Raspberry Pi 4 with Mesa 7c81

And correct backplot does not show it. Also verified on standalone gcode simulator

I wrote a simple gcode program to test. It was a rectangule with rounded corners I used g02 for the curves. Again, perfect plot on screen but the issue you saw in the first photo labeled “A”

I will look up the configs in just a minute as well post the gcode I ran for the rectangle

Ferror= .5
Min_ferror= .05

Will post both .Hal and .ini

I agree that it looks like a command motion (even on the part) but if it does not show up on the backplot then I _think_ that can only be backlash comp (bad backlash comp).

I would agree except that I created the rectangle specifically to make the motors run in only one direction throughout the curve (x only moving in the negative direction and y only moving in the positive direction) to eliminate backlash as the culprit. I really do not believe it is backlash or backlash comp (which is set to zero anyway)