Advice needed- A novice idiot wants to build and install a roll cage.

As the title states, really. I have 2 cars that I have very different goals for, but both of them involve being caged. I value the art of learning, researching, and am not afraid of sweat equity or failures and bumps along the road. So I want to learn how to design, bend, and build a cage on my own. I'm a competent welder and have a 230v Hobart Mig that I am more than confident with.

The rest... I need some help with. I've read all of the cage rules and regulations for the series' that I plan to run either car in. Then I've re-read them. I'm familiar with the terminology and basic protocol of how to assemble the cage, but I could use a lot of advice and helpful hints on making the process a little easier.

I'm also looking for input on which tools will be 1) absolutely required, 2) very strongly recommended, and 3) makes life much easier but not really required in order to build more than 1 cage. I don't want to rent or borrow, considering I plan to use them down the road as well. I also have a nice enough space that I am okay with storing bulky tools that sit idle for long periods of time.

Input on materials and design bits would also be appreciated, especially when involving E30's and E36 BMW's, haha. Basically, I'm in the process of stripping and prepping the car now, and want to start bending/welding around the holidays. I'd also be interested in reading any books that may have been written that people recommend.

Any and all advice/input is appreciated, except 'bring the car to a professional and pay them to do it'. That's not my point or goal. I want to learn how to do this. I don't care about the net cost benefits or time investment or anything else. I understand explicitly that I'll make mistakes, need to redo things, and that my first example wont be my best... but I still want to do it. It's a pride thing. I hope you guys understand.

Thanks, Paul

If there is a cage kit available, that might eliminate doing any bending. Most cage kits could be a little basic, so you could end up adding some things, but it could eliminate doing any bending. Might make things a little easier.

I'm very interested also as I think I'll need one for the Challenge this year. How do the kits do cost wise verses buying the tubing and bending it yourself?

You need a bender obviously. I have a JD2 model 3 bender with 1 die for 1.75 and a mount for a truck hitch to securely fix the bender in time and space. I also modified it with a pneumatic/hydraulic cylinder so that wasn't necessary :)

You need a tubing notcher. I have https://www.jd2.com/p-63-notchmaster.aspx this and it is excellent.

You need atleast one angle grinder but I keep 3 handy. One with a grinder for adjusting notches. One with a braided wire wheel for cleaning off sealer/paint/welds and one with a cutoff wheel for quick adjustments. THey are cheap Makita ones from Lowes IIRC $29 each.

Just ballparking the numbers - Welder $800 + bender $800 + saw $300 + notcher $150 + tools $100 + steel @ $4/ft approx. Most of the cages I have done were under 170' of tubing. Some much less.

Call it $2300 but you already have a welder. A good cage costs $2500 to 7500 depending on the quality and sophistication of the build so you break even after the first one.

You will need a bandsaw or a chop saw. I have both - and much prefer the bandsaw. I've got the cheapest 4x6 one on the market and it does the job just fine:

If you are a capable welder already then all that is left is some tube bending math which you can google easily enough and the bender will come with some examples. It looks a little like this if you are not keen on their crappy software:

After a little practice you will be able to do stuff like this without getting a headache:

For the first one - keep it simple. Plan where to be tight to the chassis so you don't make some of the welds impossible to reach. Cutting holes in the floor to drop the cage to weld the top then plating under the feet last is a good way to get tight to the roof.

Wear safety glasses and gloves!

YouTube is your friend here. Search tube notching and cage building.

Be prepared to make some scrap as you get the hang of where to bend tubes and keeping tube on the same plane (or off by the right amount)

When you go to do a weld on the cage, good chance you are going to be miserably contorted, in pain, and catastrophically positioned while overheating in your welding togs. Before you pull the trigger, know how you are going to get yourself and the gun around the joint. I dont know about others, but if I cant get in the welding "zone" I don't bother.

Usual disclaimers on clean metal makes good welds. You cant overprep a weld.

You want to weld HOT. Good looking welds with no penetration are not the plan.

Rulebook will tell you what tube you need to use. To a certain degree it will also control your design options.

JD squared is a known quantity in the tube bending world. I would buy the hydraulic version if $$$ allows.

Think ahead when designing: Know before hand how you are going to fit and weld every single tube in the car. The roof tends to get in the way. Deep recesses where tubes come together in a node can be fun to weld.

If you are only going to do this once, you probably wont save much $$$ over getting it done.

Questions already- Would you recommend a 180 degree die set, or is a 90 degree set more than enough for general cage building in normal cars?

What do you guys use for hole-saws? Quality or just junk, throwaway Chinese bits?

What about angle finders/setters? Just standard protractors and such, or are you guys using fancier instruments?

For most work 90 degree dies will be enough. If you start doing open wheel cars that need a tall/narrow roll hoop the 180 degree dies will be needed. If you ever need more than 90 degrees in a typical production car cage you can likely spread two bends apart enough to get the second bend to LOOK like it is supposed to be that way.

