After the instrument locations were scribed, I cut the first hole using a 3 1/8" hole saw. I first clamped the panel down to a thick board to the top of my work bench to hold the piece and avoid drilling into the bench top. The hole saw cut thru the aluminum very easily. It may not be easy to make out in the photos, but all cutout locations have a small dot scribed at the center of each hole to aid in locating the center punch. I then deburred, sanded and scotch-brited the hole to smooth the edges. I plan on cutting the large square for the Dynon EFIS before I cut any more of the round holes.
