Everybody talks about how PLA filament tends to spring off the spool. I decided to do something about it. This is the result. 3 rollers with F608zz bearings stay in contact with the spool's flanges preventing the filament from coming off and getting tangled. The rollers are tapered at each end to keep the spool centered in the holder and the bearings make it very easy for the extruder to pull the filament. https://vimeo.com/219591384 This thing will hold spools between about 140 and 210 mm diameter and up to 120 mm wide.