Do you really need a steel frame?

[Lou Park]

I've been looking at the old trailers and the way they were built.
Quite a bit of them had the trailer frames built from wood. So I
start thinking, (yes dangerous) and I wondering what would happen
if you were to build the floor of your trailer with 2x6 lumber on the
left and right with 2x4 spreaders. Use 1/2" plywood on top and bottom,
seal everything, bolt your axle to the 2x6's and then use steel channels
bolted to the flooring from the axle to the trailer hitch. I can see no reason
that this wouldn't work. Has anyone done this in the past? Any thoughts?
Lou

[dwgriff1]

The short answer is no you do not need a steel frame, but it will probably be a lot more work if you avoid the steel.

My trailer is built like an old VW, I have a relatively thin "pan" with a box on top. It works well, but it was not easier nor faster.

Wood has tremendous strength if used right, but there are a lot of pitfalls.

dave

[asianflava]

I agree with Dave, No you don't need a steel frame. Some members of this forum have done it. The question you have to ask is, is it worth it?

It definitely isn't a weight savings. It isn't much of a cost savings because you still need a regular steel axle and coupler. I would venture to guess that it probably isn't as durable in the long run.

Something else to think about. Those "old" trailers were built when highway traffic didn't flow at 70mph. It was also a less litigious time.

[mikeschn]

It was also a less litigious time.

Definitely something to keep in mind.

Mike...

[john]

Angib suggested a lightweight frame like this in the thread below. I wouldn't be comfortable with less metal. I see no reason a frame like this would not work.

http://www.tnttt.com/viewtopic.php?t=26891

[Arne]

I think that frame design is absolutely gorgeous...... solid. just build a tear and set it on top, and good to go.

I do think it is good to tie the tongue to the axle mounts.. other than that the tear box is strong enough to hold its own.

[mechmagcn]

I can't see why a frame as such couldn't work. The teardrop box itself should be strong enough to withstand any rigors of the road, therefore you only need a tongue and axle to move it with.[/quote]

[Steve F]

Depends where you live I think, if I took a trailer to an inspector here in Australia and it didn't have a metal frame I don't think he would pass it, we have quite rigorous inspections before you can get a plate and VIN for a trailer. I'm not saying it wouldn't work or wouldn't be safe but people expect to see a metal frame of some sort these days.

Cheers
Steve

[angib]

Depends where you live I think, if I took a trailer to an inspector here in Australia and it didn't have a metal frame I don't think he would pass it, we have quite rigorous inspections before you can get a plate and VIN for a trailer.

Yes, it would be hard. But Australia does have written rules for the strength of a 'drawbar' (tongue), so it wouldn't be impossible to prove that the trailer was strong enough.

Australian trailer rules

Andrew

[Roly Nelson]

I feel that a teardrop trailer is simply a well designed box, w/2 sides, a solid floor and usually a continuous, curved roof. Pick up any corner and the doors will open without binding. Now, add some angle iron bolted to both bottom sides, attach the desired axle to the iron and secure a continuous tongue to the floor framing and you are good to go.

Back in 1956, I built such a cargo trailer, towed it loaded 2200 miles cross country and back again, no problems. The "next" one will be built the same way, probably with a torsion axle. One suggestion I would like to make, and that would be to NOT enclose the bottom, since it can collect moisture, you won't be able to see it and it could eventually turn the unventilated area into cornflakes. (mold, dryrot and glue seperation)
Roly Just my 2 cents, it worked for me, but follow your own design, as many of us have.

[Lou Park]

Roly, I have to agree. It's a box, however with todays products I would enclose the bottom. If you use pressure treated plywood on the bottom, pressure treated 2x lumber and regular plywood on the top of the floor, filled in with Styrofoam insulation, you should be able to seal everything so moister doesn't get in. But I think the bottom ply is important for structural and anti twist reinforcements.
Lou

[dwgriff1]

I am glad that the wright brothers and their friends did not have a forum like this to follow. All of that steel would have been very strong, but it would not have flown well.

dave

[Mark McD]

Check out the Glen-L boatbuilding site. I think they had plans to build a boat trailer made up of laminations. I think it would be cool to have a woody tear on a magnificent looking woody trailer. I also think a wooden td trailer would be more practical than a wooden boat trailer given that fact that wood floats and makes launching a boat hard.

[Arne]

If you think about it, there is very little torsional stress on a tear drop. It has 3 wheels (well 2 plus the ball mount), not 4, so the trailer is free to move in many directions with no torsion activity/stress..

[dwgriff1]

A tear is a solid little box. Maybe even a very light weight box. You could pick it up by a corner and it would not flex. So why does it need a tank like frame?

I know the idea of an all wood trailer is anathema to this group, but Howard Hughes built a monstrous airplane out of wood. Wooden airplane were common not too long ago.

Early tears used a pipe like brace from the hitch to the corners of the trailer box to increase hitch strength. I did something somewhat similar using bent oak.

If you built a frame as light as Andrew suggests, it might be as light, but I am not sure it is inherently stronger. When you feel up to it, try to break an oak 2 by 4 over your knee some time.

dave