Sample Filament Spool/Holder

I've tried a few different holders for loose sample filaments, and so far this has worked the best.

This was a remix I made to enlarge the ring opening to fit over the end cap of single arm spool holders. I also re-did the holes to work with M3 bolts, since that's what I had available. Lastly, I designed some hub adapters to fit inside the rings. This keeps the arms from fully closing around the filament, or allowing the rubber bands to fall off when there's not enough tension from the filame