Printrbot Simple spool mount

This filament spool holder mounts on the top of the z-axis rails of the Printrbot Simple Metal however it'll sit flat on a desk just fine. It accepts a piece of 5/8" dowel (108mm long) as an axel and prints without need for support material.
Photos show an example printed with 0.4 mm layers.
This project was inspired by a similar mount designed by tonyyoungblood who also has some great designs for spool spacers.