NWHBC Cage Design and Build Thread

[2xtreme]

Over the last couple of years I had been considering building a cage and had several conversations with others here on as well as friends and family who have significantly more cage design and build experience than I do. After lots of discussions and reviewing other's designs I came to the conclusion that for my priorities in a cage, building a hybrid inner/outer cage would really be the best design for me. I know that according to several friends of mine who have much more experience this is NOT a proper cage and will not provide near as much protection as a more "proper" internal cage would, but it fits my needs and priorities well and I am willing to live with the compromise.

My priorities:

1. Seat 5 (two adults and 3 kids) comfortably and safely with no tubes too close to anyone. As well as easy access in and out of the vehicle.

2. Stiffen the unibody and provide some reasonable added strength with limited gain in weight.

3. Roof sliders. Protection for the rain gutter from tree's and rocks.

4. gain experience building a cage for future vehicles.

After pairing up with Jeremy (Megawatt) for the TTC event it turned out he had been thinking about doing something very similar and also had very similar priorities for his vehicle. Only he has a two door that made our two designs more different than one might expect.

One thing led to another and the two of us with the help of Han's (XJourney) and Ryan (Blkxjkrawler) built two complete hybrid cages with similar basic designs for both my 4 door and his 2 door.

Basic design:

1. Full roof halo and cross bars act as gutter sliders and flat roof rack.

2. "A" pillars protect the windshield and mount on both sides of firewall (from top to bottom)

3. "B" pillars are out of the way of passengers and provide as much lateral support and structure to the cage as possible without getting too much in way. They also provide a location for front harnesses. "B" pillars are tied into the front shoulder belt. Jeremy’s “B” pillars needed to allow as easy access as possible to the rear seat.

4. "C" pillars are out of the way of passengers and provide additional structure to the cage and provide a location for rear harnesses.

5. "D" pillars are out of the way of cargo area and provide additional support to the outer halo. Jeremy’s “D” pillars do a much better job of providing a “rear 45 deg support to match the front “A” pillar, there just isn’t much room to provide this support with the 4 door.

Again these cages were derived from our own priorities for the cage and took several others past experience and designs for our cage. These are by no means the "best" or "strongest" way of building a cage.

Pictures to follow.

Michael

 

[2xtreme]

Halo:

"A" Pillars:

 

[2xtreme]

"B" Pillar:

"C" Pillar (most are above):

Michael

 

[karstic]

Dang, That's pretty much the design I have in mind for my XJ (Going in early December).
Did you seal the gap between the roof and tubing going through the roof? If yes, how did you do it?

 

[JBweld]

As Michael mentioned, a few brainstorming sessions and help from Hans and Ryan got us started the first day we bent up the halo's and located where are pillars would be located. The material used is 1 3/4" x .120 wall for both rigs. The harness bar and some tube gussets on my rig are 1 1/2" x .120 wall DOM. I already had plated my "frame" rails with a TNT kit, and had installed my own rec. tube rocker replacements a couple years ago, so I had a good foundation. I ran some .250 wall rec. tube across from the "frame" to the rocker for a tie in, and also to land my B pillar on it. This picture shows the rear tie in, with 3/16 plate on top. Inside the cab, the B pillar is welded to plate. Also the rear spring box is welded to the rec tube.

The rocker doubled as the base to weld my A pillar tube as well. Unfortunately, I lost a few pictures that showed the lower section of the A pillar behind the fender. It is welded at the base to rocker tube, runs tight up the cowl, and is also tied into the upper and lower door hinges.

More to follow.

 

[2xtreme]

Did you seal the gap between the roof and tubing going through the roof? If yes, how did you do it?

Yes. Jeremy built some really cool plates for both sides and welded them to the tubes and bolted through the roof. I am sure he will post pic's and descriptions (I believe their was a learning experience about them . I just used seam sealer both on top and bottom.

Michael

 

[JBweld]

Yes. Jeremy built some really cool plates for both sides and welded them to the tubes and bolted through the roof. I am sure he will post pic's and descriptions (I believe their was a learning experience about them . I just used seam sealer both on top and bottom.

Michael

Yeah, I decided I wanted some plates to spread the load out on the roof panel. I made these out of 3/16 plate, so they're a little heavy. I bent them to follow the curve of the roof down to the gutter. They are welded along the gutter rail, and around the tube. I used 4-5/16" bolts through the flange and roof sheet metal on each of the B and C pillar tubes. Here is a B pillar tube extending through the roof.

The "learning experience" was trying to weld the tubes to the plate with hi-temp rtv sandwiched between the flange and sheet metal. It made a nice fire, and made crappy welds. Good thing I only tried that once. The other three I welded without any sealant, then added some seam sealer around the outside after it was cool.
here's the C pillar. Notice I was able to fit a small gusset in there.

We wanted all the tubing to be as close to the roof as possible, but it made welding the joints very difficult. Some of my welds aren't that pretty, but sometimes there wasn't much option. Here's another view of the back corner with the hatch open, and showing the 1 1/2" tube that braces the end of the halo.

