Section 6

  • Vertical stab done
    Empennage Section 6
    May 29, 2017

    It took quite a bit of time to decide on a primer and get everything ordered and delivered, so I ended skipping through sections every time something was held up because it needed to be primed. Afterwards, I was able to revisit the vertical stabilizer, and it came together rather nicely without any issues.

    Seemingly any time there is a rib with reasonable curvature, the plans calls to flute the flanges if needed. It isn't entirely clear to me when it's needed, as most of the flanges that I've come across seem to sit pretty flush with the skin after simply getting them at the right angle. Furthermore, all my attempts at using a fluting tool seems to just bend the flanges up and make it worse. Instead, I 3D-printed a little 90-degree alignment and bending tool that seems to work pretty nicely in getting the flanges nice and square. I'll try to put up a section to download all 3D printed tools I've come up with.

  • Vertical stabilizer build getting started
    Empennage Section 6
    May 14, 2017

    The vertical stabilizer took me quite a bit of time to complete for several reasons. 

    First was simply figuring out the process for how to dimple and rivet in various places, some harder to reach than others. Second and more prominently was that I hadn't decided on how to deal with primer yet. Fairly quickly in the build you have to do final assembly of parts, which need to be primed if you choose to use primer. More on that later!

    For dimpling and riveting, I found that the pneumatic squeezer is a little more versatile than I originally thought. At first, I thought it was fairly useless because the most reliable/safe way to dimple or rivet is to place the manufactured head on the far end of the yoke so that the piston compresses the shop head or female die. Other than on the edges of flat skins, however, it's rare you can get the squeezer into this position since most of material that needs riveting is on an outside flange where the body of the squeezer and the material your working with gets in the way of each other. If you reverse the squeezer dimple dies but keep the material flush now on the female side, then it's really difficult to keep the material aligned such that the pilot hits the hole perfectly centered. I found this is a great way to punch unintended holes into parts, and should in general be avoided.

    If you put the material flush against the female side on the interior of the yoke, this causes the squeezer to jump back when you pull the trigger because the piston is pushing the assembly forward. It wasn't completely obvious from the squeezer manual that the piston could be throttled by having a light touch on the trigger. It definitely takes a bit of practice, but it makes the squeezer useful in so many more scenarios. There's still a few cases, like in the image below, where there's not a lot of room for error and I kind of had to try my best to line it up then hit the trigger and pray. I'm almost tempted to get a mechanical hand-squeezer for places that require good control if they weren't $300.