I'm fairly new at constructing wings with wing tubes.

Does anyone have or know of a magic formula or standard for calculating wing thickness vs tube diameter - wing span vs tube length?

I've done some measurements on some of the planes that I and my freinds have and I'm guessing around 50% thickness and 30% to 40% of the span.

Thanks all...

I would select the same size tube as a similar weight airplane carries or you could make up a jig and do 20G test on it, if it passes that, it should survive anything.