Monday, May 17, 2010

The Shark

Two things about sharks: they have to keep moving, and they have cool gills. How cool? Cool enough that designers have been plagiarizing them for years and years.











They sure look good, don't they? Well, as it turns out they are quite functional too, and I don't mean just for sharks. Although if you ever asked a shark, I suspect he'd tell you that no one really needs them more than he does. The shark has a weakness, though: he has to keep moving to breath. And he has to keep breathing to grow. And he has to keep growing to get big enough to sink a boat out from under that twerp Richard Dreyfuss. Win-win, I figure.

Yes, you're right. This is another one of those long-winded, stretched-to-breaking metaphors. Rather than drag it out any further, here's the deal. I had to move the fuselage to the hangar. It was getting bigger and bigger and was in danger of being beached stuck in the basement. As it was, it was already too big to move in my Subaru. I had to enlist the aid of a slightly larger SUV.

Too slightly, as it turned out. It wouldn't fit in there either.

It had to ride on top.



What's that got to do with the aestheticism and functionality of shark gills, you ask? Is having to move the thing really a thick enough plank to support the weight of that overwrought simile?

Nope.

I have to stop here and share something. This is blasphemous and you may want to avert your eyes. As unpleasant as it is to say, I feel that my inherent honesty compels, neigh, requires that I confess that there are two parts of the RV-12 that I find to be absolutely hideously ugly: the wing tips and the shark gills.

The wing tips have unsightly gaps where the openings between the tabs on the flanges show through, but they are designed for function over beauty. They are (ostensibly) easier to build than messing around with fiberglass, and they have nice hand holds built into them to aid in carrying the wings around when they aren't attached to the rest of the plane. Ugly, but eminently functional.

The shark gills address another building issue. Where the front of the plane meets the back of the plane, there's one of those uncomfortable situations like the east side of a transcontinental railroad being a few feet north of the west side when they first meet in the center. With the RV-12, there's a section that would require a compound curved piece of metal. Rather than create an expensive and hard to produce piece, the designer(s) opted for some curved pieces that would attach together and work their way around the tough spot. I call them the shark gills.

For me, the shark gills have been of those iconic parts where I had seen them on a completed plane and thought "I'll rivet those in myself some day." It was right after thinking "Man, are those ever ugly!"

Today was that day.

I had to finish up a little bulkhead riveting first. Once I realized that I'd be moving to the hangar (Home of the Big Boy Power Air Riveter!) I went on a bit of a riveting strike. Why tear out my tendons using the manual rivet puller when I was going to have the power of compressed air to do my bidding? That said, there were rivets inside of flanges that I'd have to deal with. I've been doing those manually. I figured I'd burn that bridge when I got to it. For now, it was full steam ahead on the bulkhead.



Have I mentioned how easily I get spoiled by power tools? I'll spend an order of magnitude more time and effort trying to force a power tool to do the job than it would have taken to just knuckle down and do it manually. Which is how I ended up pulling the inside flange rivets with the air puller.



Oddly enough, it worked pretty well. Right up until it didn't, anyway.



Just as I did with the manual puller, I used the little metal wedge to get the rivet puller in good contact with the rivet. Unlike with the manual puller, if the little wedge gets a little crooked while I'm pulling, it gets, well, wedged pretty tightly in a bad place. It was quite a chore to get that thing back out of there.

The next step was to put in a slew of plastic bushings. They just snap right into the holes and are very simple to install, but I found that I had to lay the plans on top of the fuselage to figure out exactly where each was to go.



And, at long last, the shark gills!

First, cleco them into place.



It goes something like this:

(You might have to press the play button for the full effect)


And ends like this:



The longerons are the next iconic step. And I hear they are no fun at all.

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