Saturday, June 21, 2008

Good day


Dad and I got some good work done today. When he arrived early this afternoon, I was planning on working on assembling the vertical stabilizer frame, but I had run into a snag: the rear spar assembly was 2” too short. We spent a good half-hour trying to figure out what was going on with that – it looked like we had made everything according to the plans, yet it was short.

We decided to put the vertical stabilizer aside until I could talk to Sonex tech support (only open on weekdays).

We then turned to working on the elevators. Last summer, before my long break from building, we had made the bends for the elevator skins, but that’s as far as we got. A couple months ago, Dad and I had made a rough cut on the the angle of each elevator, and a few days ago I had neatened up the cut, and drilled holes in the hinges that attach the elevators to the horizontal stabilizer.

So today we drilled holes and cleco-ed in the piano hinge and two of the three ribs for each elevator. Once that was done, we did work on the main spar assembly for the horizontal stabilizer. By 5pm, we had all the holes drilled for that as well. Putting, the spar assembly up against the elevators we’d worked on, I could visualize the tail. Very exciting!

After Dad left, I started trying to figure out what was going on with the part we’d put aside earlier. I decided to send off an email to Sonex and wait for a reply sometime next week. I was just about to click “send” when I decided to have one more go at figuring this thing out myself. After some more poring over the plans, I discovered the problem: I had overlapped two pieces of channel that were supposed to meet, but not overlap. There are four pieces that come together at the point in the assembly, and it was a little confusing as to where they began and ended. And sure enough, that gave me the 2 inches I was missing on the assembly. I called Dad to let him know the mystery had been solved.

I spent the rest of the evening remaking the assembly: I had to refabricate both pieces of channel, and used the holes in the spar and the front plate to drill the new holes in the channel. By the end of the night, I had the assembly put back together, minus the rivets.

Remaking parts sucks, but what can you do? It probably sucks enough to make me try harder not to screw them up in the first place. I know I’m getting better at part fabrication, so usually the re-made parts are of a bit higher quality than the first time I made them. It’s probably good to make some mistakes and learn some lessons back on the tail, where it’s a little less costly to remake parts and assemblies – the wings and wing spars are pretty high-stakes.

And lastly – I was admiring our work on the elevators, and it seems like the piano hinge on one of them dips a little on the ends. Grrrrrrr.

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