Roll Cage Installation Tips?

[bulletpruf]

A few buddies and I are building a roached '72 Javelin into a race car for the 24 Hours of Lemons. I ordered a cage from Rollcage Components; highly recommended by the Lemons folks. Should be here on Tuesday.



Plan is to build it on plinth boxes and then remove the plinth boxes to weld the top of the cage. FYI - I have a caged '71 Javelin in my shop as well, and the cage will be fairly similar to it.

Anyway, I can weld, as can a few of the others, but this will be the first cage that any of us have built.

First things first, what cage-building specific tools should I have on hand?

Also, I ordered floorpan patch panels; this weekend I hope to get patches installed so that's done before we start with the cage install. Passenger side front is the worst.



Thanks,

Scott

 

[BigMike782]

Cool project.
What are plinth boxes?
"Plan is to build it on plinth boxes and then remove the plinth boxes to weld the top of the cage."

 

[Dave G in Gansevoort]

It may be me, but I’d use the other AMC in the picture. A Pacer would be different to say the least

 

[no704]

For overhead welding put as many magnets on the tube as will fit in the area. Really helps with the molten bead not dripping on your face. I know that physics says at that temperature it should not work. But it does.

 

[bulletpruf]

It may be me, but I’d use the other AMC in the picture. A Pacer would be different to say the least

The Pacer isn't mine. At least not yet...

 

[bulletpruf]

Cool project.
What are plinth boxes?
"Plan is to build it on plinth boxes and then remove the plinth boxes to weld the top of the cage."

This is a plinth box.

 

[kbeefy]

I've always liked Javalins.

 

[Brianf60]

I’d the cage mild steel or chromoly? What welding method is required? i Assume mod steel and Mig welding will be fine for this. Do you have a pipe notcher? You will want one if you can swing i. There are ways to do it without but not as user friendly. You will want an angle gauge, level.
take your time. Measure multiple times before cutting. i
dont forget to account for any trim or interior items that will be installed.

 

[bulletpruf]

I’d the cage mild steel or chromoly? What welding method is required? i Assume mod steel and Mig welding will be fine for this. Do you have a pipe notcher? You will want one if you can swing i. There are ways to do it without but not as user friendly. You will want an angle gauge, level.
take your time. Measure multiple times before cutting. i
dont forget to account for any trim or interior items that will be installed.

Mild steel. I'll be using a Miller 211 Mig.

I do not have a pipe notcher; was thinking about picking one up, but could use a recommendation.

thanks

 

[kerrynzl]

This is a plinth box.

I've built a few Rollcages to FIA regs. [they are strict]

don't use a plinth box but a flat foot plate instead .
Use a hole saw ,so the cage can drop through the holes [with the foot plates removed] , then you can weld the top of the cage.

Lift the cage up ,and slip the foot plates in.

Fully weld the rollcage to the foot plates , But only stitch weld the foot plates to the floor [this is stronger]
The FIA prohibits fully welding foot plates to the floor [for a good reason]

So check your regulations

 

[vpd66]

I've built a few Rollcages to FIA regs. [they are strict]

don't use a plinth box but a flat foot plate instead .
Use a hole saw ,so the cage can drop through the holes [with the foot plates removed] , then you can weld the top of the cage.

Lift the cage up ,and slip the foot plates in.

Fully weld the rollcage to the foot plates , But only stitch weld the foot plates to the floor [this is stronger]
The FIA prohibits fully welding foot plates to the floor [for a good reason]

So check your regulations

Do it like this and also where ever the roll cage and body come close together weld them to each other or make gussets to tie them together. This not only make the cage stronger it makes the whole car stronger. definitely helps unibody cars.
303E172D-A98F-4D4A-BD92-7A6C11F267AF-scaled.jpeg

 

[bulletpruf]

I've always liked Javalins.

They look great if you fill out the wheelwells with a decent sized tire and get the stance right.

 

[bulletpruf]

I've built a few Rollcages to FIA regs. [they are strict]

don't use a plinth box but a flat foot plate instead .
Use a hole saw ,so the cage can drop through the holes [with the foot plates removed] , then you can weld the top of the cage.

Lift the cage up ,and slip the foot plates in.

Fully weld the rollcage to the foot plates , But only stitch weld the foot plates to the floor [this is stronger]
The FIA prohibits fully welding foot plates to the floor [for a good reason]

So check your regulations

I'm getting a kit, so it's already been cut to proper length for the plinth boxes.

Thanks

 

[bulletpruf]

Do it like this and also where ever the roll cage and body come close together weld them to each other or make gussets to tie them together. This not only make the cage stronger it makes the whole car stronger. definitely helps unibody cars.
303E172D-A98F-4D4A-BD92-7A6C11F267AF-scaled.jpeg

Ok, something like this? This is the cage in my '71.

