Flying Surface Practice Project (Part 2)
Time for the first capital mistakes, and I had a few in a row. I somehow understood that as of .040 material had to be countersunk instead of dimpled. That kind of fit with the spirit of trying every technique in this little practice project. I should have known better. The instructions clearly stated that material should have been dimpled. (note to self : Read the F#@!ing instructions). If this was the real thing.. I could have ordered a new spar. So glad it was a little one and so glad it was a practice project. Guess that’s what it’s there for. Another mistake while we were at it… Countersinking takes out some material, but in the end it’s still a drill. The Middle part of the cage spins, the outer part doesn’t. What happens if you don’t hold on to the outer part?? Well I found out. Drill goes walkabout ((. Was so mad at myself after that one that I called it a day.
Having countersunk the spar of the practice project and dimpled the skin, I figured it was still good practice so I proceeded riveting the skin to the spar. That actually didn’t go together as nice as I wanted. There was minor space between the skin and the spar. Dimple didn’t entirely fit into the countersunk space, resulting in less than convincing result. Drove a few rivets on one side. Then came the dimpled ribs at the end being riveted to the skin. Those were both dimpled and went together prefect. Difficult one was the last rivet in the trailing edge part of the rib/skin. Need that tight quarters set as there is no way to fit in a squeezer in there. Need to read up on this one.
Finally there’s the trailing edge which had to be drilled under an angle. Clamped it to the skin and drilled at an angle as per instructions. In the end I wasn’t satisfied with the result. The Angles differed resulting in poor line when looking across. Next time it happens… make a jig which allows you to drill straight
With the trailing edge having failed to satisfy my quality requirements I can only conclude that this whole flying surface thing has indeed been a learning experience and I cannot imagine having had to learn all this on the real airplane. Did I learn a lot from this project? YES. Will I make other mistakes in the future? Inevitably. However I do feel more confident that the mistakes I made will not come back and as such the project served it’s purpose. I have left the final skin off as I still want to keep this project for some more practice as I go along. I have a few rivets I can drill out or practice doing so, I also have an open skin to practice on so the practice project will continue on as a guinea pig to try out lots of stuff.
Had it be a real project obviously I would have ordered a new one, I would have redone the spar, redone the trailing edge. For the 25$ or so that it cost it was a great learning experience. On to the real thing. Carefully.
