On Saturday 13 January 2018 23:56:21 Erik Christiansen wrote: > On 13.01.18 19:59, Gene Heskett wrote: > > I did get the mt5-5c adapter running pretty true, about half a thou > > of runout in the bore of an ER-40 adapter plugged into it, but the > > nut on the ER-40 is absolute trash. You can see it wobbling, and it > > pulls the nose of a collet sideways so bad the runout is .0045" at > > the front of a collet. And I haven't a clue how to polish that back > > out of its off-centered cone in the nut. Chinese crap. But I've so > > much (>$200) in the whole kit, I've got to throw even more money at > > another nut. 50mm x1.5 threads. Even the half spanner that came with > > it is way small. But that isn't your problem of course, I'm just > > crying in my nightly bottle of Miller64. ;-) > > There are a few reviews of Chinese collet chucks on youtube. The two > I've seen measure chuck internal taper runout similar to your > experience, Gene. (The outside's OK, but the bit that counts is poor.) > Once one of the Chinese collets is inserted, all bets are off, and > it's best for woodworking. > > One review showed one of the ostensibly ER32 collets in the set was > over 33mm in diameter, and couldn't be inserted in the nut in half a > minute of wrestling. > > Another video shows a Chinese collet chuck's internal taper being > ground. Nowhere have I seen anyone use one as-is. > > It appears to be best to remember how _much_ cheaper they are, and > then consider why. I wouldn't buy 'em, except as a kit to grind to > tolerance, chucking out the collets beyond rescue. > > To attempt a rescue, maybe skim the chuck internal taper, then hone > it? The chances of making it worse are slim. If it works well, there's > a very handy youtube video in it.
I thought about that, but with the size of the locally available stones, and the .0003" max metal removal per pass when using the front face of it, dressed for a slight dish and the grinder, running on about 85 volts from a 2kw powerstat, turned about a degree CW, it would have been a 4 hour video. Worse than watching grass grow. Finish is great with a 150 grit alox stone just touching. I'm happy that the runout of the interior cone of the mounted adapter is .0006", but I fully expect the finished assembly, clamped down on a 1" rod, should still run less than .001", 4" from the collet which seems to be the std distance (4xd) for measuring runout. > > Erik > I trolled thru ebay just now, and may have found a nut and wrench. Ball bearing nut, and the wrench to fit it, for about $63 shipped from powertool4less. Be here in about a week. I might try to clean this one up, but how the heck would one chuck it when the threads aren't even concentric with the body? Stuff should have accidently been washed overboard... I did find an adjustable nut, where you could dial out the runout, but it was well north of $220 plus shipping. So we'll check out the $33 ball bearing version. And get a wrench that actually fits the nut. Now thats a novel idea. :-) 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