 

[bulletpruf]

As for tools, this looks handy:






The budget won't allow for a $700 tubing notcher, but what about something like this from HF?

https://www.harborfreight.com/pipetubing-notcher-71048.html?utm_source=google&utm_medium=cpc&utm_campaign=21901739417&campaignid=21901739417&utm_content=173216753231&adsetid=173216753231&product=71048&store=3431&gad_source=1&gad_campaignid=21901739417&gbraid=0AAAAADAHb4fJdVuPsd5l2p0y2o7NnYBc3&gclid=Cj0KCQjwpf7CBhCfARIsANIETVpRfXE6vaPGXBZvc5bHnjfeXiAQC2SFGlvpPDFrB9hqQ32I7pBTBkcaAjvsEALw_wcB

 

[vpd66]

Ok, something like this? This is the cage in my '71.

Yes! Also the main hoop to the rear door jamb and along the top of the door opening to the hailo bar. Years ago we raced enduro cars and could only have a 4 point cage so we attached the body to the cage where ever we could. It really made the car more ridgid.

 

[NUTTSGT]

I’d the cage mild steel or chromoly? What welding method is required? i Assume mod steel and Mig welding will be fine for this. Do you have a pipe notcher? You will want one if you can swing i. There are ways to do it without but not as user friendly. You will want an angle gauge, level.
take your time. Measure multiple times before cutting. i
dont forget to account for any trim or interior items that will be installed.

Good advice.

I've built a few Rollcages to FIA regs. [they are strict]

don't use a plinth box but a flat foot plate instead .
Use a hole saw ,so the cage can drop through the holes [with the foot plates removed] , then you can weld the top of the cage.

Lift the cage up ,and slip the foot plates in.

Fully weld the rollcage to the foot plates , But only stitch weld the foot plates to the floor [this is stronger]
The FIA prohibits fully welding foot plates to the floor [for a good reason]

So check your regulations

I was going to suggest dropping the bars so the top could be welded.

Do it like this and also where ever the roll cage and body come close together weld them to each other or make gussets to tie them together. This not only make the cage stronger it makes the whole car stronger. definitely helps unibody cars.
303E172D-A98F-4D4A-BD92-7A6C11F267AF-scaled.jpeg

Not sure but the Javelin is a unibody car ? Better weld in some good sub-frame connectors. While doing so, make sure the roll bars sit atop of it the best you can.

As for tools, this looks handy:






The budget won't allow for a $700 tubing notcher, but what about something like this from HF?

https://www.harborfreight.com/pipetubing-notcher-71048.html?utm_source=google&utm_medium=cpc&utm_campaign=21901739417&campaignid=21901739417&utm_content=173216753231&adsetid=173216753231&product=71048&store=3431&gad_source=1&gad_campaignid=21901739417&gbraid=0AAAAADAHb4fJdVuPsd5l2p0y2o7NnYBc3&gclid=Cj0KCQjwpf7CBhCfARIsANIETVpRfXE6vaPGXBZvc5bHnjfeXiAQC2SFGlvpPDFrB9hqQ32I7pBTBkcaAjvsEALw_wcB

The notcher from HF is probably going to be hard on hole saws. Might want to account for that.

The 8 pt in my Mustang has some "out-riggers" the main hoop sits on and these are tied to the sub-frame connectors.

How many points do you need and will you be needing an "eye-brow" or halo bar ?

 

[iagsxr]

As for tools, this looks handy:

You could do that, or you could print off paper templates for free:

Pipe Notching Templates - Metric https://share.google/t8V0GHHZaZivykUNl

There's more than one source, I just linked the first one that came up.

 

[iagsxr]

The budget won't allow for a $700 tubing notcher, but what about something like this from HF?

https://www.harborfreight.com/pipetubing-notcher-71048.html?utm_source=google&utm_medium=cpc&utm_campaign=21901739417&campaignid=21901739417&utm_content=173216753231&adsetid=173216753231&product=71048&store=3431&gad_source=1&gad_campaignid=21901739417&gbraid=0AAAAADAHb4fJdVuPsd5l2p0y2o7NnYBc3&gclid=Cj0KCQjwpf7CBhCfARIsANIETVpRfXE6vaPGXBZvc5bHnjfeXiAQC2SFGlvpPDFrB9hqQ32I7pBTBkcaAjvsEALw_wcB

The difference between a good holesaw notcher and the HF is accuracy and longevity. Get the HF, you're doing one cage.

Feed speed, drill rpm, and lube are going to be you're determining factors in holesaw life. Some people swear by cheapy Menards Lennox holesaws. JD2 says homestore bi-metal holesaws are fine in their instructions. There are notcher-specific holesaws in the world. Here again, you're doing one cage. One holesaw ought to do it all. If it takes three or four that shouldn't blow the budget.

