The string works well, I've also heard of pulling a string through using a vacuum cleaner wand. With the string, you know where it is going. I also like the paper tubes, they eliminate a lot of hang up with the wire end catching on a rib.

I ran into alieron problems with a Lanier Explorer 40 and I ended up installing a servo in each wing. This was a ARF, so I cout the covering at the servo location and used a piece of thin music wire to fish the servo wire through. It worked fine, so like most problems, there are a number of solutions.

Don