Mold release residue on the inside of molded glass or composite fuselages can prevent balsa servo mounting rails from staying glued to the fuselage interior. This technique solves the problem, saves a tiny amount of weight and removes clutter. Take the four tiny mounting screws out of the bottom of the servo case and remove the case from the servo. The case serves as a template for drilling mounting holes through the fuse. After drilling the first hole, drop a mounting screw through the case hole and let it anchor the case while you drill the next hole, then drop that screw through. You can also drill the holes externally with the case pressed against the outside of the fuse—this works just as well.
Todd Rumsford, San Francisco, CA