TOTM: No Holds Barred Cage Thread

[BigDaveZJ]

This should prove to be an interesting one!

Couple subjects to cover (feel free to add your own too):
Internal vs External (and combo)
Material
Design
Frame/Unibody Tie-ins
Keeping it on a budget
Triangulation (we know we need it, but how many know why?)
Using a cage to strengthen the unibody
Keeping the COG low
What would you change on a cage you already built?
How did your cage hold up in a roll?
What ZJ/WJ specific issues did you run into?
Buggy vs full-body w/ cage

To me, cages are like entire builds, what works for one person may not work for another, for a variety of reasons. The one thing that is constant though is that we each need to be comfortable with the level of safety our rig provides for us and our passengers.

Pretty much anything that relates to cages is open game here. I think we can keep some of the basic fab stuff out though, like bending, notching, welding. Those really deserve a separate TOTM and we can beat the cage horse to death IMO without getting into those, and they apply to much more than just cages.

Let's git it awn!


EDIT: Don't forget pics or diagrams or whatever you've got!

[SirFuego]

I'll probably have multiple posts of tech and whatnot, but I'm jus going to start with some background on why my cage turned out the way it did.

OK so before I got SB406 to build my cage, I did a LOT of research that led me to an idea of what I wanted. It ended up turning out a LOT different (for the better) than what I was expecting -- but SB406 sorta got "carried away" (in his words) on the little nuances of my cage AND the plan for the rear end totally changed.

Now I wanted head room, so I opted for an exo cage up front -- but I still wanted B pillar triangulation. So the decision was made to hack everything behind the B pillar. The reason was primarily so the cage could be "picked up" and fully welded everywhere before it was tied in. Rather than building everything off of a B hoop, I wanted it from A to C so that I have a smooth sliding surface against rocks and trees. I think Mike did a REALLY good job keeping to the lines of the body for the front, but there was a LOT of work that was done to make it look as good as it does.

Basic things I learned in this process:
1) Before you put a tube in place, think of what purpose it serves. If you can't think of any purpose, there is probably no point in having it there. Think of where the stress points will be in a roll and try to strengthen that node.

2) Long unsupported spans are undesirable. This is part of the reason I have the "A" triangulation in my B hoop. Basically, if I ended up on my lid, there was already plenty of support at the B pillars, but nothing in the middle. This also proved to be better for head clearance.

3) As for B pillar triangulation, I did a lot of research on why this is needed. If you search hard enough on Pirate, you can find a couple cage threads that show pics of untriangulated and triangulated B hoops involved in a roll. The results were pretty obvious -- non-triangulated B hoops "worked" in that they protected the occupants, but they parallelogrammed to where the cage was pretty much worthless after that. The rigs with B pillar triangulation showed no signs of parallelograming and most could still be used without cutting out and replacing tube.

4) As for triangulation in general, it helps to distribute both vertical and horizontal forces -- both of which are going to be present in any roll. As a result, it significantly strengthens an area. But triangulation for the sake of triangulation may not really be very helpful, so consider (1).

5) Gussets add a lot of strength to a cage.

6) If you have a door bar tied into your rocker anel (more info on my cage tie ins later), you will feel basically any hit to your rocker panels and it will be felt throughout your whole body.

I have more to add, but I don't feel like typing much more right now...

[dp96zj]

Let's btt this.

• I know a bunch of you guys have cages, and some of you have redone them (recently, Cam and Pearce). What makes your new design better than the old one?

• And a more generic question, how did everyone tie it into the uniframe? Maxx, I'm sure you wouldn't mind throwing some pics into this thread. Or if you no longer have a uniframe, you can answer as well .

• What kinds of complications have you run into when building a cage? Or do you have any advice for people who are working on putting a cage in? (ex: rstrucks and his new cage)

• Do you recommend doing a big-ass exo with a gigantic stinger? (for Cody)

• Exo or interior cage? Or both?

And for future reference:
http://www.mallcrawlin.com/forum/showthread.php?t=22042

[ATL ZJ]

I rebuilt mine because I didn't feel safe anymore doing what we do these days. Whether it is hauling ass on the side of a mountain with no guardrail or hammering it on a ledge at the top of a steep 300' slope, I didn't think my existing "cage" would cut it in a very serious multiple roll. Mostly I wanted more headroom, more side protection, and more triangulation.

I'll get into more detail later if I have time but the keys are making triangles and nodes, strong "frame" ties, sound construction- good notches and welds, proper tube placement, and quality material.

[SirFuego]

I know a bunch of you guys have cages, and some of you have redone them (recently, Cam and Pearce). What makes your new design better than the old one?

I haven't redesigned mine, but if I had to change anything, I would change the way it ties into the front and beef it up a bit more. I already had a ton of extra work over what was originally planned, and I didn't want to add battery fuse/box, etc relocation to the list to cut the fenders as I have it now.

