I cut the flanges that I lay-up previously. I used my Dremel with router attachment to cut the flanges. I had the round patterns that I sanded the inspection covers to laying around. I used the pattern to provide a center for my circle cutting attachment that I made for cutting the initial inpection cover openings (see pictures). This made quick work of the flange cutting. A little sandpaper to clean up the edges and they are basically ready for drilling and installing nutplates.
