January 14, 2006
So the ribs look good. I still placed the cross brace behind the leading edge 10 mm off from where it should be (because I'm a bonehead), but this piece isn't essential and the plywood coverings give the rib most of its strength anyway. Everything else is dead on, including the shape of the leading edge when I compared them on top of the blueprints. Today, I did the second set of these ribs for the other side of the horizontal stabilizer. It's too bad I can only make two ribs with each jig, it's so easy to just load it in and glue down when the shape is already laid out.
Also, the manual says to make sure you bevel plywood edges when there will be skin butted up against it. This accounts for the different humidity rates of change between birch plywood and spruce, so the plywood doesn't push against the skin and make the wing look sickly. Since the outside of these ribs are covered with the skin of the horizontal stabilizer, I beveled the edge of the plywood strip like this (sorry it's a little out of focus). I'll do this on every edge that will touch skin.
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