[MrForbes]

We haven't seen any warping problems in our welded chassis this year. Of course, we cheated by using steel....it's cheap, easily welded by a freshman with little experience and no formal training, and it keeps the bottom of our wide base robot heavy enough that it shouldn't tip over too many times in competition. We also designed it so that it doesn't really have anything critical as far as being in the right place, so even if it did warp some, it doesn't matter.