[JesseK]

Is there any concern that the shaft on the reduction just prior to the 3.25" traction wheel won't hold up to the stresses of having 1/4 the robot's weight on it while transferring higher torque through it?

The shaft looks like it's 0.375" even though the wheels themselves are on a 0.5" shaft (based upon bearing holes, so it's just a guess), which is the only reason I bring it up. Seems to me that if the wheels need to be on a 0.5" shaft, then that particular reduction shaft needs to also be 0.5" since it will hold the weight of the robot when the traction wheel is down. Or maybe the wheel shafts are 0.5" since the 1/8" keyway is more preferred for the wheel?

Love the render.