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Rob's REBVAIR Project
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Date: 3-1-2011
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Number of Hours: 40.00
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Manual Reference: Chapter 5
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Brief Description: Elevator and trim tab
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The left elevator push-pull tubes couldn't be installed until the left elevator was complete (including trim tab), and the trim tab couldn't be completed until I had finalized the trim servo installation. See trim servo log for details.
Now the previous builder had provided me with a 'fresh' 0.016" skin for the trim tab, since he had apparently mis-cut the first one. The trouble was, the piano hinge and some of the trim tab ribs had also been drilled during that failed attempt. So I spent a ridiculous number of hours drilling the new skin to accept old parts and old edge distances. In the end, the piano hinge had a slight bend to it, and, with my head filled with images of failed and fluttering trim tabs, I decided that it needed re-doing. So I bought a new hinge, slightly wider to make edge distancing easier. The trouble with that was that the wider hinge was almost twice the weight of the original...I had not paid attention to the thickness change that accompanied the width change. Crap. So with a nicely fitted extra-beefy hinge just about ready to go, I considered how I'd have to ultimately add more weight to balance the now unneccessarily heavy elevator. This was all going to hell in a handbasket....fast, and all because I tried to make something old match something new. F&%K IT!, I'm going to build the entire thing again from scratch. So pulling out some scrap 0.020" sheets, and using my homebuilt 4' bending brake (every builder MUST have one of these), I creased and bent my way back to a great-looking trim tab. It is still a bit heavier, due to the use of 0.020" instead of 0.016" material, but that's only a 25% weight increase on an already very light control surface....probably only 2-3 oz. I used some of the three 6' hinge sections that came with the kit, as I couldn't figure out why I had so much hinge material anyway....I know the door and windows do, but I was going to order the expensive (but lighter) extruded aluminum hinge material for that application anyway (non structural).
W
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Cleco is holding a hinge pin retaining clip
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trim tab rib spacing
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doubled tab ribs under servo horn
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