pic: GEAR & CHAIN IN TUBE 8WD

[pwnageNick]

Here is the updated version I ended up with.

-23.33lbs, only parts missing are chain runs, and bumper supports I suppose (all hardware besides rivets included)
-24"x32" chassis
-4"x1.5" VEX Colson wheels (1/2 hex bore)
-11:70T Single Stage reduction within the drive tube
-Drive tubes are 2x2x.125" 6061, while the front and back tubes are 2x1 Versa
-All sprockets are 16T #25 VEX sprockets with the chain run fully contained inside the tube
-The middle wheel is dropped 1/16"
-In this current configuration a US Digital S4T encoder is utilized, though the CIM encoders could easily be used instead, or a Grayhill, etc.
-All parts are COTS except for the two drive rails, the two encoder plates, and the belly pan (could be lexan, wood, etc. for low cost)
-The only other modified parts are the front and back rails (lightening pattern), shafts cut to length, and the direct drive shaft is turned down on one end to 3/8" round to couple to the s4T encoder (optional depending on encoder use)

Apologies again for the large picture:

[asid61]

After initially dismissing the idea as "sketchy" because of the integrated gearbox, after looking at the lower custom part count and the resulting reduction in cost, I think this is a great idea for making a custom chassis at a low cost and weight.
I don't like your lightening patterns, but apart from that the design looks great. The dual versagussets in the corners really stand out to me as a feature of 2x2 tubes.
Do you think it's possible to make a shifting version? Can all the gears + sprockets fit?