Great Build!
One step I didn't see mentioned was the attachment of the camper box to the subframe.
I watched the videos, but couldn't decipher how you attached the two. Did you use bolts or adhesive or both? What kind & how much?
I'm trying to figure out these different little steps before I start my build.
Thanks for the question. It is a good one ... Somewhere in the thread there are pictures of the frame before everything gets mounted.
But, basically it is a 3-point mount.
Front mounts: Custom welded to the frame behind the cab there are two feet or platforms approx 8" square. These were fabricated to attach to the two frame rails (one either side) and then angled outboard. Once the camper was on the frame sitting on these pads, I bolted the camper to them with 5/8" grade 8 bolts through the floor (3/4" plywood with carbon laminate both sides) with big backing plates. These are the fixed, don't move part of the mounts (2 of the 3 points).
Rear mount: This is a teter totter sort of thing mounted on a pivot that is exactly in the middle of the two frame rails and at the rear of the camper box. The part that moves is approx 5' wide and it has approx 4" of swing either side. This means that if the frame needs to twist, it can twist as much as 4" before it tries to break the camper box. The camper box is bolted to the teeter-totter using the same 5/8" grade 8 fasteners through the floor. My guessitmate assumption is that the actual camper box is unlikely to break, but rather it would resit the frame from twisting any more than the 4". After that something else would have to give. This mounting technique is very similar to what is on the Turtle Adventure Truck and also the Earthroamers. I have taken it offroad in Colorado up Mosquito Pass to Leadville (a medium 4x4 trail) with no creaks or growns.
Besides these three points the camper is not mounted anywhere else. The structure of the box & floor is plently strong enough to bridge between these points,
I hope this helps.