Summary After making/using my printed bearing D6 filament spool holder for 8 months, the internal shaft sheared and I set about making an improvement. In reality, the bearings didn't seem to add all that much, and made the parts far more complicated to print. Thus, my new filament spool holder. The body is shaped to provide a bearing-like surface for the interior of the spool which works really, really well. Also, there's more room for a much larger and stronger central shaft to provide print strength in a horizontal direction. This is much more solid than my previous spool holder. Finally, I added a screw-on cap to replace the simple pin in the previous version, which is also a great improvement when changing filament. Hope you like it! Print Settings Printer Brand: Wanhao Printer: Duplicator 6 Rafts: No Supports: Yes Resolution: .2mm Infill: 20% Notes: 20% infill with 3 .4mm perimeters provides more than enough strength. Additional infill should not be necessary. Almost any stiff filament (PLA, ABS, PETG, Nylon, etc) should work fine. How I Designed This Designed and modeled using Sketchup Make, printed using Slic3r Prusa edition.