100% printable filament spool

There are many filament spools on Thingiverse already. But when I didn't find one that was 100% printable, I couldn't resist the urge to design my own. This is my first design so please be gentle.

I started with thingiverse.com/thing:4337 but I had trouble getting a good print, and the bearing rollers (from thingiverse.com/thing:4312) popped out. I decided to experiment with a different kind of roller: instead of a sphere, I would use a cylinder capped by two 45 degree cones. I figured th