Jim,

for the servo leads and air plumbing, what you typically do is produce a duct in the top of the wing. It can be a rectangular duct simply sanded into the core with a piece of CF (like the ones you have as spars) with sand paper on each side and bottom or you can use a piece of balsa. Alternatively, you can just make a cylindrical duct in the upper part of the core below the upper surface using sharpened brass tube. The former is a little easier but both are not that difficult. If you sand the duct into the top of the wing, you can then apply a thin piece of 1/16" balsa between the opening side walls so the sheeting has a surface to adhere to.

Once your ducts are made, you can run thread from the servo wells to the center of the panels to make it easier to route servo lead extensions and/or plumbing. Often the plumbing for the retracts is easier to pull from the center of the base of the retract well just underneath the sheeting. You make the duct and then once the base is sheeted, you can make a small hole in the sheet to pass the tube. The servo leads are often closer to the LE of the wing so you can pass them along a separate duct.

In my Tipo wing, I made arrangements to pass both servo leads and electrical connections to the retracts (they are electric Multicons) along the same path but either setup works. If you like, and you use cylindrical holes in the core, you can even line these with rolled up paper or a cardboard rocket tube. It makes passing the leads a tad easier but its not necessary. I use rolled up paper when making circular holes in the core.

Another good tool to pass leads/tubes is chain link from the hardware store. It is heavy so it naturally "falls" into the holes and "ducts" from one end to the other allowing you to tape your leads or tubes to it and then pull them in place. I would recommend that you install both your extensions and tubes prior to joining the panels but it can also be done afterward - your choice.

David.