[Kevin Sevcik]

Gabe, my welder hates you. Seriously, any of the aircraft grades are nigh impossible to weld well. Thus we use 6061 for the majority of our parts. We're actually looking at thin wall steel for next year to make the welding even easier.

At any rate, on topic, wood is just too fracture prone under shock loading for my taste. Aluminum will bend, but might be usable or salvageable after it yields. Wood doesn't yield, it breaks. That said, it can have its uses in structural parts of the robot. Contrary to the prevailing opinion here, I think wood is a rather lot easier to work with than aluminum, as it is amenable to all sorts of hand tools and, well, woodworking tools. The strength to weight ratio of wood is more or less comparable to aluminum as well. So understanding the main limitations of wood, there are still places on a robot where it might be preferable to other materials.