Gravity spool holder nuts for Printed Solid and similar spools

Printed Solid switched to a new spool design which consists of sturdy cardboard with a stepped and recessed metal hub. This makes it possible to recycle the spools with cardboard and metal recycling. Unfortunately, the standard gravity spool holder shaft nuts will not work with the new Printed Solid spools as the standard nuts are too large to fit inside of the hub and make contact with the inner area for a secure fit. This remix reduces the outside diameter of the nut while maintaining the conical shaped area that contacts the spool for a good centered fit. The nut fits inside the recessed area of the Printed Solid spool hub to secure it to the gravity spool holder shaft. A couple of tabs are provided to make it easy to tighten or loosen the nut for installation and removal.