Trevor & Dewey's RV-7 Construction Log

Fuselage - Main

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Date: 06/25/2011
Task: Mated the wings to the fuselage!

Today was one of the best days yet on the project! We mated the wings to the fuselage for the very first time and drilled the rear spar bolts. It was quite the process and took ALL day! There was a ton of setup involved, most of which was measuring, leveling, measuring, leveling...etc etc.

First I measured and marked the rear spar carry-through on the fuselage. The instructions specify that its imperitive to maintain 5/8 edge distance from all edges of all parts. I drew several blue lines to arrive at a small square in the center of the rear spar carry through. I also marked 5/8 in on the wing rear spar stub.

With hardware store bolts, drift pins, and a rubber mallet in hand, we installed both wings on the fuselage. With the help of 6 other people, it went pretty quickly. Gotchas on wing mating are the fuse skin binding on the wing as well as helpers lifting the tip of the wing too high. The first bolt went in pretty easy, it was the second one on the bottom that gave trouble. It essentially takes a large drift pin and rocking the wing up and down to get things straight. It wasn't too bad, just took some persistence.

The wings have been attached!

Once the wings were on we spent a lot of time leveling the whole fuselage assembly. We had a level on each longeron between F-704/F-705, one accross the main spar, one accross the longerons, and one on the rear deck. It took very little shimming to get everything perfectly level.

Once both wings were mated, we lowered 4 plumb bobs from the leading edges of the wings. One at the root and one at the tip. I then stretched a straight line across the floor and lined it up with the two plumb bobs on the tips.

Initially the root plumb bobs were aft of the string about 3/8". We then strung a tape measure from the center of the rear deck to the outboard most rear rivet on the main wing spars. With some finess, we got them both to 192", within 1/16". I was very happy with how square the wings were to the fuselage.

Initially the sweep of the wings was forward by about 3/8. The forward rear spar carry-through was the culpret. The instructions mentiont this so I figured we would have to remove the wings to trim those. We did remove the left wing and trim about 1/8" off the top at an angle downward. So almost no material was removed from the bottom. I then redrew the 5/8' edge distance line on the forward and rear spar carry-throughs. Taking advantage of the wing off, I used a center-punch to mark the hole location. I then ran a #30 drill through the rear spar carry-through with a drill block in place to keep it straight.

We then reinstalled the left wing and got everything level again. Measure the rear deck to the wing-tip - Check, 192".

Next we measured the angle of incidence using a tool called out in DWG 38. It was consistent at 0.2 degrees despite all efforts to make it 0 degrees. Any higher and the flaps wouldn't sit up flush on the bottom of the wing skin.

That's it! After taking a break for awhile and cleaning up the shop, we measured everything AGAIN and then made the big drill! I started with the left wing and the drill block and a #30 bit. I then increased sizes to 19/64 and finalized with a 0.311 ream. The AN5 bolt went it perfectly and the hole met all edge distance requirements.

Finally we repeated the same procedure on the right wing. It turned out great!

We were so happy to get the wings on today, it was a huge milestone for the project. Next we have to mount the F-769A fuel tank attach brackets, drill the bottom screw holes in the fuselage skin, and drill the wing root fairing.