Ender Filament Spool Insert.

thingiverse

My Ender branded filament spool have a void inside the inner diameter of the spool. I had printed a new spool spindle which contains skateboard bearing, but my Ender filament spool wouldn't fit. I measured and designed this to be a two piece insert to convert the bad spool design to work with my new spindle. Print two, insert into both ends, and fixed. This way the bearings rid on these new inserts. UPD, I am not waiting 5 hours x2 for this. Alternatively, I simply used a carboard tube which I had laying around which fit. ;)