Set the $fn some some hage value (maybe a bit overkill) so the facets
are less visible and hopefully the gears smoother.
Looks like printing with good printer makes this hole too large.
The captive nut then pushes the shaft when thightened unevenly,
ending up with the gear not turning around the shaft correctly.
My threaded rod was mounted in the other side, so if I want the gears
to turn in the correct direction, I have to flip them :)
With a 0 margin, it's not possible to fit the gear because of the