Not sixty bucks, but not $700 either:

Notch Master Tube Notcher

Notch Master Tube and Pipe Notcher

www.jd2.com

 

[iagsxr]

First things first, what cage-building specific tools should I have on hand?

Not cage-specific but, you have a mid-rise lift? Some of the things the car will have to be on the ground. Other things will be easier if it's up a ways. Pay attention to what the door gaps do on the lift. If the front subframe sags you don't want to weld off the cage with it that way.

Take off the doors.

Take out or roll down and cover the rear side windows. You will otherwise weld spatter them somehow.

I'd tack the cage completely together before I welded off anything. The dash and door bars will square it up. Then I'd knock out just the bare minimum to be able to drop it down to weld it off.

Think I told you in your build thread, I wouldn't final install the driver's side door bars till the seat mount was done.

 

[BigMike782]

This is a plinth box.

When my friend was alive and we were doing cages they were usually unibody and we welded in frame connectors then run rectangular tube from the frame connector out and welded to the body and floor.

 

[NUTTSGT]

When my friend was alive and we were doing cages they were usually unibody and we welded in frame connectors then run rectangular tube from the frame connector out and welded to the body and floor.

Exactly how mine is done.

 

[NUTTSGT]

. . .
Take out or roll down and cover the rear side windows. You will otherwise weld spatter them somehow.

Watch out for the inside of the windshield too. You won't notice the welding berry burns until you drive into the Sun.

 

[iagsxr]

Watch out for the inside of the windshield too. You won't notice the welding berry burns until you drive into the Sun.

I think the windshield's out of his Javelin.

 

[NUTTSGT]

I think the windshield's out of his Javelin.

I think we both might be right on that....

 

[zimman]

Most NHRA slower cages sit on a 6"x6" plate. We cut a 1.625" hole at each leg and drop it through to gain room at the roof. Then lift it back up and slide the plate under the leg and weld both.
I also developed a floor system to sit the cage on and once again you can drop it off the floor sys and weld the top, then lift it back to the floor and weld it.

 

[bulletpruf]

Thanks for all the input.

A few responses -

Yes, the Javelin is unibody. There's a company that sells subframe connectors; I'll order some this week. I like the idea of tying the cage into these.

The windshield is out. Interior is out. Quarter windows are out. Doors are off and gutted.

I picked up the HF tubing notcher yesterday. Watched some videos on how to notch with a chop saw (I have one of these), band saw (have a portaband on a Swag offroad table), and a flap disk (have big and small grinders, too).

A 6 point cage is required. Door bars - two per side - and dash bar are also required. You have the option of using a halo or a front hoop. More details here - https://24hoursoflemons.com/wp-cont...es/how-to-not-fail-lemons-tech-inspection.pdf

I don't have a lift at the shop, but I do have some wheel cribs; car will be quite steady on these.

 

[NUTTSGT]

You don't have to buy subframe connectors, you can build your own, possibly. Take a straight edge, tape, string or whatever to find the area where the rear subframe would attach and follow it up to the front where it would connect.


While I know you don't have a foxbody, mine is a piece of 2x2 tubing about 48" long. In the rear, it's welding flat to area of the rear subframe (front section of it) and runs up to the front subframe. The bottom of the front sub frame is cut out, the tubing fit inside and welded. 2x2x.125 (.187) tubing is way cheaper than a set of bought sub frame connectors.


ohhhh.... I sure would be welding them in and not just bolting them in.

 

[Dave G in Gansevoort]

Most NHRA slower cages sit on a 6"x6" plate. We cut a 1.625" hole at each leg and drop it through to gain room at the roof. Then lift it back up and slide the plate under the leg and weld both.
I also developed a floor system to sit the cage on and once again you can drop it off the floor sys and weld the top, then lift it back to the floor and weld it.

Wish I had seen this before I cut the roof off of my Mini To get to the top of the cage!

 

[bulletpruf]

You don't have to buy subframe connectors, you can build your own, possibly. Take a straight edge, tape, string or whatever to find the area where the rear subframe would attach and follow it up to the front where it would connect.


While I know you don't have a foxbody, mine is a piece of 2x2 tubing about 48" long. In the rear, it's welding flat to area of the rear subframe (front section of it) and runs up to the front subframe. The bottom of the front sub frame is cut out, the tubing fit inside and welded. 2x2x.125 (.187) tubing is way cheaper than a set of bought sub frame connectors.


ohhhh.... I sure would be welding them in and not just bolting them in.

I think I'm still going to order a set, but I have two Javelins, so one will get something fabricated and the other will get the store-bought ones, unless the ones I order hang too low.

