTalk: NBP-COG
I read somewhere you pioneered this technique, can i adapt a dial force guage to my system? - Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, October 05, 2003 7:41 PM Subject: Re: ShopTalk: NBP-COG > Jim, > > Generally speaking...Steel shafts are almost all Type 1, with one NBP and > one spine opposite each other. Most graphite shafts are Type 2 shafts with > two NBPs opposite each other and two spines 90° from the NBPs. The softest > NBP, call it the N1, is the NBP you want to use for the NBP-COG alignment. > When you put a flex on a shaft in free bearings, the shaft rotates to a > stable point...and the NBP is on top. But, you don't know which NBP is N1 > unless you have a way to measure the stiffness of that point. A Neufinder > with a dial indicator to measure deflection is the fastest and easiest tool > to measure N1 and N2, as well as S1 and S2, if you want to know the spine > magnatude. For this NBP-COG alignment, the location and size of the spine(s) > don't matter. You are only interested in the N1. > > > Then when you put the shaft into the housel and lay it off > > the end of the table the spine will point up and the NBP will point down > > towards the COG of the head? Does this sound right? > > If you are using a steel shaft, that is correct. I haven't used this > alignment with any steel shafts yet. Let me know how it works for you and if > you see any differences. My friend Harry used Precision Superlites with this > alignment and found them to hit the ball much straighter for him (a 90+ > player). > > Bernie > Writeto: [EMAIL PROTECTED] > >
Re: ShopTalk: NBP-COG
all i have is a tube with two bearings in it and a third free bearing that i use to load the shaft tip by pushing down on it. the spine rolls to the top to find its way away from the bend which is on the bottom, by rolling the shaft while uner a load i can feel subtle differences as i roll it. no guage, just feel. - Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, October 05, 2003 7:41 PM Subject: Re: ShopTalk: NBP-COG > Jim, > > Generally speaking...Steel shafts are almost all Type 1, with one NBP and > one spine opposite each other. Most graphite shafts are Type 2 shafts with > two NBPs opposite each other and two spines 90° from the NBPs. The softest > NBP, call it the N1, is the NBP you want to use for the NBP-COG alignment. > When you put a flex on a shaft in free bearings, the shaft rotates to a > stable point...and the NBP is on top. But, you don't know which NBP is N1 > unless you have a way to measure the stiffness of that point. A Neufinder > with a dial indicator to measure deflection is the fastest and easiest tool > to measure N1 and N2, as well as S1 and S2, if you want to know the spine > magnatude. For this NBP-COG alignment, the location and size of the spine(s) > don't matter. You are only interested in the N1. > > > Then when you put the shaft into the housel and lay it off > > the end of the table the spine will point up and the NBP will point down > > towards the COG of the head? Does this sound right? > > If you are using a steel shaft, that is correct. I haven't used this > alignment with any steel shafts yet. Let me know how it works for you and if > you see any differences. My friend Harry used Precision Superlites with this > alignment and found them to hit the ball much straighter for him (a 90+ > player). > > Bernie > Writeto: [EMAIL PROTECTED] > >
Re: ShopTalk: NBP-COG
Jim, Generally speaking...Steel shafts are almost all Type 1, with one NBP and one spine opposite each other. Most graphite shafts are Type 2 shafts with two NBPs opposite each other and two spines 90° from the NBPs. The softest NBP, call it the N1, is the NBP you want to use for the NBP-COG alignment. When you put a flex on a shaft in free bearings, the shaft rotates to a stable point...and the NBP is on top. But, you don't know which NBP is N1 unless you have a way to measure the stiffness of that point. A Neufinder with a dial indicator to measure deflection is the fastest and easiest tool to measure N1 and N2, as well as S1 and S2, if you want to know the spine magnatude. For this NBP-COG alignment, the location and size of the spine(s) don't matter. You are only interested in the N1. > Then when you put the shaft into the housel and lay it off > the end of the table the spine will point up and the NBP will point down > towards the COG of the head? Does this sound right? If you are using a steel shaft, that is correct. I haven't used this alignment with any steel shafts yet. Let me know how it works for you and if you see any differences. My friend Harry used Precision Superlites with this alignment and found them to hit the ball much straighter for him (a 90+ player). Bernie Writeto: [EMAIL PROTECTED]
Re: ShopTalk: NBP-COG
