On Friday 23 May 2014 05:36:56 andy pugh did opine And Gene did reply: > On 23 May 2014 02:20, Gene Heskett <[email protected]> wrote: > > The screw, measured from bottom of ball groove to the ball groove > > half a turn away from it, is about 8.12mm. That .12mm is probably > > the angle that the caliper is sitting at > > 1.25mm half-pitch. Pythagoras suggests sqrt(8^2 + 1.25^2) = 8.097mm. > But as you are measuring rangent to the circular grooves I can believe > 8.12. > > > I'll literally sand it off with a large dremel diamond wheel, which > > will do it without any heat to speak of at 2500 revs, a job I can > > start & check on the progress of tomorrow. :) > > I have always avoided losing the balls from ballnuts, but as far as I > can see it isn't horribly difficult to re-ball them (depending on the > design).
Already done to get them nice & tight. 20 minutes each to re-stuff AIR. 77 balls or so. > Perhaps you could face-off the flats in a 4-jaw chuck on the lathe > using a carbide or CBN tool? Carbide I have. I'd have some reservations about the alignment in the chuck. And the heat. On the mills table, the bottom side should be level. I'll run a .250" rod thru it & clamp down on the rod ends far enough away the wheel clears the clamps. I have the mill capable of moving its Z in .001" or less increments now. The mill looks rather Rube Goldbergish with the extra big alu bars on each side of the sliding head casting carrying ball bearings riding the machined track on the face of the post, but no more %$#@&^ stiction either as it doubles the "wheelbase" of the sled. I should take a pix and put it on my web page, I expect you all would get a VBSEG over that. But it works quite well! Running at a feather touch I turn off the lights and use an led flashlight to see the dust drifting away to determine first contact, and at 2500 revs on a wheel about 1.75" in diameter, not enough heat to ablate the diamond coating on the wheel. So they'll theoretically last till the rapture & leave a mirror finish. Basically, go around it in a parallelogram movement & set Z down a thou every 5 or 10 passes around the parallelogram. Slow but purty. :) A much bigger problem will be digging the pocket it will be hidden in on the mill, in the replacement nut holder block which can be perhaps 19.1mm tall from the bolt face & still clear the top of the trench in the bottom face of the table. A production run of one. 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> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free." http://p.sf.net/sfu/SauceLabs _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
