It seems that many builders end up re-doing their trim tabs while working on the elevators. I had a few stumbles with the trim tab, but not for the reasons many others do. For me, a couple of bone head mental mistakes cost me about $20 in replacement parts. Not too bad. The first mistake was the piano hinge that attaches to the trim tab. I'm still not sure how, but I somehow manged to mis-measure which resulted in the length of hinge being one hinge too short. The second mistake (which ended up really not being too much of a mistake), was that a few of the holes that were countersunk in the trim tab spar had a slight knife edge and were ever so slightly oversized. I jumped the gun and quickly reordered a new spar from Van's since it takes nearly a week and a half to get anything from them. As it turns out it is commonplace when countersinking such thin material to have an occasional knife edge. In this application the spar is sandwiched between the hinge and skin, so the added support of the hinge really negates any worries of a few knife edges. Any how, I decided to wait and use the new spar since it was already in transit. Luckily, I was able to source replacement hinge material from my local airport. It was stored coiled up and had a few minor kinks, but I was able to work them out easily and make the replacement piece.
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A whopping 45 min session this evening yielded a milestone for the seemingly endless part prep. I finally set a rivet on the elevator! Well, it was just a nut plate (or plate nut if you prefer) but it was still nice squeezing a few rivets.
Again not many pictures for today's session. Accomplished today were: Priming of all ribs, pieces, and parts, and countersinking the trailing edge.
Being the ever impatient and frugal person that I am, I did not purchase, nor build any risers/stands to go on either side of my c-frame.....Until now. I don't know how I managed up until this point (actually I do: Multiple contortionist positions along with colorful language) to dimple the skins on the VS and HS. So I decided to stop the job and come up with something.
My solution: -Spare 2x4's, cardboard from the shipping crate, and spray adhesive from the foam rib templates. I started with just a simple "H" shape of the 2x4's but ended up adding one more 2x4 in the middle of the "H" to provide support towards the rear of the c-frame. I could have done without the extra if the "H" was longer but I didn't have enough wood to do both sides so I figured this would work. As it turns out, the whole set up worked great. I was worried about the sturdiness of the cardboard but as it turns out it was a non issue. The best part about the whole thing is that it is extremely light and easily stored on the top shelf! Only one picture to show for today's session. Basically everything was clecoed together and final drilled. I was a little unsure of the elevator horns when I was clecoing them on as they seem to fit a little loose. I ended up clecoing all of the holes on each horn before drilling so it all worked out in the end.
Earlier in section 9 the plans had you bend the close out tabs on both the top and bottom skins. Although dimensions were provided in the plans I must have mis-marked my measurement on the actual skins. I didn't find this out until I clecoed the shear clip in place that is supposed to rivet to the close out tabs and the spar.
This snafu had me calling Van's on Monday morning to see what the alternatives were. My proposal was to fabricate another shear clip that would reach the close out tab. Van's agreed that would work but would end up leaving a 1/4" gap (rather than 1/8") between the closeout tab and the trim tab. The extra space in the gap would be purely cosmetic and create no performance issues. I'm ok with that since I'm not building a show plane. A rare mid week work session came to a quick halt when I became confused as to how the tip rib assemble fits together with the spar assemble on the elevator. I posted my question on VAF.
If all days in the "factory" could seem as satisfying as today I'd build 20 airplanes. Today was a marathon session that seemed to fly by with quite a bit to show for it in the end. The picture below shows where the trim servo will be mounted. Although the motor/mount skid is removable, the servo itself is pop riveted to the mounts. I don't like the idea of have such a permanent mount so I'll probably end up adding some sort of removeble mounting system.
The amount of work accomplished vs the time spent today didn't seem right. After ~3-4 hours this is all I had to show for.
After consulting with Van's an IA buddy came over to help implement the fix. Van's solution was to cut the fractured tab off file it smooth and fabricate an angle tab out of .025. After an hour and a half or so, the fix was complete, the remaining rivets set, and the HS was done.
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