Printrbot free-spinning fillament spool holder (using 608 bearing)

I wanted a free-spinning spool holder that mounted onto my Printrbot Simple Metal, and one that didn't take a lot of material to print. This design uses a single 608 skateboard bearing (readily available online) to allow the spool to spin freely, so the extruder doesn't have to do any unnecessary extra work overcoming friction.

I'll be adding more spool sizes in the future. If you need anything, please let me know the spool hole size (diameter) that you need, and the brand of your spool