Anet A8 right Z drops 2 mm during print I've noticed that after my Anet A8 completes a print, the right hand Z mount ends up 1-2&nbsp;mm lower than the left, even though I make sure both the left and right hand Z mounts of the X-axis are at the same height before switching on the printer.

Does anyone know what the cause of this might be?

I'm guessing something is causing the right hand Z to skip steps. I can't see or hear any obvious mechanical issues. I checked all guide and threaded rods were straight before assembly.  

Could it be a faulty stepper or control electronics?
My guess is your Z guides are not strictly parallel because there's no instruction how to install X guides correctly. When you install X guides, you can easily make horizontal distance between two Z-mounts either too small or too large, which puts extra stress on one of the Z motors. Move your extruder to home position, measure distance between bottom ends of Z threaded rods and between top ends, and try to adjust right Z-mount position on X guides so that these two distances become equal. Use hammer, but be accurate with plastic.