Self Supporting Universal Spool Holder (parametric)

I hate the spool holders that come with cheap 3D printer kits. Clunky, take up too much space when not in use...

Drop out the middles, and add 4 sets of these hubs and bearings, then add 4 5x16x5 ball bearings. Et voila! A self supporting spool holder! Attach with 4 M3x20 screws, nuts and washers

The bearing is a real deal printable but a steel bearing will last way longer don't be such a cheapskate ;-)

The bearing is drawn using https://www.thingiverse.com/thing:3199782 by Mirar. Comment it out of the scad file if not required.