MP Select Mini Universal Bearing for stock spool holder

The Mini's stock spool holder is hard edged and jerks the filament when it's rolling. This creates excess vibration and resistance on the extruder gear, as well as being kind of noisy. This little 30-minute print fixes it in the simplest way possible.

Just print the bearings upright with support touching the bed in the filament of your choice. drop them on the stock spool holder, and slide them under each end of your spools center hub. Taa-Daaah! A smoothly rolling filament feeding machi