This is a spindle variant on randyy's excellent parametric filament spool, with two notches 60mm apart along a supporting arm. It is designed to clip onto the two two parallel threaded rods on a mendel or prusa, and possibly other types of reprap, and hold the spool up away from the printer.
It's got a few dags on it, and could probably have some cutouts taken to reduce cost of print, but I wanted it sturdy.
Derivative of: http://www.thingiverse.com/thing:8317
Print it out, clip it into your hub and clip it onto the top two threaded rods of your printer. If you arrange it such that the filament passes out the top of the roll, you can feed the filament down next to the Z leadscrew opposite to the clip, and then across into your extruder.