Luis & Fab's RV-7A Construction Log

Ok, it’s all done!

Have I mentioned that bending the leading edge was a beatch? I got my brother to help we eventually got it. The center section looks less-than-perfect, but definitely not too bad.

Screwing the Rod-End bearings into the platenuts requires a special tool. Since the platenuts are squished for extra retention, you can’t just use your fingers for these things.

First I built a tool from PVC, to keep from damaging the rod-end bearings:

This tool worked for about 50% of the way in. At this point, it started slipping, so I had to build something else. This time I used a cutting disk on a dremel tool to cut two slots on a 14mm hex socket. After polishing it, it worked great for screwing the rod-end bearings the rest of the way as called out in the plans:

After these were in, it was time to test fit the rudder to the vertical stabilizer!

Fabiola says this thing is starting to look like an airplane!

It’s been in the 100’s here for the last few days here, so I haven’t been too inclined to go into the garage and work on the plane.

I finally got around to gluing the trailing edge of the rudder. I bought the fuel tank sealant that comes in a tube dispenser. I quickly realized this was a mistake. I probably used 5% of the material in the tube, and the rest went to waste. If was to do this again, I’d want to buy the 1 ounce bottle instead.

Anyway, the stuff is gooey and nasty. The only way to to this is with a helper and lot of disposable gloves. I got my brother to help, and it wasn’t too bad. He applied the sealant to the wedge, and I smeared it more or less uniformly over the wedge. When we had one side covered in sealant, I turned it over and held it up with one hand while he applied the sealant to the ‘other side’. I used my free hand to smear it.

We then slid the wedge into the rudder and started putting a cleco in every hole.

To keep the clecos and the aluminum angle from sticking to the rudder, I used petroleum jelly (i.e., vaseline) on the surface on the angle, and on the clecos.

Here’s the rudder all clecoed and waiting to cure. There is about half an inch between the topmost hole and the tip of the rudder, so I used a clamp to make sure the skin stuck to the wedge.

Here are the two skins riveted to the frame. The four rivets on each side that hold the rudder horn brace are kind of hard to set. The plans call out optional pop rivets. However, these require a larger hole. I went ahead and drilled to #30, but had some aluminum chips get between the sheets. I tried using a thin screwdriver, but I really need a chip-chaser. I decided to order one, so I’ll just wait for it and work on the elevator a bit. Also, the horn brace is held to the rib and to the horn with LP4-3 and LP4-4 rivets. I didn’t have enough of these, so I ordered them from Aircraft Spruce at the same time as the chip chaser. Nobody else seems to call these rivets LP4-3, etc. However, Aircraft Spruce carries them as BSPS-43 and BSPS-44, or so they say at http://www.vansairforce.com . We’ll find out!

If I were to do this again, I would probably drill the horn brace holes to #30 before putting everything together, so each hole can be cleaned properly.

Once I get these rivets I will have a few more rivets to set and then I’ll be ready to do the trailing edge.

The trailing edge is an aluminum wedge that holds the two skins together. This part is countersunk on both sides.

I had all the required pieces to put everything together and match drill all of the holes. Here is a picture of the assembled rudder

Next I’ll have to take everything apart, deburr, dimple, and countersink the trailing edge wedge.

I started back-riveting the rudder skins. One of the skins came out perfect, but on the other one I really messed up the very last rivet I put in. I hit the rivet without it being on the steel back riveting plate, and bent the stiffener and the skin. This is mostly a cosmetic issue, but I know it’s going to annoy the hell out of me every time I pre-flight the plane. So, I’m ordering a new skin and stiffeners to do it again…

Not much work today. I just dimpled both rudder skins in the C-frame. I will probably prime the skins and reinforcement angles this Saturday. The Vertical Stabilizer parts are probably as dry as they’re going to get, so I’ll put that together this weekend as well.