On Wednesday 03 March 2021 20:18:44 Gene Heskett wrote: > 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-f > >ol 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. > That should have said "Dgain". > > John > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > Cheers, Gene Heskett
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
