Project #6, adjustable bending fork for tubing and flat bar, d.fisher

[d.fisher]

I don't yet have the luxury of a hydraulic pipe bender, but I needed one the other day and this is what I came up with. I have a few bending forks I use when blacksmithing, but they are too small for pipe. I was doing 3/4 and 1" thin wall. Here's what I came up with. I started with some 3" x 3/4" steel flatbar. The jig is about 8" long overall.

[d.fisher]

I marked out several spots for where 1" holes need to be drilled. This is to accept the 1 inch round bar you see in the photos. Each one of those was cut to 5 1/4"

[d.fisher]

So back over to Big Claus, my favorite drill press in the world, to drill some 1" holes.

This jig doesn't have to be super exact (note the wide chalk lines and eyed-up centerline marks.


I start each hole by going through with a 1/2" drill bit. This seems easier than starting with the big 1 inch.


And here's the big 1 inch in action. Going at about 150 rpm. Sllllllloooowwwww.

[d.fisher]

After all the holes are drilled, I cut off the piece from the longer bar. I forgot to mention earlier, I like to leave more bar than the jig is worth for clamping on the drill press. After the holes are done, just cut off the excess. In this case, I had a piece of scrap that was about 18" long

[d.fisher]

For mounting in a vise, I welded a substantial tab onto the bottom of the jig plate. You can either grab straight from the plate, or rotate it 90' and hold from the tab, which ever you choose, it don't matter. I did this because sometimes you need to change the orientation of the jig if there is not enough room to bend large bars in the shop.

[d.fisher]

You'll notice on the pin on the right, I welded a section of pipe. This pin is interchangeable from one hole to the next. That is to accomodate larger material, or tighter radius, etc.

Notice the pin on the left, it has the same pipe welded to it, just completely filled in and blended. It is also welded directly to the plate so that it will not swivel went the pressure is on. The other pin is free to swivel about, to match your workpiece.

[d.fisher]

This is a second jig, a variation on the first. This one I made so that I could bend flat bar instead of round. It is made exactly the same way, minus the pipe welded on to the uprights.

Flat bar bending jig.


Round bar bending jig

[d.fisher]

This is just a detail shot of how the removable post stays in the flat bar jig, without falling through the hole. Two tacks were made and ground flat, so that they don't jamb into the hole and get wedged.

[67cudafb]

How well does it work? Does it kink pipe you are bending or does it make a smooth radius?

[d.fisher]

How well does it work? Does it kink pipe you are bending or does it make a smooth radius?

It doesn't give a flawless bend, you do see some marks from the pin when using on tubing. It does do nice gentle curves, anything more than that, and I'm sure you'd need a bigger die on the faceplate. I can post some pictures of the bends later this coming week if you are interested.

bending solid bar is great on this jig.