Created for the Leapfrog Creatr. The spools I use at the moment are too big to keep two of them on the turntables inside the printer as its meant to be, so one of them had to be outsourced. First I used the one armed holder from MrRockabilly but found it a bit to bulky, and fastening it with a screw was to fiddly for me.
This remix is downsized and stays put all by itself, but you need two of the arms and some rod as an axis. In the image I use the universal spool holders from RoBotnik (not included in the files, see source below) with some M8 150mm threaded rods and bearings, but chopsticks or a pencil will do as a axis as well.

The first (gray) testprint was too short for the giant spools I use, but I wanted to recycle them and added some ribs that transform them to a try to have some tools on or stuff.

The filament guide turned out to be useful to avoud getting the filament into the geared belts that drive the z-movement of the buildplate.

printed it rough draft, .34 mm layer, 15% infill in ABS.
Just print 2x the arm and hang a spool in, or make a tray with the ribs. Or both. Or just print 1 arm and hang stuff on it.