With all the subcomponent fabrication complete, today I clecoed the entire bulkhead assembly together and started match-drilling.

In addition to everything else it does, the rear spar carrythrough bulkhead supports the flap actuator arm. This is a weldment that transfers the motion of the flap motor (or hand-actuated bar) to the flaps. The arm rides in two delrin blocks that are drilled to accomodate the arm ends.

Not too much work is required to mount these blocks, just a little effort to lay out one hole and drill it on the drill press. The block is then bolted in place through that hole, aligned to the bulkhead, and the other hole is match-drilled in assembly.

Done and done!