Help! Need to make a circle.

[BIGBAMAK5]

Hey guys. I need some help. I am wanting to make an outdoor chandelier for a friend of mine. I have some 4in flat steel that I want to use for it and I need to make a circle about 3 1/2 to 4 ft. in diameter. I do not have a ring roller but I do have a torch, anvil, and welder. I was thinking about finding something round that I could rap the bar around and then weld it together but I am having a hard time finding anything that size. Are there any suggestions on what I could use or any other ways this can be done. Any help is greatly appreciated. Thanks.

Rush

[Blacksmith Jim]

Make a bending fork and use that to make the circle. Draw a good circle in soap stone on a concrete floor, and continually compare the piece you are forging with it. Bend it with a nice sized bending fork until it lines up with the circle you drew.

[Glenn]

Blueprints on Bending Forks

BP0121 Vise Bending Forks
BP0257 Bending Fork
BP0285 Bending Forks
BP0290 Bending Forks
BP0360 Multi-Position Bending Fork

[irnsrgn]

1. get some scrap cardboard.

2. get a wooden yardstick or piece of small scrap lumber, a small nail, and a pencil. Drive the nail thru the stick at the 24 inch mark, stick it in the end of the cardboard and use the pencil to draw an arc. cut on the line.

3. make a boltster of 3/4 round stock 6 inches apart, tack on a hardy shank. Lay the 4 inch flat across the bolster and gently hit it with a rounded hammer face. Use the cardboard cut out on the inside to check progress. get about 3 feet of it right before doing another 2 or 3 fit.

4. 12.5 feet is going to be hard to handle so you might consider doing it in segments and welding together after.

5. see below.

[skunkriv]

Yep like irnsrgn says

Would be a lot easier with two people.

Check both edges, top and bottom, against your pattern. Helps to keep things square. If you have a large flat surface or table you can lay your piece on that and check it with a square. You don't want to find out you are making a spiral when you are half done. Much, much easier to correct as you go along.

Sometimes it helps to mark off segments of your ring every 2" maybe to give you something to line up with over your bars and something to aim at.

That said I would probably do this by hot bending around a short section (maybe 2 foot)of strap that had been bent to a 2' radius and welded to my big table. Looking in your old posts it looks like you have a blower but no forge yet, and that you do have a torch and welder. I definitely would go with the above, cold bending method before doing this ring with a torch. The cold method works very well.

[irnsrgn]

Rush, like skunk says you can bend around a segment jig, for something 4 inches wide you really don't need a formed die. Below is a method I used to cold form some 2 inch square 3/16 wall tubing for a large radius on a hospital outside hand railing.

A. Cut up some of the 4 inch stock to make some Gussets.

B. Draw a radius on a substantial welding table. Make the radius a couple of inches smaller than needed to allow for spring back.

C. Tack weld the Gussets about 2 to 3 inches apart with small tacks as shown in ( and add one on the outside as a stop. Make sure the Gussets are square with the table top. Start Bending in the middle, bend a little of it, move it in, repeat, repeat, and work all of it one way, then go the other way from center, It will be easier to handle this way.

Note when I bent the 2 inch square around a similar radius jig, I welded a heavy piece of angle iron down to my table to use as a push point for the 4 ton porta power I used to get the leverage needed to form the square tube cold, I did 3 sections 12 foot long to come up with the top and 2 intermediate bars for the 16 ft radius required.

Also shown is a similar radius jig for hot forming 16 inch circles out of 3/8 square bar.

Hope this helps.