trailer frame sizing

[Frozen001]

OK so my plans are evolving on what type/size of trailer I want to build. I am wondering if there are some guidelines on the sizing of the steel frame members as it relates to sizing. I have evolved to wanting to build something similar to s Serro Scotty Sportsman, so I am going to have the frame build by a local welder.

[Camp4Life]

OK so my plans are evolving on what type/size of trailer I want to build. I am wondering if there are some guidelines on the sizing of the steel frame members as it relates to sizing. I have evolved to wanting to build something similar to s Serro Scotty Sportsman, so I am going to have the frame build by a local welder.

You'll have to estimate how much it's going to weigh with everything in it (gear, food, water etc) and then overestimate a bit. It's also important to know where the center of mass will be for axle placement. Will it be heavier in the front end, the rear, or well balanced? If the welder is experienced in building trailers, he should have a good idea how to build it.