Beautiful CAD. I love seeing sheet-metal designs, if only because our team doesn't have the resources to ever do one on the level that we'd like to (and I don't think we have the patience to CAD everything
).
I do have a question regarding the custom housing for the gear-box, namely, why? Don't get me wrong, I'm not criticizing the design-- I don't have nearly enough experience with custom gearboxes to offer anything constructive or unique there-- but I assume it's for weight? If so, then what are the actual weight savings over the original housing?