Bending aluminum sheet with a "big" radius

[Kbach66]

What do the guys that work with aluminum sheet (dashes/panels/etc) do to bend a sheet of aluminum with a radius of something like 1" or so?

I'm getting ready to build a dash for my car and don't want to have a small radius that the sheet metal brake in our shop will give it which is probably around .125" or so depending on how I set it up.

If I wanted a real big radius, I could run it through the slip roller, but that would be way too big.

Do I roll it around a tube? Over the edge of a wood buck? There's got to be a way, I'm just not thinking of it!!

Thanks in advance!!!!

[DUMP!]

It's really pretty simple if you have a "Tinsmith" style finger brake.

Put your material in the brake like you would normally. Then loosen up the clamp down adjustment on the brake so that you can fit a 1 inch or so diameter tube between the fingers on the brake and the material. Clamp the brake down so the the fingers come down on top of the tube and the tube clamps down on your material. Now bend. You will need to play around with how to mark your material so that the bend comes out where you want it. The other thing to do that is more time consuming and expensive is make your own replacement fingers that are shorter and have a tube welded to them at the end instead of the sharp edge.

Dump

[Kbach66]

It's really pretty simple if you have a "Tinsmith" style finger brake.

Put your material in the brake like you would normally. Then loosen up the clamp down adjustment on the brake so that you can fit a 1 inch or so diameter tube between the fingers on the brake and the material. Clamp the brake down so the the fingers come down on top of the tube and the tube clamps down on your material. Now bend. You will need to play around with how to mark your material so that the bend comes out where you want it. The other thing to do that is more time consuming and expensive is make your own replacement fingers that are shorter and have a tube welded to them at the end instead of the sharp edge.

Dump

Sounds easy enough...

I've done something similar before by bending some strips of material around the fingers of the brake, and then leaving them in the brake when I put my piece of material to bend in. This gave me a bigger diameter bend, but never thought of using something much bigger like a piece of tubing
.
Thanks for the help D, I'll have to play around with it some.

[FarrisMotorsports]

Dump thanks for chiming in. Ive never even thought of that before...Thanks again.

[LJ Kennedy]

Make sure to use 3003 material as it is better for forming and welding. I use my break to make the radius I just leave both ends of the break open so there is about a 1" to 1 1/2 gap that seems to work desent for me.

[standfast]

I thought this was typically done with a bead roller and tank roll dies? How consistent is the tube/brake method? Any other aluminum forming tricks up your sleeve dump? I have my entire car to do.

[FABRICATOR]

Bending around a fabricated tube is usually done with a box & pan, or "finger" brake. The tube arrangement can be used as an extension of the fingers or in place of the fingers, depending on the brake and the radius involved. The method has been used in race car and aerospace fabrication for many decades.

[standfast]

Anyone have any pics of this forming procedure?

[NicksTrix]

you can also make a die with a piece of tube welded onto a flat plate. you pull the head back as far as you can and use the fingers to hold the die down. obviously you can only go as large tube wise as you can fit in as far back as you can move the head. i have a number of different dies i've made with say 1/4-3/4" tube. not all brakes will accept a 1" tube.
depending on what you have machining wise you could machine up dies to work in your brake.

there is also the old tried & true method of a number of small pressure breaks to make the large radius.
hth
nick

[FABRICATOR]

you can also make a die with a piece of tube welded onto a flat plate. ...

That's exactly what I was referring to. On most AL jobs 20"-24" wide, you don't even need a full length plate. Short plates a few inches in from each end of the tube will do. As long as your plates and tubes are the same size, your box and pan brake can become a radius box and pan brake.

[NicksTrix]

10-4 fabricator.
i've seen it done where guys will just clamp down on a tube as well as the method we discussed.

don't forget the bending "arm" will more than likely want the angle iron bolted to the front.

[standfast]

I made a radius brake out of some scrap material last night. It's kinda crude but basically free and the function is there. Here is some pics and test bend pics. It took a couple hours to make and fine tune. I could go back and build it again all nice and pretty but whats the point right? It works, I am happy. :D Test piece is .050 aluminum.

The tube that you are forming to should be about 1/4" undersize to what you want it to go on. So, for 1.5" chassis, use 1.25" on the bender. The spring back makes it land up right there.

http://img206.imageshack.us/img206/5504/s6300279df5.jpg (http://imageshack.us)

http://img91.imageshack.us/img91/710/s6300280di8.jpg (http://imageshack.us)

http://img91.imageshack.us/img91/603/s6300281hc9.jpg (http://imageshack.us)

http://img91.imageshack.us/img91/9028/s6300282pm9.jpg (http://imageshack.us)

http://img142.imageshack.us/img142/778/s6300278pj2.jpg (http://imageshack.us)

[Kbach66]

Very cool. What's nice is that it doesn't hog up a bunch of space while you're not using it. It's basically out of the way.
This is what I was planning on making for home if I couldn't get our brake in the shop setup the way I wanted it. I hate it when work gets in the way of hobby....