Hello, this is the design i'm currently working on for my tiny trailer, it's designed to hold a double/full sized mattress and my initial estimate is $2,000CAD/$1,600USD for all parts (before shipping and screws and bolts and other fiddly bits) and should weigh about 200lbs or a little more
basic design uses 2x2x.125" aluminum square tube as the frame on top of torsion split axles and 8" wheels (to ensure the tounge weight is about right but the wheels don't interfere with the door, there will be fenders i just didn't model them)
that gets bolted onto a 1/2" 5x8 foot marine plywood floor (maybe I can use regular plywood and just seal it to save weight) with a shell made of 1.5" ridged foam that's reinforced with poor man's fiberglass (and maybe something on the inside that's ridged and light like thin wood paneling)
Doors are pre-made and just need to be popped right in https://www.teardroptrailerparts.com/doors.html
What are your thoughts on the basic design?
Doors
mattress
walls
Axles
outer coating (tinted orangey red to match my car then sprinkled with copper paint)
stabilizer jacks
fenders