For hole saws, you may want to look into rotor broaches instead of hole saws. Hole saw work, but you have to keep the cutting speeds down and lube frequently. Bi metal is better than cheap stuff for longer life. If a cheap hole saw chips a tooth the kick back will be sever when it hangs up in the work piece.

Angle finders are whatever is right for the job. I have about four or five different types. Some have actual indicators on them and others are more of a set it to the angel that fits and bend to that.

stafford1500 wrote: For hole saws, you may want to look into rotor broaches instead of hole saws. Hole saw work, but you have to keep the cutting speeds down and lube frequently. Bi metal is better than cheap stuff for longer life. If a cheap hole saw chips a tooth the kick back will be sever when it hangs up in the work piece.

That can actually be really painful when you use a hand held drill and it locks up. So be careful. I speak from experience.

Also, take the time to set-up your bender on the level. It makes it a lot easier to make a flat main hoop with an angle finder if you start with a bender that's straight.

The rest has been well covered.

go back and re-read the process that Josh (irish44j) went through when they installed Ozgur's cage in his e30.

my big takeaways from it:

• custom bent is worth it for the fit in the car. don't do a kit.
• box the lower points. lets you drop the upper joints down for welding access, resulting in a tighter cage overall.
• Ozgur and Josh are both friendly, nice guys who will probably be very willing to offer advice if you ask politely and appreciatively.

Fwiw I've made probably 10 cages only using an angle grUnder to fishmouth. Not saying it is the best but i could get really good fittings and it isn't that slow.

bluej wrote: go back and re-read the process that Josh (irish44j) went through when they installed Ozgur's cage in his e30. my big takeaways from it: - custom bent is worth it for the fit in the car. don't do a kit. - box the lower points. lets you drop the upper joints down for welding access, resulting in a tighter cage overall. - Ozgur and Josh are both friendly, nice guys who will probably be very willing to offer advice if you ask politely and appreciatively.

Links please?

You don't need many tools to install a cage. I had a welder, the only major required tool. To notch the tubes I used my floor standing drill press and a good vise. Also a 4or 4 1/2 inch disc grinder to fine tune the notches and to make some notches that you can't make on a tubing notcher. Also with a cut off wheel it will cut tubing and steel plate for the footings. To cut the tubes a hack saw, chop saw, or a pipe cutter will also work. I like a pipe cutter as it's quiet to use and leaves a clean square cut end.

Lots of good info so far. I'll add that on cars where I can get away with it I cut the roof right off to build the cage and then weld it back on after.

I'm just damn happy you started in the right place and read the rules first. Seen more than a few threads on other forums that had guys building up with wrong tubing or other BIG rule breakers.

Also keep in mind how you're going to access things after the build. Can inspectors see what they need, such as inspection holes, can you do maintenance, can you get the seat in and out? Can YOU get in and out within egress time limits, with all your gear and helmet, strapped in with arm restraints?

I have built 4 240Z it race cars. I ordered the basic weld in cage from Kirk racing in Birmingham Alabama. Perfect fit every time and I fabricated my own NASCAR door bars Etc adding on to the basic cage. It probably wasn't the cheapest way to do it but everything fits perfectly and makes it really simple. In the big scheme of things it really wasn't that expensive when you consider Sourcing tubing and all the specialty tools you will need . And Kirk is familiar with all the sanctioningkm bodies and knows what sizes you will need and wall jthickness Etc.

I'm basically just overdoing the tubing spec and going straight 1.75x.120 DOM. I have an OEM account through work where it works out to $2.79/ft, which is a nice cost savings. I can also extend my MSC discount as well with other tools and parts I can find on there.

In reply to Ovid_and_Flem:

And for what it's worth I totaled one of those cars and was able to cut the roof off and take the cage out and it still fit the new car perfectly. Not a single tube was bent nor did any of his Wells fail. Really quality stuff on his part

Dusterbd13 wrote:

bluej wrote: go back and re-read the process that Josh (irish44j) went through when they installed Ozgur's cage in his e30. my big takeaways from it: - custom bent is worth it for the fit in the car. don't do a kit. - box the lower points. lets you drop the upper joints down for welding access, resulting in a tighter cage overall. - Ozgur and Josh are both friendly, nice guys who will probably be very willing to offer advice if you ask politely and appreciatively.

Links please?

I'm not going to go back and dig through his thread, but it's the e30 Rally build thread that was featured in this months mag. username is "irish44j" (josh). You can use google site search (site:http://www.yadayada.com searchterm) to make it easier.

golfduke wrote: I'm basically just overdoing the tubing spec and going straight 1.75x.120 DOM. I have an OEM account through work where it works out to $2.79/ft, which is a nice cost savings. I can also extend my MSC discount as well with other tools and parts I can find on there.

