pic: 1881 new gearbox design

[Tristan Lall]

Have you considered how you will attach the CIM motors to the gearbox plates? You don't seem to be using both of the #10-32 UNF mounting holes on the front plate. Be aware that the other two holes on the front plate contain long bolts that hold the motor case together, and therefore may only be marginally suitable for mounting.

Also, while the lightening pockets are a good idea, have you considered that there's almost no clearance between opposite edges of the pocket in the lower corners. Unless you're casting it (not likely), or milling it with a tiny end mill (why?), you're going to have an issue with actually creating that detail. Also, you seem to have several non-circular curves in your lightening pockets. This implies you're going to make it on a CNC mill—is that your intention? If not, use straight-sided pockets.