• Starting tailcone
    Empennage Section 10
    Aug 27, 2017

    This particular section has been taking some time for me with work getting busy, but I'm finally getting around to writing it up. There's a bit of fabrication you have to do for the rudder stops by cutting up some angle stock. I somehow got the measure twice cut once rule backwards and frustratingly had to order a replacement but the second round turned out pretty well.

    Next is getting all the bulkheads riveted with heavy aluminum reinforcements to attach the tail components. These guys were a pain to deburr with all their complex corners and tabs. The squeezer could reach almost all the rivets so I was happy about that.

    In putting the large components together, there was a ton of dimpling and countersinking to do first. Then you start riveting the bulkheads, J-channel stiffeners, and longerons to the skins, which is exciting as you start to get a sense for the scale of the aircraft.

    Here's where I had my first bucking bar incident where the bar slipped off the rivet, and hammered a bad crease into one of the J-channels and the corresponding skin behind it. I did my best to hammer the skin flat again, but the J-channel had to be drilled out and replaced.

    Attaching the side panels was fairly straightforward, but there is a lot of riveting to do here. Some of it is easy, some are pretty hard to reach without two people. Most frustratingly for me was the aft most section where you can barely fit your hand inside to hold the bar. I found that I would inexplicably dent the skin with the rivet gun once in a while and I really couldn't figure out why. Best current theory is that I wasn't able to provide enough back pressure on the bar. I purchased a cheap dent removal tool from ebay to experiment with pulling some of the dents out, but it really wasn't very effective. I'll probably play a bit more with finding ways to smooth these out later as dents drive me crazy.


  • 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.