 

[JBweld]

Here's some of my surviving construction pictures. This one was taken while fitting the X bracing between the cross bars.

This picture kinda sucks, but you can see the location of the B pillar.

Fitting the X bracing is complete. After it was all tacked together, I pulled the braced hoop and A-pillars off the Jeep to weld it out. Note that I used tube gussets on the upper corners of the windshield, and that the sides of the windshield are partially covered by the A pillar tube. Obviously this will make windshield replacement a challenge if needed. Michael added a small offset bend on his A pillar tubes at the bottom of the windshield, and did not use the corner gussets for easier window replacement.

 

[JBweld]

Here's a shot of the rear half.

Close up of the C pillar floor plate (3/16"). It was also plug welded to the floor in 4 spots(but sanded down). The diagonal tube should meet the B pillar at the plate, but had to be raised to clear the fuel filler bump, so the plate gusset was added.

I added another tube gusset to the floor plate to spread the load over the unibody "frame" at the bottom of the C pillar. Sorry this is a later picture, but you can see the tube gusset under the other stuff. You can also see the tabs for the rear seat harness and 1 1/2" braces under them that go to floor plates

Here's the harness bar complete and getting ready for paint.

This picture shows the tie in with my quarter panels and tube fenders.

 

[JBweld]

The 2 door rear seat is already a pain to use. I have two kids and still wanted to be able to use it. I also wanted to X brace the B pillars. What I decided to do is a compromise. I know its not the best practice, but the bottom of the X braces do not meet the bottom of the B pillars. This is because I wanted the rear seat occupants to have some leg room. I plated the sill forward of the B pillar with 3/16" plate, and extended it around the lower seat belt loop. The sill plate is plug welded in 4 spots, and also welded to the B pillar floor plate, which is welded to the Rocker and frame tubing. hard to explain, but its pretty damn strong. I also had to put slight bends in the X brave to allow front seat clearance. I know the bends, and the X brace not meeting the bottom of the B pillar legs are not the greatest design, but it meets my needs. You can see the rear seat is still accessible through the cage. I decide not add a front seat harness bar for this reason.

Here's a couple pics of the outside to show what it looks like.

Overall, I really happy with it, It protects the body on trail runs, and I have faith that it will protect me and my family in a moderate roll. I still have to add some padding in the rear section before I haul the kids around in it. I've also added some brackets to hold my hi-lift and a CO2 tank. Works great. The best part is that there are no bars in the front passenger section.

Thanks again to Michael, Hans, and Ryan for all your help!

-Jeremy

 

[Starboard M]

First poster mixed up the A, B, C, and D pilers.


Other then that, they look awesome. The 2 door version is actually pretty close to what I would like to do for mine.


One thing I did notice. Arnt you supposed to have the seat belts and seat tied to the same unit? So if you have your seatbelts on the cage, arnt the seats supposed to be on the cage as well? So if the cage somehow separates itself from the Jeep, you will hopefully not get hurt.
I know that most likely wont happen, especially with your guy's cage, but is that something to think about?

 

[XJ_ranger]

One thing I did notice. Arnt you supposed to have the seat belts and seat tied to the same unit? So if you have your seatbelts on the cage, arnt the seats supposed to be on the cage as well? So if the cage somehow separates itself from the Jeep, you will hopefully not get hurt.
I know that most likely wont happen, especially with your guy's cage, but is that something to think about?

the seatbelts and will hold the seat and the person to the cage... in a hard impact, the steatbelts are what hold you in - not the seats...

 

[karstic]

Thanks for the pics.:thumbup:

 

[RlCHARD CRANlUM]

Looks great. What is the total cost for the 4 door version, how much tube did you end up needing?

 

[JBweld]

Looks great. What is the total cost for the 4 door version, how much tube did you end up needing?

I used about 120ft. of 1 3/4" and about 15' of the 1 1/2" tube
tube on the 2 door. Michael will have to chime in for the 4 door. We got the tubing pretty cheap. I think my total was about $300 for material.

-Jeremy

 

[RlCHARD CRANlUM]

Thanks for the info, and good job.

 

[2xtreme]

I used about 120ft. of 1 3/4" and about 15' of the 1 1/2" tube
tube on the 2 door. Michael will have to chime in for the 4 door. We got the tubing pretty cheap. I think my total was about $300 for material.

-Jeremy

I have about 6 sticks also (120ft) of 1 3/4".

First poster mixed up the A, B, C, and D pilers.

Good catch, I messed up the labeling of the photos. It must have been late when I was posting it .

Michael

 

[Blkxjkrawler]

:thumbup: Guys,
I'll give you another couple months off, then its on to mine:firedevil
-Ryan

 

[90exjay]

I think i need to move up north and get inline on the JMHR fab team.

Sean

 

[Starboard M]

the seatbelts and will hold the seat and the person to the cage... in a hard impact, the steatbelts are what hold you in - not the seats...

Yes, but suppose that the cage and Jeep separate. Seat goes one way and the belts go the other. I can see that ending badly.

Like I said before, I doubt that would happen with this cage, but just as a worst case scenario.

Sidenote, did you ever get your cage finished?