On Saturday 13 October 2018 18:43:25 Gene Heskett wrote: > On Saturday 13 October 2018 16:10:16 andy pugh wrote: > > On Sat, 13 Oct 2018 at 15:03, theman whosoldtheworld > > > > <[email protected]> wrote: > > > I think for your pourpose the better idea was using a very precise > > > LVDT and put the measure of your axis in a table for make a good > > > backslash linearization kinematics file .... > > > > Or use a dial indicator and a notebook. > > And a long, perfectly straight rod, turning slowly enough not to beat > the $100+ dial to bits, and try to get an average reading. I'd need a > 34" rod, a dog to turn it and an MT5 dead center, none of which I > have. > > And from my experiments this afternoon, I am going to have to find a > single spot beam green laser, this red line pistol cartridge model > isn't going to give me good data, ever with its rotating - pattern > beam. I've put a layer of cloudy poly on the cds and it helps, but it > all goes to hell the instant the knife on the toolpost starts to > interrupt the beam since the beam isn't round, and there does not seem > to be a null at exactly half the beam blocked. I changed the drive > belt to get more spindle revs, but at 1200 revs the front bearing is > smoking in about 6 or 7 minutes with the bolts loose. And the reading > still wanders around since the spindle is not synchronized with the > meters A/D. So I've got to find a different way. I was hoping I > wouldn't have to putz with building a camera, but that might yet be > the only way. > > I'm getting my cataracts fixed starting next week, so this project is > on hold for the time being. > Actually, blame it on oldtimers I guess, but I thought what would happen if I put a honking big cap across the CDS cell, so I went out and stuck a 4700 UF cap across it. This made the settling time several seconds, but worked a treat, so now I have it well within a thou from just clearing the 4 jaw with the side of a carriage, which is -3.500 in machine coords based on my homing, on out to around 23 inches. There seems to be a bump there, or the bellows is pushing, or perhaps I don't have that screw bearing properly adjusted. Shop made bracket by an amature, me. :( Thats about 1.5" from running into the tailstock. So I feel like I actually accomplished something for a change. Murphy was present and up to his usual mischief, the mouse battery died in the middle of it, and of course I had to come into ther house ands get one out of the coyote.den, and I'd give my left one to have a switch on the DVM to disable its timeout shutoff feature. Batteries for it I have.
FWIW, the maximum correction was about 3 thou, in the middle of the bed, most corrections were under a thou. there's a bump in the middle of the ways that I can't see, or feel thru a paper towel wiping it. But its better than it was. > Many many thanks for all the help and ideas I've been offered, even if > my explanations lacked clarity, its appreciated, a lot. Thanks again everybody. -- 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> _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
