Y-axis slipping causing failed prints My Y-axis on my Monoprice maker select running ramps 1.4 and Marlin makes a thud noise when moving every now and then.  I have noticed a 1 to 2 mm shift in the print when this occurs.  I tighten the belts and alas no joy.  I ordered new bearings which should be coming Monday.  I also tried slowing the print down and still get the same result.  Anyone have any ideas.
A thudding noise is usually a belt slipping through its end-restraints. A clicking noise is usually a stepper motor missing a step. Seized bearings could be the cause.