Filament Spool Holder

I stumbled upon this really cool [ball bearing design](https://www.thingiverse.com/thing:2098928) based on airsoft BBs and wanted to make something useful out of it.

I also needed to replace the spool holder system hanging on the frame of my printer with something to avoid vibrations while printing, so... Here we are, a spool holder with BBs ball bearings :)

Works only with standard 1Kg filament spools.