For the past 3 years, our team has had our chassis fabricated out of 3/16" aluminum. The sides are bent at 90 degree angles for us to mount our bearings for the gearboxes. Also, this year we had two machined pieces of aluminum as well as custom brackets for our piston system. These have been helpful for more low to the ground games and our strategies. Here is a picture of the actual chassis alone without electrical wiring and all pnuematic tubing.
I know arial views don't simply do justice but I believe you can get the picture from here. If anything, I will take a picture of the chassis we have hanging around at the school from 2 years ago. Let me know!