Which direction to bend sheet metal?

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Vern2
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Which direction to bend sheet metal?

Post by Vern2 » Sun Jun 12, 2011 6:39 pm

A newbee question.

The trouble bend, which one is it, with my brake?

Although this shape maybe okay for my small break, don't know.

Am trying to bend this shape. It will be about 16" long of 18 gage mild steel. I'm asking this because, I'm thinking, to make this easer or even possible. There should be a first bend and a last bend. Starting at some point might mean leaving the last bend as the one that can't be achieved. Or if I try to make that bend in the middle of folding this shape, it can not be achieved. Does that make sense? Of course a mallet and block of wood will bend most shapes. I don't want to go there.

I'm trying to make a tool caddy. You can tell I haven't used a brake much. I may try to have it over lap somewhere to hold it together (spot weld or rivete). Down the road, drawers are going to be made, 8 of them. Thought a small brake would be a nice tool to have in the shop. Of course I'm adding tube bending to the shop now.

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Last edited by Vern2 on Mon Aug 27, 2012 11:01 pm, edited 7 times in total.

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mechanicalmagic
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Re: Which direction to bend sheet metal?

Post by mechanicalmagic » Sun Jun 12, 2011 8:04 pm

Is that an end view of a 16" long tube?

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Vern2
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Re: Which direction to bend sheet metal?

Post by Vern2 » Sun Jun 12, 2011 8:46 pm

Sorry, yes.
The end view, it shows the folds.

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mechanicalmagic
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Re: Which direction to bend sheet metal?

Post by mechanicalmagic » Sun Jun 12, 2011 9:58 pm

My way....
The open seam is at the mid left, at the joint of the 2" and the 4.47".

The sheet is slid into the bender, ~4.47" (long side) is pulled out and:
Top right bent to angle of ~26.5*
Pull out 4"
Bottom right to 90* (will bend the backside a little)
Pull out 4"
Bottom left angle to 90* (Easy, since the long side tucks into the bend.)
Pull out 2", part falls to floor.

NOTE: I did not account for bend allowances of 18 gauge, you should.

Dave J.
Every day I ask myself, "What's the most fun thing to do today."
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Vern2
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Re: Which direction to bend sheet metal?

Post by Vern2 » Mon Jun 13, 2011 8:46 am

This type of information, detailed info on bending, is very hard to come by. I've started to gather stuff to make the cutout in sheet metal. Will post pictures.

Thank you,
Last edited by Vern2 on Mon Jun 13, 2011 6:52 pm, edited 1 time in total.

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GlennW
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Re: Which direction to bend sheet metal?

Post by GlennW » Mon Jun 13, 2011 9:06 am

You will most likely have a bit of deformation of the part when making a complete bend at the lower right corner of the drawing.

Perfect job for a Magnabend.

http://www.roperwhitney.com/bending/1-16.cfm
Glenn

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Vern2
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Re: Which direction to bend sheet metal?

Post by Vern2 » Mon Jun 13, 2011 5:09 pm

This tool wont do it. http://www.harborfreight.com/18-gauge-s ... 92148.html It's cuts fine, except the edges are rough and wavy. Bought this, http://www.harborfreight.com/pistol-gri ... 98580.html this morning, I'm hoping, I'll start with a good cut out piece of sheet metal to start with. I'm backing off on the fold 1/16" that gives a nice 1/8" bend with 18 gage mild steel. I always check the reviews on the internet, before I buy. The reviews were fine.
Last edited by Vern2 on Mon Jun 13, 2011 6:51 pm, edited 2 times in total.

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Vern2
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Re: Which direction to bend sheet metal?

Post by Vern2 » Mon Jun 13, 2011 6:16 pm

Dave J,

I only made the drawing for what I was going to insert into it, it's frigidity and ease of folding ( no sharp corners). I know nothing! The rest of this is a learning process.

Damm, you have to be a mental contortionist to fold this in your mind.

A butt corner has no overlap. Would be nice to have an overlap somewhere to tie tube together, spot weld or rivets. The bottom is the most hidden.

The top will be filled with holes of specific sizes with hydraulic punch set.

A pull back of the top leaf of 1/16 gives about 1/8" corner. I'll look at a fold that I've done and try to figure the radius length.

Glenn,
Nice brake. You tube video http://youtu.be/OipSiPSRti8

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mechanicalmagic
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Re: Which direction to bend sheet metal?

Post by mechanicalmagic » Mon Jun 13, 2011 6:43 pm

Vern2 wrote:Damm, you have to be a mental contortionist to fold this in your mind.
And, it helps if you save those little 1" edge trim drops. Makes for a real quick and cheap "trial and error" part bend test.
Dave J.
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Vern2
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Re: Which direction to bend sheet metal?

Post by Vern2 » Mon Jun 13, 2011 6:56 pm

Right now my scrip pile has been mover to, under the brake. The aluminum is a separate scrap pile to sell back.

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Re: Which direction to bend sheet metal?

Post by Dave_C » Tue Jun 14, 2011 7:08 am

Vern2,

Trying to make these bends with a straight edge brake is almost impossible. What it is normally done on is a brake called a "Pan Brake".

It gets its name because it can form all four edges without messing up one that is already bent. They look different in that the front edge is not the forming edge of the brake but instead these brakes will have moveable sections along the front edge of 2 to 4 inches in width to allow the lips already bent up stand up while you bend the next lip.

I ran one quite a bit in my 20's.

Dave C.
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Vern2
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Re: Which direction to bend sheet metal?

Post by Vern2 » Tue Jun 14, 2011 12:40 pm

Dave C,

I'm only working with two sides on this task, the ends are open.

But while you mention it, here's a box made with a straight brake. One more thing, it seems like pan and box brakes only make boxes with 3" sides. With my solution the box can have 6" sides. A pan and box brake does not bring any ridged support for the corners. Unless you weld them, that means a difficult weld in thin sheet metal.

Another solution:
First fold the two long tabs up, at the bottom sides of box, with the 45% angles cuts. The tabs are folded first, before folding the front and back of box. I believe the two long tabs will be out of the way when folding the front and back plates. Now build the two sides like I've drawn, full tabs, no 45% cuts. What's left are easy to get at locations to spot welder with 6" tongs. The box will be ridged, supporting weight and pull handle for a drawer. Tell me where I may be going wrong.

ENCO has a 16 gage, 48", pan and box brake on sale now for $600. plus shipping. http://www.use-enco.com/CGI/INSRIT?PMAK ... TPG=INLMK3

HF 220v spot welder $159. pickup at store, plus 20% off http://www.harborfreight.com/230-volt-s ... 45690.html
HF 36" Metal Brake with Stand $219. pickup at store, plus 20% off http://www.harborfreight.com/36-inch-me ... 91012.html



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