Frame tube size feedback please

[bobhenry]

If I ever am fortunate enough to have a frame custom built I will follow in Planovets footsteps. The frame c channel becomes the vee tongue there is no way this one is gonna fail. I really liked this setup. I put it in my album to show my welder guy if the day ever comes.

[Dale M.]

I used 2x2 x.120 for base frame, and uses 3x3x.120 for mono tongue.... Plan to "off road" it a bit. I think the vertical wall strength of the 3 inch tube will be enough... And Yes I would run main tongue member to at least a second cross member, it would reduce the torque leverage on first cross member considerably....





Dale

[bansil]

since you mention "offroad" and "rock crawling" I would go with .120 wall for sure as a minimum for any tube that can contact a rock the thinner tube (.078) will dent and rip open.....the sliders i build are 2x3x3/16 tube with 1 1/2" x .120 "steps" the steps will dent, the slider it's self will not.

These allow rocks etc to slide around and not get stuck between tires,I plan on something similar this winter for my trailer.

any bending/failure of tube could hurt integrety of the "cabin area"

just my .02

Here's an example:







Also make sure to reinforce the front spring perches so if a tire gets hung up you won't rip mount off frame or bend it.

[eamarquardt]

The strength of similar tubing (2X2 verus 2X3 for example) a function of the cube of the height of the tubing. 2X2 is proportional to 2 cubed or 8. 2X3's strenght is proportional to 3 cubed or 27. Almost three and a half times stronger when stressed in the vertial direction for a 25% gain in weight. Impressive!

Cheers,

Gus

[boxcar]

Nice nerfs : [img][img]applause:[/img][/img] ...Boxcar...

[kennyrayandersen]

There are equations -- no need to guess. Off road generally uses a factor of 5 rather than 3 for over-the-road trailer design. Look in the design library and if you can't find it I will show you the calculation. You just need to know the overhang from the ball to where it intersects the body of the trailer (this is where the maximum moment will occur). I wrote up something a while back on the tongue design for the uber ultra.

[kennyrayandersen]

alternately you could just factor up the loads by 5/3 to get the off-road sizing