Rudder Lower Fairing

June 25, 2020 – I worked on the lower rudder fairing some more.

The leading edge of this thing has been giving me fits.

Even when I built up the leading edge, by the time I sanded it smooth, the material in front of the rudder horns was paper thin.

So I bent the tabs of the rudder in just a bit to make some room, then I mixed some more resin with flox and caked it inside the fairing at that point. With the fairing in place, it just fills the gap. When it was set up, I removed it all and sanded to smooth it. It fits much better now.

Time to move on. I hate fiberglass.

Time: 4:20

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Elevators and Rudder continued…

May 29, 2020 – A simple plan has turned into trouble for me.

Elevators

I installed the elevators and got ready to drill the control horns.

I clamped the tips in place and in line with the stabilizers.

The left horn is farther aft, so I piloted a hole in that one per the drawings.

I was happily drilling away using drill bushings and reamers. Didn’t pay attention that the hole is supposed to be 3/16″. I made nice 1/4″ holes.

The problem is that the elevators didn’t line up afterwards.

OK. So I took them back off and a friend at the airport welded the holes closed.

I cleaned them up and hung the elevators to do it again.

I’m a moron. I finished the holes with a reamer that is the equivalent of a #9 drill. Now the holes are sloppy, and still not perfectly lined up…

Time to walk away and do other things. I did order the same rod end that goes on the elevator control rod, but with a 1/4″ bore on it. If I can get these straight, I’ll use a -4 bolt instead.

Rudder

I got a new internal rudder stop from Flyboys, since I over-adjusted the last one. This one came out much better.

Time: 7:35

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Tail Light

May 8, 2020 – I finished the wiring for the taillight on the rudder.

I installed the molex connector (provided by AeroLEDs) to the pigtails on the light.

I drilled the hole in the vertical spar for the wire to pass through. After a lot of thought and soul-searching about how to route this wiring, I looked on the RV7 Plans CD I got from Van’s. I found OP-56 which covers tail lighting. So I drilled the hole as dictated by this drawing. It goes in the upper half of the lower rudder hinge bracket. The local ground here uses one of the mount bolts for the tailwheel bracket.

So I installed the other half of the molex connector on my shielded wire bundle, and put a piece of expandable wrap on the wire where it passes through the spar.

I doubled up the ground wires. One is for the light itself and the other is for the shield ground for the wire bundle. So I will have two wires connected to the local ground; this pigtail from the molex and the separate chassis ground wire from where the light attaches in the fairing.

Here’s where the wires will exit from the lower rudder fairing.

I have since enlarged that hole so the molex will fit through it. May never have to come apart, but being a mechanic, I’m always trying to think about maintenance, unlike engineers, who just design it to put it together, and solve the maintenance problem later.

I put power to the light to try it out. Wow! I couldn’t see for 15 minutes afterwards! Strobe and position light work great.

Time: 5:00

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Continued Work on Rudder Lower Fairing

March 6, 2020 – I continued the lower fairing on the rudder to prepare for the installation of the tail light.

I drilled the new screw holes to mount the fairing. The holes you see in this picture are the old ones, and they are filled with resin, so no worries about edge distance.

I installed the nutplates in the rudder.

I installed the chassis ground for the light. Not a lot of room in there. Hopefully this will be adequate. I removed one of the pop rivets and put a screw in its place, with a terminal on the inside.

Here’s a test fit of the light.

Time: 7:05

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Continued Lower Rudder Fairing

February 6, 2020 – I stated on my previous post about the fairing that I had a couple of issues with its fit.

  • The light contour and the attach plate are bigger than the molded area the light attaches to. I’ll just build that area up to make a smooth transition.

  • I figured out that the fairing is now not vertically aligned with the rudder. I sighted up along the rudder trailing edge, and the fairing doglegs off to one side. Hopefully cutting the offending side at the screw holes will bring it back into alignment…

First, the misalignment.

Here’s a picture, best I could get, of the misalignment:

It’s kind of hard to tell, but it’s there. I cut a bit of material off the top on the right side, to hopefully pull the fairing towards the centerline when screws are installed. I filled the existing pilot holes for the screws, and I’ll redrill new holes when everything else is set.

Then I started working on fairing the light a bit better. I mixed a batch of resin and flox, and slathered it around the base plate for the light, as well as gluing the plate to the fairing. After it cured, the first sanding went pretty well. I just have to do the usual fill and sand…fill and sand… I also installed four pop rivets in the base plate to help to mechanically secure it.

Time: 3:15

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Started Rudder Lower Fairing

February 2, 2020 – I started the lower fairing for the rudder that will also hold the tail strobe.

The fairing that comes from Vans was two pieces that they put together. They provide scribe lines on the part that are suggested cut lines. I know from experience that these lines are just guidelines, and that you should do your own fitting.

