On 01/16/2017 09:01 AM, Gene Heskett wrote: > I had a dial sitting on the saddle watching X motion, and > put it in the range where it was at zero on the outer end when it had > run to completion and parked itself. Then I ran it again, and at the end > of the 2nd run, it was parked 0.041" inward from where it was parked the > first time. This difference does not show in the dro display. > > Whose stepper drivers are you using, and do they have opto-isolated step and dir inputs? If so, then make sure whatever common there is for the step and dir inputs are wired to the controller board by a direct wire that goes to no other system. One giant common ground for logic and power sounds like it might work, but my experience is it DOES NOT.
We've had problems with my PWM system when a common ground is used. It causes ultrasonic oscillations where the power transistors switching cause pulses on the common for the PWM command and that becomes a feedback loop. The fix was to have the PWM and DIR common wired back to the ground terminal on the controller by a direct wire, and then another wire from the controller ground to the system ground. You might have a similar situation. If your drives don't have opto-isolated inputs, then all I can say is "good luck!" Jon ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
