Thanks GDG 2337 for doing this investigation! We also tried the new 1/2" hex bevel gears and found they worked, but we did it in a V2 gearbox. This is a major oversight on our part that the hole pattern on the V1 is spaced differently (approximately 0.52 inches) to the shaft boss than the V2, which we designed around. The issues with the shaft collar needing to go on the outside, or having the shaft fixed via other means (if desired) is still valid for the V2 as well.
We will update our documentation to show that the Armabot Right Angle Drive only supports the V2 Versa Planetary gearbox. I apologize to anyone that this has caused problems for. PM me if you need direct support etc.