I fiddled with the X axis servo drive and tuned the parameters with P=1 and jog speed set to 60 IPM. The ferror always returned to zero but did so at an exceedingly slow pace. I tuned the drive to the limits of stability (or a little over) and the movement was always so slow you couldn’t detect it. I then went to LinuxCNC and turned up the P values until I saw instability. The machine moved much more quickly, but still lagged the commanded value. As P increased the lag was lessened, but always increased with constant jogging. The velocity command to the USC board was a clean acceleration ramp, constant velocity, and deceleration ramp. I cannot explain why my results are so poor, but I’m hoping that someone might have some suggestions on how to determine whether it’s a problem with my settings in LinuxCNC or a problem with the drives.
Matt > On Jun 29, 2021, at 8:55 AM, Matthew Herd <herd.m...@gmail.com> wrote: > > Ok I thought so. I just want to confirm that setting all PID parameters to 0 > will allow the velocity commands to pass through. I’d think I’d need P=1 or > something along those lines? > > I hope to try this one evening this week if I can get to the shop. > > Thanks again! > > Matthew Herd > herd.m...@gmail.com > 610-608-8930 > >> On Jun 29, 2021, at 8:31 AM, Les Newell <les.new...@fastmail.co.uk> wrote: >> >> I just checked the docs and you are correct. I assumed you were using a >> standard stepgen. I didn't realize Pico USC works differently. >> >> Les >> >>> On 29/06/2021 13:18, Matthew Herd wrote: >>> Hi Les, >>> >>> I’m not sure if that will work with the Pico USC board. If I’m not >>> mistaken LinuxCNC treats the motors as servos and the board handles the >>> step generation. >>> >>> Matt >>> >>> >> >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
