ORIGINAL: Boomerang1
thickness of the wall is not the issue, I work with ultralights with main wing spars that have only a 1mm wall thickness but the spec of the tubing makes all the difference.
Xair, would you like to elaborate on the spec of the tubing?
Reason: I'm scratch building a 339 & am using an ali wing tube but the spec is 'T4' tubing, not the usual 'T5'
so I'm assuming it's a little softer. It was just a matter of using what was available.
The wall thickness is 1.5 mm x 32 mm dia & it's also being used as the air reservoir for the retracts.
Fatigue issues? The model is smaller than the SM, about 2 me span.
Seems like brick outhouse material to me but you obviously know more about the aviation use of ali tube than me. - John.
Sorry for delay replying I have been away for most of the week.
T6 spec is what you want tensile strength is a bit higher but yield strength is normally double that of T4, not sure where you can go in greece but what you want to use is ultralight/microlight/homebuilders tubing or what is known as structural aluminium 6082T6 or 6061T6