Bending Steel Tubing

[buffumjr]

I have seen steel tubing in boat T-tops, and in go-karts that is neatly and smoothly bent without flattening the tube in the curve. How does one do that? I have seen tubing bent by the machines at the muffler shops, and there is some reduction in diameter and flattening in the curve. So, how does one do the neat bends?

[aametalmaster]

Use a good set of bending dies. Some are crush dies that distort the tube, some use mandrels inside to keep it smooth...Bob

[buffumjr]

So, I should go to a shop that has that equipment and let them do it.

I'll need 18 90° bends and 12 45° bends in 1-1/2" structural tubing. Not unreasonable to allow 6" on each side beyond the curve zone.

Picture a go-kart with a roll cage. 16hp Kohler vertical engine and transaxle from a riding lawnmower. Instead of 2-1/2" driving and 8" driven pulleys, 3" to 6" #35 chain sprockets and chain. May make the driving sprocket larger. By changing the driving to driven ratio, one increases the top speed.

From the $200 riding lawnmower:
Engine
Transaxle
Steering column and wheel
Front end assembly
4 wheels and tires, with mounting hardware
Outside axle bearings for rear shaft
Clutch/Brake mechanism
Wiring and starter switch
Seat
Pedals

Engine would hang just beyond rear axle.

BIG advantage to this setup is REVERSE.

[tubameat]

Hi!
Look around on craigslist for a decent bender. I got a JD2 model 32 (with a couple dies) for a GREAT price. A bender like that would do just what you need it to do.
-Steve in DC

[buffumjr]

Hi!
Look around on craigslist for a decent bender. I got a JD2 model 32 (with a couple dies) for a GREAT price. A bender like that would do just what you need it to do.
-Steve in DC

Great! Will do!

[aametalmaster]

I just sold my Hossfeld. I like this one for small tubes. http://shopoutfitters.com/ub-5h-bender/ ...Bob

[buffumjr]

Hoo boy. Craigslist had some benders. $1,200 and over. The one relief from that was a Horror Fright Tools offering being resold. New, they're $110, and $175. The $110 machine does 1/2 to 2 inch. 12 ton ram. May look into that. It may be a really nice tool to have.

Was on YouTube. Problem solved ... I think. https://www.youtube.com/watch?v=ZlSnVSrWg0M Use a steel strap across the center of the bend to hold it to the curved channel, and use steel shields on the two roller contact points. He showed some really nice bends.

I'll try the HF offering, first. If it doesn't work, up on Craigslist it goes.

[frenum49]

I am currently gathering materials for a similar project. However on a bit larger scale. I was looking into a John Deere Gator XUV 825i S4 and quickly decided that I can build my own. I will be using the engine, trans, suspension etc from a Geo Metro. The 1 liter 3 cylinder engine is more than enough to get the buggy moving at a healthy clip. It will only be FWD but I have no plans of off roading it. I just need a buggy that will seat four adults forward facing. Good luck with your project.

[aametalmaster]

I had a '96 GEO Metro 4 cyl/auto. On a good day she would do 100 mph. I put over 100,000 miles on it...Bob

[OscarJr]

So, I should go to a shop that has that equipment and let them do it.

I'll need 18 90° bends and 12 45° bends in 1-1/2" structural tubing. Not unreasonable to allow 6" on each side beyond the curve zone.

The key info that was left out is: bend radius. Once you go too small of a bend radius for a particular OD/wall combination, you will end up wrinkling the tube. A 45° bend on a 1' CLR is much, much different than a 45° bend on a 6" CLR. If you keep it reasonable, then it makes things much easier to maintain a good cross-sectional shape.

[Cickavage]

Get a JD2 Model 32 from JD2. Nothing beats that bender. Baileigh's may be close but it is also more expensive.

[Up-parts]

A little info on pipe bending. All certified benders use mandrels, referenced earlier, also called balls. These keep your pipe from distorting as the tube is pulled around with the clamp and die. Additional information, bend radius is usually calculated in quantities of diameter. A 2-D bender has a radius of twice the pipe diameter. This is the tightest bend you will find without sand packing. Good Pipe benders are 10,000 and more. We have two at work that we're over $350,000 each.

The reason I mention "certified" is that tube frames and chassis have to be inspected and part of that inspection is a cert for the bender.

Hope this information is of some help.