Next, I managed to mark the rivet holes on the under side of the ribs on both sides. Since I know where the rivet hole are to be drilled. I can start to flute the ribs. Lining the edge of the rib with the arc of the rivet holes in the bottom skin works perfectly to adjust the curve.
Now that the rib contour is roughly figured out. The top needs to be fluted. In order to determine the fluting location the mounting holes need to be marked. I dug out the seat pans and cleco'd them to the assembly.
At this point the mounting holes and defined and I can flute accordingly.
Since the mounting holes are far apart on the top of the rib. I used a nut plate to determine where to flute and not affect the mounting the nutplates.
This ended up to be quite a long tedious process. But its worth it in the end. Most important is to take your time and check the curve by continually clecoing/unclecoing the seat pans to get the right curve. Not that the curve is set, the rib doesn't want to sit in place easily as the rib is slightly too long and rubs on the main spar/F-704 bulkhead.
Reading other build logs it was apparent to pay attention to the area as some have trimmed too much and had edge distance problems. So I marked out the rivet holes drew a center line and then drew a line of where I needed to trim. The trim line still gave lots of edge distance so all good there.
Now that the ribs will fit nicely in place. I started to match drill the rivet holes...Starting from the rear and working forward. Again, a very tedious process, but the center line was very easy to see through the rivet line. I drilled the first hole and confirmed edge distance was ok as the rear most hole is quite close to the end of the rib.
I continued on, Drilling and checking.
By the end of the evening I was just about finished the right rib when I decided to call it a night.