I read this article on spines and nbp i think i get what you are saying now. I will let you know the results of my first test. Thanks - Jimhttp://www.clubmaker-online.com/spines.html - Original Message - From: "Mark A Patton" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, October 05, 2003 3:32 PM Subject: RE: ShopTalk: NBP-COG > This presumes a particular type shaft. What we feel as Spine and NBP are not > always 180*. > Actually, John K has proved that spines are planes and always exist 180* > When a spine is felt 180* opposite of a NBP, check that there is not > residual bend in the shaft. > > > > Mark A Patton > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Jim & Ivette > Sent: Tuesday, October 14, 2003 2:57 PM > To: [EMAIL PROTECTED] > Subject: Re: ShopTalk: NBP-COG > > > Hi Bernie, I agree with Doug but i strive to understand it, NBP-COG makes > sense to me and I am going to try it out on a set I am putting together this > week. I am still not sure about NBP, I am assuming that the spine is the > section of the shaft that rolls away from the bend when a load is put on it > from my spine finder, then the natural bend point will be 180 degrees out > from that point? Then when you put the shaft into the housel and lay it off > the end of the table the spine will point up and the NBP will point down > towards the COG of the head? Does this sound right? Thanks - Jim > - Original Message - > From: "Bernie Baymiller" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Sunday, October 05, 2003 10:34 AM > Subject: Re: ShopTalk: NBP-COG > > > > Doug, > > > > > The more I mess with spines and scratch my head > > > about how to orient the shafts, the more I appreciate shafts that don't > > have > > > spines. > > > > Me, too. > > > > > I suppose a strong spine properly aligned, whatever that means, > > > might be better than anything. > > > > According to those who hit the ball harder and farther than I, aligning a > > shaft's large spine (over 5 cpm?) at 12 o'clock makes a big difference in > > reducing the size of the impact area on the face. The more center hits, > the > > more longer, accurate drives. Thus, it's called a "supershaft alignment." > > Actually, though the USGA has made small deviations in stiffness around > the > > circumference of a shaft acceptable, large spines essentially make a shaft > > non-conforming to the rules of golf...at least, that's my opinion on the > > subject. > > > > > But it's hard to get bad results with no > > > spine. I just wish I could find more shafts like that. > > > > That's true. The SK Fiber shafts which I've been using almost always have > > less than .006" deflection (about 1 cpm) and play very well. Though I > > haven't used any Accuflex shafts because of their high price, those who > have > > used them report they are as good as the SK Fiber shafts. And, most > filament > > wound shafts have very little spine. If these manufacturers can do it, so > > could Penley, UST, Grafalloy, etc. IMO, the USGA should put a limit on > spine > > magnitude of 2 cpm. > > > > Bernie > > Writeto: [EMAIL PROTECTED] > > > > > > --- > Incoming mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.520 / Virus Database: 318 - Release Date: 9/18/2003 > > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.520 / Virus Database: 318 - Release Date: 9/18/2003 >
Re: ShopTalk: NBP-COG
On Tue, October 14, 2003 at 2:31 pm, Jim & Ivette sent the following > This is clearly an area i need to do more research in, I have felt more > than > one spine on graphite and some areas that had more resistance than others, > but with steel it almost always is a single very pronounced spine, in > these > instances the nbp would be 180 opposite, correct? On just about all the steel shafts that I've checked, the NBP has never been exactly 180* opposite of the spine. A few shafts have had one large spine with a smaller spine maybe 45* away and the NBP somewhere on the otherside. But very rarely is the NBP exactly 180* away from the spine. -Dave
Re: ShopTalk: NBP-COG
This is clearly an area i need to do more research in, I have felt more than one spine on graphite and some areas that had more resistance than others, but with steel it almost always is a single very pronounced spine, in these instances the nbp would be 180 opposite, correct? - Original Message - From: "Mark A Patton" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, October 05, 2003 3:32 PM Subject: RE: ShopTalk: NBP-COG > This presumes a particular type shaft. What we feel as Spine and NBP are not > always 180*. > Actually, John K has proved that spines are planes and always exist 180* > When a spine is felt 180* opposite of a NBP, check that there is not > residual bend in the shaft. > > > > Mark A Patton > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Jim & Ivette > Sent: Tuesday, October 14, 2003 2:57 PM > To: [EMAIL PROTECTED] > Subject: Re: ShopTalk: NBP-COG > > > Hi Bernie, I agree with Doug but i strive to understand it, NBP-COG makes > sense to me and I am going to try it out on a set I am putting together this > week. I am still not sure about NBP, I am assuming that the spine is the > section of the shaft that rolls away from the bend when a load is put on it > from my spine finder, then the natural bend point will be 180 degrees out > from that point? Then when you put the