Banebot 56mm gearbox - double D related

[ZZII 527]

Originally Posted by squirrel

I was pondering making the shaft to plate joint a press fit. I think it would be relatively easy to get the size for round part of the hole figured out, but I wonder what the tolerance is on the flats on the shaft. If they vary by more than a thousandth of an inch, it would be challenging to get a reliable fit.

It would be really nice from the viewpoint of the wear we are seeing....I know in automotive transmissions, once splines start to get loose, they wear out quickly.

I'm ordering O1 and A2 tool steel to test with. I can cut them on the waterjet, but the tolerances will not be great. Maybe start small and work my way up to a nice press fit? I'm hoping with the same material as the 42mm plates, I can treat them to be just about any hardness I want. The A2 may be hard enough (B89-99) without any treatment.

I am not going to try 4140 because I think other people are on top of that and I don't know where to get 5/32" by tomorrow.

I should also mention that our original 56mm carriers showed only the very tiny beginnings of deformation after driving around yesterday evening (1 CIM, 12:1), although we haven't done high-cycle testing.