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.

I wouldn't, and if I were to, I'd think that two or three Carbon Fiber rods running through the Fuse to the opposite wing?

Depending on what you are planning to do.
Plug-in wings (tube going through the fuse), plug-in one piece wing. etc.
Balsa built up wing? or Foam cores?

If I put carbon fiber tube on 40 size, I would go with 5/8" or 1/2".

Your dimensions are very similar to EZ ARFs.
It is still better to make the wing one piece for the small size plane.

Your Idea counts here!!
I often wanted a small plane 40 size that I can disassemble stab, wing, fuse in halves and go in a small rectangular case. I know there is a 2M version Pattern plane available this way.

Good luck.

I think thats the Russian built Skyline, the fuse is in two peices for transport in its own case.

Thanks for all your replies guys. I'm trying some techniques that are new to me on a smaller scale before I try them on my bigger pattern ships. The ship in question here is similar in shape (outline) to a tipo. It looks very promising and can't wait to finish it (2-3 weeks.) I'm going to use an aluminum tube I'm just stumped as to what size. Should I use a 5/8" or a 3/4"? That is the question I have. Weight won't be a problem here. Other ships I've built with similar dimensions come in at about 4lbs dry. I figure this one should weigh about 4.5-4.75lbs. By the way Parks, I'm using a foam wing with fixed gear. Again, thanks and keep them coming.

If you are using foam core, either size of tubes will do. Just make sure that you have enough foam on top and bottom of the tube.