"Old Man's Toy" offroad teardrop trailer

[old_man]

While the design isn't purely a teardrop shape, I got my inspiration from teardrops from years gone by. Let me introduce myself; my name is Tom Houston and I am a engineeri by trade. My obsession has to do with Jeep Cherokee's and rock crawling and expeditions. Here is a pix of my tow vehicle.



I've been collecting pieces and parts for a couple of years. The design consists of a custom designed steel trailer sprung with airbags, using a one link suspension configuration with a track bar. Here is a pix of the base parts laid out so I could visualize where to start.



I originally picked up a used drop axle with the plan to flip it for more ground clearance. While this would have worked, the trailer ended up being a bit too tall.

 

[old_man]

I ended up buying a set of spindles and a piece of 2x2x.25 tubing and welding up my own axle. I milled out a square plate and welded it on the axle to hold the brakes. I sandblasted all the brake parts, painted them with caliper paint and assembled the axle.

On a project of this type, it is important to get everything square, so I used one of these.



Here are a few pix of the frame as things progressed.

 

[highlandercj-7]

Perdy slick, yet simple suspension set up. I dig it.

 

[old_man]

Once the base frame was finished, I needed to generate the curved rails for the design. Being a design engineer, I whipped up a home brew bender. I snagged a round tabletop bland from Lowes. It is 24" across and has a beveled edge. I cut a 2" slot in the table top to allow inserting a 1x2 rod as a bending handle. I cut some scrap OSB and nailed and glued it to both sides to provide a guide to keep the tubing centered.







The biggest problem is figuring out your bend allowance and where to start the bend in order to get it to finish up where you want it. As in most design, trial and error is the norm.

Here are some pix of how the trailer sets as of now. I ran out of steel on the weekend and I need to replinish the build fund so I can go buy some more.





I ran out of time this weekend to finish the hitch. It is a vibration isolating fully articulating design based on one I did about 45 years ago on the farm.

 

[Mark Harley]

Looks good! Great idea on the home made bender, the curves turned out great!

 

[toymaster]

I have to say I like it and am impressed. :lurk:

 

[HARDTRAILZ]

NIcely Done!

 

[old_man]

Thanks for the compliments guys. I started fabricating on the farm about 50 years ago and on a different scale do it for a living. I just couldn't bring myself to put a HF chassis under something I was building. Everybody runs 31's on their trailer, right?

I do some pretty hardcore rock crawling and wanted something that could hold up to some serious abuse. I work in both metal and wood, but as it turns out, the wood ends up being heavier and not as strong. My wife calls me a pain in the *** perfectionist, but then in the same breath says, but you do a nice job, like there is no linking of the two.

 

[Mark Harley]

I am inpressed! Keep us posted on the build.
What brand of corner jig are you useing?

 

[toymaster]

Everybody runs 31's on their trailer, right?

I always liked the idea of having matching tires/wheels to the vic. Just makes sense. I run 35" on my trailer but now that I am stepping up to 37s on the jeep I find myself in a dilemma. I guess I'll use the small 35" trailer tires like a bicycle spare tires they put in some vics. Between the air compressor, tire plug kit, jeep spare, and open diffs (if they are not locked) I'll get by

My wife calls me a pain in the *** perfectionist, but then in the same breath says, but you do a nice job, like there is no linking of the two.

I understand....

 

[old_man]

The XJ is running 35's on 5x5.5" Ford bolt pattern while the trailer is running 31's on 5x4.5" Jeep bolt pattern.

I'm thinking about drilling the trailer drums so that they can handle the larger bolt circle as well so in a pinch I could use the Jeep's spare. I carry a full patch kit and CO2 setup. I may just throw in a inner tube for the trailer in in case the damage can't be easily patched.

As far as the corner jig, I actually have two; the good one shown(Bessey) and a HF unit. I don't totally trust the corner jigs. A large t-square and a tape measure are your best friend.

http://www.amazon.com/dp/B0006694FA...nd=1933665535604226593&hvpone=&hvptwo=&hvqmt=

This is quite a bit cheaper

http://www.amazon.com/Hobart-770565-Axis-Welding-Clamp/dp/B002AKIRIU/ref=pd_cp_hi_0

 

[jim65wagon]

Looks like a good start and a fun project!

For the record, our trailer has the same type and size tire as the truck (285/75/16 - technically a 33", but mounted on a vehicle it's about a 32-1/4")

 

[old_man]

I'm going to skin this with Filon. What have you folks used as backer for the Filon? Since my "studs" are pretty close together, I was thinking of attaching it directly to the frame with Scotch 4011 tape. Between the interior and exterior walls will be 1" styrofoam and the frame is 1" steel tubing. If I back it, my choices seem to be luan, masonite, plywood.

 

[Titanpat57]

I would be concerned about flex, expansion and contraction of unlike materials (metal vs. Filon) unless it's a proven, accepted industry standard.

I would consider products that would handle some moisture, in the event of joint failure or some water intrusion. Perhaps marine grade plywood?

One thing that has kind of been in the back of my mind...is if there a condensation concern within the metal itself, due to varying temperature extremes...ie -25 at night, and 60 inside the camper.

I guess I'm not adding many solutions...but the build is coming out great!

Pat

 

[old_man]

What ever I use, I will seal it before putting it up. Filon is routinely used on motorhomes and they have metal frames. I've seen it used on ambulances with Scotch 4011 tape. I am just wondering if the styrofoam backing is enough. I will most likely use a backer board on the inside. I plan to skin the inside with FRP.