some good roll cage buidling guides

Have you needed it?
The person I got it from had gotten it from someone else who'd gotten it from someone else who'd gotten it from someone else. I assumed if someone needed it you'd call since I've had it for awhile now. It's gotten use too. 3 cars done by it now.

Back to roll cage tech. What's people's preference on intersecting junctions, ie. roof V support to the junction of the windshield transverse bar and the front lateral roll bar? Bend Tech's default on that for my car is to go to the Windshield bar with a big notch and one side and no notch on the other. What I've always done and seen has been to come straight into the center line of the junction so big notches on both sides. On my car I did junctions like that, except the door bar X bars which I have as low as I can get. Scott's 2 door cage from Salta is similar.

Grant,
I'm not sure there is a better way than another. Sometimes it depends on the length of the tubing left over.

I consider headroom when I'm doing this. Usually I go to the centerline of the junction at the main hoop end and go fully on then windshield transverse bar right at the limit of the distance away from the side lateral. That way the bar is fudged over a bit to the middle and not directly over head to allow more headroom. Also I put corner gussets in the windshield bar to side lateral junction.

Like so:

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heymagic

No roll cage is going to stop a 2 or 3" diameter branch from coming thru the car. Seems like one of our old guys (Jimmy Wright)took a branch thru the windshield of a real Escort years ago. I think it hit the seat under the co-drivers arm, no injury.

I seem to remember that as the Pimms in their old Datsun 1200.

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NoCoast
Have you needed it?
The person I got it from had gotten it from someone else who'd gotten it from someone else who'd gotten it from someone else. I assumed if someone needed it you'd call since I've had it for awhile now. It's gotten use too. 3 cars done by it now.

And what if I did? When people sit on things for years, I forget.
Please send it back.

If you need to barrow it, I'll lend it out again.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
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is 3 hours behind Eastern Standard Time.

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Doivi Clarkinen
I consider headroom when I'm doing this. Usually I go to the centerline of the junction at the main hoop end and go fully on then windshield transverse bar right at the limit of the distance away from the side lateral. That way the bar is fudged over a bit to the middle and not directly over head to allow more headroom. Also I put corner gussets in the windshield bar to side lateral junction.

Like so:

Nice ^^^^^^^^^

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heymagic

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Doivi Clarkinen
I consider headroom when I'm doing this. Usually I go to the centerline of the junction at the main hoop end and go fully on then windshield transverse bar right at the limit of the distance away from the side lateral. That way the bar is fudged over a bit to the middle and not directly over head to allow more headroom. Also I put corner gussets in the windshield bar to side lateral junction.

Like so:

Nice ^^^^^^^^^

Between Lina's fireplace mod and now a rally car with a sunroof.. You guys have all the creature comforts figured out..

That setup looks a ton easier to fitup and weld. Do ya'll think that'll normal pass tech/logbook?



Edited 1 time(s). Last edit at 12/02/2011 11:24AM by alosix.

That's what Dave was saying.
He moves the bar to the limit of allowable distance from that junction (100 mm) and then adds the gusset for strength.
So fully legal.

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alosix

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heymagic

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Doivi Clarkinen
I consider headroom when I'm doing this. Usually I go to the centerline of the junction at the main hoop end and go fully on then windshield transverse bar right at the limit of the distance away from the side lateral. That way the bar is fudged over a bit to the middle and not directly over head to allow more headroom. Also I put corner gussets in the windshield bar to side lateral junction.

Like so:

Nice ^^^^^^^^^

Between Lina's fireplace mod and now a rally car with a sunroof.. You guys have all the creature comforts figured out..

That setup looks a ton easier to fitup and weld. Do ya'll think that'll normal pass tech/logbook?

Totally logbookable. Support bar needs to be within 4" of the junction.

What thickness for said gussets? Spec seems to say 1mm right? which for us yanks is 0.039 in, and probably not a common size to find metal in here.

3/64 seems to be about the closest but I'm not sure that's a normal size for sheet

My gut says 1/16 or 1/8 would be easier to work with.

18ga steel is .0478", so just over 1mm. but 18ga is pretty thin for cage gussets, isn't it?

Wouldn't you want the gusset to be approximately the same thickness as the tube itself, so when forces are transferred through them, there's no "crumple zone"?

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---** To be in compliance with the Anarchy **---
Jorden R. Kleier
Baraboo, Wisconsin, USA
1990 Mazdog Protege 4WD
1973

No doubt.. my brain is still stuck on some of the Jeep stuff we used to fab. I don't think anything was ever a 'gauge' metal. Normally 3/16 or 1/4 depending on what we were doing.

Need to go check the rules to see if they have any info on speed holes/dimple dies...

Yup. 18 gauge.
For triangle gussets you want around same thickness of the steel.
For taco wrap around the thinner is sufficient. I think it depends upon the goal of the gusset. Engineers would know better.
I remember the front of the Audi used roll cage tubing as support/bumper. A triangle gusset is where the tube failed in one spot as I recall. The triangle basically pushed into the tubing and tore as it bent in then the tubing ripped apart from there.
18 gauge is nice to work with. The wrap arounds are easy to do, the hole and flare process is easier if that's done, etc.

Let's think about a-pillar supports now.
Again, within 100 mm of the junction. I've done direct to the junction in the past but have also seen people go direct to the sill bar.
I've always intersected the door X directly. As I can do offset cuts now, I was thinking of doing the a-pillar support as one bar that is notched to slide onto the door X halfway. Gussets are a little harder, but keeping it straight is much easier. Thoughts?

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alosix


Between Lina's fireplace mod and now a rally car with a sunroof.. You guys have all the creature comforts figured out..

That setup looks a ton easier to fitup and weld. Do ya'll think that'll normal pass tech/logbook?

That's this car, btw, and it has a logbook and has run two rallies, so yeah.

I really like doing about what the above pictured is....

but instead i like using a "TUBE Gusset", on the windshield side of the junction, which goes to the center line of the "roof bars", then attaching the "A pillar support" bars to where this Tube gusset intersects the half laterals (the allowable 4" down from the top of the windshield)

I like it because it lets you move the a-pillar support bars forward the allowed 4", and not just have them "dead end" in the middle of the tube. It gussets the windshield area a bit. and also creates a nice load path all the way from the bottom of the a pillar, up the support tube, through the gusset tube, through the roof v-bars, to the main hoop, and down to the rear stays/strut towers......i like nice load paths to disperce energy, I don't like dead ended tubes in the middle of bars.