How to make a rod bending jig

It sounds like a 14" rim from a car would work well for a bending jig.(Or

13" to allow for springback) Or did you mean 7" diameter? I weld a small tab to hold one end of the rod fixed and use a pipe the rod will slip inside of to form the bend- advancing the pipe as the bend is formed. I have a vice mounted on a pipe outside my shop to clamp the rim in. Steve

Have you considered a simple bending fork? Two bolts in a vise, or two bolts welded to a long handle. Given the scrollwork that can be done with those, a simple 180 should not be too difficult to pull off, with perhaps a couple of practice pieces first, in addition to the 6 more you need.

How did you bend the first one?

I certainly found that bending 1/2" deformed rebar freehand, with no special attempt to constrain the bends (function, not esthetics) resulted in bends that were all of pretty similar radius (all bent cold, with simple leverage). I bent 90 degree pieces for my corners, and 180 degree hooks at the ends of straight bars. I can't see that you need heat if you actually mean 3/8" bar.

Then again, you could wander into the tool rental and get a rebar bender for an hour or two. Those have rolls to constrain the bend to a particular radius.

3/8 th inch rebar? I would just bend it cold. You mention both 7 inch radius and 7 inch diameter, so I am not sure which you mean. But pick something somewhat smaller as there will be some springback. Maybe slip a 1/2 inch pipe about three or four feet long over the rebar so it bends where you want it to bend yet you have a long lever arm. The piece you bend it around obviously needs to be securely anchored.

Dan

Are you willing to spend fifty bux? Harbor Freight has a small Hossfeld type bender that would do the job easily. Speaking from experience, I would just eyeball the bends, using the first one as a pattern for the others. You can do six in less time than it would take to set up a jig, with the trial and error to eliminate the springback error.

For a metals sculptor, having a small bender will be an asset for all future projects.

A piece of 2x or plywood, jigsaw or bandsaw cut to the proper radius, would suffice as a die. Screw a block to the back side of the die to allow clamping in a vise. Attach a stop (L-bracket maybe) on the die top to hold the rebar in starting position to begin the bend.

To further explain: The bend should be a 1/2 circle with a diameter 7" across. measuring across the rods when they are paralell. Leo, the HF bender would not give me a large enough bend. Using the maximum 3" size die would give me a an aprox 3" diameter bend. Correct?

-Mike

I think the HF bender would accept a die big enough to do what you want to do. I don't have a HF bender, just one I cobbled up. But don't think you need one for just six pieces.

Dan

"mlcorson" wrote: (clip) Leo, the HF bender would not give me a large enough bend. Using the maximum 3" size die would give me a an aprox 3" diameter bend. Correct? ^^^^^^^^^^^^^^^^^ I was not suggesting using the included dies with the bender to form the 7" semicircle. I am suggesting that you feed the rebar through the bender, making little pulls on the handle to form an arc. Then feed it through again, making more little pulls to close the bend. It will not be difficult to make a 7" semicircle in the middle of a piece of rebar, with straight legs 7" apart. You may have a little trouble getting both legs the same length without practice. If this is important, you could cut the legs afterward to the desired length.

Another way to use the bender would be to use it to make a circular die to form the 7" semicircle. That would involve trial and error to get the right diameter for the die, and probably wouldn't be worth it for only six pieces.