Here is the trailer that i built, it is made from .035 316 stainless steel that i scrounged from a old photo formatting machine. I made it so i can carry a Tupperware bin/ small stuff and still be manageable but it also needed to carry a 4 x 8 sheet of ply wood. I made it so that it would convert easily from a 2 x 3 foot bin to the 4 x 4 plus extension. The side rails can be removed and placed in the back creating the 4 x 4 foot platform. the front hitch mount also has a 4 foot extinction so the front of the sheet can be balanced.