Today I finished fitting and adjusting the hinge points of the elevators and rudder. This is the point where most people call the empennage complete. Given that it is almost a month until the wing kit is shipped, I won’t call this kit done. Instead, I’ll dive right into working on the fiberglass tips of all the surfaces.
I dare to say that the empennage is nearly done. I have spent the last two days polishing off little tinkering tasks such as trimming elevator counter-weights and trimming the length of the trim tab pushrod. We did a trial fit of the elevators on the horizontal stabilizer. It looks really good. The elevators and stabilizer are very straight and true (no detectable warp). Tanya and I spent a few moments talking about the failure mode of the elevator counterweights coming loose. That would not be good at all and would cause catastrophic control surface lockup. I’ll probably take some “extra” precautions when finally securing the counterweights.
A couple of tips for the first time you hinge the elevators to the stabilizer: Use bent 16d nails as temporary hinge pins and use the wedges created from the trim tab jig to slightly pry the elevator hinges apart when fitting the elevator. These two things make fitting much easier.
Yesterday I completed the rudder leading edge bend. I thought I had a good plan of attack, but it ended up being just an exercise in persistence. I still don’t think I got enough bend in the second edge as there was still a little (relative term) tension in it when I set the rivets. It will be fine, it was just a pain in the rear and I didn’t gain any wisdom to pass on.
Tomorrow I’ll do a trial fit of the rudder on the vertical stabilizer. I expect this to be pretty uneventful. The only thing left to do (other than fiberglass tips) is to drill the elevator control horns to the center hinge bearing. I imagine that I’ll start trimming the fiberglass parts after that as my wing kit isn’t scheduled to arrive until about the beginning of March. Bummer. I guess I’ll have to use the next month to catch up on the rest of my life :). IE. house repairs, boat prep for the up-coming summer, etc.
This week I completed riveting the dreaded trailing edges of all of the control surfaces (right and left elevator and rudder). I probably worried about them too much, or maybe just right, as I think they came out great. They are all very straight.
After the proseal had cured, I unscrewed the angle aluminum from the edge of the bench and removed all of the clecos holding the trailing edge to the angle. Then I cleaned up some of the little bits of proseal in the rivet holes. I had some extra flat rivet sets for my squeezer that I was willing to sacrifice. I ground the face of one of these sets to the proper angle (84 degrees) and carefully squeezed the rivets about half of the way. I alternated the side that the shop head was on for each rivet (one up, the next down). After I had all of the rivets squeezed about half of the way, I went back and squeezed them all about another quarter of the way. Then I got out the back rivet plate and put the mushroom set in the rivet gun and drove (back riveted) all of the rivets the rest of the way. The shop head side looks very good and a very straight trailing edge was easily produced.
Yeah! After all the work, preparation, and hand wringing, the trailing edges are done without incident. Next, we’ll roll the rudder leading edge and fit elevator counterweights.
Today I mixed up the proseal cartridge and glued all of the trailing edges and the trim tab ribs. It was very rushed to get it all done before the proseal couldn’t be worked any more. I just barely made it. I think it went well. Now I have to let all of this stuff sit for a few days before I can rivet the edges together.
This evening I finished deburring and dimpling the elevator trailing edges and did a trial fit. This leaves things ready for some quick cleaning with MEK and then setting with proseal. That will leave the weekend free from airplane building. Maybe I should take the forced down time to go hang out on the boat (different topic) and relax for the weekend. Gotta’ love Texas for 70 degree weather in late January.
Today I received the bench dimpler that I ordered from ExperimentalAero. It is pretty cool, but I’ll have to wait for the next kit (the wings) to try it out.
