Finished Dimpling the Remaining Perimeter Skin to Subskin #40 Rivet Holes

Last night I finished dimpling the remaining #40 rivet holes that will attach the outer LE skin to the subskin around the edge perimeter of the removable skin section.  There were some holes in the LE skin and the subskin that I could not reach with the pneumatic squeezer, so those would need to be completed with the C-Frame tool. First I completed all the #40 holes in the subskin, and then I completed the remaining holes in the LE skin.

To do the LE skin, I have to move even more stuff on the workbench out of the way, because all of these remaining rivet holes are on the inboard edge of the skin. This means that the rest of the skin will be hanging off the edge of the table to some extent, and so I had to ensure that there was clearance for that. It was also a trick to get the LE skin from the cradle over to the dimpling table. I needed to remove all clecoes from the LE ribs, mark them for their position I sequence so I don't screw up the location like I have done once before. After the ribs were removed I removed the skin from the cradle and careful moved it over to the dimpling table. Then I ponded out the remaining #40 holes in the top and bottom of the LE skin and placed it back in the cradle. DONE with that step!

Then I had to put some thought into how and when to locate and drill the #40 rivet holes for the nutplates. I was having some difficulty trying to remember if I should use the screw inserted method or the nut plate jig method to drill these holes in the subskin. to avoid the confusion, I had to separate how I was thinking about the Fuel Tank attach holes on the inboard edge of the subskin, from the nutplate holes for the removable section of the LE. The tank attach holes have already been drilled to #19 and are ready for the drilling of the #40 holes for those K1100-8 nut plates. The other nut plate locations for securing the removable section are still only drilled to #30.

For the tank attach nut plates, my dilemma was trying to determine if I should dimple the # 19 screw hole first, and then position the nut plate over the dimpled hole to drill out the #40 nut plate rivet attach holes, or if I should NOT dimple that hole and apply a different technique to locate and drill the #40 holes first, BEFORE I dimple the screw hole.

For the other nut plate holes the decision was a bit easier, because those screw holes have not been enlarged yet, and so I can't dimple those at all just yet for reasons stated in previous posts. A review of my Sept 2017 posts when I did the nutplates for the access panel in the subskin revealed that the #40 rivet holes should be drilled BEFORE the screw hole is dimpled. So my plan for both sets of nut plates is this

Tank Attach nut plates: Use my nutplate jig for K1100-8 nut plates to locate and drill the #40 rivet holes for each of those nut plates.

Removable LE skin nutplates: Us the #30 clecos as I did in the previous post to position the nutplate onto the subskin, and then match drill the #40 rivet holes through the holes in each nut plate.

SO I will be using two different methods to locate and drill the #40 rivet holes for these nut plates, due to the differences in the sizes of the screw holes in each of these sections of the subskin. No pics tonight - I'll do this work tomorrow when I am fresh and awake. This is no time to screw things up now. I'll repeat that same statement when I am finally ready to cut out the section of the LE skin. Still plenty of opportunity to completely mess this up if I am not careful.