Aluminum 2020 top filament spool holder

This is a single/double top mount spool holder for an aluminum 2020 Prusa 3D printer.

It uses a 5/16" threaded rod. I included 2 cones. One for a 608 bearing, and one for a 6200 bearing. The 6200 bearing requires the reducer to fit the 5/16 threaded rod. I made all the holes a bit under sized so they can be drilled out to the correct size for a better fit.
The shims are meant to stabilize the arms, and not lock them in place. You'll be able to move the arms side to side to line them up as you install the spool. Use M4 x 12 bolts to mount them. To make assembly easier, put the M4 bolt through the shims and back out before you install them in the 2020 extrusion.

Assembly on the threaded rod goes as follows:
Nut/wing nut, washer, arm, washer, reducer(if needed), bearing, cone, spool. Then reverse order for the other side. Don't tighten the nuts/wing nuts too much... just enough to hold the spool.