These are the steps I used to build the sub-assemblies for the Darwin.
1) Assemble the Darwin shell on its side. This will allow you to stand the floor and roof section up and bolt the front and back together. I placed the access door towards the back of the trailer.
2) Mount the angle iron to the inside of the front and back. This angle acts as a door stop and adds rigidity to the assembly. I mounted 1″ in from the edge so the door would be flush when after compressing the gasket seal that will be put on later. I mounted this by drilling holes in the angle iron every 12 inches and then screwing it to the ends of the camper.
3) Mount hinges for the side doors. These side doors will act as the floor for the mattress and mounting of the tent.
4) Mount side doors. I only used a couple of screws to mount the doors since they will be removed later for painting.
5) To add to the rigidity of the Darwin and have a space for placing keys, wallets, glasses, etc. during sleeping, I made a small shelf. This was screwed to the ceiling of the Darwin. This consisted of a 12″ x 64″ piece of plywood for the shelf and a 2.5″x64″ piece of plywood for the center support.
6) Inside of the side doors, I installed wood trim around the three outer edges. This will be used for mounting the tent as well as add rigidity to the door. The wood was 1″ x 2″ pine boards.
7) Install the hooks inside the corners of the wood trim. These will be used for straps that go from the ceiling of the Darwin to the outer edge of the door. They will support the door while sleeping and also act as a tent support.
8) Cut the strap off the ratcheting portion of the strap then drill a hole in each.
9) Bolt the ratchet strap to the ceiling of the Darwin.
10) In the video I also mounted the bike stands to the bike rack piping but did not bolt the assembly to the Darwin.