Simple spool hub - bearings optional

This is a compilation of three pieces I found in other spool hub designs on this site, plus a plug I made (scad included).

Print 2 hub inserts, and your choice of 2 knobs and/or plugs.

Hub inserts can have 608zz bearing inserted and held on 8mm thread-rod with knob+nut.

I prefer to use knob+nut, shimmed with washers - glued into hub directly (no bearing) and a second hub insert with plug+nut (again glued). 8mm thread-rod w/ spool affixed tightly, spins free-floating on my a-frame filame