Printed cap for vitamin pulleys on a Prusa Simplified Mendel

Ancestry of this object goes back to the first parametric file set for the Mendel, and in particular the Z pulley.

OK if we lived in a perfect world, this thing shoudn't be needed at all. Its intended purpose is to deal with the consequences of the flexing of the motor mounts related to belt tension, above all on the Simplified Prusa Mendel's X axis.

Because of the flexion of the mounts, we get a lack of parallelism of the axes, and the belt wanders on the pulley and gets grossly out of a