Your problem sounds almost certainly like the maximum velocity and or acceleration is set to something less than the maximum settings you have in Linuxcnc. In setups like this where you have multiple control loops nested within each other, the capability limits of each must be completely contained within the limits of the outer loop(s). So in your case your outer loop is the servo motor/drive control. So all of the limits of Linuxcnc must fall within those set in the drive. That would be max acceleration, max velocity, and max and min position or travel. If the limits of Linuxcnc fall outside any of those settings in the drive, weird things like you describe can happen. And the limitations of the drive could be explicit settings in the drive, or physical limitations, such as it simply can't go fast enough because of insufficient power or inadequate tuning. So your solution is to either increase the limit in the drive to be equal to (or better yet slightly more than) the max settings in Linuxcnc, or reduce the max settings in Linuxcnc to be slightly less than the capabilities set by the drive.
Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -----Original Message----- From: Leonardo Marsaglia <ldmarsag...@gmail.com> Sent: Tuesday, January 24, 2023 10:40 AM To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> Subject: [Emc-users] Servo motor in step mode reaches position after LCNC [EXTERNAL EMAIL] Be sure links are safe. Hi guys, hope you are all doing well. My brother is changing some stepper motors to servos from a machine with LCNC 2.4.3 and a mesa 5i20. The servos are D2 model from Hiwin. The problem he's having is that, in rapid movements, after LCNC completes its motion the servo motor keeps running until it reaches the desired position. Apparently scale is ok and position is reached ok too, but only works well in coordinate motion (G01) between two axes. Could it be that the stepgen timing is too fast for what the servo is waiting for? And because of that it buffers all the pulses and executes the motion anyway? The manual says max frequency in LOW FREQ input is about 500 khz so this shouldn't be a problem but maybe the timing is not quite right for what the servo expects. By the way, I can't find any info in the manuals about the timing of the step signal other than the max frequency and wiring diagrams for the different setups. I don't have direct access to this machine so there's not much that I can do right now but it might be a simple problem so I had to ask. Thanks as always for your help! Leonardo _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=05%7C01%7Ctoddz%40pgrahamdunn.com%7Ccdb546a90acd4703a76708dafe216447%7C5758544c573f47cebee96c3e0806fb43%7C0%7C0%7C638101716630663370%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=fnv01dp7r1zrCd48ecABZyIW7T%2BqS%2BycJ3MpTLRnsgk%3D&reserved=0 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
