[sdcantrell56]

If the plate in the middle is the most you can do then it probably is not worth it to make it a plate. Instead just go back to a 2x1 tube. I think the best thing for this frame would be adding flanges on the side plates which would increase the stiffness dramatically. Overall though it is very nice.

I would caution you to carefully examine the upcoming game and to make your decision to use this chassis based on the way you want to play the game. Don't lock yourself into this design just because you have prototyped it.