Hi Matt. The chassis is 8mm thick per side, which theoretically means I have 16mm total thickness to resist the forces of the ram and arm. However I think this would only work if you happened to crush everything perfectly vertically and in line which wont be the case. Therefore I have tried to design it so that one side could handle the forces on its own. I think the material for it will be ok from having a read of the Riobotz manual. Its one of the best aluminium alloys, especially with regards to yield strength which I think is was I need for the chassis and arm where the forces are. The arm is mainly made of the same stuff, but I plan to put a tool steel (or similar) tip on it. Titanium was way too expensive and the steels were too heavy so I don't think I had much choice.

The ram should give out 2.6 tonnes so I'm working on a 2.6:1 ration. Speaking of the ram......