Bending 1/4" aluminum plate

[schiada96]

Originally Posted by SRT Mike Thanks for the followup. I was familiar with AL going back to a higher temper at room temp but I didnt know you could special order it at T0. The problem with the above would be first I'm sure my metal supplier would charge a fair bit more for T0 (or anything other than run of the mill T6). Also, I have no real way to keep it at that temp around the shop. I was hoping to buy 1/4" plate and slice it up into 4"x6" sections and just press it into the shape I need, when I need it. Do you think it would be impossible to make a die that overbends the right amount so it springs back to the shape I need, or do you think that it would be impossible to do that? I'd gladly undergo the cost/hassle of having to dicker around with various die shapes rather than worrying about special ordering AL in special tempers that must be kept at freezing temps before use. Also, on the picture - thats not the actual part I want to make, just an example. If you look at the bottom plate (shown at the top of the picture), it would not have that tab part on it. It would be symmetrical along its centerline. The top plate (shown at the bottom of the above picture) would look pretty close to the way it does there except I intend to use a multitude of screws around the trim ring to provide a more 'industrial' look. Thanks - still havent made any firm decisions, gathering all the info I can - its much appreciated.

The bottom part in the picture can be rolled. It will cost two extra parts for each one produced. One a duplicate of the center and a backup plate to carry the set thru the rollers.

[parttime]

Someone noted that the edge radius would be harder to form than the center radius. In my experience with stamping, progressive dies might form a part with spring back in two or three hits. So, applying that insight to your problem, you might need to form the outer edge first considering you have limited power in a 20ton press from Harbor Freight. Then, come back and press the main radius. It is common in stamping die work to relieve the die to achieve the proper shape. So, start by building your die to bend it too tight, then you can relieve the die to back off on the bend (thus matching the radius from the first hit). Just my $.02.

[Verfur]

somthing to know,

if you are going to bend 6061 t6 pay atension to the last numbers in the temper (ie. T6511 vrs T651) such as T6511 does not take to bending and to bad because its the one you can buy at the hardware store the other is actual plate and bend very well I would still use a 2* thickness for min radi
as a min..

the parts do look Kool though

John

[rjshreiner]

My 2 cents,

I can calculate the bend radius to account for springback if you want. It is all a matter of what yield strength we use. As previously mentioned aluminum age hardens and the yield strength goes up the longer it sits around after coming from the mill. You have no idea how old aluminum is -that you get from a distributor .... It could have been sitting around for months.

One more tip .... before you cut all your lengths ... make sure you know how you are going to bend it. You might want to leave a little "extra" on the sides for flattening and/or leverage depending on the die. Email me if you want me to give you my estimate on the springback and die radius (I don't often check this forum)

[erase42]

just my even less than 2 cents worth, before you start making dies. Bike tags in FL anyway are 7 inches wide plus probably .35 on each side for frame.

[jpgdesigns]

SRT Mike,

For the parts you are making, you should not have a problem.

Springback should be very little, which as others have said can be built into the dies as overbend. Once it takes this "set" it will stay.

To hold the dies, I would start with a bottom plate with 4 guide rods, one on each corner. Next, attach the lower female die to bottom plate. Add springs to guide rods, to open dies when pressure is removed. Then upper male die attached to a top plate with guide tubes to accept guide rods. Figure about 1.5" of travel.

This is one self contained unit that will stay aligned and accurate and can be placed on the press, used and removed without any real setup time involved.

E-mail me at jpgdesigns@yahoo.com I can whip up a sketch in CAD, if you need.

JPG

[SMW Precision]

Originally Posted by SRT Mike The preferred material would be 6061-T6 aluminum. I'm guessing the radius of the bend would be 6 to 10 inches depending on application. The size of the aluminum would be approximately 6" x 4" x 0.25". Questions... Will 6061-T6 bend to this spec without cracking? Any tips or advice on doing the bends? Thanks for any info!

I suggest not using 6061 it does poorly on bends. There is another version I believe 6063 that is the bendable form. Though likely you will end up special ordering it. That is what I had to do!

[ezg55]

When working with relatively small pieces of aluminum you can heat to between 500-600 degrees F and quickly quench in cold water. This will allow you to bend with out the aluminum cracking. It also makes it much easier to bend and almost no spring back. Good luck.

[SRT Mike]

Thanks everyone for the replies.

I got my 30-ton shop press from Grizzly a few weeks back. I've been tied up with other projects but I had a chance to play with it today. The idea for a spring loaded unit that can be loaded in as a cartridge and used/removed is a good one, and I will probably go that route.

I was playing with the press today - bending some AL and with a slight radius there was some light stress cracking at the bend, but it was a very tight radius. I'll look into the suggestion to use 6063 instead, and also look into trying the actual radius to see how it does with cracking.

Thanks gents

[parttime]

I"ll post some pics of the parts I just finished bending. I had a problem with cracking. I switched material and the problem went away. I knew I had a material problem because the test pieces I made before didn't crack and the difference was the material. I bought some remnant from the local steel yard. I also modified a V-block by rounding the top edges and using an aluminum top blade that had a bull nose. (Put some grease on the block and part as well since it couldn't hurt to lube up.) This way it puts a 2x radius bend on the part and allows it to move into the v-block during bending.