Filament spool roller w/ ball bearings

Produce two sides, two end and two rollers in ABS or PETG.
I recommend printing the rollers standing on one end and the sides and ends lying flat.
Assemble using 4 ball bearings 10x15x4mm.
First insert the bearing into the rollers by placing the bearing on a flat surface and the roller slanted a few degrees on the bearing persuading the roller onto the bearing with a nylon mallet. Then place one of the sides on the surface and insert the ends with the mallet and then the rollers. Finalise by