THE BIG CUT!!!!

Well, it almost took two weeks for everything to be "optimal," but wouldn't you know it, on Thanksgiving day, conditions finally allowed me to make the big cut. This is the cut to remove the section of the leading edge that will be replaced by a removable piece of metal that will contain the nacelles for my special project, as well as a plain sheet of aluminum that emulates the section that I am removing. This way I can change the type of LE that I want on the airplane depending on my needs and desires for any given flight.

I started with the bottom most inboard edge cutline, and then cut the outboard edge, moving the Dremel tool from the right to the left, after starting the cut from each of the drilled holes in each corner. the skin was clamped to ensure that it would NOT move at all during the cut, by placing the cutline as close as possible to the edge of the board/table, with just enough clearance for the Dremel cutting wheel to make the cut. The goal was to try to leave no more than 1/16th of an inch of extra material, which has to be filed and sanded away in the final preparation steps for the LE. So you have to take into account the thickness of the cutting wheel itself, and then move it just inboard of the cut line to leave just enough excess for final filing and sanding.

The forward part of the LE was set as closely as possible to the other edge of the table prior to clamping, since I anted to make certain that each edge cut would extend as far forward to the halfway point of the bend in the LE as possible, so that when I flipped the LE over to perform the edge cuts on the other side of the LE, I could easily see the previously cut lines from the other side and align the cutting wheel to meet them so that the entire cut line matches from side to side as much as feasibly possible.

Here is the most inboard cut on the bottom:

And then I unclamped the entire LE, and shifted it outward on the table until the most inboard cutline was just beyond the edge of the table, and re-clamped everything in place again. Then completed the cut in this side in the same manner as the other one:

And here are the two cuts shown together, just after I repositioned the LE again on the table for the rear-most cutline:

And here is the bottom after making the rear-most cut on the bottom of the LE:

Each time I repositioned the LE and re-clamped it, I had to decide how best to re-hang the Dremel tool from the shaft of my bar clamps, and then made a dry run without the tool running to make sure that the flex shaft, electrical cord, etc. was free from any binding or interference that might cause me to completely ruin the LE with a rogue cut. Once I was satisfied that the tool was properly positioned for the cut, I turned it on, started from right to left along the tangent line of one of the predrilled holes, and used two hands on the tool at ALL times. I would periodically stop and remove the tool from the LE if I felt that the cut line was drifting in the wrong direction, or getting too close the pre-drawn Sharpee line. I would reset the cutting wheel as necessary to ensure that each cut stayed within the boundary of each drawn cut line.

Next step was to remove everything, and flip the LE over to perform the same cuts on the top side. Here is the sequence of pics for each of those cuts. I followed the exact same procedure as I did for each cut on the bottom side - doing each of the edges first, and then the final cut on the top rear-most edge.

The last pic above shows the chunk of the LE completely removed and sitting on the floor next to the leg of the saw horse. This last part of the rear cut that would completely free the entire piece of metal was the most worrisome part of the cut, because as that cut moved closer and closer to the final edge, I forgot to account for the fact that the entire part will try to bend itself away as the area holding it in place weakens and the gravity of the part being removed starts to fall. This left a small sliver of metal that had not been cut cleanly that I had to carefully remove with the cutting wheel to completely remove the section from the rest of the LE. Fortunately, EVERY cut went more or less as planned, and the part finally fell cleanly away from the rest of the LE. 

Now the bottom half of that bay on the LE looks like a very holey piece of Swiss cheese. The full coffee can of clecoes was very important for this entire process as well, since no clamps could easily be placed in the area just behind each cut, the only thing I could do was find something heavy enough to secure the area of the LE skin just behind each cut to keep it as stationary as possible. The heavy can of clecoes worked extremely well for that. SO with each cut I would place the can as close as possible to the LE skin area, just behind each cut area. This provided enough resistance to the skin to prevent it from rising up or buckling while the Dremel was making the cut. So no bowing or bending of the metal was allowed during each cut. Here are some final pics showing the state of the LE skin along the cut lines, and piece of skin that was removed:

The next steps are:

1. File down the newly cut edges of the LE so that they are straight and smooth

2. Finish drilling the remaining #40 nut plate attach rivet holes in the subskin.

3. Reassemble the LE for hopefully the last time and mount it securely back onto the Wing spar.

4. Make the file folder template and mark the positions of the #30 drilled screw holes in the subskin onto the file folder template

5. Remove the file folder template and use it to draw the boundary lines of the new removable section, and match drill the screw hole locations on the top and bottom sides.

6. Cut and trim the new .025 removable LE section and start clecoing each #30 screw hole of the subskin and the new part, starting from the bottom of the LE.

7. Check the alignment of the new part against the edges of the cutout in the LE and make absolutely certain they are correctly aligned along the bottom edges, with no binding, interference, or bowing, etc.  

8. Continue wrapping/forming the removable section of metal around the bend of the LE skin and subskin, maintaining the contour of the rounded LE.

9. Check the alignment of the screw holes and edges along the top side of the LE, and clecoe all #30 nut plate screw holes, working from the most forward holes along each edge of the removable skin to most rearward holes

10. Make certain that the contour of the front of the LE bend on the new removable section matches the contour of the rest of the LE skin. If not, remove the part, determine if screw hole locations or more trimming of the part is needed, make a new template, and start the clecoing process over from the bottom of the LE once again.

11. IF everything aligns with the rest of the LE skin properly, remove the removeable section and make another section on .025 aluminum sheet to make a second part, by using the contour of he edges of the current removable section and the screw hole locations. 

12. replace the original removable section back on the subskin and LE assembly, and match drill all screw holes with a #19 drill bit.

12. Remove the LE from the wing and the removable section and subskin for hopefully the last time.

13. Debur all remaining screw holes in the subskin and removable LE part, then dimple them with a #8 dimple die for a #8 screw.

14. Reassemble the standard LE parts and the subskin in the cradle, and follow Vans instructions for assembling the LE for the final time. Then place the assembly on the wing and permanently attach to to the wing.

So that's it. Fourteen more steps should result in a completed LE on the left wing with the mod that I had originally intended on making so many years ago.