This is (yes another) filament spool holder. I decided that I wanted one that was like a little Mendel frame - a nice little triangle.
It has a very smooth action and feeds filaments reliably (mine does at least).
The frame vertex is based on the Prusa part with an added hole in the middle and slightly thicker. The hub and spokes that hold the spool are of my own design. Enjoy.
print up the following parts...
4 - frame-vertex_plus_foot.stl
2 - frame-vertex_plus_no-foot.stl
2 - spool-hub.stl
6 - spool-spoke.stl
to build the frame, you will need 8mm threaded rod - I cut it in the following lengths, but I'm not sure it's the best configuration
6 - 25cm, for the outer triangles
3 - 20cm, to connect the two triangles together
3 - 15cm, to connect the two halves of the spool holder
to hold the frame together you need...
48 - 8mm nuts (and same for washers)
and to connect the spokes to the hub you need...
18 - 4mm bolts, 20mm long (also with nuts and washers)
Start by putting the two outer frame triangles together. For one triangle, you need two of the vertex-with-foot and one without. Use the 25cm long 8mm rod.
Next put the spool holder together. Attach the spokes to the hub (3 spokes to 1 hub) with the 4mm bolts. Set a bearing in the center of the hub with 3 of the 4mm bolts. Make both halves.
To make it easy to load the filament spool, I would recommend putting the 8mm connecting rod in ONE SIDE only and laying that side down flat (see photo) -- the rods will all be sticking straight up. Just drop the filament spool down on top of the holder, and then attach the other side.