Bending Brake Question

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Joe Casey
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Bending Brake Question

Post by Joe Casey »

I recently saw a Chinese made 48 inch sheet metal "box type" bending brake at a garage sale..I "googled" the part #, and found out they sell for about 500 dollars new, from Northern Hydraulics. The asking price was reasonable enuf to go back with some 20, 32, 40, and 60 thousands aluminum scrap to try it out. All of the bends (with the exception of the .020), left a fracture in the sheet at the bend.. my question is, has anybody had any experience trying to re-machine/smooth out the nose piece on the brake, to try and soften the radius of the bend?
TIA Joe Casey RV-9

Spike
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Post by Spike »

I have not, so I can't help there. However, I am into the fuse on the 9A I am building and can't think of too many times when I needed a brake. I used one for the trim tab of the elevator and I think that's about it. The other control surfaces of the 9 don't require one.

If you want one more power to you, but I don't think it's required for the build.

Spike
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bullojm1
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Post by bullojm1 »

Joe,

I have used a bending brake here at work a couple of time with the same result. What I did to improve the bend was place a sacrificial scrap of aluminum the same thickness on top of my material to be bent to help make the radius larger. Worked like a charm. However, I don't know how it is supposed to really work.
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TomNativeNewYorker
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Re: Bending Brake Question

Post by TomNativeNewYorker »

Joe Casey wrote: All of the bends (with the exception of the .020), left a fracture in the sheet at the bend.. my question is, has anybody had any experience trying to re-machine/smooth out the nose piece on the brake, to try and soften the radius of the bend?
You need to look at your aluminum that you are trying to bend. It does have a "grain" very similar to wood if you look close enough.

In most cases just bending perpendicular to the is enough to bend 2024-T3 without cracking. 7075-T6 is a different story, more subject to cracking.

Adding a piece of scrap on top of your bend line is also another cure.

Depending on the brake, you can also make adjustments to move the radius portion of the brake towards the rear giving a larger radius.

Try doing a google search for "bend allowance" or 'bend deduction" for flat pattern sheetmetal layout, that may explain a little better.

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