My Tapmatic tapping heads seem to hold taps just fine. If I recall correctly (I'll look in the shop later), they have two mechanisms: 1 -- A vise like mechanism that closes on the flat sides of the square -- that provides the driving power 2 -- A rubber flex collet -- that provides the alignment
Since it is designed to be used in a drill press, the Tapmatic also has a mechanism with "slop" so that the tap can self align with the hole. Ken On Tue, Mar 29, 2016 at 4:40 AM, Gene Heskett <ghesk...@wdtv.com> wrote: > On Tuesday 29 March 2016 03:25:55 Neil Whelchel wrote: > > > Hello everyone, > > Thank you very much for your comments and suggestions. To me the tap > > is not the issue, a broken tap in a hole IS an issue, so it is all > > about not breaking the tap if the spindle faults out. As long as the > > axis stays slaved to the spindle, the tap can be removed by hand. > > There is not much point of restarting on the same hole, as that one > > can be completed by hand tap if needed. However, having just said > > that, I have found that since the axis slave operation starts on the > > index mark of the spindle encoder, I can actually tap a hole again, > > and with quite impressive results. I will look at motion.feed-inhibit, > > it looks promising. The docs say that it allows synchronized motion to > > complete, but it is unclear if it will work in the case of manually > > backing a tap out of a hole. I will report my findings. Thank you, > > -Neil- > > > I agree with 90% of that. Restarting the operation here at the > WOWElectronics shop has generally not been practical because the tap has > slipped in the chuck, or the whole chuck holding the tap has turned in > the boring bar type holder I use to hold taps on the carriage of my toy > lathe. I lack the ability in a tap holder to grab the square rear end > of the tap in a tool holder and positively prevent its moving. If I had > that problem solved, and I drive the tap to the starting position in my > G33.1 wrapper, then a rehoming of the lathe should put it close enough > to restart the hole if the spindle faults because the tap is bigger than > the spindle can do w/o bogging down. Editing the wrapper for a smaller > peck so it doesn't trip off again of course. > > Much the same problem exists on the G0704 as there is not a precision way > to hold the tap there short of welding it into a tool holder, which > would of coarse anneal the tap into some about as strong as a peep. > > I broke a 3mm.5 tap the other day because that POS chuck that came with > the g0704, with its taper mount, had so much runout it forced the tap > sideways and snapped it off. I measured the tapered section, finding > the taper had a runnout of about 3 thou, but so did the chucks rear > socket, so by knocking its adapter out, turning it a bit and driving it > back in, I finally arrived at about 2 thou of runnout on a 6" piece of > 1/2" A2 drill rod, and it seemed to be repeatable, the R8 it was being > held in was pretty true. > > Pretty good considering my first measurement of that runout was in the 55 > thou range immediately after I broke the tap. Measured on the remains > of the tap stickout. I was by myself and the shop air was pretty blue > for a while. > > I have searched the net, but have largely come up empty when looking for > a tap holder that actually grabs the square on the butt of the tap. If > I was a tool maker trying to design such a beast, I would first try to > convince the tap makes to standardize the square. I have close to 60 > taps sourced from various places, and I don't think I have 2 taps that > are close enough to the same size that a machined holder could hold > both. > > Tap holding, precisely and repeatably is a problem I would love to solve. > > Thanks folks. > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > ------------------------------------------------------------------------------ > Transform Data into Opportunity. > Accelerate data analysis in your applications with > Intel Data Analytics Acceleration Library. > Click to learn more. > http://pubads.g.doubleclick.net/gampad/clk?id=278785471&iu=/4140 > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > -- Kenneth Lerman 55 Main Street Newtown, CT 06470 ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785471&iu=/4140 _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
