Marked and cut out both doublers on the bandsaw. I dilled a starter hole and used a copping saw to cut out the large hole in the doubler. Next I used a sanding drum in the drill to finish the hole. I filled and sanded the edges then marked and drilled the pilot holes.
Welcome to my builders log for Sonex S/N 767. It won't be as big as a real 767 but if you scale the speed I bet it will be almost as fast
Dave's Sonex Builders Log 