Re: ShopTalk: swingweight

[Alan Brooks]

Thanks, Bernie, you could also x-ray the tip or use ultrasonics.  My point is that it isn't done routinely and we therefore don't know how many tips that do not fail have epoxy as far up as the top of the hosel.  The claim has been made that epoxy in the shaft tip to the level of the top of the hosel contributes to shaft failure.  I haven't seen anyone claim that every shaft that fails has epoxy in the tip, only some of them (in fact, I have seen failed shafts that did not have epoxy anywhere near the top of the hosel).  I, as a mechanical engineer, can see no reason for epoxy in the hosel to contribute to shaft failure.  I can argue just as easily that it would reinforce the tip as I can that it might cause some slight stress concentration.  Neither of these arguments would be convincing, however.  If there is an effect of epoxy in the rod tip it is going to be (I believe) so slight that it's "lost in the noise".

The only shafts I have had fail did so because I trimmed too much off of the tip and removed most of the reinforcing the shaft manufacturer puts in there to strengthen the tip and prevent failure at the top of the hosel where the stresses in the shaft are the greatest.

A second potential culprit, I believe, is using a belt sander to abrade shaft tips.  There is great risk of removing too much of the graphite fiber, or possibly putting a shallow groove in the composite right at the top of the hosel.  Both of which can lead to failure and have nothing to do with what's inside the shaft tip.  Incomplete bonding of the shaft to the hosel can precipitate failure by concentrating the loading in the part of the shaft that is bonded to the hosel.  Burrs on the hosel that lead to stress concentration can cause failure.  These are failure mechanisms that I can readily recognize.  A 3-mm diameter column of epoxy in the middle of the shaft tip doesn't fit.

Thanks,

Alan Brooks



At 02:14 PM 10/19/2005 -0400, you wrote:

Alan,
 
You could use a long rod with a smaller diameter than the hole in the shaft and push down through the grip hole, mark the point where the rod stops at the top of the grip, pull the rod out and lay along the shaft to compare. Home Depot has small diameter 48" rods.
 
Bernie
Write to: [EMAIL PROTECTED]

----- Original Message -----

From: Alan Brooks

To: ShopTalk@mail.msen.com

Sent: Tuesday, October 18, 2005 10:23 PM

Subject: Re: ShopTalk: swingweight

How do you check for the amount of epoxy in tips that are not broken?  It's easy to tell that there is some epoxy in the tip.  How do you tell if there is a lot (say, all the may up to the top of the hosel)?

Alan Brooks

At 08:45 PM 10/18/2005 -0400, you wrote:

In a message dated 10/18/05 8:30:14 P.M. Eastern Daylight Time, [EMAIL PROTECTED] writes:

Does anyone examine the tips of shafts that don't break to see how much

epoxy has been squeezed up into them and that the presence of epoxy in

shafts that fail is not unique?

Every shaft that gets removed from a head is checked for the tip being filled with epoxy!  The easiest to inspect are those that come in broken off at the top of the hosel. Just look into the part stuck in the head and see the center is filled with epoxy. Drill the epoxy, insert a tool for removing broken screws, heat the hosel and pull out the shaft tip stub.  
Every complaint of "noise in the shaft" is treated first by blowing off the grip, cutting off the tape over the butt of the shaft then turned butt down so that the epoxy "rod" or tip weight lead rod can fall out. Then the grip is blown back on or replaced. Cheap, fast, easy fix.
 
What's the big deal! Just don't fill graphite shaft tips with epoxy! The shafts will be more prone to break if you do.