A while back I had a brainstorm when I was thinking about how to haul R2 around on his back in my SUV. So I quickly threw together a cart that fits him custom and that carries his weight without damage when he's on his back. I've made a few improvements on it and a number of builders have been lusting after it. So here's some video to give you an idea of what I did. Eventually I'll try to get some real dimensions up, but chances are, if you're tackling this, you're good enough with wood tools to be able to figure this out from the video. I'll probably do a small run of these too, but I'm busy getting ready for the Maker Faire this week.
The other huge advantage to having this cart around is how easily I can flip him on his back and work on the drive system. That would be impossible without the cart.