Universal Filament Spool Holder

This thing is a remix of two already published solutions for a filament spool holder, so first of all the honor goes to the two guys who did the basic designs:

http://www.thingiverse.com/thing:52927
http://www.thingiverse.com/thing:467008

I liked both designs, and as the spool ends of the "Simple Holder" did not fit perfectly to the spools I wanted to use, I thought combining the stands of this solution with the "Spool Holder with Bearings" from the other one would lead to a more universal solution.

To reach this only a small modification was necessary:
- The spool ends themselves are taken as they are - I did not modify them at all, being designed for 6mm bearings (17x6x6).
- The spool holder stand then did not fit to the spool ends - it was designed for 8mm threaded rod originally. So I changed the size of the hole to 6mm,

The whole filament spool holder now consists of the following components:
- 2 printed Stands
- 2 printed spool ends
- 4 bearings 17x6x6mm
- 1 t