The first consideration is that the fairing needs to clear the tailwheel spring. I cut about 3/8″ off the top to give the fairing a 1/4″ clearance above the spring. You also have to make cuts to clear the control arm for the rudder.

I also needed to cut the front of the fairing to give clearance for access to the lower hinge bolt.

Then I trimmed the top to allow the fairing to fit along the lower edges of the rudder, where the fairing will attach.

I drilled screw holes through the fairing and the attach flange on the rudder. I’m going to use #6 screws and nutplates, since I want the fairing to be removable for the light.

This all sounds pretty easy, doesn’t it?

Well, when I got the fairing fitted, I found that the trailing edge of the fairing was mismatched with the trailing edge of the rudder by about 1/4″.

I figured the easiect way to fix this would be to split the trailing edge of the fairing, remove material from the pulled side, then resin the fairing back together.

It took two iterations of this process to get the fairing aligned.

In the meantime, I made an adapter plate to attach the light to the fairing. The plate is 1/8″ aluminum, made to match the contours of the light. I drilled and tapped the screw holes to directly attach the light. I had to chamfer the edge of the hole where it meets the back side of the light housing.

Still not done. Two problems…

  • The light contour and the attach plate are bigger than the molded area the light attaches to. I’ll just build that area up to make a smooth transition.
  • I figured out that the fairing is now not vertically aligned with the rudder. I sighted up along the rudder trailing edge, and the fairing doglegs off to one side. Hopefully cutting the offending side at the screw holes will bring it back into alignment…

Time: 9:25

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Finished vertical stabilizer prep

April 25, 2016 – I finished up the parts for the vertical stabilizer.

I took everything apart from the drilling session, and prepped and primed the parts.

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I assembled the splice plate to the forward spar.

042516005

I put everything back in place and tried the rudder. I had decided to use the internal rudder stop, so I drilled the lower hinge bracket and tried the stop out. Some people put the stop on top of the bracket, some put it in between the two pieces:

042516007 042516001

I think I’m going to stick with putting it on top.

Here’s the rudder attached to the vertical:

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Awesome. It swings effortlessly.

I took the empennage back apart and put everything back into storage. My next step is to drill the wings to the fuselage. To make it easier to move, I put the tailwheel in place for the first time.

042516002

Time: 4:15

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Rudder is Complete!

Rudder completeFeb 20, 2010 – Woohoo! The rudder is complete! Some of the fun stuff I’ve read about that are challenges are now behind me.

Rudder wedge rivetedI started by riveting the trailing edge that I had assembled a week or so ago using the L-angle to keep it all straight. Riveting was interesting, because the rivets are double-flush, meaning that they have to be flat on both sides. It’s also necessary to keep the trailing edge straight. Riveting incorrectly could result in the trailing edge bowing. During the process, I had a very slight bow in the center of the edge, but it worked itself out nicely. I’m kinda not fond of the “acorn-in-a-dimple” look that Van’s describes. I may fill these with sealant, or just wait until the airplane gets painted and fill them then to make it smooth.

The next thing I had to deal with was a few rivets that were in the trailing edge of the top and bottom ribs for the rudder. Since the rudder tapers to a very thin edge, the ribs also are very thin at that point, so I couldn’t get a bucking bar in there to rivet the aft two rivets on each side, top and bottom. So I back-riveted them indirectly, using a long, thin bar with the rudder sandwiched in between the bar and a bucking plate. Shot the top of the bar with the rivet gun. Works great.

Then it was time for the fun. I had to roll the leading edges of the skins to produce the airfoil shape. I had an extension for a ceiling fan lying around (Now I know why I don’t throw things away). I taped it to the skin, and turned the tube using a screwdriver on one end, and vise-grips in the rudder hing cutout areas. The challenge is to keep the skin from creasing at the spar.

The rolls came out OK. Had to manually finesse the skins a little bit, but I got them to cleco together. This was really hard at the lower end of the rudder, because the rudder is wider there, and the material has to roll farther to mate up.

I then removed the clecos, ran a bead of sealant along the mating surface, and clecoed them back together again. THAT was hard. If I was doing this again, I wonder if I wouldn’t make a thin narrow strip of aluminum to go on the inside of the leading edge, just to reinforce the skin where it is riveted.

Rudder leading edgeThe leading edge then gets riveted with pop-rivets. Looks great.

Rudder balance skinI used some leftover sealant to fillet seal the balance skin that I talked about earlier.

Time : 4:15

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Rudder Skeleton and Skin Assembly, Part 2

Feb 11, 2010 – Over the course of two days, I’ve gotten a lot done. To begin with, I fit and installed the rudder counterbalance weight. This is just a block of lead that I needed to trim to fit past the rivets in the balance skin.

In the first picture below, you can see where I’m notching the weight where it interferes with rivets and structure. The second picture shows the weight installed.

