Originally posted by Rcav8torjc33
I'm designing a 40 size pattern ship with a ws of 52.5" and a projected weight of 4.5-4.75lbs with a wa of 540sq". What size of wing tube would you guys recommend. Thanks and hope you guys have a great day. 
Just my opinion but I wouldn't use a wing tube with a .40-size plane, especially if I was tryingto keep it light. Wing tube structure adds extra weight (4 to 6 oz. min - maybe more counting the tube) and with that small a wingspan, a single-piece design will be stronger and lighter. Heck, with only a 52.5" winspan, you could easily build the entire airplane as one piece with a hatch for radio gear access.