Clecoed R-904 bottom rib to the R-902 Spar and enlarged the center 0.125 hole of the forward flange of R-904 to 3/8 " using the hole in R-902 as a drill guide. I clamped a piece of wood on the back to drill into with the unibit and got great results. Final drilled the rudder horn with the spar, rib and shim in place( pics on previous entry ). Clecoed the R-606PP, R-607PP and R-608PP reinforcement plates to the R-902 rudder spar and final drilled. Fluted the R-903 tip rib and R-912 counterbalance rib and clecoed to the spar for final drilling. Then I clecoed the R-913 counterbalance skin to the ribs and final drilled those.
I love unibits--Great Tool
Rudder horn top radiused to fit snug in rib flange