May 25, 2008

Got in a good bit a work this weekend on the elevator hinge alignment. I nervously started drilling holes in my spars. I know if I screw up, it's easily fixable with dowels but it still makes me nervous. Because my elevator spar is slightly twisted, I kept it clamped down to the table extensions and put the stabilizer spars down on that.

Following the checklist, I started drilling holes while checking alignment over and over again. The elevator hinges were first starting with the middle control arm. I'm using plain hex nuts temporarily until these get installed more permanently.

Here's a shot of the outer hinge clamped to the elevator using the tape method and to the stabilizer with clamps, while lining things up. You can see that I'll have to add a little wood to the plywood hinge pad because I made those hinges with rivets.

I was worried that my homemade channel nuts wouldn't be flexible enough to account for any slight misalignments but so far, it seems to be working out. It's a good thing the bolt holes in the channel nuts are oversize. Here's an outer elevator hinge after the holes have been drilled.

The next steps are to start drilling holes for the corresponding hinges in the stabilizer spars. This seemed much more delicate since it can really start setting the alignment in a fixed position, so I spent more time making sure centerlines were aligned and perpendicular when necessary. When I clamped the center hinges to the vertical stabilizer spar, it was apparent that the hinges were pulling up too much for good alignment of the hinges. The surface needed to be built up by a very slight amount. I decided to do this with epoxy since the surface will have to be protected with epoxy anyway. I just slathered it on there pretty thick.

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