Wade's Small Gear with Ring Nut

I found that if your motors run hot, and your gear is printed using PLA, the set screw can loosen because the gear warps a little. This is a Bad Thing(tm). To address this, for people with the right tooling (e.g an M3 tap, a 2.5mm drill bit and a hand-drill), I added a slot for a nut into which you pre-drill a hole and tap a thread for the setscrew. I also made a depression for the setscrew head so that it does not protrude from the hub of the gear. This allows it to be installed inside the moun