Andy, Of course one pulse per revolution can work. Those who argue it can't are likely not thinking how to compute shaft velocity. Still, you get a tighter loop with more pulses per revolution and as Gene wrote, it is not hard to make an encoder.
Thanks for the hexagonal boring video. I would have never guessed this could be done so easy. Now of course I have a use for it and "need" the feature. I'd been connecting motor shafts to aluminum parts using round holes and set screws. Now I see I can bore a "D" shape with will ft the flat on the motor shaft. On Fri, Oct 13, 2017 at 5:40 PM, Gene Heskett <[email protected]> wrote: > On Friday 13 October 2017 18:21:15 andy pugh wrote: > > > On 13 October 2017 at 23:13, John Dammeyer <[email protected]> > wrote: > > > The desire for the Beagle with me was originally that with LinuxCNC > > > and a quadrature encoder on the spindle along with the hardware QEP > > > handled by the PRU we'd have an awesome little lathe controller. > > > Alas, that's the one thing in MachineKit that hasn't been addressed > > > yet. > > > > I lost track of Machinekit a while ago. Do they have any > > encoder-counting facility in the PRU? > > > > If they have then the rest is just config. (editing text files...) > > > > > Mach3 and my ELS both use one pulse per revolution for threading. > > > And before this starts a massive thread on how that just can't work, > > > it does work and as long as the spindle is reasonably steady it > > > works well. > > > > Indeed, and LinuxCNC can be persuaded to work that way too. > > > > > But you obviously can't just stop the spindle mid thread and then > > > turn the spindle by hand manually. So there are limitations. > > > > LinuxCNC can do this (and yes, I am turning the spindle by hand): > > https://www.youtube.com/watch?v=T4q8gCpeY1A > > You can also rigid tap that way, by turning off the spindle power once > the G33.1 has started, I have done it on TLM, easy because its spindle > has AC ball bearings. Weird feeling to watch the carriage following the > encoder, while you are turning the spindle by hand, in either direction. > I've now built 3 encoders from scratch, all with 240 or more A/B edges > per revolution. Usually works a treat. Or tells one quickly that its > screwed up. > > 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 > -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ 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
