How to make large radius bender?

[Odonnellp24]

Any ideas on how to make a DIY large radius tube bender? I mostly work with 1" square tube and for my project I need to make a 18"+ radius bend. I think it would make a pretty trick looking roll cage for my son's kart.

Something like this http://www.hawkebender.com/ without the $1200 price tag. Shouldnt be too hard to make one. Pick up some steel casters and weld up a frame and put a crank on the middle one with a screw on the top to put downforce on the middle....

 

[fowler]

u should use round tube for the cage as it is stronger and safer if a head hits it

as for the frame
u will find gend square tube is very rare in any class, (mainly because they dont use square) but if u do then just cut and reweld angles together

pipe benders are cheap and easy to use

but if u are set on makeing this then go aheah
it doesnt look complicated

u can get a screw like that from a G clamp
or use a hydrolic jack

 

[Bluethunder3320]

im not sure whats the best way to bend that, but....

definately get some pool noodles, slot the ends, and put them over the steel like on a trampoline, so it wont hurt as much if your skull happens to strike it...

 

[Odonnellp24]

im not sure whats the best way to bend that, but....

definately get some pool noodles, slot the ends, and put them over the steel like on a trampoline, so it wont hurt as much if your skull happens to strike it...

Pool noodles.........sweet idea! Never thought of that

 

[Bluethunder3320]

Pool noodles.........sweet idea! Never thought of that

thanks, well as long as the hole inside is big enough (need to be hollow of course) it would work and be cheap.

if you cant find any with a big enough hole try trampoline foam padding for the bars.

maybe kart foam is special but from what i have observed it looks the same.

 

[Rustydog2010]

pipe benders are cheap and easy to use

What pipe benders are you talking about? I want one!

Doing multiple bends is very difficult from what I have experienced, it is a real skill to get it accurate. Cheap benders are okay, they usually don't have very nice bends and can kink the pipe easily. A good quality bender will normal cost a lot of coin.

As for making that large radius bender, it doesn't look to hard. Making the dies (S?) would be the hardest part. If you have a lathe it could be done.

Jeremy.

 

[fowler]

iv seen them for $100

true the good ones dont make good bends though

is it just be but i find bending multible anges is easy

it only becomes hard when the orentation changes between bends
(what i mean is it is hard when the finished product wont lie flat on the floor)

 

[Odonnellp24]

What pipe benders are you talking about? I want one!

Doing multiple bends is very difficult from what I have experienced, it is a real skill to get it accurate. Cheap benders are okay, they usually don't have very nice bends and can kink the pipe easily. A good quality bender will normal cost a lot of coin.

As for making that large radius bender, it doesn't look to hard. Making the dies (S?) would be the hardest part. If you have a lathe it could be done.

Jeremy.

Thats where the square tube comes in, the casters would be perfect since they are flat too.

 

[Rustydog2010]

Thats where the square tube comes in, the casters would be perfect since they are flat too.

Ahhh, roger, I read that at 1" tube, my bad.

Jeremy.

 

[Odonnellp24]

What pipe benders are you talking about? I want one!

Doing multiple bends is very difficult from what I have experienced, it is a real skill to get it accurate. Cheap benders are okay, they usually don't have very nice bends and can kink the pipe easily. A good quality bender will normal cost a lot of coin.

As for making that large radius bender, it doesn't look to hard. Making the dies (S?) would be the hardest part. If you have a lathe it could be done.

Jeremy.

Found this thread on a welding forum for making the dies. Bend 2 180 deg pipes that have an inner diameter that matches the outer diameter of what you want to make, slice in half lengthwise and weld them around a wheel. Bam instant die.

http://weldingweb.com/showthread.php?t=26904

 

[redsox985]

That one you posted seems to just be two rollers, a central force point, and a way to roll the metal through. You could probably make it with some time in the garage. Use a compact car jack (the little ones you're given with a car) as the center piece to apply pressure and cause the bend.

 

[wooley]

http://www.motherearthnews.com/Do-It-Yourself/1980-09-01/Homemade-Tubing-Roller.aspx
maybe...

 

[Odonnellp24]

http://www.motherearthnews.com/Do-It-Yourself/1980-09-01/Homemade-Tubing-Roller.aspx
maybe...

That would probably work pretty well on soft metals. I'd have to question its durability for mild steel applications. The design itself looks pretty solid, it just comes down to construction material. Personally I think metalworking is easier than wood work. Easier to fix the oops

 

[Odonnellp24]

That one you posted seems to just be two rollers, a central force point, and a way to roll the metal through. You could probably make it with some time in the garage. Use a compact car jack (the little ones you're given with a car) as the center piece to apply pressure and cause the bend.

That would work. The 3rd roller would be the force point and just roll the metal back and forth, tighten half a turn and repeat until you get the radius you want. If you wanted to get fancy you could do some trigonometry and calculate how far down the center roller would have to go to achieve the desired radius.

 

[redsox985]

If you went with the jack and 3 rollers idea, you would have to make this thing VERY strong, as those little jacks pump out some power.

 

[Odonnellp24]

If you went with the jack and 3 rollers idea, you would have to make this thing VERY strong, as those little jacks pump out some power.

I have some 2" square tube thats 1/4" thick and some pretty stout flat iron for building this up. All the forces would be tensile forces and a proper weld can hold upwards of 60klbs tensile. You wouldnt be making the bend in one fell swoop, it would take many passes through the machine making very small adjustments to minimize stress on the bender as well as the tube. The tube tends to crinkle if you bend it too hard, but a little at a time should work. Ever use a pipe cutter? You dont cut through the pipe in one twist, you tighten it a little bit every few times around.

 

[flamed181]

tube roller

Habor freight for 159$

 

[redsox985]

$160 for that?!?! If you have the heavy enough metal and a welder, make your own. Go pick a jack from a junk yard and then use it to slowly add pressure each roll as said above. It should be fine. Since you're rolling square steel, you can just use flat rollers, but make sure you bolt them on with some strong bolts there!

 

[Odonnellp24]

Habor freight for 159$

Dude youre my frikkin hero

 

[Odonnellp24]

$160 for that?!?! If you have the heavy enough metal and a welder, make your own. Go pick a jack from a junk yard and then use it to slowly add pressure each roll as said above. It should be fine. Since you're rolling square steel, you can just use flat rollers, but make sure you bolt them on with some strong bolts there!

The casters I plan on using are rated for 1000lbs so I figure the bolts are too? One would certainly hope so