Tube Benders and Roll Cages

[Bundy]

Hey All-

I've been messing around looking for tube benders and just overall getting my learn on before I make any purchases. I have a couple of questions that I am sure you guys know off the top of your head. I want my first cage to be able to handle severe roll overs but nothing NASCAR... just hard core wheelin stuff.

For the ease of learning I am focusing on the JD Squared stuff as far as die and component terminology and reference. Here are some questions I have:

1. What are the standards common to dealing with tubing? The ones I know about are square tube, round tube, tube radius, OD, wall thickness, and type of metal (like chromoly?). Have I missed any common standards?

2. What is the most common sized tubing standard used for roll cages? 1.5"? 2"? Wall thickness? preferences for type of use?

3. Looking at die sets there are SO MANY options. If I were looking at this die set that says M32B Die Set - 2” (7.5-180) 2” Round Tube... it talks about the 7.5 being the center line radius... I think I'm having a problem understanding that term

4. I've heard of people using carts instead of a stand bolted to the floor... would I be able to bolt a bender to my welding table or do they make a special cart?

Any input would be greatly apreciated!

 

[SteveL]

For tubing 2" .120 wall hrew is what most are made out of. For the bender buy the tightest radius they offer. That makes it easier to get your cage tight into corners saving headroom in the rig. As far as mounting the bender I made a rolling stand that I can anchor to the floor when I use it.

 

[hyghlndr]

I am tuning into this thread, I have most of the same questions.

Has anyone thought of a group buy on tubing benders? Any recommendations on the best bender and die set for the buck?

 

[fungus]

I am tuning into this thread, I have most of the same questions.

Has anyone thought of a group buy on tubing benders? Any recommendations on the best bender and die set for the buck?

I picked up a used JD-2 model 3 bender out here with 4 dies for $300! Still need to get me a 2" die for cages and the like but I think they're the best bang for the buck even new. They have kits that you can upgrade them to hydraulic later if you want too.;D

 

[Apogee]

Hey All-

I've been messing around looking for tube benders and just overall getting my learn on before I make any purchases. I have a couple of questions that I am sure you guys know off the top of your head. I want my first cage to be able to handle severe roll overs but nothing NASCAR... just hard core wheelin stuff.

For the ease of learning I am focusing on the JD Squared stuff as far as die and component terminology and reference. Here are some questions I have:

1. What are the standards common to dealing with tubing? The ones I know about are square tube, round tube, tube radius, OD, wall thickness, and type of metal (like chromoly?). Have I missed any common standards?

2. What is the most common sized tubing standard used for roll cages? 1.5"? 2"? Wall thickness? preferences for type of use?

3. Looking at die sets there are SO MANY options. If I were looking at this die set that says M32B Die Set - 2” (7.5-180) 2” Round Tube... it talks about the 7.5 being the center line radius... I think I'm having a problem understanding that term

4. I've heard of people using carts instead of a stand bolted to the floor... would I be able to bolt a bender to my welding table or do they make a special cart?

Any input would be greatly apreciated!

There are a variety of tubing standards depending on the industry, however all tubing is defined by its outside dimesions and wall thickness. The most common structural tubing for automotive applications is 1020/1026/A513 mild steel tubing. The most common tubing used is ERW, which stands for Electric Resistance Welded and basically means that the tubing was formed out of sheet and then welded. DOM is just ERW which has had further processing in order to homoginize the wall thickness and remove the weld flash from inside the tube. DOM is the best material choice since it will bend the most consistently and has equal material properties in all directions, but it costs substantially more than just ERW tubing, so many avoid it for that reason alone.

Chromoly is typically only used where the highest strength to weight ratios are required. Since chromoly is stronger than steel, you can theoretically use less (typically thinner wall) and still maintain an equally strong part, however it should be TIG welded and needs more attention to weld details like pre and post-heat operations. For maximum strength, chromoly fabrications should be heat-treated and tempered for the application it has been designed.

You can get mild steel or chromoly seamless tubing, however seamless is manufactured by piercing a solid bar rather than forming it from relatively consistent sheet metal. Seamless tubings tend to have larger wall thicknesses than is typically used or needed for our applications and the wall thickness tends to be much less consistent and therefore less conducive to any sort of bending operation.

The most common tubing size varies depending on the application. Weight and speed potential play a big part, however for any rig over 4500#, you should be looking at running 1.75" to 2"x.120" for all of your main structural elements and then 1.5" or thereabouts for everything esle. Grab handles and such can be whatever you want, although 1"x.095" is pretty common. Interestingly, 1.625" tubing is very common in drag racing...not sure why.

Die bend radius is what defines the curvature of the bend. If you were to measure from the centerline of the tube to the theoretical center of the bend, which coincides with the center of the die, that would be the die radius. Smaller is typically better, however it also limits how thin you can go on the tubing wall thickness without wrinkling the material. Based on my brother's Pro-Tools 105 bender, the 2" x R6.0 die can only bend 2"x.120" tubing...it will wrinkle .095" wall material, whereas the R7.5 die can bend down to .083" IIRC. Most of the bender manufacturers have charts showing the limits of their dies. I have R6.0 dies for 1.5", 1.75" and 2" tubing.

