Topic: Electrics Tray - Adding Ribs - Preventing Warping

[Ellz10]

So after mocking up my electrics tray, running my measurements twice, I went ahead and did my first electrics tray. Everything went great honestly, especially for my first go at it (I knew I would probably fail, but that's how I learn), aside from the fact that the sheet warped and my measurements were only a tad bit off (about 2mm) and I'm not sure if the raised side of the rib should be on the inside of the tray or on the underside of the tray. I'm also not sure if the ribs should be connected or stop just short of being connected (refer to my beautiful drawing).

So how do I go about preventing the sheet from warping? I used 22ga here, should I try 20?

[calj737]

If you’re trying to make a steel box from a flat sheet, you need a sheet brake. And you need to cut the corners out before attempting to “shape” the recess.

When you bend, brake, or planish metal, the metal needs somewhere to go. If you don’t have reliefs cut out, the metal will push into itself and warp or rack.

Might be easier to cut the pieces and weld them unless you have a brake and can make a box?

[Ellz10]

If you’re trying to make a steel box from a flat sheet, you need a sheet brake. And you need to cut the corners out before attempting to “shape” the recess.

When you bend, brake, or planish metal, the metal needs somewhere to go. If you don’t have reliefs cut out, the metal will push into itself and warp or rack.

Might be easier to cut the pieces and weld them unless you have a brake and can make a box?

I do have a brake. It's the 12" Eastwood one with 6 adjustable fingers, it works pretty well. And what do you mean cut the corners out? How it looks in the first pic is how it needs to be to bend up. I'll have to weld 1 small square up in each corner.

What do you mean by reliefs?

[Don R]

 Some of the TV body guys planish the metal to put some stretch in it before bead rolling, they say it   pre-stresses the metal giving it somewhere to go.

[Ellz10]

Some of the TV body guys planish the metal to put some stretch in it before bead rolling, they say it   pre-stresses the metal giving it somewhere to go.

After reading up and watching a few videos I realized that you're correct, I need to pre-stretch the metal, so I went ahead and ordered an English wheel. Should solve the problem.

[Don R]

 Awesome. I hope I helped.

[RAFster122s]

How much is the Eastwood sheet brake? You but the Eastwood English Wheel or Harbor Freight?
I don't like giving money to the Chinese, but hard not to on some products...

[calj737]

You don’t need a bead roller to make a box. You don’t need an English Wheel to make a box. English wheels are used to smoothe the metal after planishing or to pre-stretch it before shaping. Putting a bead in the flat sheet prior to using a brake is a good part of your problem.

Cut the flat sheet to remove the “corners” so the side edges extend beyond the bottom. Place the bottom beyond the fingers, and brake the sides. Hopefully your brake will permit you to do all four sides this way. Avoid bending from the bottom as this will cause warpage.

[Ellz10]

Awesome. I hope I helped.

Thanks Don! (:

How much is the Eastwood sheet brake? You but the Eastwood English Wheel or Harbor Freight?
I don't like giving money to the Chinese, but hard not to on some products...

I bought my brake last year for $299 and then I ordered the Eastwood Elite English wheel last night. I contemplated getting the Harbor Freight, but certain things I won't fork over that kind of money on - quality wise. Eastwood products have always been high quality, for me anyway.

You don’t need a bead roller to make a box. You don’t need an English Wheel to make a box. English wheels are used to smoothe the metal after planishing or to pre-stretch it before shaping. Putting a bead in the flat sheet prior to using a brake is a good part of your problem.

Cut the flat sheet to remove the “corners” so the side edges extend beyond the bottom. Place the bottom beyond the fingers, and brake the sides. Hopefully your brake will permit you to do all four sides this way. Avoid bending from the bottom as this will cause warpage.

I know I don't need the bead roller, but I wanted to use it to strengthen the structural rigidity of the box. I also wanted to emboss the letter "Z" in the center (gaudy, I know  ) 

I did remove the corners and braked all the sides as you can see in the last picture I attached. I might just go ahead and see how it goes by making a tray up without a bead and see how it looks.