April 4, 2009

Forming curve in lower aft end of fwd. skin, started drilling- 6.0 hrs.

Today I continued preparing the left forward side skin. I'm putting the curve in the aft lower end that wraps around the bottom of the fuselage. I did the right one a couple days ago, and it turned out pretty good.

I left off last time with about half the clecos drilled to the angle seen here. After drilling the rest, my crescent wrench is tightened down on this angle and used as a lever to lift up on the skin and bend it to form the conical-shaped curve. The steel plate is used as a stop clamped down to the workbench. It not only holds the skin so it won't move, but it defines a line where the curve starts (or ends). I used the round wood dowel as sort of a "pusher" to help form the curve and avoid any sharp bends or lines. It's hard to explain, but I sort of wrapped the bent up corner around it and pushed down on it.

Here are a couple more shots, showing how it turned out when I was nearly finished and ready for a trial fit to the fuselage.

When I nearly had a right angle, I quit. Time to put it on and see how well it fits. After doing two of these with no cracking (whew!) I think I know one more reason why some builders have a crack develop. While I was bending it up and letting it go, and then doing it again, over and over, trying to bend it just a little at a time until I had enough, I thought... wait a minute... what am I doing? What happens when you take a piece of metal and bend it and unbend it, bend it and unbend it, over and over? Eventually, it cracks and breaks, right? I've done that countless times with wire and other metal things, as I recall. So the manual says to go slow and take your time, but that shouldn't mean bending and relaxing over and over as I found myself doing. When I caught myself doing that, I changed tactics. It's far better, in my opinion, to lift up on the wrench as few times as you have to until you get the bending you want. Otherwise, you're asking for trouble. I hope that makes sense.

Here's the skin, clecoed back in place. The fit of the curve turned out to be very good.

Another view from further back.

Here are a couple shots of the curved area, all clecoed in place. Not bad! I'm going to call this good to go.

Now, with everything clecoed in place, it's time to start drilling! I went back and read the manual again because I wasn't clear about when to drill the skins to the bulkheads and to each other where they join. It talks about drilling the longerons, but how about the rest of the drilling? So I read it again. While it's not totally and specifically clear, it does say that at this point I should "Begin drilling all the holes through the skins and longerons, starting at the tail and working forward." I saw it differently this time. When it says ALL the holes through the skins AND the longerons, I'm taking that to mean that we do all the drilling now. Which makes perfect sense to me, after the way things have been done all through the project up to this point. So I'm going to do all the drilling. What you see above, looking toward the tail, is the progress I made tonight. The right side is drilled from the tail up to the F-707 bulkhead. Basically, I started at the tail and drilled up to the next bulkhead, and then alternated from one side to the other, drilling the longerons to the skin one segment at a time.

And here's the left side, drilled about as far as the right side. I'll continue here tomorrow.

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