Do you have a metal shop in your area? Bending metal of 1/8" in a hand brake would require a hefty brake. Most hand brakes are limited to 16ga usually. Sure you could probably bend it but it might spring the shoes.
Brakes for that thickness are big hydraulic things. Not even the $1000 pan brake I'm eyeing can do that. A local steel shop here does custom bends on lunch hour. Might want to check out a local steel shop.
Cheers!
-= Gregg =- Fine wine comes in glass bottles, not plastic sacks. Therefore the finer electrons are also found in glass bottles.
Spent a few years running both hand brakes, hydraulic, and for the lack of a better term mechanical brakes. I have run some smaller mechanical brakes that will bend 1/8 steel with ease. To build a chassis one must consider that the material will have to be notched for the corner bends prior to making the brakes. Consideration will have to be given to the size of the bottom die also. Your not going to be able to make the brake with a 1/8, 1/4, or 3/8" bottom. A 1/2 bottom die would probably be pushing things. A 5/8" or 3/4" bottom die is probably what would have to be used.
If I were to brake a piece for a chassis I would consider two brakes per side for a total of 8 brakes. This would give a bottom lip in which a bottom plate could be attached.
One could complicate things even more if you considered the tube socket placement, transformers, controls mounting holes for the mentioned devices as well as mounting holes for the bottom plate.
So, prior to any other work you would have to plan the holes needed and have them punched on a punch press. Clearance for the bends would dictate notching for the corners prior to braking. Lastly the braking but this would be after braking a piece of known length same material and figuring an allowance for the brakes. Material can be gained or lossed in braking and this is a factor of the bottom die size, top die used and hardness of the material just to name a few.
High zinc or "yellow" brass is pretty bendy stuff.
I used to make chassis from kickplate brass that was really high zinc content before they cheaped out and "brass coloured" zinc slag crapola and increased the price by a factor of ten
Cheers!
-= Gregg =- Fine wine comes in glass bottles, not plastic sacks. Therefore the finer electrons are also found in glass bottles.