How to arch 1.5" square tubing

[Jim-TX]

Guys, I have a job coming up where I might need to arch some 1.5" 14 ga square tubing. It would need to be arched about 6 inches in 3 feet. I can do up to 1" in my ring roller. I really don't want to buy a $1000 roller to do this. I've looked into the subject and the ones for sale are $$$. Any ideas? I'm thinking that I might run a series of mig beads and just let the shrinkage do it. The 6" dimension is not critical. Anything close to that will work. I'm open to ideas.

[milomilo]

Since the 6" isn't critical and the length is only 3', I would find something that has the arch you want, or make a quick jig on the welding bench and use a rosebud to heat, clamp and bend it to match the curve you want. I was figuring the arch did not have to be absolutely smooth??? This is the cheapest way I know of to get what you described without expensive tooling.

[Jim-TX]

It doesn't have to be absolutely smooth, but it need to look smooth from several feet away. It's for the top of a gate in front of a house that will be seen from the street..... maybe 30 feet away.

Thanks for the idea. I've thought that might work with a little careful bending.

[rusty ripple]

or contact a machine shop or a fab shop and have them do it.

[camdigger]

Personally, I'd cut an arc out of plywood or OSB sandwich and bend it cold. Make sure the OSB/plywood sandwich is higher than the tubing is wide, otherwise the curl quickly becomes a spiral

As a first guess, maybe allow 3/4" for springback. Allow 6" minimum at the ends of the workpiece for the jig to grab and to slip a pipe over - see below.

Wonder where I put the one I made to bend curved legs for a 36" tall table went... They were 1 1/4 16 ga tubing. The arc was 12" high/deep over an overall length of 36"

If material is tight (too short), I'd slip a pipe over the outboard end for more leverage.

[OleDog]

I arched some 2" upset wall square tubing to make an arch over the ends of a cattle guard. I ran it thru my 30T press, bending a little then sliding 6" or so and bending it again. The 1/4" wall tubing didn't crimp or buckle, but you could see the round imprint of the press shoe. From a distance you cant tell. 14ga, wouldnt bend the same way, but you might be able to use this method.

OleDog

[Pat]

Jim,

In the past when I needed to bend tubing and had limited equipment to bend it with, I would use a bandsaw, chop saw, or a grinder with a cut off wheel in it, and cut through the bottom of the tube and continue until I reached the bottom of the top side. Several slices evenly placed will produce a fair quality bend. The closer the slices the smoother the radius. After the slices are made, bend the tube to close the gaps in the slices. When you reach your desired radius, slightly bevel the slices and weld the sides and bottom. I generally weld the center of the bottoms first to lessen the chances of the tube twisting form the heat. I do not bevel if strength is not an issue.

Then use a flap disc and smoothe the welds. It is surprising how much bend you can get from removing 1/32" (or whatever the cutting blade thickness is).

[randydupree]

the plywood buck is the easy way out,i have done this many times.
The buck is 2 pieces of 3/4 plywood screwed together,the round edge was sawn on a bevel,so theres a crown in the middle when they are screwed together.
This crown will dimple the tube and help with the bend,
I used an arm with a roller in it to roll over the tube to form it,the buck was held in a vise,and theres a stirrup that holds the dumb end of the tube in place.
Building the buck and the roller arm took maybe an hour,all made from junk laying around the shop,the roller was about 2'' diameter.

[D York]

Randy how much spring back do you get?

[randydupree]

Originally Posted by D York

Randy how much spring back do you get?

I don't remember,but it does spring back,i had to "adjust" the buck to get the right radius.