[Nemo]

Our team has used Bosch framing for robots. The oldest ones use some 45x45 and even 45x90, and that is SUPER overkill for FRC. Then they moved to 30x60 and 30x30, and it's still significant overkill in my opinion. In 2009 we used 20x40 and 20x20, and it worked fine. The weight savings are substantial. The 20 mm stuff is the best size for FRC in my opinion.

The thing is, even though it sounds simple, it can take forever to get a frame designed and cut and built out of extrusion. We dinked around with that drive base frame for weeks in 2009. In 2010 we switched to pre-made drive bases from AndyMark and Vex, and it has been a valuable time saver. The pre-made drive frames are good and inexpensive, and they get better every year.

T slot framing can be nice for building upwards from a drive base. It has its advantages and disadvantages. I do love regular aluminum square and rectangular tubing, though. It's strong and light and not that expensive if you can buy it in full size lengths from a local distributor. No pricey fasteners required.