pic: 2x1 gearbox

[Chak]

Thanks for the suggestions everyone! For the third revision of this gearbox, I decided that it would be part of the drivetrain rail only. By moving it to the corner wheel, I was able to produce a drivetrain rail with gears and chains in tube.
http://imgur.com/a/QucQK

Since the gearbox is part of the drivetrain rail now, the CIM shafts are extending too far and would hit a 4" wheel. And well, if I have to space the motors back anyways, I might as well use the 3D printed CIMcoder instead of the SRX mag encoder.

Unfortunately, sticking with 3x1 means that

1. this needs a modified gear (in the render, it's a 70t)
2. this also needs a custom 17t sprocket
3. the chain barely clears the surrounding parts by .01"
4. the gear blocks the CIM mounting holes, which is annoying, but still possible. The shaft comes out with one shaft collar, so it's not that bad, but still annoying.

But hey, the drivetrain is still in theoryland, so these potential problems are okay.