Any manual bender is going to need to be anchored to something since you're going to be pulling on it to bend the tubing. The up side to manual is cost. The down side is effort and the fact that your bender is somewhat fixed unless you like dropping concrete anchors everywere. Mounting it to a table could be problematic with respect to feeding the sticks of tubing since more complicated bends can route back and get in the way, which is why most are pedastal mounted to minimize interference issues.

If/when you convert to hydro, then your bender pushes off of itself, so it just needs a cart or something similar. My brother and I just designed our own cart that looks somewhat like a modified engine stand and bought a Haldex hydraulic pump to run it. We made a custom cylinder because we could, but there are off-the-shelf options from the low to high range depending on what you want to do and how much you want to spend. Aside from a few test bends, I have yet to spend any significant time with the new cart, but that's about to change. I just had a ton of DOM show up last night, so it's time to get to bending on a variety of projects.

HTH,
Tobin

 

[NateMob]

Apogee did a great job explaining things! My entire cage is built with 1 3/4 .120 DOM, that i rely on every time i turn the key, i drive my parents, fiance and anyone else who asks for a ride. I also like the idea of knowing when i square up to any obstacle offroad that ill be safe regardless of the outcome. The fact that DOM doesnt have the risk of splitting when hit like HREW does is worth the premium price i paid for all 120 feet of it.

I know people are going to post after me saying that cheaper alternatives suffice for them but why cut costs here? Design is key, and tying everything together makes the most sense. Seats and belts both need to be tied to the cage. As far as tying into the frame, there are two sides to it.

Nate

 

[NC-Fordguy]

Just a tip from experience for a manual bender..........

Instead of having a fixed position (ie bolted to a concrete floor) tying up shop space, The pedistal can be modyfied/fabbed so it fits into a trailer receiver hitch on a pick-up truck.

Simply slide it in the receiver as you would a drawtite ball mount and you have a fixed position in which to bend tube. No drilling holes in concrete, no bender in the middle of the shop. No trying to finagle a 20 foot long piece of tube around a bunch of stuff in the shop

When you're done simply pull the pin and store the bender in the corner.

 

[Apogee]

The receiver hitch idea is a good one, although something that a lot of guys don't seem to do with their benders is account for being able to level the die. All of your angular measurements are going to be relative to whatever working angle the die is at...ideally, it will be horizontal in a conventional Pro-Tools or JD2 type bender...vertical in some other designs, otherwise your compound angles can get a little confusing when you're trying to do more complicated parts with multiple bends in multiple planes.

When I have set up manual benders in the past, I've always shimmed the pedastal in order to level the die as best I could. The new bender cart that I've been working on has outriggers to lift it off of it's casters and level a spherical bubble level mounted to the top of the center die pin. I'm too good at screwing things up when they're simple, so I try to do everything in my power in order to give myself the best chance to succeed.

 

[fungus]

Instead of having a fixed position (ie bolted to a concrete floor) tying up shop space, The pedistal can be modyfied/fabbed so it fits into a trailer receiver hitch on a pick-up truck.

Simply slide it in the receiver as you would a drawtite ball mount and you have a fixed position in which to bend tube. No drilling holes in concrete, no bender in the middle of the shop. No trying to finagle a 20 foot long piece of tube around a bunch of stuff in the shop

When you're done simply pull the pin and store the bender in the corner.

Exactly what I was thinking of doing with mine! Portable too & makes it easy to take to your buddie's house to bend his cage (cuz you know he's gonna want one!). Great minds think alike.

 

[broncosport]

I picked up a used JD-2 model 3 bender out here with 4 dies for $300! Still need to get me a 2" die for cages and the like but I think they're the best bang for the buck even new. They have kits that you can upgrade them to hydraulic later if you want too.;D

You get this yet??? Its awesome!!! all guess work out the door!!!
http://midmoracing.com/bendit/bwinstall.exe

 

[Bundy]

Wow, really great info fellas!

A few more questions for you-

- If I went 2" .120 wall DOM would my little 110V lincoln MIG be sufficient?

- If i pickup a used hydro system then I don't need to bolt it to the ground but might be able to use my welding table? It's a pretty damned heavy welding table...

 

[Apogee]

Most 110VAC wire-feed welders are more than capable of achieving full penetration welds with material up to 3/16" with hard wire and slightly thicker with flux-core, so you shouldn't have any issues there.

As for any hydro unit, it allows you to put the bender wherever it works best for you. If that happens to be the corner of your fab table, so be it. I've seen some guys leave it as a pedastal with some heavy steel plate or a concrete block attached to the bottom to keep it upright but still be semi-mobile...always seemed a bit sketchy to me, but whatever gets the job done I suppose.

 

[41willys]

woodward fab makes a nice tubing bender

 

[Bundy]

Great info- I don't shit about geometry but I figure some trial and error will suffice. My main concern was not buying the wrong dies since there are so many to choose from.

Speaking of dies, I see JD2 has so many it hurts my brain- I understand the sizes now but they aside from the obvious of square die sets being square, they list Metric Round, Metric pipe, and non-metric... I'm assuming I don't want metric and the only reason I would want metric is if I move to the EU?