This video demonstrates the operation of the Silent Auto-Rewinding Gravity Spoolholder for the Prusa MMU2S. This model is available for download at:
https://www.printables.com/model/507473-silent-auto-rewinding-gravity-spoolholder
As filament is pulled for printing, the spool rolls up the inclined ramp. As filament is retracted, the slack is taken up by the spool rolling back down the ramp.
