Trailer Design

[ntsqd]

It seems (to me anyway) that there have been a lot of questions about frame design and weight distribution. How much tongue weight will one design vs. another result in, questions like that.

I had been thinking to try to provide some reference material for those that wanted to figure this all out, but I found that it is already on the web. I don't recall seeing any of these links posted here in the past.

http://www.angib.pwp.blueyonder.co.uk/teardrop/tear83.htm

http://www.angib.pwp.blueyonder.co.uk/teardrop/tear81.htm

http://www.angib.pwp.blueyonder.co.uk/teardrop/tear84.htm

Mods, depending on reception might I suggest that this thread be stickied for easy future reference?

 

[cruiseroutfit]

Great links Thom. You get a couple packages today?

 

[ntsqd]

Great links Thom. You get a couple packages today?

:victory: :wings:
Now to get the rebuild of Patch's front end out of the way so that the 60 mods can commence!!

 

[Martyn]

Great links.

When we prototype we do mock ups of the trailer to get the balance point where we want it.

As most home built trailer designs change as they progress, the initial goal of a well balanced trailer is often lost as the project moves ahead.

In an ideal world the trailer design is done ahead of time, and all the components are on hand. As we all know the real world is some what different.

 

[R_Lefebvre]

Nice pages, this stuff makes me laugh though:

Perhaps the most common advice is that the hitch (or tongue) weight should be 10-15% of the total trailer weight, although some sources quote 10-14% and others quote 8-12%. Alternatively, you may want to stay within a hitch weight restriction on your tow vehicle of, perhaps, 200lb.

Darn it, all these conflicting numbers, which one to use! If we settle on an average of the recommended numbers, the trailer tongue needs to be 11.5% exactly. :coffeedrink:

It just doesn't matter that much. If the trailer is significantly lighter than the tow vehicle, the relevance of the balance is reduced. Heck, if the trailer is really light, and you want 40% tongue weight, go for it. I've had no problems with trailers with 5% or less tongue weight.

Anyway, I'd love to see a thread or sticky with some of the better threads attached. Trailer weight is another big one, maybe some recommended frame sizes. Also, 2x4 box section could be added to those tongue ratings because a number of us with... uh... porkier trailers have used that. :elkgrin:

Back to the weight thing... I re-read the thread about the OJ trailer review and the weight discussion a few weeks ago, and was wondering. The weights in that article, I think like 1400 or 1500 for the Horizon, was that "as configured", ie: with the RTT, spare tires, etc. Or was that fully loaded including all camping gear (food, sleeping bags, etc.)

 

[ntsqd]

Re: Stickies.
What some forums do is instead of having a whole bunch of stickied threads on top they have one stickied thread with a bunch of links. Usually this thread is locked so that only the Mods can edit it.

I hadn't really digested what that page was saying about the various weights. At first skim it seemed like the guess' may hold true for the intended audience, but may not for other applications. At the worst they're something slightly better than groping around in the dark.

 

[R_Lefebvre]

Maybe there's still room for streamlining it. As we discussed, I think most people here would be more interested in assuming a box of evenly distributed mass, where to put the axle, and how long for a tongue.

 

[ntsqd]

I've been thinking on this as time allows. the bulk of the trailer's structure and it's loading could easily be covered by the Partially Distributed Load FBD, but I think that high density objects, like fridges, batteries, H2O/Fuel tanks, and possibly even propane tanks should be added in as point loads. My reasoning is that structure adjacent to those features may need to be more robust than the rest of the trailer.

If the process could be streamlined down to work with that I could see it being very helpful.

Has anyone downloaded that Excel file in the links and played around with it?

 

[Borrego60]

Great information for the future trailer builders.