pic: FRC3880 - Tiki Techs - 2015 Prototype Drive

[nathannfm]

Originally Posted by Andrew Lawrence

I really have a hard time believing that this drive system even without the electronics is 25 lbs.

He says in the previous image that EACH gearbox weighs 15lb. Something is very wrong somewhere with weights in this CAD model as the WCP 3 CIM shifter this looks similar to would weigh 8.5lb with 1 CIM and 1 MiniCIM. I suppose the 15lb could be referring to each SIDE of the drive, ie. 2 of these put together, that gives a much more reasonable number. Still thats 30lb in just gearboxes, so, going under the stretch assumption that 25lb is this drive WITHOUT gearboxes thats a 55lb drive, which sounds much more reasonable.

All of that is a moot point though because OP has stated that the only reasons that there are 2 gearboxes per side is because they don't currently have the ability to make large enough plates to combine them, and that they want to be able to use the gearboxes elsewhere when the project is done.
A side note to that, MOE has had some success making plates that are larger than the travel distance of our mill by splitting the drawing into 2 parts with 1 shared hole. The shared hole is used to align the second drawing to the plate. You will also need 2 flat reference sides. This may not be possible in your situation and it may not be accurate enough for gear spacing but it worked well for chain.