shaft into the housel and lay it off > the end of the table the spine will point up and the NBP will point down > towards the COG of the head? Does this sound right? Thanks - Jim > - Original Message - > From: "Bernie Baymiller" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Sunday, October 05, 2003 10:34 AM > Subject: Re: ShopTalk: NBP-COG > > > > Doug, > > > > > The more I mess with spines and scratch my head > > > about how to orient the shafts, the more I appreciate shafts that don't > > have > > > spines. > > > > Me, too. > > > > > I suppose a strong spine properly aligned, whatever that means, > > > might be better than anything. > > > > According to those who hit the ball harder and farther than I, aligning a > > shaft's large spine (over 5 cpm?) at 12 o'clock makes a big difference in > > reducing the size of the impact area on the face. The more center hits, > the > > more longer, accurate drives. Thus, it's called a "supershaft alignment." > > Actually, though the USGA has made small deviations in stiffness around > the > > circumference of a shaft acceptable, large spines essentially make a shaft > > non-conforming to the rules of golf...at least, that's my opinion on the > > subject. > > > > > But it's hard to get bad results with no > > > spine. I just wish I could find more shafts like that. > > > > That's true. The SK Fiber shafts which I've been using almost always have > > less than .006" deflection (about 1 cpm) and play very well. Though I > > haven't used any Accuflex shafts because of their high price, those who > have > > used them report they are as good as the SK Fiber shafts. And, most > filament > > wound shafts have very little spine. If these manufacturers can do it, so > > could Penley, UST, Grafalloy, etc. IMO, the USGA should put a limit on > spine > > magnitude of 2 cpm. > > > > Bernie > > Writeto: [EMAIL PROTECTED] > > > > > > --- > Incoming mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.520 / Virus Database: 318 - Release Date: 9/18/2003 > > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.520 / Virus Database: 318 - Release Date: 9/18/2003 >
RE: ShopTalk: NBP-COG
This presumes a particular type shaft. What we feel as Spine and NBP are not always 180*. Actually, John K has proved that spines are planes and always exist 180* When a spine is felt 180* opposite of a NBP, check that there is not residual bend in the shaft. Mark A Patton [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Jim & Ivette Sent: Tuesday, October 14, 2003 2:57 PM To: [EMAIL PROTECTED] Subject: Re: ShopTalk: NBP-COG Hi Bernie, I agree with Doug but i strive to understand it, NBP-COG makes sense to me and I am going to try it out on a set I am putting together this week. I am still not sure about NBP, I am assuming that the spine is the section of the shaft that rolls away from the bend when a load is put on it from my spine finder, then the natural bend point will be 180 degrees out from that point? Then when you put the shaft into the housel and lay it off the end of the table the spine will point up and the NBP will point down towards the COG of the head? Does this sound right? Thanks - Jim - Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, October 05, 2003 10:34 AM Subject: Re: ShopTalk: NBP-COG > Doug, > > > The more I mess with spines and scratch my head > > about how to orient the shafts, the more I appreciate shafts that don't > have > > spines. > > Me, too. > > > I suppose a strong spine properly aligned, whatever that means, > > might be better than anything. > > According to those who hit the ball harder and farther than I, aligning a > shaft's large spine (over 5 cpm?) at 12 o'clock makes a big difference in > reducing the size of the impact area on the face. The more center hits, the > more longer, accurate drives. Thus, it's called a "supershaft alignment." > Actually, though the USGA has made small deviations in stiffness around the > circumference of a shaft acceptable, large spines essentially make a shaft > non-conforming to the rules of golf...at least, that's my opinion on the > subject. > > > But it's hard to get bad results with no > > spine. I just wish I could find more shafts like that. > > That's true. The SK Fiber shafts which I've been using almost always have > less than .006" deflection (about 1 cpm) and play very well. Though I > haven't used any Accuflex shafts because of their high price, those who have > used them report they are as good as the SK Fiber shafts. And, most filament > wound shafts have very little spine. If these manufacturers can do it, so > could Penley, UST, Grafalloy, etc. IMO, the USGA should put a limit on spine > magnitude of 2 cpm. > > Bernie > Writeto: [EMAIL PROTECTED] > > --- Incoming mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.520 / Virus Database: 318 - Release Date: 9/18/2003 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.520 / Virus Database: 318 - Release Date: 9/18/2003
Re: ShopTalk: NBP-COG
