Roll Bar Fabricators...anyone know of one?

I have come up with a rollbar hoop design that fits the contour of the speedster body lines.The hoop will fit nicely under the convert. top and have plenty of head clearance. The only problem is finding someone with enough experience to bend an eliptical shape. I have made a few attempts resulting in failure. We tried filling the tube up with sand ,preheating with a oxy-acet. torch and bending it around a wooden form. We could never get a nice uniform bend. Larger tube fabricators want $5000 to make the die. That a bit too much. Jesse James makes custom tube bending look so easy. If anyone knows a reasonable fabricator that can perform this task please send the info my way. Attached is a partial drawing of the rollbar hoop.
Thanks
Joe S

I've generally had pretty good luck with custom auto exhaust houses (like Midas Muffler, or some place like that). Ask around at local auto parts stores to find out who can do it in your area.

I doubt that you've got REALLY heavy wall pipe there, since you've been trying to heat it and bend it around a wooden form, so they should be able to bend it on a hydraulic tubing bender by incrementing it a bit at a time (making a lot of small, gentle bends to simulate the ellipse). If the operator's good, it should come out just like your drawing.

If they don't think their bender is robust enough, they probably know someone else in your area who has a beefier one.

gn

P.S. no surprising that the "heat it with a torch" routine dissapointed you, that type of heating is usually done in an oven.

Joe,

"Roll Bar's or Gas Tanks" in this area most shops indicate they can't
do much with because of Insurance Liability. Just don't say what it is.

As for your design, most muffler shops should be able to get "Close" and you will have to "Form" the final stages.

As for your material, Chromahle Tubing .095 or .125 is the commons wall thickness. Most Main Roll Bars are .125 wall thickness.

As for the eliptical design, this will be difficult because as you say "Die" design. This is the part where "Forming" the final Stages will have to be considered.

Good Luck,

Jack Blake

Thanks Jack. I have tried a few muffler shops .. no confidence level there! We even tried a fellow racer's hydraullic tube bender. Unfortunately his dies are up to 1.75 OD. I didn't want to spring for a set of 2" dies at $400 a pop.As for my sketch it shows a material selection of .120 wall- ERW tubing. ERW is cheaper to practice with. The finished product would be DOM or Cr Mo tubing. This a show roll bar just like most of the roll bars that can be purchasd by theSpeedster kit manufacturers. Below are a few roll bar spec- requirements for a few race orgs.if any one really wants to know.

SCCA - The bar is 2

drop a note to Rick at Corvair Motorsports
www.corvairmotorsports.com/
I am not sure if he has the dies for the size bar you want

Rocky

Anyone in a nascar race cage shop, would be a prime resourse.

They would have to be able to do it.

I can't think of anyone who could handle it better.

Getting them to do it. That's another story.

I did a ton of research on it about 2 years ago. Basically you want a metal shop that can make the bends without deforming the tubing. To give you an idea, in the DFW area I found only two shops that people really had confidence in. There were probably 4 or 5, just everyone in the metal business that really knew what I was trying to do kept referring me to these two. To give you an idea, they had about a $350 set up charge, and were going to charge $75 for each roll bar after that. You can see some drawing in the files section under rollbar. That's just the bend. Not the material or fabrication.

Back in the early 70's I was working on the Apollo program at Hamilton Standard and we needed a piece of 2.75" diameter, .125 wall Stainless Steel tubing bent into a Horseshoe shape of about 10" radius, but the bend could not distort (wrinkle) the metal or cause a weakness in the metal beyond 40% of the original (it would later be pressurized with helium).

We tried a bunch of places in the central Connecticut area to no avail and were about to give up and try a different approach when one of the little old German guys in the prototype shop said that he thought he could do it. We let him give it a try and he came back the next day with the tube perfectly bent without a flaw in it.

When we asked him how he did it, he laughed and said they had to do a lot of bends like that for the cooling system on rockets he used to work on, and all he did was make a wooden bending jig the size he needed, shaped to fit the tube, then filled the tube with dry 0000 sandblasting sand and capped the ends. He then heated it in an oven overnight (don't know how hot, but up there) then quickly pulled it out and bent it around the jig before it cooled.

The guy was good.........gn