Fabbing a Chassis

[RSLaser]

I am helpin a friend of mine build a from scratch rock crawler with a tubed chassis, and were tryin to figure out how many triangles we need betweent the main tubing, and the secondary rails(sidewalls). Im guessing since its only 8 feet long probably need about 10-12 on each side right, or is that too many, too less?
Thx Matt

[duplox]

Originally Posted by RSLaser

I am helpin a friend of mine build a from scratch rock crawler with a tubed chassis, and were tryin to figure out how many triangles we need betweent the main tubing, and the secondary rails(sidewalls). Im guessing since its only 8 feet long probably need about 10-12 on each side right, or is that too many, too less?
Thx Matt

I'm not sure how exactly you're approaching this.. I'd recommend copying someone elses design. Search around for fabricated off road chassis, I'm sure there are plenty out there.
You're most likely going to settle on a laddar type frame to build your chassis out of, right? In this case, I recommend saving your piping, and using shear panels instead. Make it all out of squares to begin with, then weld a piece of thick sheet into the inside of the square. This provides the best rigidity in all directions.
Like this:


Doesnt look very stiff because there is almost no triangulation, but the extensive use of shear panels makes it extremely strong. Not to mention thats probably chromemoly tubing.

[mike@af]

Just a basic tip, there can never be to much triangulation.

[RSLaser]

That pic is siliar but it almost looks like a goofy dune buggy. The guys dad started buldin it in his shop about 9 years ago, suspended it ffrom the ceiling, and left it. Its all scratch built. So theres no squares yet, just a basic shape, almost a roll cage, if you will. if i can get a camera in the near future ill upload them. The dimensions thus far are:
8 1/2' long x 5' wide x 4 3/4' tall (in the driver seat).
It will be equipped with DANA 44 front end, with Ford 9" rear.