Spool Hub / Holder for 608ZZ bearing and 8mm rod improved

This is a remix of the spool holder / hub my mateddy (James Lee), thing #545954. I have eliminated the sharp edges in the original design and reinforced a few elements, but the looks are basically the same.
I also modified the source code somewhat, significantly improving its readability.

OpenSCAD sources are included so this thing can be further remixed.