Robo3D Top Mounted Dowel Spool Holder

This is a top mounted spool holder for the Robo 3D printer. It uses two 3/4 inch dowel rods -- one to act as a stabilizer (the lower rod) and one to act as the spool hanger. The upper end of the printed piece is open to facilitate easy removal of the dowel to add or remote filament spools. The lower slotted ends fit into the hole on the top of the printer.

I really like Keraynopoylos' design at http://www.thingiverse.com/thing:188820 but I wanted something that could hold multiple spools inst