On Tuesday 11 August 2015 21:43:46 John Dammeyer wrote: > I'm thinking of ordering one of the Probotix Breakout Boards for my > Beagle Bone Black. Probotix has a downloadable image of LinuxCNC so > getting it up and running shouldn't be an issue. > > http://www.probotix.com/CNC-CONTROL-SYSTEMS/BREAKOUT-BOARDS/PBX-BB-Bea >gleBon e-Breakout-Board > > I've not looked at LinuxCNC for some time but I'm wondering how it > does with lathes nowadays. For example if I mount a stepper motor to > drive the spindle does LinuxCNC support standard step/dir signals to > drive the spindle motor? > > Thanks > John Dammeyer
I am one who is running a small lathe with LinuxCNC, which it does far better than I can. This subject has come up in the past, and I don't recall anyone saying "no it can't be done." Given a big enough motor, I see no huge show stopper in substituting a stepgen for the pwmgen module. But the high speed performance as a spindle motor might not be universally usable. One might have to get creative for a motor/controller source. I have seen pix of someone using the huge stepper motor out of a modern washing machine, which would seem to have the torque, and since its also doing the spin cycle, might have the high speed performance too. But in terms of positional accuracy, those do not have the pole count of a moderm stepper. Someone who has actually done it should pipe up and testify. Searching ebay, the largest motor I can come up with is a nema 42, rated at 4120 oz/in. I believe that I have seen nema 56 motors on ebay in the past, but not tonight. Here is one candidate possibility, but its 3 of them for $900 USD: <http://www.ebay.com/itm/big-force-3-nema-42-stepper-motors-4120oz-in-8A-3-drivers-DM2722A-9-8A-12-months-/261930438088?hash=item3cfc454dc8> I note that the driver remembers what microstep it was at in the sequence, even if power cycled, provided it has been stopped for at least 5 seconds. That is not something the smaller drivers like the DM860 does, but I can see where that could be handier than bottled beer. No loss of machine positioning from power cycling the whole machine. 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-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
