Ball-joint filament guide

thingiverse

I am using a TUSH-style filament spool holder which appears to work all too well, allowing the spool to rotate both forward and backward when the extruder retracts. This back-and-forth motion causes the filament to become loose and unwind - sometimes resulting in the filament forming a knot and seizing up. The filament guide prevents the filament from whipping around and I really liked the ball-joint versions, as it allows for full 360-degree motion (it's also a cool design!). I've remixed this one to fit a 2040 aluminum extrusion and be 40mm from the rail.