I did the mock up of the main wings with wing tubes.

Ive drawn in a 5/8" wing tube that extends 10.625" into the wing.

Is this wing tube diameter big enough? Should I use 7/8"?

Does the tube go into the wing far enough? Im using 24" wing tube

Each wing panel will be about 29" in length. wing root will be cut at an angle to match the fuse sides. Fuse will be about 5" wide at the LE of wing panels, add the wing panels and the fuse, you should get about 65" span.

EZ