Crikey. It's another Tinkeriffic bearing spool spindle.
My Faire Play Kickstarter was funded to the tune of 120%, and now I'm printing backer rewards. I got myself a new roll of gold filament and of course it doesn't fit any of the bearings I've made so far, because that would make things easy and apparently Hera's mad at me for only making an Athena Makeover Kit.
A wiser man would take the time to create a Tinkeriffic bearing in Thingiverse's customizer, and then adjust bearings parametrically as needed.
But Lao Zheng ain't got no time to be learnin' no Customizer, foo!
So I banged this out in Maya in like eight seconds. Enjoy.
This spool spindle is designed to fit a 58 mm spool, like this one I got from BuMat.
This three-part solution (thirteen parts, if one counts the 4.5mm BB's) is designed to use a Tinkertoy rod as an axle and is a much, much smoother ride for your filament spools.
I found inserting BB's into the original 608 bearing to be frustrating so I split the bearing in two and left it to the end user to super glue the parts together.
The walls of the inner spool are by necessity quite thin; I recommend multiple shells or high infill for that part.