Modding wide radius bends?

hey everyone,

how would you go about making a wide radius bend in say, aluminium?
maybe my rather weak paint-fu can explain.



any tips/ideas?

thanks

 

What's it going to be attached to?

So if the curve is the side, then the top & bottom pieces would act like a jig, so as you bolt or rivet or whatever the alluminium down, the curve is held in exact posistion -if the alloy isn't too thick and the top & bottom are tough enough for this?

Or you can make a jig from some wood to bend the alloy over. Heating the alloy in the oven (if it fits?) would make it easier to bend and i think letting the alloy cool in the jig will help to retain it's shape. Don't blame me if you burn yourself though

You could always just make the jig a tiny bit tighter than required instead of heating the alloy, to try and form the desired shape

 

I would find a form that you can bend over. Paint can, pipe, etc.

 

A while ago I needed some 180-degree, 200mm diameter bends in 25x3mm strips of aluminum. The bending worked easily enough by hand. I drew a semicircle with a compass on a paper and clamped a strip in a small portable vice. Then I just nudged here and there until the bend matched the one on paper. Your knee is the best bending tool by the way! Bending by hand left some small irregularities here and there but nothing you'll notice unless you know where to look.

 

Bend it around something that has the same diameter (Steel Pipe is a good idea...) as that which you are trying to achieve. That seems the easiest and least prone to mistakes option.

Laz

 

Actually yes, that could be much easier

 

http://grizzly.com/products/G7148
Slip roll is the proper way, 3 rollers, 2 are geared together, and feed the sheetmetal, and the 3rd one determines the bend radius by adjusting it in and out.

The cheap way is to use a form and bend it by hand.

 

Will you have to heat the metal in order to do this? Or can you just use a hammer and some wood?

 

You'll need to be more specific. How thick is the metal you want to bend, and what radius do you need?

Hammer modding is instant win though

 

Probably 2mm aluminium. I'm gunning for a 25mm or 40mm radius

 

in that case a wooden jig, a hammer and a strong arm for polishing afterwards will be your best tools

 

For a complicated curve that's big and does not match any objects you can find, you could cut wood into an appropriately shaped setup.

For example, you could cut your desired curve onto multiple (identical) pieces of plywood. These pieces would be setup in parallel or sandwiched together. Presumably the assembly would be also mounted to something else. Sand before using to make sure it's perfect, and you're in business!

For more complicated materials that can bend or deform more than just along an axis, you can have each iteration of wood change.

 

Al is probably soft enough to bend without resorting to power tools. The biggest trick will be to make sure that the bend is continuous, not a series of smaller, sharper bends. some sort of form is a must, but there is no reason you'd need to heat the metal. Anything hot enough to matter would be to hot to have in close proximity to your body anyway.