Filing rudder counterweight Rudder counterweight installed

I then clecoed the skins to the structure. The first picture is a nice shot of the skeleton and the skin with the stiffeners. I then had an issue about whether the balance skin should go inside or outside the main rudder skin. Per the drawing, it goes inside the skin, but that would have the rudder skin edge facing the windstream. I opted to place the balance skin on the outside. I beveled the edge and will run a bead of sealant there as an aerodynamic seal.

My next problem was installing rivets in the side of the rudder horn brace.These were very difficult to get to. So to handle the rudder, I set it up on blocks to protect the leading edge of the skins, then supported it with safety wire to keep it standing. I was able to get on the upper 3 rivets with the squeezer, but I caved and put in pop rivets on the very bottom ones on each side.

Then it was time to install the wedge in the trailing edge of the rudder. This wedge is very thin, and ties the skins together. The challenge with this part of the project is keeping the trailing edge straight.

I bought a 6′ section of 1/8″ L-angle at Lowe’s. I attached it to the edge of the table so the top of the angle is flush with the top of the table. Using the wedge as a drill guide, I drilled the holes through the L-angle.

I mixed up some sealant, slathered it on the wedge and the inside edges of the rudder skins, and clecoed the mess together, attaching it to the L-angle.

After the sealant sets up, the trailing edge gets riveted. These are double-flush rivets, set in a certain order so that the trailing edge stays straight.

Rudder wedge Rudder wedge

Rudder wedge

On another note, Van’s called yesterday to let me know that my servo for the electric trim is back-ordered, so I’ll have to wait until the first of the month before I can work on the left elevator. It’s just as well. I need to try to slow down since I’m not ready to order the wings yet, and I’m running out of work to do on the tail. Pretty soon I’ll start on the elevators, and that will be it.

Time : 4:20

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Rudder Skeleton Assembly, Part 1

Feb 9, 2010 – Began the assembly of the rudder structure today. It was nice to be able to use the squeezer on much of the rivets, except for the four rivets connecting the horn to the horn brace. I was able to put solids in there. I put a small tungsten bar in the hole, and held it with a finger while I shot the rivets. Worked great. I’ll probably continue with by attaching the skins tomorrow.

I did have to order some LP4-3 blind rivets from Van’s. I got ahead of myself back in the horizontal stab, so I ran out. I’ll need them to attach the top rib in the rudder. Ordered 20, they’re cheap enough.

I also finally went out on a limb and ordered the electric elevator trim kit. I’ve been going back and forth about this; I finally decided that if it came down to it, it would help with resale. Still trying to save for the wings, but I’d rather install the electric trim while building the elevator, than try to retrofit later.

Time : 1:45

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Parts Prep and Paint Part 2, and Rudder Skins

Feb 8, 2010 – Got to paint the rest of the rudder skeleton yesterday. Today I riveted the stiffeners to the rudder skins. Had a couple of close calls because of the number of rivets to install and how routine it became. INSTALL EVERY RIVET LIKE IT’S THE MOST IMPORTANT ONE ON THE AIRPLANE. The skin is pretty thin (.016″), but I think it’ll be OK.

Note the use of the rivet tape in the second picture below. This tape is sticky on the edges, but not sticky where the tape lies over the rivet. This holds the rivet in place, because the rivet is shot backwards.

Here are the completed skins with the stiffeners installed.

Time : 4:15

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Parts Prep and Paint

Feb 2, 2010 – It’s been cold the last few days, so it’s been a little hard to get anything done. I’ve finished cleaning and alodining the rudder parts.

I probably pushed the limits a little bit today on the temperature for painting, but I wanted to get the rudder skins and stiffeners primed so I could at least assemble them the next time I’m able to work. I’ll let the primer cure for several days before I do anything with those parts. Hopefully next week we’ll have a decent day to paint the rest of the parts.

Time : 3:45

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Beginning the Rudder

Jan 27, 2010 – Sorted through the rudder parts. Dry-assembled the rudder skeleton to check for fit and to make sure everything was drilled properly. Remember that the tail kit was bought from a third party, and the drilling and dimpling appear to have been done.

I disassembled the rudder again and started cleaning the parts for paint. I won’t get any painting done this week because of the weather.

These photos are of the rudder horn assembly.

…and the assembly for the rudder balance.

I described before how I identify the parts before cleaning and painting. Some parts that are obvious, I don’t bother with this, but where there are left- and right-hand parts, or many ribs, etc, I am doing this. I just attach a piece of safety wire, and then attach a short piece of aluminum tape. I then just write the part number or a way of identifying the part on the tape. This will stand up to the alodine, even soaking in it, and to the painting process. When I’m ready to use the part, I just remove the wire, and the part is ready to go, and I know exactly where it goes. Van’s suggests etching some part numbers into the aluminum, but I don’t like that idea.

Time : 2:20

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