Match drilled spar reinforcing plates (E-610PP, E-611PP) and nut plates to the right elevator spar (E-702). Prepped, finished and fluted counterbalance ribs (E-703, E-704). The plans called for using countersunk rivets to attach the inboard rib to the spar. I attempted to use my micro-stop countersink to ream the metal. Before I did it on the rib though, I practiced on a piece of scrap to adjust the depth. When I did this, I kept wallowing out the holes. If I tried to use a shallower depth, the head of the rivet would not be flush as I would have preferred them. I was able to put the countersinking bit into a hand drill and turn it slowly enough to get as close as I think I could without going too deep. It worked out okay.
