On Thursday 10 May 2018 17:24:41 Gregg Eshelman via Emc-users wrote: > To use those with a TTS or other 3/4" R8 (or 4C) collet you'll need > adapter rings. Like these. > https://www.tormach.com/store/index.php?app=ecom&ns=prodshow&ref=32432 > They used to have thinner ones that had to be glued on with epoxy. > Looks like they're going (or already have gone) to making only the ATC > compatible TTS tooling. > > Since you have a CNC lathe it shouldn't be difficult to make your own > rings, any dimensions you need to work on the mill. > > Some quick searching turned up nothing of collets with D shaped holes. > Take a standard 3/4" R8 and have a couple of holes EDM cut so you can > pin a piece of steel inside?
What I had in mind would have resembled a larger disk, 5/16" or so, with a 50 tpi thread on its periphery, and a matching hole, threaded to match, but that would have to fit between the slots, or maybe straddle a slot so when it was compressed by pulling up the drawbolt, it would squeeze down on the threads. But getting a balance so as not to pull it eccentric, is the subject of bad dreams too. Not worth pursueing IMO. Anyway, I've made a box that can corral 100 of the "tap hats", all of which now have a 4mm cap screw in the side, whose head matches the slot I cut in the lip of the 7/8" R8's. So that problem is partially addressed. Thinking on finding the right sized drill for the axial thru-hole of the tap hat, and not yet investing in a quality (if such a beast exists today) set of letter drills, the thought comes to mind of EDM'ing 1 lengthwise slot all the way to the bore, and 2 more about 25 thou short of the bore so I could use the collets compression to close the gap and arrive at a more accurately centered tap, with no rattle room left. I like the idea, but not the time involved since those 3 slots will eat a days work per "hat" made. Skip that idea. But sleep on it. Go stuff a weeks worth of pills into my pill-tainer, and maybe something will come to mind. Thanks all. > On Thursday, May 10, 2018, 5:26:34 AM MDT, Gene Heskett > <ghesk...@shentel.net> wrote: Greetings; > > Looking around for some more cheap metric ER-20 stuff, I stumbled over > a kit on ebay that had the TTS like adapter as part of the kit. So I > bought 2 sets of them. $40 a copy, or $79.something for 2 sets. > > The adapter looked like it was the std 3/4 diameter stem. But when > they arrived, the 3/4" diameter stem had a full length flat, like it > was intended to be used in a spindle with a 3/4" bore and set screws. > > This would, if a 3/4" R8 collet could be found with a D shaped bore, > be yet another way to remove one potential slip point in trying to > hold a tap for rigid tapping. > > Has anyone else seen such a R8 critter, and what would it be called so > it can be found in the throngs of such stuff from the asian's? > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
