Thanks for all the encouraging tips, ideas, and warnings! I had some beginner's luck on the first twist. I'm convinced that my simple idea will work, so I'll document the result here. Might not be today. Got some loose end projects to wrap up, i.e. carve the bowl. DanK
On Monday, July 25, 2022 at 10:27:07 PM UTC-4 aussiman wrote: > Curts jig he made does that I haven’t got one to see if it will work on > the revo > > I index by undoing the leadscew nut and moving the saddle along in > multiples of ¼ inch which is the threads per inch of the leadscrew > > I use set up blocks for this so I don’t have to count threads then > re-engage the nut again. > > > > Be warned too don’t trust the index drive centre of the revo the nut that > holds it can come slightly loose and it can be sloppy on the square > > And you wont notice till your spirals or reeds and flutes are not all the > same I welded a leadscrew locking collar to the back of the drive centre > > So I can clamp it to the headstock shaft as well as use the nut now it > never ever moves. You will rack your brain trying to work out what is wrong > with your spirals and indexes when this happens it drove me insane till I > worked it out, it was more noticeable on larger dia work I worked it out > when I was doing my big bolts and nuts on the revo , same as on the legacy > you need to clamp the index gear from moving when doing heavy indexed cuts > . the legacys all legacys have slop problems in some way once you know them > you can overcome the problems, > > > > Bill > > > > *From:* legacy-orna...@googlegroups.com <legacy-orna...@googlegroups.com> *On > Behalf Of *Dan Krager > *Sent:* Tuesday, 26 July 2022 11:17 AM > *To:* Legacy Ornamental Mills <legacy-orna...@googlegroups.com> > *Subject:* Re: First LOM twist > > > > I got side tracked from spoon bowl cutting (with Austrian spoon knives) by > going on to do the next twist on a smaller spoon (used up the stick). I > guess I didn't get the math right and buggered it up. It was too small to > use the regular drives on the spindle, so I used my little square drive > that threads on. It came loose on a reverse movement, further buggering up > the twist. So I will fix that by milling wrench flats on it so I can > wrench tighten it. Now that brings me to a BIG question. > > > > WHY IN BLUE BLAZES DIDN'T THE PHANTOM ENGINEERS USE THE INDEXING FEATURE > to do twists? Couldn't they figure this out? Instead, it appears that you > must go through this Rube Goldberg procedure, do some math to get the > right number of starts taking into consideration the size of the cutter and > the diameter of the work.Then one must break the sync by moving the > carriage. This risky uncontrolled procedure severely limits the diameters, > cutters, and patterns in most cases. The only use for the index is to do > lateral cuts without syncing to the drive spur. The solution appears to be > so simple that even I will figure it out and do it. > > > > The basic principle of LOM is that the sync between rotation and lateral > travel is maintained by the gear train. To move to the next start requires > breaking that sync somehow. And I want to move to the next start in a > mechanically controlled manner using an index (dividing) plate to keep it > simple. It would also seem reasonable to have different plates available or > a plate with all the commonly used factors like 2,3,4,5,6,8,9,10,12. > Putting fine divisions on approximates checkering and that many sync breaks > leads to trouble. Unless mechanically controlled. Using a direct index > plate eliminates the math and other limitations. > > > > So I'm looking for the simplest, cheapest and most reliable solution. Me > thinks such a solution will focus on the connection between the "standard > index gear" and the drive spur shaft. Right now the SIG is screwed onto > the outboard end of the drive spur shaft and locked to it by a square on > the shaft penetrating the SIG. If the SIG were moved outboard onto a free > wheeling arrangement essentially extending the shaft a bit, then a flat > finger placed onto the drive square, and that assembly secured to the > outboard end, one could break and re-establish the sync at will > mechanically. The SIG would have moved leftward 1/8" displaced by the 1/8" > thick finger that is locked onto the drive spur shaft where the gear used > to be. The SiG would be fitted with a bushing to allow it to freewheel to > the immediate left of the drive square. Now the finger is pointed and the > point bent 90° to engage the holes in the SIG with its 24 holes (until a > better deal is reached). > > > > So the setup starts out the same, but one notes which hole the finger is > in. Make the cut. Spring the finger out of the hole and rotate the spur > (and work) to the next index location. The SIG remains stationary while the > spur shaft turns controlled by the finger moving to the next index, thus > breaking the sync for a moment and re-establishing sync at the next index. > Next cut. Rinse and repeat. > > > > No further changes need be made because there is enough "slop" in the gear > alignment to allow a 1/8" shift of the SiG without any trouble. This > totally eliminates any math and allows a predictable number of starts on > any diameter. One might adjust depth of cut, size of cutter, or make other > adjustments at will without affecting the basic index positioning. This > also works for the rotary table. Changing out the SIG to different ratios > will have to be considered, too. Perhaps instead of a finger, another 24 > hole plate that is small enough to fit within the smallest gear is used. > Still ... > > > > How simple is that? > > > > DanK > > P.S. YOU BET IMMA DO IT. > > On Monday, July 25, 2022 at 5:03:22 PM UTC-4 aussiman wrote: > > On the contrary its very much to look at very nice work Dan cant wait to > see the bowl > > > > Bill > > > > *From:* legacy-orna...@googlegroups.com <legacy-orna...@googlegroups.com> *On > Behalf Of *Dan Krager > *Sent:* Tuesday, 26 July 2022 2:49 AM > *To:* Legacy Ornamental Mills <legacy-orna...@googlegroups.com> > *Subject:* First LOM twist > > > > Hi guys. I'm still riding a high of successfully cutting my first > involute spur gear for one of my machines. > > > > So, riding that high, I decided to do some wood turnng. Utensils came to > mind, so very soon a couple of spoon blanks were on the LOM for another > first...the first twists cut on the REVO. Used a straight 1/2" up cut > spiral bit against the side. Six starts. Not much to look at for design > and the handle is much to large, but the pear wood cuts beautifully. > Another smaller spoon is on its way. > > > > Now to carve the bowl. This stuff is HARD. > > DanK > > -- > You received this message because you are subscribed to the Google Groups > "Legacy Ornamental Mills" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to legacy-ornamental...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/legacy-ornamental-mills/cba288e3-f046-44ae-95d6-86745def2e50n%40googlegroups.com > > <https://groups.google.com/d/msgid/legacy-ornamental-mills/cba288e3-f046-44ae-95d6-86745def2e50n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "Legacy Ornamental Mills" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to legacy-ornamental...@googlegroups.com. > > To view this discussion on the web visit > https://groups.google.com/d/msgid/legacy-ornamental-mills/62b010a8-72e8-4a43-a12b-11c30315ef76n%40googlegroups.com > > <https://groups.google.com/d/msgid/legacy-ornamental-mills/62b010a8-72e8-4a43-a12b-11c30315ef76n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Legacy Ornamental Mills" group. 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