I have a handful of ball bearings left over from an old pair of inline skates. Since I have no more spools with small inner diameter, my trusty old broomstick spool holder had to step aside. 3 variants for different screw diameter sizes. The holder has to be printed twice, one as is and one mirrored. - 2 ball bearings, 8mm and 22mm inner and outer diameter - 4 screws M4/5/6x40 - 4 nuts and 8 washers, for whatever diameter of screws you have at hand The long M8 screw for the drum is about 100mm. The drum axis is slightly tilted up, the drum stays close to the inner end even with my screw being 10mm to long.