On Monday 27 November 2017 00:38:26 Chris Albertson wrote: > about $100 per axis here, assuming NEMA23 size > https://www.omc-stepperonline.com/stepper-motor-driver/closed-loop-ste >pper-driver-0-70a-24-48vdc-for-nema-17-23-24-stepper-motor-cl57t.html > Thats a much more realistic a price. I also looked at the 3 phase steppers, but info and pricing are both hard to nail down. They should be a lot quieter, needing a smaller microstep, like a /8 for faster work, whereas the 2 phase stuff needs a /16 just to make its singing tolerable.
> I have a 3NM NEM23 meter I'm going to install as the z axis on the > mini mill with no spring or counterweight. If it does not work well > I'l use a $100 per axis closed loop. It will need some screen door springs to go up at anywhere near the down speeds. A Ball screw might help, I've got nook acme screws at 10 tpi and double nuts for backlash adjustment on mine. Can do 34 ipm if the post is freshly oiled, with 17 teeth on the 3NM motor, and 42 on the pulley wrapped around the nut carrier which is sandwitched on preloaded AC ball bearings. I can generally keep the backlash comp in the .002" region. > > I also have a 4" rotary table I want to motorize. Mine turns very > freely and I can't see why I would need large motor. This motor is a 235oz/in I think. The tightness in mine was an attempt (failed) at controlling its backlash by making it hard the push so cutting forces wouldn't take up the backlash. They did anyway, so the chain sprockets I made wound up with fat teeth that needed a few strokes of a file before they would begin to fit #25 chain. Still hangs enough to feel it, but drives the fence on my bandsaw ok now. > >> 2) The other option, more expensive is the now closed loop steer > >> motors. These use an encoder in the stepper motor that connects to > >> the driver, so you'd need to replace both bt it uses only enough > >> current to make motor step. They run much cooler > > > > I've looked at those, but pushing $300/axis is just too much. If I > > was making money, yes, I could pay for them, but I'm not, this is > > pure hobby. > > > > Thanks Chris. > > > > > > 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 > > [email protected] > > 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
