After reading Fromeo's build about a dozen times I decided to strip the thing down to the frame and start over and built one based on his.
I will just barely show the trailer build because it is outlined pretty good in this topic http://www.tnttt.com/viewtopic.php?t=40011&sid=6926ea0bf82553904b413d95224e5583
I wanted this one to be a bit different. I wanted a slide out. I don't mind a manual crank one so I got to designing in my head and by trial and error. The solution I came up with is pretty economical, easy to build and easy to operate. It is also completely adjustable and serviceable. Only the couch will slide out so it isn't like it would be the whole side.
So I guess let's get started.
Here is a few pics of the basic trailer build.



Here's what it looked like after paint. My progress after that except for the canvas was documented in the other topic but this is basically what it looked like after I stripped everything off to start this build. Well almost. I did cut off all of the popup components. I braced the top pretty good to hold the quads good and sturdy.


This is basically the slide out section after installing but before adjusting. I took it all apart for paint so I didn't spend any time adjusting it.

Here's how I got there. Basically it rides on bearings on the outside, it has bearings on the bottom on the inside so the upwards pressure will ride along the bottom of square tubing on either side. To run it in and out it is simply a grade 8 piece of all thread that you can use a drill or a hand crank. The coupler nut that works it is the same size as the stabilizer jacks bolt.
This is what the outside of the 1 1/2" square tubing rolls on. These bearings are double sealed and will take over 600 pounds of radius pressure each. In between the bearings are plastic spacers.

This shows the plastic caps that will finish it off.

The next two pics are of the inside bearings. I just took some square tubing and drilled it and pup a pipe nipple through the holes and welded it. I guess I could have brought longer pipe nipples and cut the threads off but I didn't think about it before I did it. There is square tubing on either side of both sliding arms for these bearings to roll against. As you can see they will be easily adjustable and replaceable should there ever be a problem.


I then welded the crossbar and started on the mechanism to make it actually go in and out. I got a weld nut from McMaster Carr along with the other pieces. The weld nut allows you to weld it without screwing up the threads. Here is what it looks like both in and out of the hole.


On the crossbar I just welded a piece of angle, drilled a hole in it and slid the all thread through it with double nuts on either side to keep it from slipping and threaded it into the weld nut. The pic of the weld nut end is when it was tacked, not welded.


These pictures show how it looks slid both out and in. There were 2 men over 200 pounds standing on it and it slid in and out like butter so I'm sure it will work.


I don't show a pic but I did weld a piece of square tubing over the inside of the frame that cover up the all thread. First of all to help keep dirt and stuff out and second because if you use a drill, it starts wobbling pretty good in there when there gets to be more rod coming through. Not so bad when you hand crank it. There is way more bracing on this thing than it will ever need but I just didn't feel like cutting it off so I left it.
I am a lot further than this and will post more pics later and definitely before the weekend is over.