On Sunday, January 16, 2022 2:51:28 AM EST John Dammeyer wrote: > Thanks Gene, > Amazon says it will be here on Tuesday so doesn't look like it will be > an issue. > > The bigger problem for me at the moment is I put a dial indicator on > the harmonic drive output hub and used LCNC to spin the A axis. I > then radially measured 0.0015" deflection and same with the face which > also had 0.0015" change over one rev. > > Maybe it's dirty inside or has been reassembled poorly. But that's a > lot of run-out I would think. > > John
That's one thing I've got some of too, but considering I've got maybe 10 bucks in it, I'd look foolish crying about it. I also am belt driving the A chuck, which sits in its own cheap ball bearings. My major accuracy problem is caused, I think, by an error in the armatures ellipse, it is printed, including the shaft hole and its dflat, and the theory is that the dflat may be causing a thou or so differential in the height of the ellipse, the motion can be see to vary some in speed on a motor revolution cycle. The overall error I'm not equipped to measure accurately, but I'm guessing it might be 30 arc seconds max. That is still more accurate than one can set the compound angle on a lathe, and until I grow some experience, its main use might be sharpening HSS lathe tools using a 1200 grit CBN wheel on that mill at a leisurely 18k rpms. HSS destroys diamond, and vice versa, but CBN contains no carbon, and you have not used a sharp HSS lathe tool until you've done it with CBN, Cubic Boron Nitride. Your ground faces will have a finer, smoother finish, no brittle wire edges to dull rapidly, than a brand new stick of HSS has OOTB. If it was big enough, you could use it for a shaving mirror. That printed part is simply pushed onto the motors shaft, after the 8mm shaft's existing d-flat, has been widened until the caliper says about 6.5mm from d-flat to back side of round. Every time I print one, I am reducing the 8mm hole, which started at 8.4mm because my print has a .4mm nozzle, by .05mm and its tighter and better each time. The pressure from the d-flat is pushing it off center. With an 8mm shaft, and only a 1NM motor, I've stopped the motor several times w/o damaging the press fit. No hub, its just printed PETG. Running on the kitchen counter for about a week now. With enough holding torque to let me carve steel square threads in a 1" or bigger rod. Not as pretty as Nooks, but usable. :o) I'm thinking woodworking bench leg vise bolts. But those might be maple wood. And I'll have fun doing it. Cheap. > > > -----Original Message----- > > From: gene heskett [mailto:ghesk...@shentel.net] > > Sent: January-15-22 11:36 PM > > To: Enhanced Machine Controller (EMC) > > Subject: Re: [Emc-users] ER-32 Collet Wrench > > > > On Wednesday, January 12, 2022 3:47:37 AM EST John Dammeyer wrote: > > > So my Collet chuck arrived a week or so ago. Today the ER-32 > > > collet > > > set arrived. I no longer have an excuse for not completing my 4th > > > axis driven by a real harmonic drive. (Well it is raining and > > > can't > > > cast). So I have drawn up the face plate adaptor and that looks to > > > be > > > a pretty easy LCNC project for the mill plus a bit of lathe work. > > > > > > However, I foolishly did not order a collet wrench. This seems to > > > overall be a pretty easy CNC project with the exception of the > > > 'teeth' > > > that engage the collet. I suppose I could mill out the profiles in > > > some oil hardening steel, then file the teeth to have straight > > > edges. > > > Finally harden it. > > > > > > Alternatively make it out of 1/4" or so steel plate (or even > > > aluminium) and drill and tap holes for screws to protrude out > > > where the teeth are. Turn down the screw ends to be smooth or > > > even square and lock the screws in place. > > > > I don't see any good reason that wouldn't work. > > > > > Looking for suggestions here. Don't really want to wait 2 months > > > for > > > one wrench with either low price and horrendous shipping or high > > > price > > > and low shipping. Cost ends up being the same at about $28. > > > > > > Thanks, > > > John > > > > I'd think, at 3/8" thick, designed in openscad, printed in PETG, > > might > > get you by until a good real one arrives. > > > > I'm late to this party, my e-mail server was one that got attacked > > last wed morning at 3AM, and is just now coming back to life. > > > > 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, 1940) > > If we desire respect for the law, we must first make the law > > respectable.> > > - Louis D. Brandeis > > > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > _______________________________________________ > 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, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
