A couple of minimalistic filament spool holders for the two variants I've encountered so far.
It uses threaded rod to hold the two legs together and two 22mm bearings to make it rotate easily.
Admittedly, the legs could be made more sturdy.
holderleg2.stl | 23.5KB | |
spoolholder.stl | 103.7KB | |
spoolholder50.stl | 103.7KB |