Horizontal Spool Holder using BBs as rollers.

Horizontal spool holder. Why?
Because I have more bbs laying around than 608 bearings and the bearings I have are junk this rolls way easier. The extruder has a very easy time pulling filament from this design almost effortless. It's kind of like a lazy susan for filament.
I do recommend some tape on the bottom just in case, as the spool gets lighter it may want to slide more than spin.

Note: you may want to scale the nut by 2% in the X and Y direction only, makes it thread a bit easier.

there are 3 parts required for the design.