April 7, 2009

Drilled the Remaining Longeron Holes, made attach straps - 3.5 hrs.

The next step, according to the plans, is to make 4 little straps to attach to the F-704 bulkheads on the inside, to help hold it to the longerons. So I dug through my inventory to find the appropriate material. This is one place where the parts aren't labeled. Others have had some uncertainty here, too. But I found 4 pieces of .063" stock in bag #1982 that are the right width but about an inch too long. This must be the stuff to use, so I cut them to a length of 2-1/16", deburred them, and drilled them to the fuselage.

Here they are, attached to the inside of the F-704 bulkhead. I can see how this strengthens this area, since the bulkhead just sits on top of the edge of the longeron. There's another pair like this on the other side.

Next, the remaining holes in the skin are drilled all the way to the forward end of the longeron. Nice, easy work.

Here's a view of the other side, looking from the inside. This structure is now ready to receive the firewall. Wow! However, when I pulled out the forward bottom skin to check for fitting it to the fuse, I got a big bad surprise.

About three weeks ago when I riveted the bottom skin to the center section, I didn't pay enough attention to the drawings and plans, and put in way too many rivets. The skin was riveted to the seat ribs, and the seat ribs were riveted to the bulkhead, so in my mind none of this was going anywhere and it must be okay to rivet it together. I knew enough to leave the forward row open, because the forward skin must attach there, but I didn't realize that the skin overlaps far enough to reach the rear half of the F-704 bulkhead. What a dumb mistake! That's the kind of self-reasoning that gets me in trouble. When am I gonna learn... study the plans! This could have been so easily avoided. I now have 47 rivets to drill out. And I better be careful not to cause any damage to the bulkhead underneath. I don't even want to think about what a disaster that would be.

Almost all the mistakes I've made on the fuselage have happened because I didn't study the plans enough or pay enough attention to details. I think I need to frame up a big poster for my shop that says "Time spent studying the drawings is NOT wasted time!!!" I guess I'm still not used to the fact that this is not like building wings, where there's so much work and not as much thinking involved and the manual is more explicit. The fuselage kit has an endless number of little details in the drawings that are not spelled out in the written instructions. I'm still in the mode of going down through the written instructions checking things off along the way and I still don't have it in my head to spend more quality time with the drawings. Okay... enough talk.

I spent the next few hours carefully drilling out one rivet at a time. I wasn't about to rush this. I guess if I have any bragging rights at all, it's that I'm now very good at drilling out rivets. I guess I should be... I've certainly done enough of them to qualify for some kind of award, if there were such a thing. Fortunately, there's a very small dimple in the middle of each rivet head. The rivet manufacturers must have had me in mind. It makes a perfect pilot for a drill bit. My technique is to carefully drill down just part way. Then I use a punch, inserting the pin into the rivet. Rocking gently on the pin usually snaps the rivet head right off, then I can gently punch the rest of it out with a careful tap on the pin. Done carefully, this can result in drilling out rivets with no enlarging the hole and no damage.

My careful work and taking all the time necessary resulted in 47 empty holes where there were once rivets.

I'm happy to have this stupid mistake behind me. I sustained no damage to the skin or the bulkhead flange underneath. I feel fortunate that all it cost me was a few hours of my time and a small handful of rivets. With a big sigh of relief, I called it a night.

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Contact me: swayze "at" europa.com (replace "at" with the @ sign... no spaces... you know the deal)