Maybe I'd better elaberate a little---not commenting on whether the scale was accurate in the lower ranges----but rather that I think your construction methods are running unnecessarily toward the heavy side ---It takes an effort to build something at the minimun weight and choices about whether to use the material for minium weight or what ever you have laying around usually is the deciding factor as how the total is arrived at--

I see a lot of heavy wall retangle and square tubing, long heavy flat flanges--no evidence of trying to build lite---sorry if I seem harsh----

Jerry