Here is a horizontally rotating, low friction dispenser for a spool of filament. All you need are x5 16mm ball bearings. You could adapt the gasket to cope with whatever ball bearings you happen to have lying around. Simply lay your spool on its side onto the ball bearings and watch your filament feed through to your 3D printer effortlessly. 50mm core and 35mm core spools are provided for. But its very easy to adapt the core to fit whatever size you require. I will produce more as I need them. Also used in Thing:316951 as a Lazy Susan for entertaining.Print out the base, gasket and whatever size core base you need. Place the core base on your table, Put the base on top of the core base, Put the Gasket in the base, Put your ball bearings in the holes in the gasket, Rest your spool on the ball bearings with the centre of the core base coming up through the spool core. I have found it seems to work best with the spool placed more than 30cm from 3D printer feed. The slack in the filament can then cope easier with any retraction movement.