Tubing Bender

winkelhawk · **Posted:** Fri Jan 20, 2006 7:32 am

Does any one know of a resonably priced tubing bender? I am looking to make some parts for the Libby. I am looking at the JD Squared Model 3 bender, http://www.jd2.com. But I wanted to see if anyone has used something else the JD can get alittle expensive with the dies.

dog_party · **Posted:** Fri Jan 20, 2006 8:46 am

I don't think you're going to get more affordable than that JD. But there are a few options here.

The only bender I've used that would come in under the JD's price point was a metel bar tube-bender I used for sculpture in art school. It was a big long metal bar with a concave curve on one end. Extremely manual and extremely hard to use. I don't suggest it.

JJsTJ · **Posted:** Fri Jan 20, 2006 10:14 am

I am real happy with my JD model 3. The dies are pricey but you will probably only need a couple different ones. I bought mine with a 1" round knowing my first project was going to be a roof rack. I have a 1.75 on order for some other projects I am going to start working on. Of the couple of different benders I looked at while shopping, the JD2 #3 was the best for the money.

hankwood · **Posted:** Fri Jan 20, 2006 4:20 pm

i have a JD2 that i've used for 10 years now building tube chassis and roll cages. the dies are expensive but they wear very little, even with constant production use, as long as you always spray some type of oil on the follower that the tubing slides through.

boxhead · **Joined:** Fri Jul 08, 2005 11:14 pm **Posts:** 186

Here's some cheap ones. http://www.harborfreight.com/

winkelhawk · **Posted:** Fri Jan 20, 2006 6:26 pm

Thanks for the input, it looks like I will be getting the JD. I always like to here some opinoins about a tool before dropping $500 on it. I just picked up a milling machine for a shop that is converting all their manual machines to CNC. All I need is a lathe and I will be all set. Now the hard part is what to make first! :lol:

bennybmn · **Posted:** Fri Jan 20, 2006 7:51 pm

Can I come over and make stuff too? :shock:

Cacher123 · **Posted:** Fri Jan 20, 2006 8:16 pm

Quote:

Can I come over and make stuff too?

Me too! Me too!

winkelhawk · **Posted:** Fri Jan 20, 2006 10:51 pm

I still have a lot of setup of the shop to do and not enough time to do it. When it is ready, I'll let you know.

bennybmn · **Posted:** Sat Jan 21, 2006 7:22 pm

Sounds good. Let me know if you need a hand with anything.

B

by4x4 · **Posted:** Sun Jan 22, 2006 1:01 pm

boxhead wrote:

Here's some cheap ones. http://www.harborfreight.com/

The way a "bender" bends the tubing is crucial to the success of the project you are working on. Harborfreights bender is not a tubing bender, but a pipe bender. A pipe bender just pushes the pipe in the center and pushes the bend into it. It results in a bend that can kink and that ovalizes the tubing. A true tubing bender (like the jd2) pulls the tube through the arc of the mandrel and bends it a little bit at a time to prevent kinking, ovalizing, etc. For structural projects, a true tubing bender is crucial to maintain maximum strength throughout the bend.

FYI, you can fabricate a true tubing bender on your own and acheive good results. I have a buddy who built his entire racecar on a homebrewed bender. His design incorporates the hydraulic ram from a HF pipe bender to pull the tubing around the mandrel.

Here is a link with a few more resources on the homebrew version if you want to investigate that route:
http://www.buildyour4x4.com/index.php?id=46

bennybmn · **Posted:** Mon Jan 23, 2006 11:04 pm

Quote:

A true tubing bender (like the jd2) pulls the tube through the arc of the mandrel and bends it a little bit at a time to prevent kinking, ovalizing, etc. For structural projects, a true tubing bender is crucial to maintain maximum strength throughout the bend.

