Front cage hoop with plate steel bottom half instead of tubing

[bax]

The OP asked me to post this link on his thread.

http://classicbroncos.com/forums/showthread.php?t=246390

 

[lowbush]

so if I take my lower legs and bolt through the side firewall and on the other side there is also a plate, but that plate has a piece of tubing running from top to bottom that's cut in half.....would that provide some decent 3 dimensional strength?????

Yes so long as the outside tube and the inside tube meet at the transition point. If you have a span of area between the two e.g the inside tube ends at the top of the internal plate and the external tube begins at the bottom of the plate, it will be just as weak as not having it at all, the tubes have to overlap, and they need to be isolated so that they cannot separate from each other in a roll over, e.g a plate welded to it, with 4 bolts that hold it in axis with the other tube, this of floor plates for frame tie in, it's kind of the same principal.

 

[ntsqd]

Why not just narrow the dash instead of slotting it? Fit the dash between the windshield legs. Then you can forget about all of these gyrations to keep the tube out of the window cranks/glove box/door openings.

 

[u10072]

Mainly because the dash real estate is so small. The behind the dash isn't a bad idea at all if you are so inclined.

 

[ntsqd]

Seems to work fine in mine. ~5 inches of width isn't a huge loss. Looked for a pic of it and I don't have a good one.

Raided Quinn's FB page & got some.

 

[bknbronco]

im trying to keep mine stock not chop it all up and turn it into another trailer queen. Plus how you gona run a dash pad like that? Totally NOT what I wana do

Thanks bax....ill look over that this weekend

 

[ntsqd]

Not what you want to do, I get that.

I do think that what you do want to do isn't something that can be done SoP on a forum. It really should be designed & engineered by someone who knows what they're doing.

 

[jim3326]

Looks like it done got squated in the back.

Kinda gives it that HumVee look.

Jim W.

 

[bknbronco]

Not what you want to do, I get that.

I do think that what you do want to do isn't something that can be done SoP on a forum. It really should be designed & engineered by someone who knows what they're doing.

Oh god here we go another crash cage able to withstand 400mph wall crash.

You cant have NO I your heart! I know it can be done...hell im half way to being done. There isn't much in designing a cage to keep your truck on its side in a tip over. A single hoop behind the drivers seat is sufficient, so how come so much negativity about wanting a tad bit more protection than a stock style single hoop.

Maybe if I wanted some help I should have started another "my 351 overheats in July and I live in Arizona" thread

Maybe ill let this thread die and then repost my finished pics next summer. Thanks to those that helped along the way...I appreciate the negative comments as well, keeps me on the right path.

 

[STD]

Honestly I don't mind the design but it needs 3 dimensional support.

 

[jim3326]

It's not the slow flop on the side that needs to concern you, it's the blowout at highway speed that directed the way I designed my cage.

Jim W.

 

[ntsqd]

Oh god here we go another crash cage able to withstand 400mph wall crash.

You cant have NO I your heart! I know it can be done...hell im half way to being done. There isn't much in designing a cage to keep your truck on its side in a tip over. A single hoop behind the drivers seat is sufficient, so how come so much negativity about wanting a tad bit more protection than a stock style single hoop.

Maybe if I wanted some help I should have started another "my 351 overheats in July and I live in Arizona" thread

Maybe ill let this thread die and then repost my finished pics next summer. Thanks to those that helped along the way...I appreciate the negative comments as well, keeps me on the right path.

Such drama!
Don't worry, I won't bother you again but if/when it collapses like tin-foil because it was poorly designed and/or fabricated I will say that I told you so.

 

[savage]

What is the difference from bknbronco's design, and the cages you can get from poisonspyder and I see other company's are making the front cage using the same design as poisonspyder. It looks like they are using flat steel to support the front cage. Having some type of front support is better than nothing. http://shop.poisonspyder.com/Jeep-Full-Cage-Kits-s/68.htm

 

[Steve83]

...if/when it collapses like tin-foil because it was poorly designed and/or fabricated I will say that I told you so.

If he's around to hear you say it, then you'll be wrong.

If he's not around to hear it, why waste the time to say it? ?:?

 

[u10072]

My thoughts are simply that the idea is fine if the structure you're bolting to is solid. What he's bolting to ISNT solid. The design he's referencin is bolting on a jeep door frame that has a much more structural component than that of the EB, THE ONLY reason that jeep front cage is built that way is to give the garage/driveway bolt on part jeep guy the ability to add a cage in a couple hours with his 121 piece husky tool set he got for Christmas. If you want to add some welding in there then that can be encouraged. For the effort it took to build that a couple tubes to the floor and some Stroppe style feet would have done so much more. Again if you're going to copy or base a design why not use a proven design.

 

[bax]

If he's around to hear you say it, then you'll be wrong.

If he's not around to hear it, why waste the time to say it? ?:?

Old bronco proverb ?

 

[rjrobin2002]

What is the difference from bknbronco's design, and the cages you can get from poisonspyder and I see other company's are making the front cage using the same design as poisonspyder. It looks like they are using flat steel to support the front cage. Having some type of front support is better than nothing. http://shop.poisonspyder.com/Jeep-Full-Cage-Kits-s/68.htm

Thats my take on it, way the hell stronger than factory, a 80s style smittybuilt rear hoop, or a 4 point. Just not as strong as a 6 point. There are some hardcore people on here that i guess think 6 point all tube is the only option or your a retard. Then there is the fact that 95% of 6 points are not frame tied and i think they are fine not tied to the frame if they meet the factory tub channels the body bolts hit. But thats a whole new debate like pipe or tube, or tube or DOM tube.

Some peoples comments on design would of been better recieved if worded more like 'I like the design, some 1/4" thick 1" angle would probably fit with minimal trimming and add alot of lateral structure" instead of "that design will fold , like tin foil and kill you and your passengers"

 

[ntsqd]

I have no problem with the design concept. It is the details of the design and the execution that need to be well thought out. It needs to be looked at from both bending and column/compression failure modes at a minimum. And what it's bolted to, where the loads go, and how they're transferred and/or distributed also need to be addressed.

You're proposing something different, you're setting the standard that all of those that follow in your foot-steps will try to copy. You owe it to yourself and them to do the best job of it that you can. That doesn't mean designing for a 400 MPH impact. It does mean having a realistic grasp of what the loads are likely to be and tailoring the details appropriately.

 

[xcntrk]

Interesting design. I agree it's far better then having no support. I've always been a proponent of some roll-over protection regardless of design is better then nothing at all.

With that said, I don't agree there's enough structure there to support the sandwiched plate. Maybe if it was an all steel tub. The other option would be to bend one of the vertical leading edges of the plate, maybe the inside back. Give it a 90 degree small bend making it that much harder for the steel to collapse with downward pressure. The downside however is that to make that bend on such a long piece of steel would likely require a professional press - which at that point you might as well use tube in the first place

 

[TonyPDX]

bknbronco, did you make any changes to the design you were talking about? I would love to see an update on it....

I have been trying to figure out how to do this myself for several years but I have not pulled the trigger yet.

Certainly are a lot of self-proclaimed experts willing to chime in on a thread like this. Anyone ever model up their cage and Bronco Tub to do a FEA? I bet the amount of force this design would take will astound most people, especially if it is tied into the a-pillar/kick panel and dash and/or cross tube.