Filament Spool / Reel holder bearing adapter. Fits spools with centre hole between 5cm and 6cm. Uses 608 bearings.

thingiverse

Note: SpoolBearing3.stl is the best working model, however my first version required hammering the 608 bearing in, so I have renamed it to "Tight-Bearing-Fit" and made a new version that is "Less-Tight-Bearing-Fit" so you can choose what is best for your printer! Print two of these, preferably the final 3rd design (I've included all versions, and all files) and then press them into each side of your fialment reel. Don't forget to add a 608 bearing beforehand! I plan to let the bearing ride on a metal bar I plan to mount horizontally from my workbench or something. I wanted a centre-bearing filament holder because the filament reels from Microcenter are cardboard, and the edge-running reel holders might tear up the reels. Furthermore I have some old filament that breaks easily, and I wanted the least amount of tension possible.