A holder for the most common filament spools: 48mm, 38mm and 32mm. It allows the spools to spin freely on a 8mm shaft.
It can be used as printed but it can also take 608 bearings at one or both ends..
Print at 0.4-0.5 layer height (not terribly important), with support. With some luck it is possible to print without support, but cleaning is much harder.
Clean the internal hole with a 8mm drill, if necessary (there should be a 0.2mm clearance around the shaft).
Push a 608 bearing inside with the help of a vise (and some pieces of plastic to prevent bearing and holder marks).
I enjoy designing minimalist-functional 3D objects.