You can BUY a full set of drawings to build that trailer plus about six to ten different trailers from Northern Tool/Hydralics for about $35.00. Takes all guesswork out of the project gives material list, axles to use and best of all an engineers's review of design stamp. I built a 40' 5th wheel hotshot trailer weighs 8000# and can haul 10,000#. PS. GO PENS