Flashforge Creator Pro Super Duper Spool Hanger

Edit: Sep-19-2016: changed the design to metric.

This is a super duper hanger for the Flashforge Creator Pro and similar printers. This design has a few advantage

* Bearings based, virtually zero friction.
* Easy to mount and remove the spool. No screwing required.
* Easy to install and remove holder from the printer (e.g. in tight places)
* Fits all common spool form factor and spool holes, including Hatchbox spool with 1" hole.

Printing: print in the orientation of the provided ST