Making a step in sheetmetal

[chevynut]

I am often in need of bending a short step in sheetmetal, something like a 1/8" to 1/4" step. I'm talking about a "Z" with a short step in it. How do you do that on a regular brake? I don't really see how you can even do it on a press-brake since the lower die is wider than the step. I see parts made like this all the time, but don't understand how they do it.

I can make a short step on my bead roller, but that means I have to have every die they make and it probably won't bend as straight as a brake.

[Rick_L]

What you're trying to do is what's called a "joggle" bend. A good sheet metal shop would do that with a press brake and a "joggle die". (Not one that builds a/c ducts, one that builds cabinets and enclosures for industry.)

I agree that a bead roller would produce the same shape but you might have a problem keeping the piece straight. Didn't you buy a lathe? That's how you have the dies you need for the bead roller without buying all of them from a supplier.

Another way to do that is with a hammerform. Or just a homegrown joggle die used in your shop press. Often you'll need dowel pins and corresponding holes to keep the piece from slipping. You'll have to weld them up if the holes can't be there in the finished part.

[chevynut]

Thanks for the input Rick. I saw that these are called "joggle" bends like you said or "offset" bends.

Well, if I had a mill I could make some tooling to do this on my press brake.

http://sheetmetal.me/offset-tool/

I could make some "weld-up" tooling out of a fewpieces of steel too. I may try to do that. I just bought a shop press so I guess I need to put it to work.

Another way I thought of to do this is make the first bend using a brake, then lay the part on a hard table with the leg pointing upward. Then clamp a piece of steel on each side of the vertical leg, and bend it over with a hammer or mallet. Pretty crude, but I think it would get the job done.

Seems like there must be a better way....hmmmmmmmmmmmmmmmmmmmm

[chevynut]

Check this out....

http://www.youtube.com/watch?feature...&v=OipSiPSRti8

[Bihili]

The Magnabend is very impressive.

[Troy]

That Magna Bend is great. I would love one at home.

[Rick_L]

What a cool clamping system! The best stuff is the simplest, and the magnetic clamp makes it very simple.

[MP&C]

Laszlo, how about using a tipping wheel in your bead roller?

[chevynut]

Robert, I don't have a tipping wheel for my bead roller, and never really understood what it was for. I've seen you use one quite a bit on your projects but don't know how and when to use one. It seems to me that a brake would be the quickest and easiest way to make a joggle, but most of them I've seen can do a minimum of about 1/2" offsets. I may have to get me a set of tipping dies from Mittler Brothers. I saw some new dies that had at SEMA.

[MP&C]

The tipping wheel is especially useful for bends in panels that aren't straight, but that doesn't necessarily exclude using it for straight pieces. Here is a tipping wheel used on a 58 p/u windshield panel, and had about a 1/2" reverse in the middle there. This one uses a skateboard wheel at the bottom, I have since replaced that with a 75A durometer skateboard wheel that seems to work a little better...






The down side to this is the bends are done "free style" and you need to take care to follow the same line as you progressively "tip" the bends. Another good use for this would be for making a door skin, adding the crown via e-wheel, than use the tipping dies to fold the flanges, even around radiused corners.

For other applications where you have a set flange distance, it may be better to use a stepped die vice the skateboard wheel, to use the step as a backstop... Where before you rely on the tipping wheel forced into the skateboard wheel to provide the fold, with the stepped die at the bottom you will need to lift up on the panel as it's rolled through to provide the fold.














Where you were looking at a 1/8 to 1/4 reverse bend, few apron brakes are capable of such tight reverses, those that are will need to be a heavier gauge rating to hold the metal from moving and with that comes price. Not sure on your bead roller, but mine has the lower shaft that can slide in and out. This will allow you to use the dies shown above and offset the top to the bottom to dial in the reverse bend you're looking for. The other option is the joggle dies that Rick mentioned above, but with multiple bends you are dramatically increasing the tonnage requirement for a press brake. Could work well with some of the bottle jack adapted presses though..