Also drilled Aileron nose ribs to accept balance tube. I did not have good luck with the forstner bit. The rib I tried it on got damaged and I ended up using a dull harbor freight step bit to finish out the remainder. Also pictured is the easiest way I have found for removing rivets without damaging the hole or surrounding material. The Vampliers screw extractor is perfect for gripping the rivet and gently twisting it out once the manufactured head is drilled to the level of the material, a punch is inserted, and gently break the head off with the punch.