End-of-Days Trailer Build (1 Viewer)

[HesterFab]

I finally broke down and decided to register to the site after a long time of stalking silently for ideas from all you guys.

I started building a trailer that is going to be designed as sort of a combination of my go-to-H*** trailer, as well as a good expedition/camp trip trailer.

The basic design premise was to keep it small, have lots of space for water/fuel, make it super tough, and have it so that everything can always be locked and secure. It will have air bag suspension on trailing arms, and the main frame is all 3x2x1/8" steel tubing. The main box is 48"x48"x30" and is made from 1/8" plate.

I've (hopefully) attached a rendering of the basic design (LOTs of little details missing). I've got some more pics to upload that show my progress to date. I hope that you guys can tell me when I'm sucking or doing something stupid cause this is my first offroad trailer build.

 

[HesterFab]

Here are a few pics making the box. I wanted it to be waterproof so I built a return flange on the lid and the bottom section. The end sections I welded and ground all the way around.
I was in sort of rush building the box so I screwed up a few details towards the ends of the return flanges....but nothing that couldn't be fixed later with a grinder and some welding rod.

The box is freaking heavy! So i got some 100# gas struts (Mcmaster part #4138T63) to help open the lid. I've got them mocked up right now and they seem to be a good amount of force. I could have probably used lighter duty ones....but that isn't bigger always better???

Since I'm a noobie I can't upload anymore pics until I get some more posts up I guess....I'll get busy on that so that I can get some feedback on my handle/hinge/latch design.

 

[greentruck]

Looking good so far.

Once upon a time, I wanted to do a lid on our trailer. Using it convinced me to not bother with a lid for now, because that meant everything had to fit under the lid -- and we take a lot o gear when we "rough it." You may want to consider adding a means to tie down gear on top of the lid.

 

[HesterFab]

Thanks greentruck!
I think you are right. I am already realizing that I maybe should have opted to build more of a "medium" size instead of the small one I built. I've got a couple ideas for building a rack on the top of it. I was thinking that if needed, I could switch out to some bigger struts to help hold to lid open if I had a pile of stuff on the top of it.

 

[HesterFab]

Also, I got my Firestone 6781 Air springs yesterday. I'm super excited to start building the trailing arms for them.
Do most people run the compressor on the trailer or mount it in their pull rig? I've never used air springs for anything so I've got some reading up to do on it.
One (stupid) idea I had was to just put a air fitting on the tube frame and use the frame as an air reservoir. That way I would have a fair amount of air if needed for adjustment, tire inflation etc. I know that sort of opens up a bag of worms....anyone have experience doing this?

 

[bikersmurf]

I'd mount it on the rig.

People use bumpers all the time, why not a frame reservoir... But you'd still need a compressor. Although, it could be a smallish 12v one if you've got a reservoir, and aren't inflating tires with it.

 

[bikersmurf]

Air rams would lift it quickly...

 

[HesterFab]

now if I'd only had the idea of using the frame as an air-tank when I welded it to make sure my tie-ins were all good and tight....
I TIG welded all the frame connections so far so even if there is a pinhole leak somewhere I can fix it easily w/o much rework.

 

[bikersmurf]

I can picture a pneumatic ram in each corner to lift the top up about 2 feet... Or a pair in the middle if you've got strong hinges.

 

[ntsqd]

Put enough pressure in it and those square or rectangular tubes will try really hard to become round. Strongly Not Advised, air tanks are round with rounded ends for good reason. There's a lot of history about why air tanks are made like that, some of the lessons learned were fatal. Others were merely catastrophic.
If you really need compressed air storage find a new or used truck air brake tank. They come in lots of different sizes and are both safe and legal to transport on public roads while pressurized.

 

[HesterFab]

Thats a good point ntsqd. I guess I'll leave the idea of pressuring the tank on the shelf.

....but pneumatic rams does sound cool!!!

 

[HesterFab]

So here are some pictures of the frame going together. All the tubes are 3x2x.120. I mitered the front angled connection, but just butted the end tubes together and put a cap on it. I was trying to do something fancy with the cap....but i'm not sure it worked

 

[HesterFab]

Since I hate welding the outside of mitered corners I decided that I would just put bend a doubler plate and put it over the outside corner. The doubler is 1/8" thick. For some reason I thought it would be cool to put some circles in the middle of the plate and run a bead around inside a 1.25" circle.....MIG welding them would have been easy, but TIG welding them sucked. It was a pain trying to get the torch and the rod in there while still being able to see what I was doing.

 

[HesterFab]

Here are some of the end caps I put on the back of the trailer, and the doubler plate all tacked up.

 

[HesterFab]

I started putting the brackets for the trailing arms on the frame rails. Feel free to call me out for fully welding everything before all the pieces are fitted up.....I sort of got ahead of myself. There will be a second bracket on each side mounted to the cross brace

 

[HesterFab]

Here's Pretty much how it sits now. I've got the frame welded out. I added another cross brace right at the angled miter that is not in the pictures though.

I've been working on designing the trailing arms. I'm going to make them from 1.75"x.25 wall DOM, and use 5/8" Heim Joints on the ends. I figured that will give me some level of adjustment for both the length of the trailing arm but also for aligning the wheels. ....If the parts arrive today I might start piecing the trailing arms together this weekend.

 

[HesterFab]

I got the hinge, Latches and handle put on the box. The hinge and latches I bought from Mcmaster, but I couldn't find a handle that I liked so I wasted some time making my own.

 

[HesterFab]

I made some brackets to mount the strut out of 1/8" plate. Since I wasn't exactly sure of the location I wanted I made the mounting brackets with 3 holes so that I could adjust it if needed. The 100# struts are plenty to lift the lid.

 

[HesterFab]

Part of the reason for building the trailer is to store survival equipment when not camping. I live in the Bay Area, and I don't want to be screwed when the "Big One" hits so I wanted to be able to store a lot of water. I found a tank that hold 42 gallons and fits nearly perfectly inside the box. I have started making the brackets to hold the tank, but allow it to be removed when needed. There are 4 total brackets (2 on each side) that will cradle the tank in the corners. I will build two other strap pieces that will bolt into the cradle pieces to hold the tank in place.

 

[HesterFab]

Here is how the box sits now. I haven't riveted the latches on yet. I might wait until I powder coat the box and then put them on.
I have no idea how much the box weighs right now but it is effin heavy! Until it gets mounted on the frame its a nice lunch table for the shop.