Universal Spool Holder

I got sick of making different spool holders for different sized spools of filament, so I designed one that would fit most spool types.

The advantage of this type is that you don't have to fiddle around with a shaft through the centre, you can just sit the spool right on top.

Other hardware required for this:
* 4 scooter/skateboard bearings
* PVC pressure pipe with a ID of 17.5 mm. (DN 15 / NPS 1/2)

UPDATE:
Version 2 can be found here: http://www.thingiverse.com/thing:204244