Originally Posted by
rhklenke
You say that you have an F15 and F18 with carbon tubes, and I believe you,
We resorted to testing one of them to destruction in order to make sure. Not really a viable option for the average modeler with a limited budget.
.
Bob
just as interest sake, they are both jet legend jets. The wing tubes are probably 5/8" diameter and about a .100" wall thickness. The weakest point is the attachment of the clamp socket they plug into bolted to the plywood former.
as for testing, if you are scratchbuilding a model you are going to put a 2k + turbine in, I would have zero issue spending the 20 bucks and aluminum tube is going to cost to test as a baseline and then buy a $50 carbon tube to destroy and compare. If you spend a couple hundred bucks on wing tubes for piece of mind on a 4k or more model who cares. It's not hard to test to destruction. As much as I hate to sometimes say it, all the calculations in the world dont work much better than the TLAR method (that looks about right). We put a ton of faith in hollow composite wings that have a thin foam core and you cant see any internal structure.
I have destroyed more items than I care to admit by trying to determine if its up to the task or not. The other thing I have done many times if I am concerned a tube may be not quite strong enough is put a dowel into it where the wing meets the fuse. Usually about 4" long. A hardwood dowel that size weighs very little and what it mostly does is makes it so the tube cannot collapse on itself.