• Elevator trim tab complete
    Empennage Section 9
    Jul 13, 2017

    The elevator trim tab took surprisingly long to complete, given its size and apparent complexity. First was a fair bit of countersinking through material that is right on the threshold of too thin in my opinion. When countersinking the spar with the hinge cleco'd to the backside, the countersink essentially went completely through the spar and just touches the hinge. A new element I haven't used in the build so far was the use of foam ribs that had to be adhered to the aluminum skin with ProSeal, which is a bit of a mess to work with. First the contact surfaces need to be scuffed and cleaned.

    You mix the ProSeal at a ratio of 10:1 by weight, which was actually a bit challenging given the goopyness of both the accelerator and the base. I hear this stuff doesn't have that long of a shelf life, and I'd like to use it for the wing when I get to it, so now it's sitting in my fridge. Then I clamped it all together and riveted the spar, skin, and hinge together.

    The rivets along the hinge were the hardest part, as a squeezer could barely fit in there, and the rivets were so long that it was extremely hard to get them to compress straight. I probably ended up drilling out half of the rivets due to this. I've found one of the side effects of drilling out rivets through sandwiched material is that it's easy to start creating space between the layers that you can't compress back down. I ended up with a few small pockets of space underneath the hinge that I'm not too happy about. I've flagged it to show to a tech councilor, and may have to redo it. Furthermore, despite doing most of the riveting clamped to a steel beam that I know is perfectly straight, the tab ended up with a very slight bow, but no twist. I'll have to see how well it attaches to the elevator afterwards, but it annoys me slightly.

    The rivets along the hinge were the hardest part, as a squeezer could barely fit in there, and the rivets were so long that it was extremely hard to get them to compress straight. I probably ended up drilling out half of the rivets due to this. I've found one of the side effects of drilling out rivets through sandwiched material is that it's easy to start creating space between the layers that you can't compress back down. I ended up with a few small pockets of space underneath the hinge that I'm not too happy about. I've flagged it to show to a tech councilor, and may have to redo it. Furthermore, despite doing most of the riveting clamped to a steel beam that I know is perfectly straight, the tab ended up with a very slight bow, but no twist. I'll have to see how well it attaches to the elevator afterwards, but it annoys me slightly.

    In the mean time, onward to working on the rest of the elevator!


  • Elevator horn alignment
    Empennage
    Jun 23, 2017

    After checking measurements and alignments multiple times between the elevator horns and the corresponding ribs, I'm convinced the E-905 rib at the root of the left elevator is mispunched. Measuring the right-side E-00906-1, there's about a 3/32" difference in the hole centerings compared with the E-905. As a result, the horn doesn't even come close to fitting on the left side, but the right side lines up perfectly. Now I'm awaiting to get another response from Van's to see what to do about it.

    Update #1: I got a reply from Van's and indeed the rib is mispunched. Supposedly some other RV-14 builders had similar issues. They mailed out a new rib very quickly, but unfortunately they sent the wrong one :( I'm now waiting again to hear back from the service department.

    Update #2: After calling Van's, it was no problem to have them ship out a new E-905 rib. They covered the cost again, and were very friendly about it. The annoying part was that I had to reprime this rib. I am starting to really hate the process of priming parts. The time it takes to scour, degrease, dry, wipe down with alcohol, mix the primer, prep the spray gun, prime, and cleanup takes half a day. That and half of my parts always end up with some orange peel which annoys me to no end. I should probably revisit my spray gun setup, because clearly something isn't quite right. At any rate, I decided to clean up and deburr all the remaining parts in the empennage to prime them together which was a major pain, but hopefully saves me some time in future.


  • Refolding closeout tab
    Empennage Section 9
    Jun 23, 2017

    To deal with my previously botched fold on the closeout tab on the elevator here, I got a response from Van's that suggested to fabricate a new closeout tab from the same type and thickness of material. After putting some thought into this, I couldn't figure out a way to cleanly fabricate one and get it attached flush with the existing tab. Instead, I decided to try and hammer out the existing fold, and refold the tab in the correct position. If it failed miserably, I would just purchase a new skin from the factory.