Hi Bernie, I agree with Doug but i strive to understand it, NBP-COG makes sense to me and I am going to try it out on a set I am putting together this week. I am still not sure about NBP, I am assuming that the spine is the section of the shaft that rolls away from the bend when a load is put on it from my spine finder, then the natural bend point will be 180 degrees out from that point? Then when you put the shaft into the housel and lay it off the end of the table the spine will point up and the NBP will point down towards the COG of the head? Does this sound right? Thanks - Jim - Original Message - From: "Bernie Baymiller" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, October 05, 2003 10:34 AM Subject: Re: ShopTalk: NBP-COG > Doug, > > > The more I mess with spines and scratch my head > > about how to orient the shafts, the more I appreciate shafts that don't > have > > spines. > > Me, too. > > > I suppose a strong spine properly aligned, whatever that means, > > might be better than anything. > > According to those who hit the ball harder and farther than I, aligning a > shaft's large spine (over 5 cpm?) at 12 o'clock makes a big difference in > reducing the size of the impact area on the face. The more center hits, the > more longer, accurate drives. Thus, it's called a "supershaft alignment." > Actually, though the USGA has made small deviations in stiffness around the > circumference of a shaft acceptable, large spines essentially make a shaft > non-conforming to the rules of golf...at least, that's my opinion on the > subject. > > > But it's hard to get bad results with no > > spine. I just wish I could find more shafts like that. > > That's true. The SK Fiber shafts which I've been using almost always have > less than .006" deflection (about 1 cpm) and play very well. Though I > haven't used any Accuflex shafts because of their high price, those who have > used them report they are as good as the SK Fiber shafts. And, most filament > wound shafts have very little spine. If these manufacturers can do it, so > could Penley, UST, Grafalloy, etc. IMO, the USGA should put a limit on spine > magnitude of 2 cpm. > > Bernie > Writeto: [EMAIL PROTECTED] > >
Re: ShopTalk: NBP-COG
Doug, > The more I mess with spines and scratch my head > about how to orient the shafts, the more I appreciate shafts that don't have > spines. Me, too. > I suppose a strong spine properly aligned, whatever that means, > might be better than anything. According to those who hit the ball harder and farther than I, aligning a shaft's large spine (over 5 cpm?) at 12 o'clock makes a big difference in reducing the size of the impact area on the face. The more center hits, the more longer, accurate drives. Thus, it's called a "supershaft alignment." Actually, though the USGA has made small deviations in stiffness around the circumference of a shaft acceptable, large spines essentially make a shaft non-conforming to the rules of golf...at least, that's my opinion on the subject. > But it's hard to get bad results with no > spine. I just wish I could find more shafts like that. That's true. The SK Fiber shafts which I've been using almost always have less than .006" deflection (about 1 cpm) and play very well. Though I haven't used any Accuflex shafts because of their high price, those who have used them report they are as good as the SK Fiber shafts. And, most filament wound shafts have very little spine. If these manufacturers can do it, so could Penley, UST, Grafalloy, etc. IMO, the USGA should put a limit on spine magnitude of 2 cpm. Bernie Writeto: [EMAIL PROTECTED]
Re: ShopTalk: NBP-COG
- Original Message - From: "Jim & Ivette" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, October 13, 2003 9:02 PM Subject: ShopTalk: NBP-COG > Bernie, can you break this down for me a little more, im not following it > exactly, maybe? i have a spine finder made out of atube with two free > bearings and a third tip bearing. i push the tip down untill it rotates to > show the spine. how does that relate to what you are saying. - Jim > I am not Bernie but I'll try to answer. If you find one spine with your finder, the NBP should be 180º opposite. It will usually be pointing straight up when the shaft is at rest in your spinefinder. If you have two spines 180 apart, then your NBP is between them, hopefully 90º. These are usual scenarios, but there are exceptions. The basic thing is that NBP is (up) where the shaft wants to sit when it is under tension in the spinefinder. Anyway, if you use that info to find NBP, then you take Bernie's instructions from there. NBP stands for natural bending point or plane, something like that. If I'm wrong someone will correct me. I got this from the Spinetalk list a couple of years ago and haven't really kept up with any updates. Pretty interesting theory, Bernie. The more I mess with spines and scratch my head about how to orient the shafts, the more I appreciate shafts that don't have spines. I suppose a strong spine properly aligned, whatever that means, might be better than anything. But it's hard to get bad results with no spine. I just wish I could find more shafts like that.
