Been thinking about the frame size a lot lately. We thought about using an aluminum I-beam that is 3 inches high. The motor would mount nicely in the middle section and the wheels being 5 inches, would stick out 1 inch above and blow the frame. Sounds pretty good.
Shopping for I-beams, we found that the options were limited and we couldn't find a 3 inch that didn't have a pretty huge dimension for the horizontal parts. So, we visited a local store that has a customer counter where they sell odd bits left over from customer orders. We found a 3 inch square aluminum tube, 6 feet long. So, if we rip this, we'll end up with some 3x1 channel which will work out just fine!
To the right, you'll see a frame that is 21" x 24". The motors are drawn in to scale as are the wheels. Now, I need to get that tube ripped and make detailed drawings of the frame pieces. I'd like to weld as much of it as possible so that it will be strong. I might still bolt on the side pieces that cover the wheel mechanics.
