I made this as a very simplistic way to support a spool of plastic over my RepRap, since I'm short on desk space.
It works just fine with charlespax's nice cardboard spool design:
I have now also designed my own printable spool that will fit on this stand:
The slot at the top takes up to a 10mm shaft, while the slots at the bottom are sized to grab hold of the top 8mm studding on a RepRap Mendel.
It's designed to require as little assembly as possible, and you should be able to make one out of wood too, although that might be a bit wasteful, as it's also designed to be lightweight.
If people really want it to be secure on there, then I'll make a design with flanges to bolt on with something like a y-bar clamp.
The included bushings are for gluing to a cheap cardboard spool so that if you use threaded rod it doesn't cut away at the cardboard.