Finished the file folder template, match drilled the #30 screw holes, Transfered the template to the metal

A productive day in the shop today, even though I still don't have much to show for it. I decided to prepare a new file folder using the same measurements as before - 11.75 inches long and 7 13/16 inches wide, since the first one got trimmed to the point that it was no longer a very good match. This time I used a pencil with a very fine point for all the measurements, and I was a bit more precise in my measurements and line drawing, etc. The new file folder template came out pretty good, and was a precise match for the space on the top side of the LE. However, when I taped it all down, I was coming up a bit short on the rear edge of the bottom side of the template. But side-to-side and in the corners everything seemed to be aligned pretty well. I did not worry too much about the short length issue because I knew that the bending of the metal will stretch it just a bit, and I am also going to cut the metal a bit larger than the template, and then scotch brite the edges and sand it  down to the precise fit that I need. SO the edges will be exactly how I need them when it is all said and done. Here is the new template re-taped in place on the top side of the LE:

And next is the bottom side. You can see the gap on the bottom left edge near the corner. 

You can also see some of the screw holes that I have "hand drilled" by using a #30 drill bit and my hands and fingers to align it from the inside of the LE through the outer rib, locating the #30 drilled holes in the subskin, and then turning the drill bit just enough to poke the hole through the file folder template. Here is the view of how I did this from the inside. it wasn't too difficult to locate and drill most of the holes, but the last 2 or 3 tested my creative ability to contort my arms, hands, fingers, and body to get the drill bit into the correct holes.

Of course when I drilled the hole through the template  aligned the drill bit as best I could so that it was going straight through the hole in the subskin, which is not the way it is positioned left free-standing through the hole so I could take the picture.. This actually turned out better than I thought it would, and seemed to result in all the holes being properly transferred to the template.

Here is a closeup of what it looks like when the drill bit poked through the file folder template. I used my finger on one hand to apply opposing force on the paper template from the outside, while I used my fingers on my other hand to turn the drill bit from the inside - quite the parlor trick if I do say so myself.

I continued this process until all the screw holes in the subskin were transferred to the template, then I removed the template frome the LE to continue with the rest of the  steps to transfer the shape and hole locations to the .025 T3 2024 aluminum sheet that I had purchased from Vans long ago.

Next I performed yet another not-quite-so-orthodox procedure to transfer the screw holes to the aluminum sheet as shown below. I used the hand-held drill bit once again after taping the template to the aluminum sheet to "mark" the metal through each of the template's screw holes to drill a small amount of material to mark the locations. I also aligned two of the outer edges of the metal with two of the edges of the template, to reduce the amount of work required to cut the part out of the metal by only needing to cut along two of the 4 edges of the part. I did check the metal first to ensure that the two existing edges were square and straight with each other.

All the screw holes locations were marked after I removed the template from the aluminum sheet:

So far so good. I removed enough material with the drill bit to ensure that it would find its center once I was ready to actually drill each hole. I should also mention that the grain of the metal needed to be aligned similar to the rest of the LE skin, so the orientation of the grain, which parallels the magenta printed info on the sheet, was important to note while positioning the template on the metal sheet. You also have to make sure yo specify how you want it cut when you order it from Vans, so specifying the grain direction should always be done, in addition to the other dimensions and the thickness.

Next was setting the sheet up on the drill boards, clamping everything down, and final drilling all the screw holes to #30. Once I know that this is working out well, the #30 holes in this part and in the subskin will be final drilled to #19, and dimpled for the #8 screws that will be inserted in these holes to secure it to the subskin.

I drilled the holes without the template in place with the protective vinyl covering still in place, clecoing the metal to the drill board as I went. Then I removed the vinyl covering from the metal, deburred the holes on both sides of the sheet, and clecoed the template back onto the metal so that I could redraw the outline of the edges again on bare metal. Previously the lines were drawn on the vinyl covering, so when that got removed, I had to redraw the edges again on the bare metal. Here is the template clecoed onto the metal sheet and the drill board so I could redraw the edges on the metal sheet.

And here is a final shot of the metal with all the #30 holes drilled and deburred, and the vinyl removed, and the lines redrawn. Next steps for tomorrow will be to cut out the part from the metal, trim down the edges, and start form fitting and trimming the part until it fits nicely into the cutout on the LE skin. Before I do that, however, I may decide to go ahead and make another metal part with the edge dimensions but no screw holes. The real trick to this is going to be if the screw holes are in the exact position that is needed to ensure that the part lies completely flush and tight with the rest of the LE skin. If it does not I will have to reposition the screw holes a bit. SO this may take 2 or 3 or more iterations before I have it exactly right.

If the holes are right and the fit is right, the next step is to cleco it all in place and final drill the #30 holes to #19, debur and dimple them in the part and the subskin, which of course also means removing and disassembling the LE once again. Getting there (I hope).

KPR