I tried almost all micro-stepping from full step to 10,000 on DM542T (including 1600 s/r) Sometimes was better, sometimes bad.
And yes, the only reason to replace it with G540 was the Adjust Trimpot. I wished this option to solve all the problems but it is still not smooth on low speeds.
Next week I hope to receive the 3 phase closed loops and fingers crossed to be much better. Better or not I'll leave it with the closed-loop drives. The machine works fine just like that with the G540 but you can see some small unperfections on the part where accelerations and decelerations are activated because of the slow speed vibrations.
P.S. I'm just guessing... the Y motor is close to the controller electronics. Is it possible all the problems to come from electromagnetic interferences? I can make a small metal box/shield to cover it with a small fan on it. Attached is a picture and video link:
Stepper vibrations with G540 and Stepperonline
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