4.0 Hours -
Today, my work on the airplane was very slow-going, and it resulted in two bent drill bits, one drilled finger and bunch of neighborhood kid becoming incredibly interested in finding out what I’m building in the garage. The goal for today, which I achieved, was to finish the leading edges to the point where it is time to move on to the fuel tanks.
I started by getting the leading edge inboard ribs ready. Unlike all the other ribs, these ribs are not pre-punched. Using the holes in the leading edge skin as a guide, I roughly marked the locations where the holes will be on the rib. With these marked, I could straighten the rib and not end up with a flute where a hole needed to be.
Once each rib was straightened, I inserted it into position on leading edge/forward spar and drilled the spar to rib holes. Then, I had to prepare the joint plates (W-423).
The joint plates are just strips of aluminum (already cut to size by Van’s). My job is to mark where the holes will be drilled, bend them, jam them between the inboard leading edge rib and leading edge skin, and then drill them at the same time the inboard rib is drilled using the holes in the skin as a guide. Simple enough.
Van’s has you draw a line 1/2″ from the edge of the joint plate. This line serves as an alignment guide for drilling since it can be seen through the holes in the skin. If the line can be seen through the holes, 11/16″ of joint plate should be left exposed. Later on, this exposed portion will receive platenuts for attaching the fuel tank. After the line is on the joint plate, I pre-bent it using one of the inboard ribs as a guide.
Next, I had to insert the joint plate between the inboard leading edge rib and the skin. This is a really tight fit, requiring a little pounding with a soft mallet to get the joint plate in place.
A line drawn on the joint plate is used to position the joint plate under the skin.
Once in place, I hade to carefully measure to make sure the proper amount of joint plate was exposed and the rib was in the proper location. I then started to drill the joint plate and rib using holes in the skin as my guide. After each hole, I would insert a cleco and then carefully recheck the alignment before moving on to the next hole. On one of these holes, I had my hand in the wrong spot on the back side and got nicked by the drill bit…not too deep or painful, and I managed to keep all the blood off the aluminum!
Partially drilled, getting everything to align is a serious pain.
The outboard leading edge rib and joint plate.
Another view of the outboard leading edge rib and joint plate.
Once this process had been repeated for each hole on the inboard rib, I started final drilling the rest of the holes on the leading edge. While doing this, I managed, to “set down” my drill a little harder than intended a couple of times, causing me to bend two #40 drills. I guess I’ll have to order some more.
A picture of me final drilling the leading edge skins.
Finally, I used a unibit to enlarge the holes for the tie-down eye bolts. This was pretty simple to do, but it would be easy to destroy the threads in the tie-down assembly if you try to go to fast.
The tie down eye bolts fit nicely after I enlarged the holes with a unibit.
It was kind of interesting today because a bunch of neighborhood kids kept coming over to watch me work. At first, they just stood at the sidewalk and watched, coming and going occasionally on their bikes. Eventually, a girl decided to ask what I was making. When I told her it was an airplane she said, “cool,” and ran off. She must have told her friends because she returned with two other kids a few minutes later. As if they didn’t believe her, they also had to confirm that I was building an airplane. Of course, they wanted to know if it was a real airplane and where I would fly it. When I told them it was a real airplane and I could go anywhere I want in it, the first girl gave the newer kids a big, “I told you!”
The leading edges are now finished until it is time to take everything apart before riveting. The next line on the instructions says, “Assembling the fuel tanks.” I’ll be elbow deep in black death (tank sealant) soon enough!
