[GeeTwo]

Back to the original question: if you're going to fold or weld the metal, get 5052, especially over 6061, 6063, and 7075. All of the high strength aluminum alloys are dependent on appropriate heat treating in the final configuration, and lose a lot of that strength when welded or plasticly (permanently) deformed. If you have the appropriate ovens and quenching baths that can hold your robot chassis, go ahead and re-treat :sigh:*.

As to our 2014 kicker shaft - yes, I concur that it was a brutal abuse of any conceivable material. The point is that, unless you really have worked out the details with a wide margin, a few extra ounces of steel in those key spots is way better than having to replace a mangled aluminum shaft between matches.

Along these lines, on the "importance of doing it right the first time": The down-geared TB-mini I mentioned a few posts above was assembled on Thursday with the axle plate backwards. That is, the plate was bent towards the wheel rather than towards the motors. It took four students (three rookies and one veteran who was not one of our lead/pit crew people last year) about two hours to make the swap-out, even after direct advice as to what had to be removed. Even though we always have our best guys and gals in the pits, I'd much rather over-engineer a key component than have our robot miss a match (or two or six) because our drive system or a key manipulator is out of commission.
This is pretty much where we were in 2013 (Aerial Assist), late in the regional. Our Frisbee trigger/lifter broke (metal fatigue), and two hours of work in the pits (including myself and our lead mechanical mentor, as well as several students) did not resolve the issue. It was more than a year later before we had our 2013 chassis frame tossing a Frisbee again.

* This emoji ought to exist, so I'll use it anyway!