    I used a backriveting plate and a flush rivet set to hammer out the crease of the previous fold, then used the edge of the same backriveting plate to make a new fold. It actually turned out a little better than I was expecting, albeit my expectations were fairly low. There's still a noticeable blemish between the two creases, but I think I'll actually keep it and hope it gets hidden by the paint.


  • Starting elevator
    Empennage Section 9
    Jun 20, 2017

    The elevator is a surprisingly long section, so I tried to pull out all the components and get them prepped and primed first. What a pain in the butt this is between cleaning, degreasing, scuffing, priming, and all the resulting cleanup of the HVLP gun. It probably took me a half day for one table of parts.

    For my last attempt at priming, I took the advice of only putting on enough paint to just notice a change in coloration (I'm using SW-P60G2). In the end, I think it was much too thin. This time I put it on much heavier, and I think they came out much better. At least it's a noticeable green, as opposed to the barely tinged silver from before. I also reduced slightly less than 200% to about 175%.

    It was inevitable that I missed a part, however, and it had to be a big one like the trim tab spar. Oh well, I guess I'll collect all the tailcone parts soon and try to prime the whole lot next.

    Everything seemed to be going fairly swimmingly until I got to match drilling the closeout tab on the skins near the trim tab. There's about a 1/4" gap from where the shear clip is and where the skin closeout should be. Doh! Not sure how to compensate for this one, so awaiting some feedback from Van's again.


  • Rudder finished
    Empennage Section 7
    Jun 7, 2017

    Got the lead counterbalance installed in the rudder. Not sure if I'm just being paranoid but I'm totally not touching that with my bare hands!

    I've heard of people using ProSeal to fix the nuts on the interior of the counterbalance since there's no access once everything is riveted together. I actually don't have any ProSeal yet, so used Loctite instead before torquing the bolts down. Fingers crossed they don't back out or that's going to be a mess to fix.

    For the trailing edge, I made sure that everything was perfectly straight when getting everything cleco'd together, and indeed it was almost perfect as-is.

    My perhaps less-than-brilliant scheme to keep it that way was to use a steel square beam I found at the hardware store as a backrivet plate, which was also perfectly straight when I bought it.

    I used a standard flush rivet set on the front face. It turns out the force of backriveting just knocks giant dents into the steel, and leaves the trailing edge with a small indent and a bad rivet that needs to be drilled out. So much for that idea.

    Instead, I used some extra aluminum wedge-stock that was used for the trailing edge as a backing plate such that I had 2 parallel faces to use the squeezer. The aluminum stock definitely took some damage and the manufactured heads ended up slightly rounded, but at least the rivets were consistent and cleanly fastened. I alternated sides between rivets, which is what everyone seems to do for aesthetics, but honestly I think it would be more consistent to have all the shop heads on the same side. The resulting trailing edge wasn't quite as perfectly straight as I hoped, but at least there's no warp in it. I'll attempt to use a tool to get out the wavy sections at some point and hopefully straighten it out some more.

    One thing that I forgot to do was to rivet the flanges on the outside rib before closing up the trailing edge. This left me with basically zero room to get any kind of bucking bar in there. In fact, it was so narrow that the rivet couldn't even be fully inserted without hitting the shop head of the rivet on the other side. I purchased some steel chisels from the hardware store that were angled enough to slip it behind the rivet to serve as a makeshift bucking bar, and it shouldn't be a surprise that it didn't really work. This ended up with a cracked rivet. I'm currently leaving it as-is, because I don't think I can do any better at bucking that rivet. I may drill it out and use a flush blind rivet instead, however, which is what I should have done in the first place.

    In the mean time, I'm a few rivets shy near the corners by the horn where I need to find a specialized bucking bar with a toe, but otherwise I think the rudder is complete. On to finishing the horizontal stabilizer!