You can also get a little more rigorous with the lightening pattern. Try triangles and maybe even isogrid. (Unless your sheetmetal sponsor cannot do these types of cuts.
You're going to want a bellypan to make your chassis stronger and less prone to warping.(Or add cross members) I know FRC 2168 makes their bellypans into their front and back members as one piece. If you do this, make sure your sponsor can do the exact bends that you need. You don't want gaps in your assembly. Another tip on the bellypan, I know 2168 does this as well as many other FRC teams but on the bellypan make a cut on both sides so that both gearboxs can slide out the bottom of the chassis without having to remove the bellypan or superstructure. I hope Justin doesn't mind me posting this but this is what I was talking about with the bellypan.
