Drop down about 1/16" from the top of the aileron to start your hole. Make sure you drill downward at an angle into the "meat" of the aileron stock. Use the same angle on the trailing edge as well. Use 30 minute Epoxy or something similar to install them and don't forget to put something like vaseline on the hinge pin to keep the glue from seeping in and freezing it. You should be able to get about a 1/16" minimal gap when finished. And as always, dry fit first. Good luck and let us know how it turns out.[8D]