Thanks for the input.

Scott

 

[zimman]

A few buddies and I are building a roached '72 Javelin into a race car for the 24 Hours of Lemons. I ordered a cage from Rollcage Components; highly recommended by the Lemons folks. Should be here on Tuesday.



Plan is to build it on plinth boxes and then remove the plinth boxes to weld the top of the cage. FYI - I have a caged '71 Javelin in my shop as well, and the cage will be fairly similar to it.

Anyway, I can weld, as can a few of the others, but this will be the first cage that any of us have built.

First things first, what cage-building specific tools should I have on hand?

Also, I ordered floorpan patch panels; this weekend I hope to get patches installed so that's done before we start with the cage install. Passenger side front is the worst.



Thanks,

Scott

A 1.625 tube (chrome Molly) will fit into the "hat channel" on most unibody cars. I think you can see them in the floor pic. Just cut the top open and lay the tube in the floor. It's a good way to keep the "sub frame" connector not above the floor, or below the floor but in the middle of the car.
It's pretty neat and I've done a few, or six.
Zim

 

[bulletpruf]

A 1.625 tube (chrome Molly) will fit into the "hat channel" on most unibody cars. I think you can see them in the floor pic. Just cut the top open and lay the tube in the floor. It's a good way to keep the "sub frame" connector not above the floor, or below the floor but in the middle of the car.
It's pretty neat and I've done a few, or six.
Zim

Zim - That's interesting. So that would be a channel that extends from the rear subframe to the front? It's not evident from looking at the floors, but you're saying that I should be able to see it from underneath?

 

[zimman]

Zim - That's interesting. So that would be a channel that extends from the rear subframe to the front? It's not evident from looking at the floors, but you're saying that I should be able to see it from underneath?

If there is one. Yeah look under the car. If you see a box that runs from the firewall to the rear of the car, that's the unibody.
Never seen one on a AMC tho.
EDIT; It is a unibody car. No frame. So there must be some sort of stamped bracing under the car.
Z
Zim

 

[bulletpruf]

If there is one. Yeah look under the car. If you see a box that runs from the firewall to the rear of the car, that's the unibody.
Never seen one on a AMC tho.
EDIT; It is a unibody car. No frame. So there must be some sort of stamped bracing under the car.
Z
Zim

Yes, it's a unibody car, and the stamped bracing is evident from the front going towards the rear of the car, but I don't recall if the channel continues all the way to the back. I'll check.

Thanks

 

[zimman]

Okay did some research.
This is what it should look like except I use round tube. Mild steel is easy, Chrome Molly is nuclear. LOL
See how the subframe connectors start under the car, go through the floor and out the back. That's how it should look.
Zim




I don't like this below so much. It adds to the bottom of the car and makes it more difficult to lower the car and in road racing that's important.

 

[Ohmthis]

Nutt’s and Zimman, those are great ideas! I especially liked cutting the floor to fit the subframe connector up against the floor!

 

[bulletpruf]

Okay did some research.
This is what it should look like except I use round tube. Mild steel is easy, Chrome Molly is nuclear. LOL
See how the subframe connectors start under the car, go through the floor and out the back. That's how it should look.
Zim




I don't like this below so much. It adds to the bottom of the car and makes it more difficult to lower the car and in road racing that's important.

Thanks for taking the time to find those pictures. Much appreciated.

Scott

 

[NUTTSGT]

Just wanted to add these pics of my Mustang for reference to feed the mind.

This is where the main hoop sits and the kicker bar that rides down from it to the outrigger from the subframe connector. Since everything is black, it does make it hard to see.




Here's the outrigger (2x3 tubing) from the bottom. Compared to the top pic, you can now understand where the hoop/kickers are welded to.



The front of the sub frame connector (2x2 tubing).



The friend that put in my roll bar has put in numerous roll bars/cages and back half'd 25-30 cars over the years. Mine was the first foxbody he had done this way. The next one he did, he lengthened the sub-frame connectors up to past trans mount and brought them up through the floor a bit.

FWIW, you can see the scratched paint on the sub-frame connector, that's from me jacking up the car.

 

[bulletpruf]

Ok, the subframe connectors are in. Pics to follow. I ended up using the Control Freak subframes, but it would have been almost as easy to make my own and go through the floor.

Now that the subframe connectors are done, I plan to patch the floors and the front passenger inner rocker so the roll cage is sitting on solid metal. The seat mounts will need to be fabricated and welded to the floors as well.

 

[zimman]

It really doesn't matter how ya do it. That's why I love to do mine from scratch. As long as it's able to pass the tech inspection you're cool. I'm loving your pic of cars and can't wait to see it.
Zim