I was tired of having to adjust my filament roller for different width spools so I designed this one to accommodate spools up to 100mm wide. To assemble it you place a 608 bearing in one end of the roller, insert the rod through the opposite end, insert the second 608 bearing. After doing this for both rollers, you simply place them on the holders and tighten the nuts. You can adjust the tension of the nuts to adjust how freely the spools turn.

Update: I’ve been running this for a couple months, and while it works well I just can’t seem to stop knocking it around and breaking the axle shafts. Today I replaced them with 8mmx200mm threaded rod. Hopefully, I won’t break them now.