3D Printer Filament Spool Insert

myminifactory

My first 3D printer is a STARTT.  It's wonderfully inexpensive and yet still does a good job.  They even provided spools of filament and a nice filament holder.  Unfortunately, the spools have giant holes in the center so the holder was useless because the spool just sat on the legs of the holder rather than floating on the arm... until now! Original spool hole diameter: 54mm (2.25")Holder arm end diameter: 20mm Insert DimensionsOuter diameter: 54mmCenter hole diameter: 20mmCenter gripper depth: 10mmOuter flange diameter: 64mmOuter flange depth: 3mm I made the insert with minimizing friction in mind, so it's inner hole has a curved (fileted) surface.  The way it's printed ensures that it stays firmly in place in the spool and doesn't "walk around" on the holder arm.  The outer flange is also curved to allow for easy grip and removal.  It's strong, but not over engineered so it won't waste much material.