Have any of you guys ever built armor or roll cage out of square tube? If so I am interested in photos and your input on this.
Square tube armor and roll protection
- Thread starter baldilocks
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It looks ghetto. I have seen a few do it.
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- #3
Easier if you don't have a tube bender and think that they are over priced. I just did some reading on round vs. square tube as I'm no engineer but it seems that with equal wall thickness and equal diameter, the square is stronger because it takes more material to make the circumference and stiffer due to moment or distance from the center of the tube to its outer most diameter. Round tube is easier to work with in some ways and supposedly stronger pound for pound. I rolled my 80 and I'm thinking of doing an economical chop and hack job to make a thrasher out of it. Square tube is much cheaper and I don't own a tube bender.
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- #4
Thanks but I'm looking for facts.
I wheel with a guy local who's run a couple different square tube buggy/things, and witnessed him rolling one of them. Other than some scuffs in the paint, the rig was fine (it was a pretty hard and fast roll). I don't think he's on here, but if you search W Harold, you may find some pics of his rig.
Here's a pic.
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- #7
Do you recall specifics on what tube dimensions and wall thickness he used mostly? I'm thinking that 1/8" wall 2X2 with plenty of gusseting and triangulation would be sufficient since 1.75"X.120 wall round tube is the norm.
40Habits
Sure... why not
I wonder how well that dana 50 holds up to 54's?
Thoughtful design and welding capability will factor into a cage's strength more than the shape of material used.
What type of cage on what type of vehicle and what do you use the vehicle for?
I don't like exo cages and any cage without internal and lateral cross bracing is far weaker. A poorly designed cage could also do more harm than good to occupants in a crash. Without a bender you'll be doing multiple times more weld joints increasing your risk for failure. Can it be done, maybe but if you're here asking it probably denotes that your experience and technical ability is not up to the task.
They also look like s*** so there's that.
What type of cage on what type of vehicle and what do you use the vehicle for?
I don't like exo cages and any cage without internal and lateral cross bracing is far weaker. A poorly designed cage could also do more harm than good to occupants in a crash. Without a bender you'll be doing multiple times more weld joints increasing your risk for failure. Can it be done, maybe but if you're here asking it probably denotes that your experience and technical ability is not up to the task.
They also look like s*** so there's that.
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- #11
Rockzilla is badass and very much the exception. Yes, I know that more weld joints means more risk for failure and that weighs heavy with me because I'm no stranger to rollovers. Just looking for educated input.
That rebodied Excursion looks like a big glossy turd, your rolled 80 is a much more capable rig.
I'm no expert but I am building a interior/exo hybrid right now on my FJ62. I started welding 12 years ago and was lucky to have an experienced teacher who helped me buils a flatbed/bedcage out of... wait for it... square tube! The guy I sold it to flipped it 3 times with three passengers in the cab and had zero deformation. That said, exception does not prove a rule and there are a ton cheap bender options out there like the JD2 and my personal favorite Affordable Tube Benders, tube notchers, metal fabrication welding of which I've owned both. I use the Affordable bender now, it stores easy and works great. Just doesn't bend over 90 and is 7" radius.
My advice is to buy one, build your bumpers and sliders first then when you feel confident enough to build something that can protect you and your family dig in.
I'm no expert but I am building a interior/exo hybrid right now on my FJ62. I started welding 12 years ago and was lucky to have an experienced teacher who helped me buils a flatbed/bedcage out of... wait for it... square tube! The guy I sold it to flipped it 3 times with three passengers in the cab and had zero deformation. That said, exception does not prove a rule and there are a ton cheap bender options out there like the JD2 and my personal favorite Affordable Tube Benders, tube notchers, metal fabrication welding of which I've owned both. I use the Affordable bender now, it stores easy and works great. Just doesn't bend over 90 and is 7" radius.
My advice is to buy one, build your bumpers and sliders first then when you feel confident enough to build something that can protect you and your family dig in.
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- #14
I have mauled the bender idea to death. It's just not cost effective for me because I would much rather be wheeling in the mountains than in my garage tooling. I think I will continue to pay a fabricator to build such items so I don't spend ten times longer than it should and waste tubing in the process.
So many people think square tube is "ghetto". That's stupid. Look at the rollover protection on heavy equipment. If done right, I think it can look great.
I called a fabricator who did some work for me three years ago on a different rig. He told me that if I buy a bender not to skimp and go hydraulic. A JD2 model 32 with hydraulics is in the neighborhood of $1000. That's fine for a shop but for me.........??
So many people think square tube is "ghetto". That's stupid. Look at the rollover protection on heavy equipment. If done right, I think it can look great.
I called a fabricator who did some work for me three years ago on a different rig. He told me that if I buy a bender not to skimp and go hydraulic. A JD2 model 32 with hydraulics is in the neighborhood of $1000. That's fine for a shop but for me.........??
