Well, another day another failure.
The BMC V3 freewheel failed, so I got it welded.
Then the Keyway failed, so I got the freewheel welded to the axle.
But a welded freewheel puts enormous shock loads on the gears, as they never get a break - when you roll down a gutter, the gears get the full force of that bump.
So the gears lasted 20k's.
The MAC motor is now officially DEAD, and I'm now in the market for a direct drive motor (with a big axle).
On the upside, my Tab Welder for making packs out of Headway cells is working, just need to actually make a pack now. I guess I have some time....