Horizontal Stabilizer Update

I’ve gotten quite a bit of work done since my last update. I finished deburring almost all of the parts for the elevators, and after speaking with Ed Kranz about priming before drilling I’ve decided to stick with the original order of priming just before riveting. He pointed out that in the process of assembling to drill the parts and then disassembling to debur them that I would probably scrap off a lot of primer. It turns out that he had to clear primer out of the holes on his plane as well and he suggested just using the reamer by hand. He also suggested attaching a drill stop to the reamer to help with turning the bit in the holes.

I also found time to get the HS spars primed. It took two nights of priming because I was spraying them in the backyard and I ran out of daylight. This was pretty frustrating so I’ll make sure that any more priming I do outside happens much earlier.

I finished deburring the ribs that I replaced as well as the nose ribs. The nose ribs need to be shaped a little bit at their tip so that they don’t create little dents in the HS skin. The plans show you changing the shape of the edges to look more like where I drew the lines on the part in this picture:

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I wasn’t sure about how to do this without removing so much material that there wasn’t much left on the flanges between the hole and the edge of the flange. I emailed Van’s with the picture below to clarify how it was supposed to go and was told the one of the right was more like what I needed to do. Apparently the dents mainly come from the curved part of the flange where it isn’t very flexible.

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Here is what the nose ribs looked like when I was finished:

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I also spent some time fluting the flanges of the ribs. The process that is used to bend the ribs into shape causes them to develop a curve along there length. Fluting involves putting small crimps into some of the flanges which straightens them out. You can see the crimps I added to the rib in the picture below and how flat it sits on the work bench. I was worried about over-fluting it so I went slowly. They aren’t perfect, but they’re much better than they were and are good enough for me.

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Next, I finally started riveting together the front and rear spar assemblies.

After that I clecoed the ribs to the front spar and final drilled the holes they share with the spar web. It’s really cool seeing such a large part coming together.

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Once that was done, I deburred the HS skins and got the cradles ready that will be used to hold the whole stabilizer up while I work on it.

I also had one stringer left that I needed to trim (because I wasn’t happy with the first one I trimmed so I replaced it) and I learned a few things. First, don’t touch the aluminum right after cutting it. It gets very hot, particularly if the band saw blade is dull. I have a nice burn in my thumb showing the edge of the part that I grabbed. Second, don’t try to use a band saw with a dull blade…it doesn’t work very well. Third, I do much better with a hacksaw. I’ve made this same exact type of cut on eight or nine other pieces of aluminum angle, and the ones I did with the hack saw after burning myself and realizing how dull the band saw blade is, are by far the straightest cuts I’ve made so far.

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