Hey if it works for you thats cool. Its not for me and I have only seen a handful of square cages, and haven't been a fan personally. Here is some info I pulled up on square vs round...
In general, any structural member gets stronger in bending and twisting when you get more material farther away from the "neutral axis." Assuming a symmetrical section, the neutral axis can be thought of as the center. A 2" square tube is much stronger than a 2" round tube of the same thickness, because the square tube has a 2" wide flange located 1" from the neutral axis, where the round tube has a flange width of essentially zero at 1" from the center. (Of course, it doesn't hurt any that a 2" square tube actually has more material than a 2" round tube of the same wall thickness.)
Or if you are a physics buff, you can call it "parabolic dissipation" Which is basically just a fancy way of saying that a parabola (something round) will dissipate force over the entire structure rather than any one specific point.
I cast my vote with Eagle. Round tube is stronger in column strength and torsion. Square tube is stronger in beam strength. For a roll cage, the ease of bending makes round the winner. The sweeping bend of a round tube is stronger than the sharp, mitered joint required by square or rectangular tube.
In any case, always triangulate for ultimate strength.
I'm a licensed architect and had several years of structural engineering. If you run the numbers, square tube is stronger than round tube in bending, for the reasons I stated above. But you have to remember that there is more material in a 2" square tube than there is in a 2" round tube of the same wall thickness. The square tube is also stronger in compression and tension, too, but only because of the additional material. Round tube is sometimes easier to work with, and with round tube the strength is always the same in any direction -- there is no diagonal.
Frames aren't made of round tube (Unless you drive a go cart or a motor pickle).
Seriously, the factor you look for in resisting bending is called "section modulus," and for twisting it's "moment of intertia." As one increases, so does the other, but one is by a factor of 3 and the other a factor of 4. For simplicity, let's look just at the section modulus of a 2" tube with a 1/4" wall thickness.
We have a small problem because round tube is designated by inside diameter and square (rectangular) tube is designated by outside dimension, but I'll still go with a 2" nominal round pipe because a 1-1/2" pipe only has an outside diameter of 1.900".
Okay. 2" round pipe, 1/4" wall (actually 0.218): Section modulus = 0.731 inches cubed.
2" square tube, 1/4" wall: Section modulus 0.766 inches cubed. Not a huge difference, but better by about 5%.
The round pipe, however, is stiffer in resisting twist (moment of intertia), as well as being lighter per lineal foot. So it would appear that there is no single "right" answer here -- it depends on what the application is. Rectangular is better to resist bending, round is better to resist twisting.
With rectangular tube, of course, you aren't limited to square. You can choose a deeper tube to stiffen it even more without increasing the weight, if you have the space available.
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- #16
That's what I was thinking. Joking! Damn, that was a great post! So what it boils down to for the average Joe is, how much do you want to spend, what tools do you have, and which tube looks good to you?
An expensive bender will not make you a better fabricator or a better cage, it will make it easier. The $299 Affordable Bender is a great option for somebody on a budget, it'll easily save you time by not having to miter all your corners and net you a safer, better looking final product. Even a rolled 80 deserves better than a square tube cage.
Are you chopping the top off? Are you really going to do this or is this thread an excersize? Post pics!
Are you chopping the top off? Are you really going to do this or is this thread an excersize? Post pics!
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- #18
I'm thinking this is more of an of an exercise. One year ago I sold a 78 Dodge Ramcharger that was built to the hilt because I got tired of trailering everywhere and the lack of flexibility that goes along with a rig that's not road legal. I should have stripped it and saved all the good, expensive components. The atlas and front high pinion 60 cost me about what I got for the whole thing. Those parts would have helped to make a bullet proof crawler out of my rollover rig but that's not a possibility so.....
So now I'm face with a part out or strip it sort of situation and the fact that the 80 is fine other than the body has me thinking and remembering how fun the rubicon and Fordyce can be in a vehicle that you don't give a s*** about. My inclination is to have one 80 that's well equipped and armored. Perhaps my favorite thing about the 80 is that I can simply then the key to "off" and sleep in it. The 80 series is truly an awesome vehicle and , imo, the pinnacle of Landcruiser offering here in the USA.
So now I'm face with a part out or strip it sort of situation and the fact that the 80 is fine other than the body has me thinking and remembering how fun the rubicon and Fordyce can be in a vehicle that you don't give a s*** about. My inclination is to have one 80 that's well equipped and armored. Perhaps my favorite thing about the 80 is that I can simply then the key to "off" and sleep in it. The 80 series is truly an awesome vehicle and , imo, the pinnacle of Landcruiser offering here in the USA.
maxamillion2345
Franken-80
Well said and amen to that!
