It's been designed with a couple design parameters in mind:
Aerodynamic
- Rounded corners everywhere
- Tapered Rear
- Air Splitter between TV and trailer
- Wheel Fairings
- Extendable top to minimize size when towing and maximize size when parked
Light
- Getting a custom trailer frame fabricated to cut undesirable weight and unnecessary strength
- Using foam to construct non-load bearing components (air splitter, rounded corners)
- Using construction techniques similar to old-fashioned airplanes
- Using a CNC to lighten plywood sheets by cutting pieces out. (~100 lbs. saved)
- Covering wood panels with canvas and exterior paint then assembling panels.
Easily Buildable
- Delegate as much cutting as possible to the CNC
- Use as many right angles as possible
- Light panels that are easy to handle
- Very simple window design
With that out of the way, here are some pictures of the design.
Side Profile
Front. The trailer doesn't stick out past the car very much. The wheels might be slightly closer to the trailer depending on the axle I get.
Rear. The tail lights may change yet, these are placeholders.
This is how the rounded corners will be created, the white pieces are plywood pieces and the red is foam.
The foam can simply be cut into a rectangle and glued into place. I'll be 3D printing a curved sanding drum and sanding the corners into the correct shape.
The design is essentially 2 plywood boxes, one inside the other. The inner box is mounted to the plywood floor. The outer box is connected to the inner box by 10 drawer slides oriented vertically, it is raised with 4 custom pneumatic cylinders.
The door and door frame are removable and are replaced by a travel cover which covers the hole left by the door when the trailer is collapsed.
Here's an animation of the setup process.
You can also see the lightweight skeleton style frame for the roof.
The front, right, and rear windows can open 20%. They're designed such that rain won't enter the cabin even if there's some wind. They'll be hinged at the top and the hinge will be covered by a 3D printed flashing. The window in the door doesn't open. There are 2 holes on either side of the front window for the computer fans I'll be using for ventilation.
Cutting specific sections while leaving others allows me to keep most of the strength of the sheet while decreasing the weight significantly. Here's one of the panels (inner box right side). Cutting these pieces out reduces the weight of this panel by about 45%. The 3 wider vertical sections are where the drawer slides will be attached.
I haven't delved into the electrical much, but the plan right now is to run very basic 12V wiring to the computer fans, several interior lights, and one or two exterior lights. There will be a car battery either inside the air splitter in the front or possibly inside the rear hatch depending on how my tongue weight works out.
The pneumatic cylinders are already partially built, I'll be running some pneumatic tubing to each of the corners and pressurizing the system will a small car tire compressor. The roof should lift around 30-40 psi and once it's up I'll place supports in each corner and halfway along the longer walls and then depressurize the system.
The kitchen area in the back has a countertop 40" wide and 35" deep which should give me plenty of room for a propane camp stove and anything else I might need to use. The entire area behind the cabin is storage and there should be plenty of room for a cooler and several containers for food and other supplies.
There should be enough room inside the cabin for clothes and a couple other things if needed.
This is a size comparison to the Generic Benroy plans I found under design resources. The blue lines are the interior of my design and the black lines are the Benroy. My design has a ceiling about 12" higher and the cabin is quite a bit longer as well.
Thanks for looking this over! I realize it's a pretty long post, but I've already done a lot of work on this so I don't want to leave stuff out.
If you have any thoughts on this thing I'd love to hear it!