Thursday, September 30, 2010

Roll me up to the bar, boys!

I started Section 24 last night. This is the section that was previously known as "The Section When I Have to Move to the Hangar," but lost that designation when I realized that there was no way I wanted to do all of that Section 23 riveting by hand. Section 24 initially held the title because it is the section in which the rollover bar/hoop gets installed. With the rollover bar/hoop on the fuselage, there would be no way to get the assembly out of the basement.

As I said, I started the building of the roll bar/hoop assembly last night. It comes in four parts: a front and a back, each comprised of a right and a left. The first step, not surprisingly, is to cleco the parts together. The left and right halves of front and back pieces are held together with a plate in the middle where the halves meet, and the front and back are then held together with two long aluminum strips. It's hard to describe, but easy to see. I started by joining the left and right halves of the front hoop.

The strip of aluminum sitting at the edge of the table is the strip that will get clecoed on the inner flange at the top of the hoop. I started by clecoing it at one of the corners of the hoop.

The arrow mark is there to ensure that I get the strip back in the same place after the inevitable disassembly that is assuredly coming in the near future.  There is a similar strip that gets clecoed inside the lower flange.

The upper strip gets slid in between a gap in the upper flange.

I was clever enough to figure that out on my own; the drawing of this in the manual leaves a loy to be desired when it comes to clarity of detail. What I wasn't clever enough to figure out was that the clecos would have to go in from the other side of the front hoop. Otherwise, the hoop halves couldn't be joined.

Do-over. Or mulligan, if you prefer.

As I started clecoing the front and rear halves together, I quickly realized that I didn't have nearly enough of the silver clecos on hand. The preponderance of my collection was safely at home, sitting on the abandoned workbench and not doing much of anything to help. I'd have to go get them. Or, as I finally decided, just call it quits for the night. The roll bar is made of a heavier grade of metal that the for more malleable aluminum I've become accustomed to and is by its very nature somewhat objectionable to work with. It had taken quite a bit of cleco coercion to get the front and rear halves to even come to the negotiating table; arriving at an agreeable alignment was going to be more of a task that I was willing to bite off.

I went back tonight armed with the bucket of silver clecos that had been unconscionably lounging in the basement while their copper colored brethren did all of the heavy lifting. Slackers. They remind me of puppy Cabot, who has recently discovered the Rag Doll Defense when faced with a command to remove himself from a piece of furniture when he has worn out his welcome.

"Cabot, down!"

"Down? Me?? Surely you can see that I have suddenly lost all of my bones and muscles and therefore could not possibly remove myself from this extremely comfortable bed. Without skeletal structure for support and  musculature to provide motive force, it should be clear as day to you that I simply have no choice in the matter."

"Cabot! DOWN!"

"No, seriously. Just look at me! I'm lying here like a mass of hairy Jello. Why, the only way that I could conceivably be moved would be for you to... HEY! PUT ME DOWN!!"

My prediction of the previous evening was almost immediately proven to be true: it took a lot of convincing to get those parts lined up. A lot of cleco wiggling, metal pounding, and swearing finally got the parts closely aligned.

Looking ahead in the manual, I saw that these holes are to be eventually filled with the ubiquitous LP4-3 rivets. Odd, that, since those size holes have always been filled with the copper guys. Hmmm. That could only mean one thing. And that one thing is, of course, a whole lot of match drilling.

Yep! Match drilling, and lot's of it! The metal ended up being more receptive to the bit than I had thought it would be given my first impression of its nature as being inherently obstreperous.  First impressions can be wrong, I suppose. The drilling went easily enough. I finished just as the 6:30 dinner bell started ringing. Tomorrow will find me disassembling the whole deal for deburring. I also caught sight of a couple of words in the next step that sent shivers down my spine: machine countersink. Uh-oh! That's gonna be a big job!

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