[asid61]

What power is in the elevator? In the drivetrain?
Why BAGs for the grabbers over 775s or something similar?
What size wheels are those? Can it go over the step?
You look like you're going over the height limit in the picture due to the can stabilizer elevator, not sure if I'm just seeing that wrong.
The only thing I would add to this would be some way to stabilize the stack as you move, as right now it looks like it could topple fairly easily with a quick turn.