Robert asked for build pictures, so just to be a smarta** I posted a picture of a rubber-powered ship.
Then I got this:
Dang Tim, I'd like to see a finished shot of that!!
So as not to pull the topic of Robert's thread completely off of what I'm sure he intended, here's your answer, Randy.
The two pictures of wheels are because the wheels on that are home-made from Depron, by squeezing disks of Depron in an aluminum die and heating them in my oven. The Depron puffs up into the available space, then takes a set. Little 1/64" plywood disks act as hubs.