[dtengineering]

Nice. You may want to consider a bearing to support the outboard end of the gearbox shafts. There has been discussion of this in other threads, and the advice generally seems to be that if you are not using an outboard support bearing, then make sure you mount the sprocket as close to the gearbox as possible to minimize the cantilevered load on the gearbox shaft. (You can also cut off the unused shaft to save weight, in that case.)

We used a six wheel drive setup last year and loved it... we added omni wheels to one end of the robot, however and found that helped our turning significantly. Not all teams need to do this, but we had very grippy wheels on all corners... even with the centre wheels lowered slightly we still had a problem turning.

Jason