Bending 6061-t6 aluminum sheet?

purplepickup · February 18, 2013, 03:20:50 PM

I'm making a tail light bracket for one of my dirt bikes and want to use a piece of 6061-t6 aluminum that I already have. I need to make two bends. One is 90 degrees and the other is about 10 deg. I googled it and some of the answers are, can't do it, anneal it, can do it, bend fast before it work hardens, bend it slow, use a large bend radius, use 5052, & more. I thought I'd ask you guys....the experts.

If I want to use the material I have I'm thinking I should anneal the 90 deg bend area. That bend will be gusseted at each end so if it's softer I don't think it will compromise the bracket. I can't easily change the bend radius on my homemade bracket and it is pretty sharp.

I've got a lot of this material so it's a potential for future bracketry and such.

Pics below are: practice cold bend (questionable), my brake, closeup of brake radius, and a mockup of the bracket. Suggestions are welcome.

Digger · February 18, 2013, 04:17:51 PM

Part of the answer depends on how thick the material is George, if it iunder 1/8 in I would just go ahead and bend it-anything thicker I think I would anneal it.
Good Luck

purplepickup · February 18, 2013, 04:24:30 PM

Quote from: "Digger"Part of the answer depends on how thick the material is George, if it iunder 1/8 in I would just go ahead and bend it-anything thicker I think I would anneal it.
Good Luck

Oops, I forgot to mention it is .125".

Charlie Chops 1940 · February 18, 2013, 04:29:47 PM

With 1/8" I think you're fine without annealing it. Your sample looks good.

GPster · February 18, 2013, 04:41:33 PM

Just something I was told years ago by a sheet metal journeyman. There should be 1 1/2 times the thicknes of the metal between the edge of the top jaw of the brake and the edge of the jaw that swings up to make the bend. Now he was showing me this on a brake while he was explaining it so it made sense at the time but I don't know if my explanation does. If you don't allow for a radius in the bend the metal gets it's thickness squeezed and it will tare/break at the bend. I can't see any place on your brake to make that adjustment. Maybe you'd be better off finding someone with a press/brake like Sumner has. GPster

phat rat · February 18, 2013, 05:31:21 PM

George, your brake looks a lot better than mine. Mine is two pieces of angle or square tubing in my vise, then my hands or various hammers to get the degree bend I want. This is for whenever I decide to bend something myself rather than take it to a shop. It's not always as crude as it may sound. Here's a cover I made out of 1/16 diamond plate aluminum for wiring in my new sleeper

enjenjo · February 18, 2013, 07:37:00 PM

I have the similar brake to yours. With material that thick, it tends to crack at the bend. So I anneal it at the bend. Real easy to do, mark the bend with a black Sharpie. Heat with a propane torch until the Sharpie line disappears. Let it cool, and bend it. Once it's bent, it will be back to near a T6 hardness at the bend.

With some complicated shapes, i may anneal it, then work it, reanneal, and work it, repeating several times.

chimp koose · February 18, 2013, 07:52:32 PM

I was taught that if you cover it with acetylene soot and then go back and heat the aluminum until the soot burns off you will have annealed the aluminum. The sharpie one I had not heard of before. learned something today.

enjenjo · February 18, 2013, 08:01:15 PM

Quote from: "chimp koose"I was taught that if you cover it with acetylene soot and then go back and heat the aluminum until the soot burns off you will have annealed the aluminum. The sharpie one I had not heard of before. learned something today.

Same principal, the black pigment in a Sharpie is carbon.

kb426 · February 18, 2013, 08:10:07 PM

George, I used to anneal alum. alot in the irrigation pipe plant. Alum. doesn't change color like steel or copper. It will get shiney. That means you went to far. It will be about to fall on the floor at that point. Rather than anneal the material, I do 2 45's close together rather than risk breaking the material. If you have a small radius bender, you can do a 90 because it stretches the bend over a wider area. Even if you do 3 small bends close together you minimize the fracturing.

wayne petty · February 21, 2013, 01:32:03 PM

yes.. i have gone of on another BENDER... ever seen something like this

i think if i was making one of these for my shop press.. i would also create holes so i could use another set of pins or big long bolts to hold it in place on the vertical rails of the press..

or build it on a second beam that i could drop in and pin like the conventional press beam..

http://www.4wheeloffroad.com/techarticles/131_1110_swag_off_road_press_brake_kit/

purplepickup · March 04, 2013, 12:06:06 AM

Here's a little update on my tail light bracket. I tried kb426's tip on making two 45 deg bends and it looked good.....but....I thought I'd try to make it out of ABS plastic. There was a bit of a learning and trial & error involved but I'm happy with the way it came out. Here's some pics.

Gotta clean up the edges.

The other bike is still stock.

The two compared

kb426 · March 04, 2013, 01:04:48 PM

I like it, George. I find that abs is a pretty useful material to have around. Did you glue or weld the braces?

purplepickup · March 04, 2013, 01:53:14 PM

Quote from: "kb426"I like it, George. I find that abs is a pretty useful material to have around. Did you glue or weld the braces?

Here's a long answer to a simple question.The first attempt was to weld with a woodburning tool and a zip tie as filler. It didn't hold very well. Then I tried using a strip of ABS as filler and it was stronger but still didn't hold well. Failure of welding was probably due to lack of the right tools, methods, & material. Next thing was JB Weld and that was the strongest yet but when it did break loose you could see where it didn't bond to the ABS real good. What I ended up with is ABS cement from the hardware store. It sort of melts into the joint and is tough to break.

wayne petty · March 04, 2013, 06:14:43 PM

ABS cement is a good choice....

there is also an ABS PRIMER solvent to be applied seconds before using the abs glue. this creates a better melt joint when doing plumbing on PVC, ABS and CPVC..

i would think some creative bent sections to reinforce the joints... or bending tabs so you have surface to weld face to face with..

one could even grind the tabs to a taper after bending to blend them before using the abs cement..

be sure to read the descriptions of the plastic welding rod materials..

http://www.harborfreight.com/catalogsearch/result?q=plastic+welder