Lite frame for small trailer

[loaderman]

I am designing a 3.5 by 7 foot trailer. This would serve as a base for a tent top. The walls would be about 14 to 16 inch. The idea is to build the box with hinged flaps for a lid then when opened up put a tent on top.
I am doing this to have a roomy 9 by 7 area, decent beds on both sides, ability to stand in the center and it would be lite. Also easy to tow as it would only have a very small frontal area.
Weight is a huge concern. With all the gear for 2 people I would like it to weigh about 600lbs. The trailer including the box at 300lbs or less.
Any advice on the frame design would be appreciated.

I was thinking of using angle iron and making it shaped like a boat trailer. I would put a piece across the back then about 2 or 2.5foot from the back. The sides would angle in at about 4 to 4.5 feet from the back to form the a at the front, no one would be standing within 2 feet or so from the front of the box.
The 1/4 inch plywood sides would would.be glued and bolted to this angle iron frame which would add strength. The 1/2 inch plywood floor would be glued and screwed or bolted on.

What size of angle iron should I use? A 250lb person will be standing on the floor.
Tanks for any help you can give.

[greygoos]

Follow this link to the Design Library. http://tnttt.com/Design_Library/The%20U ... hassis.htm

[loaderman]

Follow this link to the Design Library. http://tnttt.com/Design_Library/The%20U ... hassis.htm

I did look at that. It is designed for a small teardrop where there is no load from people standing. My boat trailer shape is an adaptation from the lite frame shown.
I think that just the box of the trailer with someone standing at the back center with no support under it may break of flex too much.