Like many others, I managed to crack mine by tightening the screw too much.. It wasn’t clear what i was trying to achieve. I thought I was trying to pull the nut flush, but when I looked closely, the indent for the nut doesn’t recess it all the way like the parts on the Y-Axis..
The manual should simply say, tighten the screw until 1-2mm of thread protrudes through the nut..
Really struggling to get the belt to align as its rubbing on the pulley lip close to the motor.. It seems like the motor needs to move a few mms (away from the pulley) as you the pulley hits the motor before the belt runs centrally on it.
So I have created a spacer which moves the motor 2mm… And it appears to have done the trick.
Others on teh forum have confirmed this, so I believe Prusa need to consider changing the mount to move the motor slightly, allowing more of the shaft to be useable.
For now I have made a 2mm spacer which appears to have done the trick: