hi fellas. i,ve been cruising the forum for a while, and have decided to get started on my project. i am a retired pilot and consider myself to be an amateur machinist. i am going to have a lot of questions and hope i do not turn into a bore. some additional info. i work part time out of state for a company that parts out airliners. my boss has given me free rein to use parts that would otherwise be crushed for scrap. i have access to every size tube, rods, end bearings, honey-comb panels, cables....you name it.....except steel. i want to be able to use these materials all i can. so lets start with the first two questions... 1.i have the plans for the tandem airbike. what are some thoughts on using 1 x .058 6061-t6 round tube in place of 3/4 x .035 4130 round tube. 2...instead of 1/16 and 1/8 wood ribs use 3/16 or larger honey comb. i am still studying the plans, so i might learn something that prevents this swap. thanks