Help bending 60thou 3ft long.

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ukmxer
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Joined: Fri Jun 20, 2003 5:48 pm

Help bending 60thou 3ft long.

Post by ukmxer » Sat Dec 27, 2003 3:26 am

Would someone please offer advice on how to bend the above sheet.

I am making a wind driven sign and my rolls are not heavy enough to bend it.

The piece starts at 18inch but I am rolling a 3 inch arc on each side for the wind to hook into.

Any suggestion gratefully received.

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Jacin
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Location: Near Cleveland, Ohio

Re: Help bending 60thou 3ft long.

Post by Jacin » Sat Dec 27, 2003 10:52 am

Can I assume we're talking mild steel??? Actually in steel that's a pretty good trick without the right tools.

Do you know anyone with an English wheel??? Using a "rubber band" and the appropriate lower anvil would be easy enough with a 'wheel.

A large bend brake (or press with a brake die) could also be used - make a series of small breaks (bends)- smaller and the closer together will make them more "invisible"

You could aways get a piece of tubing and split it and weld it to the "flat".

I built a makeshift radius brake using tubing and bent a similar size on .060" 3003 H14 (aluminum) but it was closer to 5ft long - it worked amazing well for thin walled tubing - but I did work up quite a sweat.

You could always get a piece of heavy walled tubing and use it as your brake die in a hydraulic press - pushing it into a chunk of urethane as you female die. - again - multiple breaks may be necessary.

You might even toss it in your kids sandbox with a piece of heavy walled tubing and run it over with your truck - <grin>


Depending on how you appraoch this you might be better off using a WIDER than required sheet - this way you can fully roll you part around and THEN trim off the excess - my experience has shown me that it can be more difficult trying to get a perfect radius right up to the edge of a part, but instead it is far easier to "over roll" it (length of roll) and then trim back to proper size. Again I wouldn't necessarily do this if I were using a series of breaks but would if I were using the radiused break die method. Again - your particular setup would dictate the appropriate method.

Just some quick ideas - maybe one will lead to a better way based on your available resources.

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Steve_in_Mich
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Location: Mid Michigan

Re: Help bending 60thou 3ft long.

Post by Steve_in_Mich » Sat Dec 27, 2003 4:01 pm

Jacin I like your " quick ideas " espically the one about driving your truck over it (with proper size sandbox and mandrel of coarse). Believe me I have been there on that one. How many times have you heard a guy say "I wish I had a way to bend an edge on this or that" or to "press this in or out" only to see his log splitter setting parked beside the garage. 2 X 4's, angle iron, pipe, C clamps and the right truck is all a guy really needs for some jobs.
Just because you don’t believe it - doesn’t mean it’s not so.

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hairspring
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Location: UK

Re: more bending suggestions please?

Post by hairspring » Sat Dec 27, 2003 5:22 pm

I'd welcome comments on a bending job I have coming up. it's 3mm mild steel for the top of a rivetted boat cabin, (10feet long, curved in two dimensions before bending) which has to be flanged over the sides at the edge, to replicate the one in the attached pic.
My proposal is (with the side plates rivetted in place) to tack weld some heavy flat bar (I have some 150 x 10mm to hand) to the inner top edge of the side plates. Then bolt the top plate into place, trim the edges to size, & tack some more flat to the top of the top plate, just inboard of the planned bend, to stop it lifting as the flange is dressed downwards. Then gently dress the flange over with hammers. The last 1/4" or so can, of course, be drawn up by bolting, before drilling & rivetting the whole seam.

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Steve_in_Mich
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Location: Mid Michigan

Re: more bending suggestions please?

Post by Steve_in_Mich » Sat Dec 27, 2003 7:17 pm

Well it's already in the sand, so now you only have to pick the truck. [img]/ubb/images/graemlins/wink.gif"%20alt="[/img] [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]

It won't be easy to hold the sheet without some help but rolling the edge is the way I think I'd try. You have the pattern and can mark it out on your material to follow a line with a hand crank bead rolling machine and lots of gentle passes to avoid a kink at the wide point. Sorry that is all I can offer as I understand the job.
Just because you don’t believe it - doesn’t mean it’s not so.

ukmxer
Posts: 24
Joined: Fri Jun 20, 2003 5:48 pm

Re: Help bending 60thou 3ft long.

Post by ukmxer » Mon Dec 29, 2003 4:28 am

Thanks for your advice guys. I might have to look at using a thinner mild steel.

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