Unspooled filament retainer/confinement arm

thingiverse

This is an armature built to keep small rolls of unspooled filament - remnants, samples, and so on - from coming off my spool holder when using them for prints. I have a bunch of loose filament rolls, mostly because I like buying filament sample packs. They have a tendency to come off the spool holder and fall down during printing. Obviously, this is bad and leads to damaged prints, so I came up with an armature to get that under control. So far, it works. The armature attaches to the standard Ender spool holder and lets you confine small loops of filament in such a way that they are contained, and stay on the spool holder. Depending upon how you position the armature, it can also let you put up a barrier to help keeping large unspooled loops from sliding off the spool holder and - again - falling down. The armature is attached with wedge-shaped friction clips. The small rectangular tabbed end of the armature is inserted through the grill of the filament spool holder, turned 90 degrees, then locked into place by sliding one of the clips between the rectangular tabbed end and the filament spool holder. Two clips are included with the design because while the small one does the job, some might find it a little awkward to handle, so I made a larger one that's easier to manipulate. The larger one may also work better if your spool holder's metal is thinner than mine for some reason. Use whichever works best for you. The armature retention disk is intentionally oblong to provide flexibility. For very small loops, push the short edge of the disk all the way up against the spool holder. For medium loops, use the longer edge of the disk instead. For very large loops, point the larger side down, and attach the armature towards the bottom of the spool holder arm to provide a little tension and more importantly have the disk serve as a de facto spool wall, keeping the filament better confined. While I am using a printed/upgraded spool holder with bearings, there's no requirement that this upgraded spool holder be used with my armature. It will work exactly the same way with the factory standard spool holder.