ULTRALIGHT CHASSIS using 1’’by2’’tube 14 gauge is that bad?

[saywhatthat]

I have been dragging by build very concerned on what I have planed for my frame build. Had hope to do a ULTRALIGHT CHASSIS .The planes call for 2 by-2 by 1/8’’ angle.
Here at work shipping crates are constructed from 1’’ by 2’’ tube 14 gauge. So low cost to me.
The pod will be less than 500 pounds. Can survive a 18 wheeler pushing it around..
Dose anyone think that be unsafe.

[Aguyfromohio]

You'll need more frame members than the typical layout using heavier steel, but there's no fundamental reason you can't build a sturdy frame with it.
Since you're getting it very cheap the extra design work, cutting and welding might be worth the trouble.

[QueticoBill]

I'm inclined to think that axleless suspension on a torsion box floor deck would be fine without a separate frame but the stresses in the tongue would still have to be contended with. Short of building up an "I" or tube of tubes, the bending stress at the front edge of the floor would be hard on a 14 ga 1x2.

[swoody126]

you might consider SISTERING 2 sections of 1x2 to achieve the 2x2 spec'd in the plans

for load bearing points like where the suspension attaches you could simply add a length of flat 2"x3/16" to stabilize the sister

my builder built the 10'x30' front porch on my barn w/ sistered 1.5"x1.5" sections giving 1.5"x3" sections and it has held thru some rather fierce stormage

he did use some 3"x3/16" flat for reinforcements on long(10' & 12') spans

if the price is right why knot make up a couple sistered sections and do a bit of load testing

just a ponderment while you're still in the pondering stages

sw

[working on it]

I'm inclined to think that axleless suspension on a torsion box floor deck would be fine without a separate frame but the stresses in the tongue would still have to be contended with. Short of building up an "I" or tube of tubes, the bending stress at the front edge of the floor would be hard on a 14 ga 1x2.

you might consider SISTERING 2 sections of 1x2 to achieve the 2x2 spec'd in the plans

• Maybe not the same thing you are looking to build, but I was aiming for a "light", under 1000 lbs, trailer, to pull behind a HHR or Cobalt. But, I always had as a long-term goal, to make it durable, above all, for future usage in moderate off-road venues. But things got a bit out-of-hand, as more ideas came forward, along with increasing weight.
• I started out with a small, undersized frame (probably under 150 lbs), composed of 11 gauge tubing and c-channel. I added 1.5"x2.5" tubing (front 12", rear 24") to enlarge it to hold my 4'x8' floor, to start. I welded in a central spine running full-length front-to-rear, for floor support, longitudinal rigidity, and as a "sister" piece for the 3"x3"x.187" tubing welded in under it as a single drawbar.
• With a beefed-up steel frame, and the 8" wheels converted to 14", just adding a 3/4" floor brought the weight to 400 lbs; without yet starting on the upper structure, I knew it would never end up a lightweight.
• The trailer frame, with a "torsion box" structure above, and a central spine of tubing below ('not to mention the tongue is welded to three crossmembers), has survived an airborne incident without bending or cracking, so I am glad I added all the extra steel, instead of just building over the original frame, with just plywood. Made it a bit heavier, but definitely stronger.

• 

  original frame.png (397.42 KiB) Viewed 1234 times

  it stayed 50" wide, but length extended to 96"; tongue replaced with longer & stronger piece

• 

  tubular steel for added length and strength.png (298.59 KiB) Viewed 1234 times

  was thinking of using original frame, with treated lumber extensions bolted on!

• 

  different types of steel used in frame.png (498.49 KiB) Viewed 1234 times

  a) 1.5x2.5 tubular, b) 11 ga c-channel, c) 3x3 square tube (6 ft) welded under
• The original trailer's axle and suspension were not up to the job, of handling the 1700+ lbs weight of the finished trailer (are they ever finished?), so those were replaced with a 3500 lb axle (w/brakes), and new springs. The trailer wouldn't have survived the flight over the massive pothole, unless I hadn't reinforced the undercarriage. I'm sure that the axle-less Timbren will be strong enough to handle a similar occurrence, if ever, especially if the trailer is lighter in weight, Just don't skimp in building the foundation!

[QueticoBill]

The OP's 14 gauge is pretty thin compared to the last poster's 11 gauge - 0.0747 versus 0.1196, not to mention substantial size difference. We probably all overbuild, but some of that - for me at least - is to save having to do the engineering so exactly. Hard to even find tables for this material.

[saywhatthat]

Thank you everyone for the fine input. I'M having the caravan frame built for me .
A little more detail .The pod is 82 inches long 52 inch wide. Should be under 400 pounds .
The fabricator for the frame has planed to use a frame like this one by Larry C http://tnttt.com/viewtopic.php?f=35&t=39508&start=15 .
Again thank you