Updrilled flaps: Match drilled hinges to flaps using the press I made from 2 book shelves and updrilled all parts to 1/8".Important to keep the flaps flat and in the press when drilling and riveting to insure a flat control surface. Would have been nice if Sonex included a couple extra ribs to use as hight spacers when drilling the leading edge of the flaps & hinges. Cleaned and deburred everything, now ready for riveting.