One of the problematic things is estimating where the aileron cables pass through the wing skin. I made a tool by welding a piece of tubing to an inexpensive clamp, cutting it in two and passing a 3/16 inch rod from each direction from the strut and from the pulley. That ended up indicating the penetration taking place about 2 inches away from the strut tabs and about 11/16 inches inboard of where the tabs meet the skin. After drilling there, the actual penetration ended up being 2-1/16 inches and 7/16 inches respectively. Both sides were about the same. I also fabricated the left and right front galvanized aileron cables.
