Two bearing-based spool holder

I went to the store to buy bearings and they had no 608s and I could only get 2 609s. So I decided to design a whole new filament spool holder around a pair of 609 bearings.

Unlike many other designs, the base is printed as a single upright print. The spool is centred using pyramidal endcaps held together with a central threaded bar - this ensures good alignment with the centre for arbitrarily-sized spool holes.

In addition to the parts printed here, you will/may need 2x 609 bearings.

UPDATE (28 Feb 2019): Added a fake bearing, since using real bearings had so little friction that some of my spools unwound too easily. Added crossbar3, which is slightly longer so does not slip off the bearings.

UPDATE (28 Mar 2019): Added a simple no-bearing fixed bar as an alternative to the whole complicated centred-screw bearing contraption. For this approach, all you need to print are the cage and simple_bar.