Rivet count: 1819 + 0 new = 1819
(Updated counts shamelessly lifted from E’s RV14A)
I started working on the elevators this week. I actually got a couple of hours out in the shop on Tuesday, Wednesday, and Friday nights. It was slow going to start with. I spent pretty much all of that time doing the initial prep work. I managed to get the E-1008B ribs cut, smoothed, and primed; then I got the E-00924 and E-01408 foam ribs cut and smoothed; and the two tip rib assemblies put together. It was a bit demoralizing since I managed to get through about a page and a half of the 30 pages in this section. Very slow going.
Well, on Saturday, I really got a good head of steam going. It’s clear that the instructions are getting denser (Van’s assumes you pretty much know what to do now, so it is no longer so specific about deburring and other instructions) and also that I’m getting a bit better at this.
The first thing up was to cut some excess aluminum off the trim tab skins.
With the tabs already bent (yay!), it was hard to use the bandsaw, so I just used my snips. The aluminum is quite thin, so it was an easy cut for both. Just had to pay attention as to which way the scrap was bent off with the cuts. Smoothed out the edges using a combination of a bastard file, my belt sander, and the ScotchBrite wheel.
The next steps looked a little more daunting. I had to make the bends for the close out tabs in the left elevator skin. I was a bit nervous as I just read a post about someone who bent theirs pretty badly. Somebody else made a little custom bending brake to do theirs. I decided to follow the method specified in the instructions and bend the tabs along the side of my EAA table.
This is pretty much lifted right out of the instructions. I used a Sharpie along the bend line and carefully set it up along the edge of the table. I clamped down a piece of particle board to hold everything in place. I was nervous about using my rivet gun to make the bend. I had the pressure turned way down. In fact, there was only about 10 pounds pressure in the compressor (left over from the night before). This worked out perfectly. The gun hit very lightly and slowly made a bend with a very nice radius on it.
When it got closer to 90 degrees, I finished it off by using a 2×4 and a hammer to make a nice clean bend (still with a nice radius). Later on, when I assembled the skins these fit together perfectly.
The left rear spar is a little shorter than the right because it stops short at the root rib. So, the instructions ask to cut off 11/16″ parallel to the beveled end. Luckily, I had a measuring gauge to do this. The awl point made a light scratch (OK since I was about to cut this off) which I enhanced with a Sharpie to make the bandsaw cut. The gauge kept the mark nice and parallel to the original end. Another perfect fit.
The trim tab is attached with a piece of piano hinge. This is not predrilled, so first you add a couple of pilot holes. Later, you have to carefully keep it parallel to the skin edges to install. This part was easy though. I used the edge gauge to make the 1/4″ and 3/16″ measures and lightly scratched at the intersection. I used my pin punch to start the holes and the drill bit didn’t wander at all. The hole eliminated the tiny scratch marks.
The spar on the trim tab side of the elevator (left) is modified to let the trim arm connect to the motor. I needed to use my step drill (first use!) to make a couple of large holes. The 3/8″ bit shaft didn’t fit in my pneumatic drill which was good since it is a much better idea to use a drill press here.
It had been pretty rainy the night before. While cutting the spar holes, I noticed that the bench near the drill press was wet. I looked up and saw:
Yep. The roof is leaking. Right over my work bench (and my recently completed horizontal stabilizer). One of the rafters has a little rot in it too! Because I’m renting the garage, I don’t have a huge new roofing bill to pay, but my landlord isn’t going to be nearly so happy. For the moment, I just hung some plastic between the rafters to drive the drip (as that is all it is) over to the wall.
The next page has you cleco the bottom skins to the 26 internal bits of the elevators. All those internal ribs, and corner brackets, and sheer clips! Suddenly, the former pile of parts looks suspiciously like a pair of elevators!
Things line up beautifully. Time for some match drilling and part fitting. We start with fitting the trim hinge. The illustrations did not quite match my hinge (since my 3 foot section was cut on the next tooth), but it seems to work fine. The positioning instructions are a little dense.
“…cleco the forward half of the trim tab hinge to the bottom side of the top flange of the rear spar…”
You first cleco the hinge half through that pilot hole you made earlier and then clamp the thing to the spar whilst keeping it parallel to the skin. I realized that this was the first real set of measurements that would effect the flying trim of the plane. I was able to keep the hinge parallel within a 64th or so. I made a mark on my steel ruler for the depth I wanted to maintain and adjusted as I went. I had a clamp at the end to hold the whole thing roughly parallel and then clamped and adjusted as I went. The red handled spring clamps were perfect for this part (I abandoned the gun style clamps after the first photo).
Then you do the same on the front spar for the actual trim tab (the one part I hadn’t dug out of the shipping box — but it was easy to find).
After match drilling, you trim the ends to fit. It looks really nice.
Then I had to do a little more match drilling. The E-921 gussets sit on the inboard corners holding the spar to the root ribs. The left one is easy to get at. The right one is too tight to get my drill into with the long 8″ bits I normally use. I just used my right angle drill (another first for the project) to get into the tight corner.
The tip rib assemblies get clecoed in place (and labeled!) for some more match drilling.
The top skins and trailing edges are next. It seemed weird to put the thick edge of the trailing edge wedge aft, but it seems to work. It provides a much beefier trailing edge than the thin wedge used in the rudder. Pretty much your standard cleco, mark with a sharpie, trim to fit deal except you have to add a taper to the outboard edges. Eventually, the elevators get fiberglass tips installed. Those taper to a smooth point instead of the unmodified trailing edge size. So you thin out the edges to improve the final fit. I used my calipers to get matching size. The fiberglass tip is next to the trailing edge for comparison.
I match drilled the close out and sheer clip on the left elevator. I was very pleased with the bends I got earlier. The fit was very nice. You use one of the foam ribs to help hold the shape when you drill. (no pictures).
The elevator horns are the next thing to install. The fit is very tight. I’m glad that I didn’t have to fab these. Lots of precision cuts, welding, and powder coating too. I needed to push pretty hard to get these to seat. But once clecoed in, everything lined up great for the final drilling.
Then the instructions blithely ask you to mark all the parts for proper reassembly, to disassemble everything, and to deburr/finish all edges and holes before dimpling and reassembly. That’s going to take a while!
With no time to finish all that, I used my soldering iron to start stripping blue plastic before calling it a day. I promised the wife I would make lasagna for dinner!
Hopefully I’ll get some time on Sunday to finish the part prep and do some assembly.