Rod Bender

This was one of the easiest little tools I have ever made lately. Like a lot of the things I do there is a behind the scenes story to tell. This one starts maybe 30 years ago when I made a cheesy little bender for forming 1/4 inch diameter steel rod. The shop were I was working in used the steel rod as wiring looms to route bundles of wire inside high voltage switch gear. These wiring looms were kind of fun to build a little like road building for wires. When I first started making the looms I just bent the rod in my bench vise with a mallet and welded them to the interior of the switch enclosure. When I switched to copper jaws on my bench vise this rod bending operation just shredded the jaws for any other work. Right then I decided to build a dedicated rod bender. Don't laugh but I still have it. I'm pretty sure that is the original dowel pin in the center. I cannot ever remember breaking one.

Like I said don't laugh. I made it from junk I had lying around the method of all good scrounges. The frame is a chunk of angle iron that I bushed to hold a hardened dowel pin as the forming pin. The back fence is cold rolled steel that I milled the slots in using a drill press of all things. I have used the crap out of this bender making hundreds of bends in the quarter inch cold rolled loom rod.

It got borrowed all the time by the other guys that had to do looms in the equipment they were building. Well all things end eventually so when I left that shop Trayer Engineering my little rod bender went with me. Sure enough I started using it for other things since it worked so well on the rod. After a few years I had quite a little collection of bushings and blocks for doing all kinds of weird little forming jobs that came up.

So this little rod bender just moved around with me from shop to shop. We used it quite a bit at CVM and that's were the story gets  a little more interesting. It was only after I left the company and the little rod bender went with me that it gets funny. One of the guys from CVM came by my new shop for a  shop tour and social visit. We were walking around the shop shooting the breeze when he spotted the little bender and said, "Jeez you just about crippled us when you took your bender" I asked Marty why they didn't just build another one and quit whining about it. He then told me he had tried to get one of the other guys to draw it up for him without success. He even sweetened the pot with this guy trying to entice him by telling him he would build two of them one for him if he would just make a drawing for him. Well I'm part deaf but I know an invitation when I hear one. I kept my mouth shut and started thinking about it. The cool part was I already had it in mind to make a better one but it was a low priority because I already had one that worked.

 It always starts with a sketch around here. I have no business jumping on the computer until I can put something down on paper. It helps to stay in practice hand sketching. You never know when you might have to communicate with an alien species.

Part of the appeal of this bender is its simplicity. I didn't want to lose that in the new design. So I spent a few hours on Solidworks and made a nice little drawing package for Marty. I never told him I was working on it. I sent the drawings in a package through the mail with some other stuff  to him at the shop. Not wanting to miss a chance for a joke I labeled the outside of the box in big letters with "Erectile dysfunction home test kit" and addressed it to him. I'm sure there were a few laughs from the mailman over that.

A few weeks later I still haven't heard anything from him so I'm starting to wonder if he got the package. Finally he emails me with a question so I know he's working on them. True to his word Marty walks in one Saturday at the shop and he has the metal version of the new design bender in his hand. He did just like he said and build two of them at the same time.

They work great and behave like the original but smoother and tighter. The new bender has a much larger bearing surface on the pivot and the bending pin is removable so you can change pin sizes and add other types of dies (like tubing) to it easily. To make repeatable angle bends you just make a witness mark with a sharpie on the rotating part of the pivot. You could put a graduated scale but then you would have to remember the number. For each diameter of rod or tube the barrel will have a different position. So a witness mark in this case is less confusing. I suppose I could make an adjustable reference mark. Hmmm, might be a good upgrade. I also added a measuring scale along the front to make gaging the bend lengths easier. Its just one of those adhesive scales which happened to be numbered in the right to left direction. Where did I find that? I'll give you one guess, McMaster Carr.

The rod I just bent in the picture is 3/8 diameter steel. I haven't tried it yet, but I think this one will do up to 1/2 inch in steel. You can slip a tube or pipe over the spud on the right side for more leverage. So all in all it was a really fun project because of the collaboration. Marty had the time and willingness to do the machine work and I had fun designing it and seeing something useful come to life. Hope you will like it also.