I would also cutout the rockers and raise them up as high as possible and practical for boat sides.

I would have also put skins on ASAP. I've been meaning to do it for a while (like basically everything else), but never did. There is LITERALLY 2-3 inches of solidified mud where the rear seats used to be. I got one side mostly cleaned up and will hopefully tackle the other side tomorrow.

And a more generic question, how did everyone tie it into the uniframe? Maxx, I'm sure you wouldn't mind throwing some pics into this thread. Or if you no longer have a uniframe, you can answer as well .

I still have my uniframe from the front crossmember to a little past the rear coil perches. Ideally, I'd like to have cut out the floor/frame rail behind the front seat -- but again it came down to the fact that I can't weld, so I wanted to minimize the work being done.

My rocker cutouts are each tied into the frame rail with fish plates three times. My cage ties into each rocker cutout thrice. It also ties into the front bumper, rear bumper, and rear spring perches.
Here is a post showing the rocker cutouts tied into the frame rail:
http://www.mallcrawlin.com/forum/sho...&postcount=234

Here is a pic on how it is tied into the rocker, rear spring perch, and rear bumper:


Here is some additional uniframe stiffening:


At some point, the rear floor is probably going to go bye-bye, so I'm hoping that additional uniframe stiffening will allow me (or whoever works on it) to build off of that for the rear frame.

Exo or interior cage? Or both?

IMO, that is a matter of what you intend your cage to do. An exo will help to protect your ZJ's body, but an internal cage would be safer in a roll.

I usually don't like the look of exo cages, but I wanted an exo up front primarily because of head room and in anticipation of the fact that I'd probably be cutting out the B pillar and windshield at some point anyways. The key to a good looking exo, IMO, is keeping tight to the body -- which can be difficult because of all the bends you need to make. IIRC, SB406 needed to do 8 or 9 bends on my lower windshield spreader and 4 or 5 on my upper part.

[SB406]

Looks like Jared has hit most of the major points regarding his build.
Two things to add though-
#1 - Don't start with a truck that is rotted. I ended up replacing most of the floor in the front of Jared's truck. His seats were literally falling through the floor. Part of the job had been started, so my options on repair were limited (hence all of the different pieces of material welded on underneath).
To regain the strength, I used 1/4" plate. It's welded into the area above the "framerail" (see circular welds on floor in Jared's posts), the center tunnel, and the top of the slider supports. This adds huge rigidity in a side load situation, and triangulates the rock rail supports.

#2 - Don't start with a heavilly abused truck. Most of the reason why things got "carried away" on Jared's cage is because EVERYTHING was smashed. As I explained to Jared, shapes add strength, but smashed is not a shape. His truck was wheeled HARD, half rotted, with no doors, pivoting on the B-pillars. Anything that would protect you in a roll was now kinked. So, I wrote off any strength from the roof and decided to build a cage that could hold the rest of the truck together.

Overall, I think it turned out pretty decent for what we started with.

[SB406]

How have people's cages held up with different materials?
Some of my cage is DOM and some is HREW. Both types are 1.75" .120 wall. Have have dented some of the HREW. I can't say for certain if it would or wouldn't have dented had those pieces been DOM.
This pic shows one such dent. I got side hilled and used a tree to stop me. The tree hit right behind a supporting tube under the hood.

[SirFuego]

Well, I can't say I have HREW experience, but I do know that I've bashed the A-to-C bar hard off of trees in situations where I wasn't paying attention and it hasn't dented. I also had an arguably hard hit on my tailgate tubing backing up with a lot of throttle directly into a tree. I know DOM's not indestructible, but I've been happy with the hits it's been subjected to so far.

[ATL ZJ]

DOM is a lot more crush-resistant than ERW. For an unscientific test, bash two pieces of the same OD and wall thickness with a hammer or crush them in a press. A situation where DOM dents will usually cause ERW to dent deeper or fold flatter.

[indy242003]

I would like to see some pics of some full body rigs with cages from the inside with explainations as to why you built it that way. I've been planning to build mine for a year now, and can tell you that the Grands bring thier own set of challenges for tubing. I don't want to start hacking sheet metal to "buggy" mine. I want it to still look like a grand. That was never my intention when I started building it. You can do a lot of reading on cage designs, but the Grands are a different beast that requires attention to detail. I'm subsribing to this and look forward to using the leasons learned from you guys. I think this has the potential to be one of the best threads of all time on MC.

[SirFuego]

Here is a good thread with an exo-internal combo:
http://www.nagca.com/forum/showthread.php?t=36535

[ATL ZJ]

here is what I did for an internal cage back in the day... It was pretty minimalistic but that configuration didn't last long... If I were to build another internal cage I would add an X in the B hoop and a harness bar. The hardest thing about internal cages is how many bends you have to make to clear parts of the interior and still have room for the occupants.

