Dave’s RV-7A Building Log

Clecoed one aileron together in preparation for finishing off the riveting. Set half of the remaining rivets on one aileron.

In addition to the aileron work, I primed the inside of the push tubes. I did this with some rattle can self-etching paint, it was kind of difficult to get good coverage all over inside.

I also tried riveting the ends of the bellcrank-to-aileron push tubes. I tried squeezing them. I tried using the C-frame with a hammer and with the rivet gun. Nothing worked very well. Out of 8 rivets, 2 of them set correctly. I’m now thinking about just getting new parts and getting them welded. Drilling out those rivets will be very difficult. The camera seems to be focusing on the background instead of the subject, but here’s one of the shop heads that sheared off.

Pulling the blind rivets on the stick-to-bellcrank push tubes was much easier, although it was difficult to get the holes aligned again especially with primer making it a very tight fit. Those push tubes turned out great. I still need to prime the outsides, but that will take just a few minutes with the rattle can.

I also pulled the conduit into the left wing.

Another big day. Julie helped me rivet the top and bottom skins of the ailerons to the top of the spar. From this point, I think I can do the rest solo. It looks like the remaining riveting is blind or squeezable.

I screwed the aileron spar to a 2×4 on each end and clamped that to the workbench and rolling tool cart. It worked out great. We each had great access for riveting and bucking. I’m not sure why some people have trouble with this step. I found it to be pretty easy.

Super productive evening. I started off cleaning up the push tubes to get them ready for priming. But then Julie announced she was ready to rivet. She helped me get the tough rivets on the aileron brackets done. Then we riveted the flap braces to the rear spars. That could probably be done solo, but it’s much easier with two people. I then squeezed the rivets on the aileron gap seals. The wings are really starting to look done. Just one more big hurdle left–the bottom skins.

I finished up the prep on the stick-to-bellcrank push rods by marking and drilling the holes for the rivets. I started with a #40 drill in the drill press and hand drilled them to #30 on the bench. I removed the ends and deburred everything. They’re ready for primer.

Looking for something else to do, I worked on the bellcrank bushings. First I used the Scotch-brite wheel to clean up the ends and shorten the bushings a tiny bit. The plans call for them to be 1/64 to 1/32″ longer than the bellcrank, and mine were 1/16″ longer. I also reamed out the middle to 1/4″ with a reamer I bought a few months back. I put the bushing in the vise, dipped the reamer in cutting oil, and went for it. No sweat.

After months of debating on whether to use conduit in the wings for wiring or just use snap bushings, I finally decided to use the conduit. I think it’s overkill, but I already bought it and everybody else is using it. The entire length of the wing is accessible from the access panels, so I still think the snap bushings would have worked. However, looking in AC 43.13 (which I recently bought), the wires should be supported with a clamp every 2′. That sounds like more hassle than the conduit.

I installed the conduit in the right wing. It’s a hassle to pull it through, especially with 3/4″ holes, but it works.

I’m darn near done with the prep work on these wings. After a few more hours, I’ll have nothing but riveting left to do. I’m hoping that Julie is willing to do some riveting this weekend.

By the way, if you don’t have AC 43.13 “Acceptable Methods”, buy it. It’s only $20. There is a ton of useful info and charts in there. Do you want to know how many wires you can put in a conduit? It’s in there. Do you want to know what the marks on the bolt head are for? In there, too. And a whole lot more.

I drilled the second bellcrank-to-aileron push tube. This one seemed much easier than the first. Two tips here. First, drill just a tiny bit until there’s a small divot. Check to make sure the drill bit hasn’t walked on the slippery surface. If it has, adjust the tube so that the drill will go straight through. The second tip is to make sure the threaded rod end doesn’t creep out. For some reason, it seems to want to pop out just as the drill bit is going through. Hold it in place.

Both push rods are now ready for primer and then riveting. Since only the outside is powder coated, I’m going to shoot some rattle can GBP-988 in there.

I pulled down the super long aluminum tube very carefully and cut it for the stick-to-bellcrank push tubes. I cut it at 66″ with a hack saw and then used the stationary disk sander and Scotch-brite wheel to trim it down to the 65-25/32″ called out on the plans. I wrapped a piece of tape around the tube and measured the circumference as 3.55″. After dividing by 6, I marked the tape every .59 inches. I never thought I’d use the side of the ruler with the 1/100″ marks, but it came in handy for this.