On Tuesday 07 July 2020 19:45:42 Gene Heskett wrote: > On Tuesday 07 July 2020 19:23:28 Phill Carter wrote: > > This post on the forum seemed to solve a similar issue. > > > > <https://forum.linuxcnc.org/38-general-linuxcnc-questions/38929-linu > >xc nc-2-9-jogging-velocity-fluctuations?start=10#165711> > > That also makes perfect sense. The stutter then is a false key-up > before the next keydown. Somebody writing kbd software thought he was > doing it right by making sure they stayed balanced. A pile of > key-downs in the buffer would be guarded against just just because it > seemed like the right thing to do. > I finally heard my rpi4 do that. I didn't hear it at the former top speeds I could get with the analog motor supplies, but in fitting the much smaller motor to the Z, I was forced to switch both supplies out for 48 volt 7.5 amp switchers because the analog supplies were more z volts than I needed, and the x supply took up any room for the much longer switchers. Both supplies turned down as low as the would go, about 42.5 volts. I had x limited to 30 ipm as it stalled if asked for faster, but on the switching supply its still running well at 48 ipm and about double the accels. I had the old z limited to about 57ipm else the huge motor stalled, but with the new motor and driver, its now moving at 75 ipm. Stuff laying on the bed so I had about 8" of play room, and I hear it sneeze once in about 3 runs over that 8", either direction.
So I've finally observed the glitch. But I've no clue how fast I can tickle this new drive, so its still doing the DM860 pulse timings which are a bit glacial. A full microsecond for leading and trailing hold time on a direction change, and 4500 ns for step strobing. Wired active low of course. If anyone has a better src for those pulse timings, which are not in the 2 page driver pdf for this 3 phase driver, I'm all ears. Its an LCDA357H, and it comes no closer than 200khz for max steps. I've driven it faster than that with a function generator. > But it still boils down to flaky hdwe. And its surprising to me that > he found a way to control it on an individual key basis. A play by > play of how to do it would have been nice though. Thanks all, 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis 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