Go with what the rules specify - they are mostly overkill already. 1.75x.120 is ridiculous heavy tubing to fit and bend. If you are going 1.75 you want to use .095 DOM (always DOM!!!). If you are going .120 wall go 1.5". the 1.5x.120 is slightly heavier than the 1.75x.095 but in tight places it's easier to get headroom/clearance on the tubing. The thinner wall 1.75 is a little easier to bend and a little lighter per foot if you have the space. If your car is light enough to use smaller tubing DO IT.

Dusterbd13 wrote:

bluej wrote: go back and re-read the process that Josh (irish44j) went through when they installed Ozgur's cage in his e30. my big takeaways from it: - custom bent is worth it for the fit in the car. don't do a kit. - box the lower points. lets you drop the upper joints down for welding access, resulting in a tighter cage overall. - Ozgur and Josh are both friendly, nice guys who will probably be very willing to offer advice if you ask politely and appreciatively.

Links please?

irish44j's build thread is here: Linky link

Ozgur is known in these parts as thewizard

Huckleberry wrote:

golfduke wrote: I'm basically just overdoing the tubing spec and going straight 1.75x.120 DOM. I have an OEM account through work where it works out to $2.79/ft, which is a nice cost savings. I can also extend my MSC discount as well with other tools and parts I can find on there.

Go with what the rules specify - they are mostly overkill already. 1.75x.120 is ridiculous heavy tubing to fit and bend. If you are going 1.75 you want to use .095 DOM (always DOM!!!). If you are going .120 wall go 1.5". the 1.5x.120 is slightly heavier than the 1.75x.095 but in tight places it's easier to get headroom/clearance on the tubing. The thinner wall 1.75 is a little easier to bend and a little lighter per foot if you have the space. If your car is light enough to use smaller tubing DO IT.

Okay, well the E30 will absolutely be light enough to run either 1.50 x .120 or 1.75 x .095. I guess I figured if it's worth doing it's worth overdoing, but I do understand your point with it being my first cage and starting with something that isn't forgiving or bender-friendly is probably not the smartest path...

Off to do more research.

Also, is the general consensus that it's easier to run the main hoop with Driver/passenger door bars than it is to run a main + front hoop and connect them? I'm a little unclear as to which would be best for my case. The dash will be removed, so front space is not a concern. Or is it simply personal preference? Both seem to be acceptable for all sanctioning bodies.

I use a main hoop, then front down tubes following the roof above the windows to the floor in front of the door. They are connected with a windshield bar.I tack them all in place then drop them thru holes in the floor and weld the top. Then, jack it back into place and install the plates/plinth boxes under the tube and weld to the sill plate.

On an E30 the strength is coming from the side of the sills rather than the floor so you will be plating them and tying any floor plate or box to them so running a hole saw thru the floor 1/2 bigger than the tube is no big issue. Much less invasive than cutting the roof open.

Rear X and door bars are last as they can be fully welded in-place if you positioned your tubes correctly and didn't hide them behind things being all clever. The first cage I made I did exactly that - plan the whole thing before you start cutting because do-overs are really, really irritating when you are almost done :)

The worst part of an E30 cage is the driver foot protection - there isn't a lot of room in there and it's easy to place the front tubes so you can't weld around the back of the tubing going out to the left of the clutch pedal. You can't weld it in first - because the main tube needs to drop thru the floor to let you weld the top of the dash bar. Take the fender off, cut a nice big hole in front of the door opening and away you go!

Make a plywood form of each section you are making. Sort of like a cross section of that area. Doing so in several pieces is okay, just make sure you have a fit you like, and can lay your piece on top of on the form the ground. Halos are easier to weld. Get it tacked firmly to your main hoop, and maybe you can foll it forward for finish welding(note: do not weld main hoop to base plates until halo and main hoop are fully welded).

Ya'll Know I've been whinning about cost of bars and cages and Still feel they shouldn't be part of challenge budget, Looking through ATL craigslist last Saterday I see a Buick GN body on a pallet, No Intrest really, but a shot from the rear and there it is a complete G-Body 16 point roll cage,unassembled in boxes IMAGONNAGET IT for 200.00 bucks,so I'm Good !!!!! STUFF is Out There.so I still Got Two 6 point bar sets one mustang one Camero,I have around 150 in Each Get close and they are yours.

THANK YOU

for being the only place where all the responses to this thread aren't "you're crazy, your cage is your life" from guys that don't even own a welder.

The only response that's more predictable is "I motor swapped this track car" = "Why didn't you use an LS?" from guys that have never swapped a motor, or driven a GM product for that matter.

Or maybe, posting any picture that happens to show something you welded yourself, gets you at least one post from a guy who doesn't weld saying "it doesn't look to me like you got good penetration there; there's no way I'd trust MY safety to that."

I haven't tackled the full cage YET but it's in the plans. Thanks for the good experience with the Kirk weld-ins because it's a viable shortcut for me.

A friend of mine that does this says he has trouble with the planning part, so he gets cheap electrical conduit and a hand bender to mock it up before he starts bending the DOM. What do I know; I haven't tried it myself.