Spool holder brackets for M3D printer and 1/2" tubing

**UPDATE: an updated and customizable version is available here: http://www.thingiverse.com/thing:731318 . The newer version makes it easier to lift out the spool holder rod, so i suggest to use that instead**

The M3D printer has a built-in internal spool holder that has some limitations. I opted to simply mount the filament spools on top of the unit, above the extruder, and using the printer chassis as base.

These are brackets only. Two sets are needed, one for each side, then simply