Some complicated multi-plane bends in this one.
This thing is mostly to prevent people from putting their hands on the acoustic panel behind it.
I hated math as a kid, with the exception of geometry. Now, I think it's cool, but maybe I'm just jumping on the bandwagon of "math is cool!"
Anyway, a project like this involves bending tube in three dimensions, which is more advanced geometry than I ever studied in school. Ultimately, I just eyeball and fudge it. When I need to, I cut, re-weld and grind down, to cover my ass. A powder coat covers a multitude of sins.
I made a sweet receiver-hitch mount for my tube bender:
Tube bending requires a lot of force. You're stretching the outside of the tube through the curve and compressing the inside. Without the benefit of heat to soften the metal. Even with a cheater bar on the handle, I often put my full weight and strength into bending large tubes.
Thankfully, cars are really heavy! I periodically stop in to weigh stations just to make sure I'm not putting on too much truck-weight, and the last I recall, this truck (legal name: "Dakota Jesus Fanning") weighed in at 2,150kg (4750lbs). This makes for an awesome place to mount tools that have to withstand a lot of external forces, and I'm planning on taking better advantage of this in the future. It'd be a great place to mount a vise, or a bike repair stand.