Migs fine. Thousands of buggy cages have been built with mig welding. Tig looks cleaner and maybe only a tiny bit stronger.

*edit* that is only if your a competent welder. Ive built bumpers and rockers and stuff like that for my Jeeps but a cage I take to a certified welder. You can cut, bend and tack it together yourself then take it in to a shop to have a pro finish the welds.

 

I'm guessing you guys change the stock mounting points to stronger ones that connect the cage to the chassis? What pipe size and thickness is most common?

 

Racer tech sells awesome a-pillars. I have a set. The tube size is 1.75 and I would say the most common thickness would be .120 wall. I'm sure there are duners that use .095 to save weight. DOM is also most likely the most common used tube.

 

All my cages are 1.75"x.120 wall or 1.5"x.120"wall tubing. I only use dom tubing as well.

 

For a rzr .095 x 1.75 (diamater) is fine if constructed properly. Building it out of .120 will add some weight.
.095 4130 would really be the way to go but your going to get mixed feelings about mig vs. tig. From what I've read on aftermarket cages they are built with .095 DOM
To be honest 4130 was out b4 tig and held up just fine with proper welding techniques.

 

4130 should be TIG welded. Before there was TIG, they used Oxy. Because of the dense nature of 4130 it can be difficult to weld with a MIG and get the proper penetration of the welds. If you do TIG and you use high strength alloy rod you need to heat treat it or the welds will crack under stress. You can TIG 4130 with a standard welding rod, and it will not be required to be heat treated.

As far as material goes. 1.5" x .095 DOM would do just fine. As stated, current cages are 1.75" diameter, so many people just use 1.75 x.095 or .120 wall. You DON'T need .120 wall for a cage on a RZR, it just adds more weight and for the overall weight of the vehicle doesn't add enough extra strength. The key though is cost. I know that my steel distributor stocks 1.75x.120, but has to special order 1.75x.095 which actually costs more than the .120 wall. I actually am planning on building my cage from 1.5x.120 just for that reason.

 

Also the benefit to 4130 is that you can drop down a size ex. .095 4130 will be as strong as .120 steel so you save weight while keeping strength.

Cons
4130 is that it's expensive but you don't need a lot. Maybe 40'-50' would be my rough estimate (haven't built one yet) in money terms that's about $600-$700 in material but its a small price for safety and weight savings.

Hope that helps

 

The ones I have built, the weight was never an issue. I haven't had anyone claim to notice a difference in performance yet. Here chromoly tubing costs 2x what the Dom does. For a rzr application, I would even say that chromoly is just overkill. But what's stated above is true.

 

@offroader1
Your only saving what?? 40lbs at most? Large cage...
Kick out a passenger or lose a cooler! I agree with you on it being hardly noticeable. I'm into building bumpers and crap. Once I master that ill build a cage for myself only. With novalty 4130 lol
Off topic but one of my bumpers

 

I figure if .095 is good enough for Sprint cars going 90+ around a clay track, my RZR should be fine with it. .120 is good but not necessary in a RZR. DOM tubing is lighter and stronger pound for pound than mild steel. It truly boils down the cage design moreso than the thickness of the tubing going on it. Either one will work and as far as tig vs mig, your call. mig tends to be a harder weld but tig in the right hands will make a more consistant weld.
A bad welder can make either one worthless. I went with mig on mine. I didn't weld it cause I suck at welding but it looks great and I'll bet it will stand up to anything I can throw at it.
One last thing, tig takes forever to do. We often have to poke our welders at the tig tables to make sure they haven't died on the job.

 

Is DOM really lighter? I feel it's the opposite of mild steel HREW tubing. I've worked with both but I've never weighed a foot of each to compare. To me DOM is a bit heavier based on 10' pieces

 

No I think what he meant to say is that DOM is stronger. 4130 and 1020 mild are the same weight by the foot. Where you save weight with 4130 is you can go with a thinner wall tube and have the same strength.

1020 1.5x.120 is 1.7688lbs per foot
4130 1.5x.120 1.7690 per foot

virtually identical in weight.

 

Bumper looks good. If you can build a bumper you can build a cage. Just back up your nodes with something that will take the impact to as much steel as possible. Usually the frame, but rzrs are notoriously weak. All my cage tie ins on the frame are very reinforced. I make my own a pillars that are gusseted, they gusset down the frame, and have solid steel tube connectors instead of the factory cast connectors. B pillar is beefed up and gusseted as well. I really dig the fj cruisers

 

I've seen a handful of rally raid wrecks that resulted in high speed, multiple roll, rollovers. I have seen even .120 wall cages bend. I have seen cages shear off at the b pillar, shear off a pillar, collapse a pillar, and poorly built cages simply crush.

 

Thanks and thanks for the advice. I will use plenty if dimple die gussets and tie into the frame with plated reinforcements, a/b pillars (when in doubt, over build) I am aware of how weak mounting points can be especially after welding directly to it. When I'm ready I'll be searching cage builds like crazy to get plenty of ideas

 

Research welding forums. It's 100% safe to weld 4130 with mig. Proper gas and wire of course.

Quick tip:
You can weld chromoly with mig and then beat the $hit out of the weld with a 5lb. Hammer and see what happens.. If done right nothing will happen except some deformed tubing.

 

I have done quite a bit of research on it. My son is also a master welder and we have spoken at length about it. I didn't say it couldn't be done. I said it is difficult to get the proper penetration with a MIG when welding 4130. So in the context of this discussion it is not a material that most home builders would want to use because of the added cost and skill set required.

 

Should still be the same weights for equal size. .095 chromoly is closely matched to the strength of .120" dom, but since its thinner, it will inherently be lighter. The .095 chromoly May still actually be a little stronger. Honestly proper cage design and welding technique/skill are more important than the material. You can build a fully tig'd 4130 cage and not have a clue as to proper design and it will still be as unsafe as the stock cage.

 

Yeah the weights should be the same for the same diameter tubing with equal wall thickness. I agree. Its not about material, its about design and fabrication skills. SCORE allows mild steel cages (or they used to, its been quite a few years since I last read the rule book), it doesn't have to be 4130, but it still has to pass tech, which means proper design, proper wall thickness and diameter and that is for racing.

 

Lol I was going to say I could weigh 1.75 x .120 DOM vs. HREW but not till the weekend. Job gets in the way of the hobby

 

I wouldn't waste the time. If there is any difference it would be so slight it would be splitting hairs.