[slim616]

For my cage right now the only thing I would change is a bunch of rookie mistakes i made as i was bending it and would of moved a few spots were i connected the exo cage into the endo cage. I built my cage with the idea that not if it rolls but when so i reinforced everywhere I though would take a hard hit. Also I kept in mind to build it so the jeep could be lifted by the cage.








ill have to get some pics of how i tied the B and C pillars into the unibody The A pillar is tied right into my sliders.

[BigDaveZJ]

Bump.

Was hoping for a bit more info in this thread. If you've got a cage in your rig, at least post up some pics and talk about how it was built a little bit.

[rstrucks]

I'm hoping to be finishing up my internal/external cage over the three day weekend. I'll post pics when I do.

[dp96zj]

maxx, chad, kraqa, any pics of yall's cages?

[CrawlerReady]

I'll be posting pics in a few days. Made a few changes since I originally built it.

[chadjans]

chad, any pics of yall's cages?

See my build thread for photos, including the internal cage and the changes made to it to date. Putting a cage in a unibody is somewhat difficult but begins with a good suspension system. They all need to tie together.

• 
  What I have learned over the last 10 years:
  
  • Good cages begin with a good suspension.
  • Rockers should be stupid thick and tucked up out of the way (on my to do list).
  • EVERY cage should be made with DOM. HREW dents horribly and does not belong in a cage, only playground equipment.
  • Gussets can never be overused.
  • Invest in a GOOD angle finder and digital level. I use a Bosch http://www.boschtools.com/Products/M...px?pid=DAF220K and Craftsman http://www.craftsman.com/shc/s/p_101...?keyword=level
  • Some of my best tube copes have been done with a chop saw and angle grinder.
  • Long unsupported tubes bend.
  • Dead nodes should be used very sparingly. I have only three. And two of those are on the bumper.
  • Seat mounts and seat belts should be simple and part of the cage (on my to do list).
  • Storage, make sure to think about it during the build, not last.

[SirFuego]

EVERY cage should be made with DOM. HREW dents horribly and does not belong in a cage, only playground equipment.

That's the most common argument for not using HREW, but what about supporting bars (i.e. B pillar triangulation) that aren't going to see any direct impacts even in a rollover?

In the grand scheme of things, I don't know that would really save you much money to run HREW for those supports, but if you are out of DOM and have HREW lying around -- why not use it for those supports?

I agree with the rest of what you said, though.

[ATL ZJ]

• 
  What I have learned over the last 10 years:
  
  • Good cages begin with a good suspension.
  • Rockers should be stupid thick and tucked up out of the way (on my to do list).
  • EVERY cage should be made with DOM. HREW dents horribly and does not belong in a cage, only playground equipment.
  • Gussets can never be overused.
  • Invest in a GOOD angle finder and digital level. I use a Bosch http://www.boschtools.com/Products/M...px?pid=DAF220K and Craftsman http://www.craftsman.com/shc/s/p_101...?keyword=level
  • Some of my best tube copes have been done with a chop saw and angle grinder.
  • Long unsupported tubes bend.
  • Dead nodes should be used very sparingly.
  • Seat mounts and seat belts should be simple and part of the cage (on my to do list).
  • Storage, make sure to think about it during the build, not last.

agree with all these as good rules of thumb. I have a mix of DOM, ERW, and chromoly in my current cage. The ERW is only used as bracing- it is not the primary structure, and none of it is located where it could ever get hit by a rock.

storage is not the only thing that should be considered before building a "cage"... suspension, seating, fuel containment, etc. all need to get figured out before any tube is bent.

And I just use my iphone for a digital level.

[paulkeith]

I've said it before, I'll say it again. Cages should not rely on welds or tubes in bending or tension. Steel tubing has strength in compression. Your cage design should be such that if each node were theoretically a pinned joint free to move, your cage should still be a rigid structure.

[SB406]

One note about HREW-
If you bend it, you're supposed to put the seam to the inside of the bend for the most strength.

[zj95maxx]

posting all my cage build pics here to help out anyone who is planning on making a cage and doesn't feel like searching too much to find pics of ZJ cages inside.




not AMAZINGLY happy with the A pillar, but it works


C pillar, there is like no room to mount plates underneath, so what I did, if you remember I have 1/4 plate where my coils are for my coil traps, perfect spot for tube.




Rear Halo



Top C pillar bar



dash bars






D pillar




seat bar






Spreader bars









Speaker bar









how it connects underneath, the tube inside is welded to a plate, 4 bolts go through to underneath, another plate and tighten the bolts

[zj95maxx]

D pillar

[SB406]

Nice pics.
Another best practice is to not make the plates on the top exactly the same size as the plates underneath when mouting to a body. As the body flexes, you can develop cracks along the edges of the sandwiched plates if they are the same size/ shape.