Bending Question

This is rosebud country.

Gunner

A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Lazarus Long

Yes, that's right.

I was trying to leave heat as a last resort, but I do have a rosebud, be it rather small, with small tanks.

Lay out the radius you want on the floor with chalk. Lay the stock on something solid so the there are 2 supports about 4 inches apart. Hit the stock in the area between the supports with a 3 pound hammer. This will set a bit of a curve. Move the stock about 2 inches and hit it again, with about the same amount of hammer. Continue to the end of the bar. Check curve against chalk line. Repeat as nec.

Pete Stanaitis

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Gary Brady wrote:

It's way too easy to confuse radius with diameter - one more time because I'm stupid, you want an eight foot circle with 4' radius, right?

Grant

I want the flat bar to be a segment of a circle (the chord would be about 2-6) bent to a curve with a 4' radius. The whole circle would indeed be 8' diameter, but I only need segments.

Spaco's idea sounds interesting. Here's what I would do. Since the material is cheap, and rebendable, I'd scribe a line on the floor, bend it around whatever I thought would give that bend, then tweak it to fit.

You should be getting the hang of it by the tenth one. Too bad you only need four. That's the trouble with these. By the time you have a system figured out, you don't use it again for twenty years. A ring roller would do it, too, taking it just a little at a time, but don't know if you would want to go out and buy one just for this, even though they are not very expensive.

Steve

You need a roller.

And there's no way at all you can get any time on a powered slip roll? If not, then you will indeed have to do the old blacksmithing method as Pete Stanaitis suggests. I like his idea of drawing the arc on the floor, but I suggest you grab the stock in a vise and bump it with a hammer instead of trying his support pin method.

It's not all that tough to bump a correct arc. Ernie showed me how a year or so ago and it's a great technique.

Grant

I didn't really mean a "support pin". What I was trying to describe (as you accurately suggest) is to lay the stock on the anvil, using the step and the edge of the face as supports. This way you have the stock supported at two points and you hammer in between them. I often bend

1/4" X 1 or 1 1/4 the hard way using this process. To make it even easier, once you understand the process, is to slap the stock over the horn where you want the bend to be. Obviously, if you go too far, you just lay the too-tight part over the face of the anvil and hit the high spot.

Pete Stanaitis

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Grant Erw> Gary Brady wrote:

Don't know if this will help you, but I found it a couple of weeks ago when trying to find arc length to calculate 1,000 to 2,000 arc lengths when all I knew was the chord length and height from midline of chord to midline of arc length. It may be useful when cutting the starting pieces. I'd leave them a bit long on each end, and cut them off when you get it right. If you use a circle roller, you will have a little on each end that won't go through the roller.

For all you others, bookmark this site. It has lots of handy calculations in there, and all you do is enter the info you know, and it spits out the answer.

With those short of lengths, you could do it with a line scribed on the floor, something to bend it on, and a bit of time. Just go slow so you end up with a nice round (as much as possible) curve, and you don't have kinks, or have to straighten and redo and redo and redo.

HTH.

Steve

An impromptu bollard; works well and costs nuttin'.

Just take note of how straight you hold the bar on the supports so you don't get any bend along the width and make a section of a spiral. :)

Hit 'em easy and often. By the second one, you'll develop a feel for it.

An old tire on its rim clamped to a sturdy bench works great. Adjust the pressure for the desired firmness - a little give helps to avoid kinks. I used to use a 20" truck tire for putting the long 5-10 foot radius sweep in SS ornamental tubing for sailboat stern rails. We had a demo of a fancy commercial roller, but found the tire was quicker and just as accurate for the typical run of 1 to 5 rails.

Ned Simmons

On Sun, 08 Apr 2007 16:49:45 -0400, with neither quill nor qualm, clare at snyder.on.ca quickly quoth:

If bumpy/wavy is OK, he could hammer it. Otherwise, a roller is the cleanest way. Building forms and pressing it into shape is another possibility, but 3/8 is a bit stouter than plywood.

Mayhaps he could try a pair of bandsaw-matched 4x12" beams with a 20% (WAG) smaller radius? Drive a truck over 'em to press 'em into shape.

--- Is it time for your medication or mine?

Good idea. I am always saving circular things for these purposes. A friend who has a Hossfeld bender uses the area above the frame a lot for bending circles. He has (and continues to) make "wheels" with 1" holes to fit the top pin. I find cast iron farm equipment flat pulleys and wheels that I can bush for the same purpose on mine.

Pete Stanaitis

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Ned Simm> >

Larry Jaques wrote: > If bumpy/wavy is OK, he could hammer it. Otherwise, a roller is the

Here's how I did it:

I believe the picture is self-explanatory. I started with a form with a 42" radius and it yielded a 78" radius bend(more or less)in the steel. I extrapolated the next form down to a 30" radius and it gave me a curve of slightly less than 48"radius, which is OK because it easy to spring it out just a bit. The metal also might have a slight spiral to it, again easy to tweak with a vise and pipe wrench once I cut it to size.

On Mon, 09 Apr 2007 23:38:26 GMT, with neither quill nor qualm, Gary Brady quickly quoth:

Wow, only 7% spring? I thought it would have considerably more.

Goodonya, mate.

--- Is it time for your medication or mine?