Dave’s RV-7A Building Log

Riveted the trailing edge of the rudder. It’s time consuming to keep checking the straightness of the trailing edge, but it’s better to do it right than to redo the whole thing. It’s not perfect, but looks pretty darn good. It’s well within Van’s recommendation of 0.1″. I’d say the trailing edge doesn’t vary more than 0.05″. This picture is kind of fuzzy, but shows what the shop heads look like after being driven into the dimple.

Here are a couple of glory shots with the rudder temporarily pinned to the vertical stabilizer. It swings nice and smooth.

Bonded the trailing edge of the rudder together with fuel sealant. I used a cartridge with the Semco sealant gun, which worked great. This stuff isn’t that bad. Personally, I think epoxy is much worse to work with. I put the sealant on both sides of the wedge and then clecoed the whole thing to a straight piece of aluminum angle. After it set for a couple of hours. I removed the clecos and cleaned off the excess sealant from both sides and then clecoed it back together again to set overnight. Looks mighty straight.

Finally ready to seal up the trailing edge of the rudder. I was waiting for a part that was missing from the Semco sealant gun I bought on Ebay last week.

I used lacquer thinner on the wedge and a small strip of the inside of the skins to remove the primer. Need a good surface for the sealant to grip. I also carefully drilled the trailing edge to a piece of aluminum angle that I picked up at Home Depot. That should keep it straight while the sealant sets up. Not enough time tonight to get into the sealant. I’ll do that tomorrow.

Steve helped me form the leading edge on the rudder. The process was not as bad as I had feared from reading other web sites. It is tough to form the curve just right.

We followed the instructions and bent the edge around to about 90 degrees with a 1/2″ (outside diameter 7/8″) galvanized pipe I had laying around. We worked on one section at a time. On the wider part near the bottom, we also moved the pipe back from the edge a bit and formed the metal around the pipe to encourage it into a nice round form. In the end, we still had to do some serious squeezing to line up the holes for clecos and drilling.

I must say the leading edge came out looking sweet. Here’s a shot looking down the length of the rudder.

We also tried to buck some of the rivets in the tight spots of the rudder and elevator with a cold chisel. I’ve read that other people have made that work. It didn’t work for us. I put in MK-319-BS blind rivets instead. In every case these rivets are on a bottom surface or will be covered up by the fiberglass used to fair in the tips. If I had noticed that before, I wouldn’t have even tried to buck them.

Squeezed the remaining rivets on the rudder ribs. Well, almost all of the remaining rivets. The forward most rivets are unreachable even with the thin-nose yoke. I’ll get Julie to help me shoot them. I guess I’ll use a cold chisel as a bucking bar. I think I saw someone else do that. If that doesn’t work, I’ll just use blind rivets.

Waiting on the sealant gun to glue up the trailing edge.

Squeezed most of the rest of the rivets in the rudder skeleton. The rivets in the rudder horn are especially tricky. I tried various combinations of yokes and sets until I settled on using the longeron yoke, one medium length set and one short set. It was still tricky to get the yoke in there around the nut plate.

I left until later the rivets toward the rear and the entire trailing edge. I want the technical advisor to be able to look in there, if needed.

The rudder is looking great. Can’t wait to finish it off, even though two of the trickier parts are ahead, riveting the trailing edge and bending the leading edge.

Started riveting the rudder skins to the skeleton. Discovered that I had made a mistake a while back. I forgot to dimple the two holes on the front side of the top rudder rib. I wish I had noticed that before I riveted it to the spar. Luckily, I was able to pivot it out to the point where I could get the dimple dies on it and fix the problem.

I also had a problem getting some of the holes to line up perfectly. Some of the rivets were sitting crooked when I dropped them in. I borrowed a trick I read somewhere and re-dimpled both the skin and the rib together on the problem holes. That fixed it great. I’m about 1/3 done on riveting the rudder skins to the skeelton.

The replacement screws and nuts for the rudder counterweight showed up. I ordered them Saturday and they showed up Wednesday via FedEx Ground. Not bad. Van’s only charged a few bucks handling and a few bucks freight. I probably could have found them locally, but didn’t want to waste the time running around.

After staring at a few of the rivets on the rudder reinforcement plates a while longer, I decided I still didn’t like the lookes of them even after redoing them once already. I took some advice from the Yahoo RV7 list and bumped up the pressure to 100 psi. The gauge that came with the tank definitely needs to be replaced. It varies +/- 5 psi for no reason. The higher pressure along with concentrating on lining up the squeezer better produced very good results. I’m happy with all of the rivets on the reinforcement plates now.

I attached the rudder counterweight with the new hardware and then clecoed the rudder skins onto the spar. The instructions are pretty good about spelling out the steps. There are 9 rivets in the skin per side that must be set before putting on the top rib. Did that, but didn’t get any further. Somebody had a piano recital tonight (and she did great).

This shot shows that I had to make the slot in the skin a little bit larger in order to provide some space around the rudder horn.

Riveted on the rudder horn. I’m not too proud to use pop rivets. This is not an area where it matters, and it’s very difficult to get a yoke in there.

Riveted on the counterweight skin with the handy thin nose yoke. (It’s out of focus, but there is also some overspray contributing to the fuzziness. I primed the outside of the skin where it is overlapped by the rudder skins.)

Attached the lead weight. Had to do some minor trimming of the weight in order to make it fit around the rivet heads that are now present.

I also screwed up using the torque wrench. The bolts holding on the counterweights are AN509’s, so I stupidly used the torque value for AN5 bolts. They’re actually AN3 sized “structural screws.” After way over-torquing these bolts, I’m going to order some new ones. That puts a halt on further rudder progress for a while. Bummer. At least it should be a cheap part to replace.

While I’m waiting for Julie to help me on the VS, I decided to work on the rudder a bit. Started by back-riveting the stiffeners to the skins. After reading other builders’ logs, I was being extra careful not to rivet beyond my relatively small back-riveting plate. Still, I managed to do it on the second stiffener. After that point, I used a piece of blue tape to indicate where I needed to stop. It’s too easy to get wrapped up in riveting and not notice when you’ve gone to far. Back riveting rocks. Goes fast and looks great. I had some help from some little fingers with those tiny 3-3 rivets.

This shows the riveting of the last hole and then one of the finished skins. In the first picture, note that I routed a recess in a piece of plywood for the back-riveting plate. Took a while to do that with my cranky old router, but the end result works great. No chance of scratching the skin on the edge of the plate.

Started working on the rudder skeleton. For some reason, I had a hard time with the rivets on the reinforcement plates. They kept squeezing over to the side. Had to drill out several. And then drill out two again. Very frustrating. It was tough getting to the rivets right next to the lower spar flanges. First I tried shooting the rivets. That was a disaster. Drilled them out and then discovered the longeron/flange yoke could just barely reach them.