Today I finished placing and drilling the left nose ribs to the main spar. I then deburred the holes and reattached them.
The next step is to locate and drill the rear ribs that are at the root end. To line them up properly with the top rib, a plumb bob is dropped from the rear spar and the location is marked. Then the plumb bob is dropped from the center of the last jig hole and marked and the distance is measured. Then the plumb bob is dropped from the rear spar at the root end and a line is marked. Then a measurement from that line is made the same distance as the tip end and marked. Finally, the rib is placed and a plumb bob is dropped from the last jig hole and lined up with the mark. The rib is then clamped into place for drilling.
