pic: Drivetrain Concept

[Orion.DeYoe]

This is impressive. I really like it. I'm assuming you want suggestions so here are a few:
1) I would change the framing to 2 x 1 x 1/16 tubing (someone pointed out to me that this is lighter as well as stronger than pocketed 1/8th material).
2) The structure for the middle module could be made simpler. I'm not sure which part is spring loaded so I may be missing something. You seem to have several pieces of flat bar (3/16?) acting as stiffeners across several of the frame members in the middle. This could be redesigned to use sheet metal or standoffs to save weight and space.
3) Aluminum gears? I'm assuming that's what you're using but just checking.
4) I would take your high gear speed down to 16 fps. Just my preference after running a 20 fps drivetrain this past year. We made the change to 16 fps and really liked it. That was with 4 cims though so you could save weight by taking 2 out or leave the ratio the same and using 6.