Today I did most of the work on building the trim tab. I clamped the E-717 and E-718 horns for the electric elevator trim to the E-619-1-020 skin. I then match drilled all the holes. A couple of these holes also line up with holes for the riblet.
I then aligned the E-721 hinge to the top flange of E-607PP and clamped it down. I match drilled all the holes for the bottom flange of E-607PP and the trim tab skin and then flipped it over and match drilled all the holes between the E-607PP, skin and E-721 hinge.
I disassembled the trim tab and machine countersunk the top flange of E-607PP. I dimpled the bottom flange.
I used my band saw to trim the inboard edge of the aft portion of the E-721 hinge. I smoothed the edges. Finally I deburred and dimpled all of the parts I just drilled. The riblets were challenging to dimple but I managed to dimple all of them using the bucking bar I made during the practice project and the dimple die holder from the C frame in the rivet gun.