Quote Originally Posted by Neale View Post
Seen something like this on my own machine. In my case, it was on Z and the more direction changes, the worse it became. It was because the Z stepper driver wiring between the motion controller (integrated with breakout board in my case) and stepper driver had its polarity switched. The stepper driver interprets a level change to generate a step to the motor. If it steps on the wrong pulse edge, you effectively lose one step (microstep, in practice) on every direction change. With only a few direction changes, this might not show up but adaptive clearing generates a lot of direction changes.

Exactly how you fix this will depend on how the breakout board is wired to the stepper driver (in mine, this was a differential connection which has a lot of advantages but is a bit unpredictable from the polarity point of view) but the fix is likely to be as easy as s swapping a couple of wires, or changing the pulse polarity setting on the step port/pin for the Y axis. Can't help directly with that as I do not use UCCNC.
Cheers for the help Neale, that sounds very similar to my issue.

Think my wiring would be in a 'single ended'/common anode config at the moment. Whats the benefit to the differential connection?

I know where the pulse polarity setting is so can try to change that later, not sure if i can see why one axis would be different to the other two (if my wiring is correct.......).