I clamped the aft stabilizer spar and the elevator spar together with a 5.5mm offset for the hinges. Then I drilled four of the five holes. The fifth hole will be drilled once I get some aluminum and make my control horn. After the holes were drilled, I bolted up the hinges to test fit them. Everything moved smoothly with no binding. Then I removed all of the hinges, cut the 1/4" ply doublers and glued them on.