Thanks everyone, Played with P and D of the PID to change some of the motor parameters to see if I could get rid of that harmonic noise that sometimes comes up but only in one direction. Nothing helped. I'm of the opinion that under load in one direction but not the other the 0.0137" backlash is impacting the motion. It gets a bit of momentum and then the motor speeds up to catch up to it and then over speeds and has to be throttled back and that's what's causing the noise. Only during acceleration during that particular speed and in one direction.
Ultimately either preloaded ACME nuts or ball screws should fix this. Using G01 Y6.5 F35 from Y0 is nice and smooth and the Shumatech DRO matches the PC DRO. G01 Y0 then moves back and the DRO still matches so I have the backlash adjusted fairly accurately. I can do that from F10 all the way up to F150 and only during acceleration in the one direction back to Y0 do I hear a tiny rumble. And sometimes at around F30 to F35 it may make that stepper motor harmonic type noise. But it's not reproducible every time. Hey! Perhaps also tighten the gib on the Y axis to make it stiffer so it will always loaded. I'll try that. John > -----Original Message----- > From: Jon Elson [mailto:el...@pico-systems.com] > Sent: June-02-21 8:52 AM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Servo Motor Tuning. > > On 06/02/2021 01:20 AM, John Dammeyer wrote: > > I really don't know if this is the right forum for this question but in > > working with the mill over the last few months every once in a > while the DC Brushed Servo Y axis makes this horrible noise like a stepper > motor at the harmonic instability. > Try turning P down a bit and see if that helps. Also, try > different values of D, that changes the damping. it may > only take a small adjustment to get rid of the oscillation. > > Jon > > > _______________________________________________ > 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
