So I decided to build my own popup toy hauler. It is like a cross between a cargo and a popup. I got a lot of inspiration from all of the posts here, especially the build by Fromeo.
I started by buying an old rotten Starcraft for parts. I tore it apart as soon as I got it.
Then I started building a new trailer.
Once I got the base frame done, I started working on integrating the popup components. I first mounted the assembly for the winch and wiffle tree.
I then started laying out the floor framework. I doubled up the square tubing where the tires would go as to keep from having any problems with the floor sagging when it is loaded.
It ended up looking like this once I got the flooring framework done. The jacks are welded on, bearings are all packed and the brakes are all adjusted.