On Wednesday 03 March 2021 19:42:25 John Dammeyer wrote: > I made another video with the new 3D printed pulley. Much better > balanced as I made the inner hole and outside hub thicker and then > bored and turned it to the correct diameter and concentric with each > other. Now just shows the Z axis jogging up and down after homing. I > still get the occasional following error but it seems that's a > LinuxCNC issue and not the motor. Or it's electrical noise because > the table is loaded down with two vices and a rotary table. I think > close to 200 lbs extra. I'll have to weigh it. > https://youtu.be/AJWI09C6h7U > > I've read through this thread. I'm using the MESA 7i92H which is > Ethernet based and it's only the PC and the MESA on the network. > https://forum.linuxcnc.org/10-advanced-configuration/27171-joint-2-fol >lowing-error?start=10 > > Without all the extra weight on the table there is no following error. > If I remove BACKLASH compensation there is no following error. It > appears to go away if I make sure that the STEPGEN_MAXACCEL is set to > double the MAX_ACCELERATION. > > My parameters are > P = 1000.0 > I = 0.0 > D = 0.0 > FF0 = 0.0 > FF1 = 1.0 > FF2 = 0.0 > BIAS = 0.0 > DEADBAND = 0.0 > > PCW on that forum stated that "For PID control of the stepgen, the > stepgen is put into velocity mode and a basic velocity mode PID > setting is used (FF1 = 1.000, FF2 = .001 (servo period) P= ~150)" > > My SERVO_PERIOD = 1000000 > So should FF2 be set to that? Or is the stepgen even in velocity mode > and does it matter? > > What I don't understand is why extra weight made it show up. The AC > Servo Drive is not showing an error and motor current rarely goes > above 3.5A at 220VAC or about 770W. > Put the halscope on it, trigger on the home switch, and watch the control, fb, and error sigs.
Adjust FF1 for zero error while its cruising, I think it will be higher than 1.0 Small amounts of FF2 and gain should be investigated. > John > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users 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
