Planetary Spool Holder and collars

Here is my spool holder for 52mm centred spools and an 8mm shaft.
The openscad files can be edited to change the sizes.

The spool hub uses a printed in place planetary bearing.
There is a choice between a collar that requires a 3mm nut and bolt or a screw together collar with a tapered thread using the threads library by Dan Kirshner.

No need for metal bearings and the planetary gears give a little resistance so the spool does not run on and release too much filament and prevents tangles.
Both collars interlock with the centre of the bearing to prevent the bearing spinning on the rod. Its a good idea to restrain the rod to prevent that turning as well.
Then the spool will only turn on the planetary gears providing some resistance to prevent the spool from running on.

Obviously inspired by Emmett's gear bearing and AndrewBCN's spool hub.
And the threads library by Dan Kirshner. See file for details and licence.

19 June 2017: Added MiddleScrewCollar.stl and modifies Scre