When I am doing a big move down on the z axis, there is a squealing sound from the right hand side, sounds kind of like a mechanical grind/bearing noise. Doesn't happen on the way up, or doing small moves.
I have checked:
The x carriage is level.
The vref on the drivers is set.
Swapped left and right motors.
Any ideas? doesn't seem to impact functionality, but is annoying.