Is that called a Mandril bender?

hankwood · **Posted:** Tue Jan 24, 2006 1:13 am

yes, that is whats called a mandrel bender. since it bends in a continuos arc, it does not create kinks or stress points which weaken the structural integrity of the tubing. the cheaper "crush type" benders weaken the tubing and therefore are not allowed for cages and chassis building if it is used at a sanctioned event with safety inspections.

winkelhawk · **Posted:** Tue Jan 24, 2006 7:05 am

A Mandrel bender actually pulls a die thru the inside of the tube to prevent the kinking of the tube. The JD Model 3 is not a Mandrel bender. The tubing used with the bender needs to be a certian wall thinkness in order to prevent the kinking of the tube.

brpn#1 · **Posted:** Tue Jan 24, 2006 7:55 am

check this one i saw in their new catalog i got yesterday in the mail.

http://www.sportsmansguide.com/cb/cb.asp?a=245526

by4x4 · **Posted:** Tue Jan 24, 2006 11:15 am

brpn#1 wrote:

check this one i saw in their new catalog i got yesterday in the mail.

http://www.sportsmansguide.com/cb/cb.asp?a=245526

Nice bender for the $$, but it won't do big tubing like you need for cages and whatnot. It's "round" dies are not concave for tubing, and will only work on flat or solid-round stock. It would be very useful to have in the shop, but wont replace the JD2

hankwood · **Posted:** Tue Jan 24, 2006 12:37 pm

being a mandrel bender has nothing to do with whether there is an inside follower or not. look up the definition. the only commonly used benders you will find in the metal working industry using followers are the ones bending square and rectangular tubing since the straight side walls want to wrinkle in when you bend them. the sectional follower only minimizes the amount of wrinkle. round tubing doesn't need a follower when "pullled" into shape around a rotating center due to the inherent strength of its shape, as long as the outside diameter of the tubing is the same as the inside diameter of the relief in the die. this is why mechanical tubing is measured in outside diameter, with metal thickness affecting the inside diameter, so that the ouside diameter always fits the relief in the die. water pipe, on the other hand, is measured by inside diameter, with metal thickness affecting the outside diameter. in this way, when using those hydraulic "crush" type benders, there is only one size of water pipe with a particular wall thickness that actually fits the die exactly. when you use smaller pipe in a die than it is made for, it squishes the pipe into the shape of the die, then flattens the outer half of the pipe because the structural shape of the circle has been lost.

winkelhawk · **Posted:** Tue Jan 24, 2006 1:59 pm

Not trying to beat a dead horse, but here is a link to the definition of a Mandrel bender. http://www.vansantent.com/definitions.htm. If you were to bend a very thin wall metal in the model 3, it will most likely crush the tube. This is why they have a minumim wall thickness to used with their dies. This is because there is nothing supporting the inside of the tube. A good example is exhaust tubing. Most factory exhausts have kinks in the bend, this is because they do not Mandrel bend pipes. Aftermaket exhausts have smooth bends because they Mandrel bend using the internal follower.

hankwood · **Posted:** Tue Jan 24, 2006 5:18 pm

don't worry, it's not a dead horse, and i know what you are referring to with the link. there is a few other companies besides that one that define their bender as a mandrel bender and say that the others are not. a "mandrel", as it applies to this situatuaion, is an object which metal can be wrapped or pulled around on a rotating axis. so in the 60's, when drag and stock car racing began utilizing tubing to increase strength and decrease weight, benders like the jd2 were designed and they were called mandrel benders, and that is what they are still commonly referred to as. large diameter exhaust pipes are hard to bend without the inside follower, unfortunately for most of us the only machine on the site you refered to with that capability has a starting price of $34,700.

either way, the jd2 is very capable of bending thin wall tubing. they don't actually list a minimum thickness on their website, they just say you have to use the locking bolt when bending .060 or thinner. which is very true. i've bent a lot of 1 5/8"x .060 and .045 when making headers to fit the chassis i build, and if you don't lock the tubing into the u clamp it will spring back and wrinkle the inside wall. you also have to lock down chrome moly or it will spring back and wrinkle, also.

winkelhawk · **Posted:** Tue Jan 24, 2006 5:38 pm

Thanks for the info on the thinner wall tubing with the locking bolt. If I get real ambitious, I want to make a set of headers for the Libby. That though, will be awhile from now.

Tubing Bender

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