Here is our robot cart that we put together this year.
Features:
Holds 2 Battery's in back tray's.
Holds 6 Battery's and 2 chargers on front tray.
Has 2 compressors from prior years robots.
Has ~3 gallon air tank.
Has 3 drawers for tools.
Holds 2 joysticks and the RC on the top tray.
Robot height can be adjusted up and down 1 foot.
At current height a full sized robot can fit through most doors while on cart.