Wing sweep and incidence set
Julie agreed to help at the hangar tonight. I got down there earlier and finally got a picture of the wings on in the light.
While I was waiting for her, I took care of a few things. I mounted the rudder and hooked up the rudder cables. After I tightened down the rudder bolts, I was surprised to find there’s a slight drag in the swing of the rudder. To this point, I’ve never had the bolts tightened. It’s always swung really freely. It makes sense the bearings would add a little drag.
I calculated how much to trim off the fuel lines sticking out of the side of the fuselage. Before trial fitting the wings, I got them pretty close but intentionally left them 1/4″ long. I also worked on the vent line for the left wing. I got it all bent to shape and flared one end. It’s an odd shaped line.
That’s when Julie showed up. We grabbed something to eat (not a lot of good options in Renton) and then got to work. We removed the left wing. I marked 5/8″ edge distance on the rear attach bar from each side, including the amount I planned to trim. I used a drum sander in the Dremel to trim the top corner of the wing rear spar and a little bit (about 3/32″) off the front spar attach bar. Last item was to cut the calculated amount off the fuel line. We then re-installed the wing. We did a quick check of the sweep and it looked much better.
Repeat for the right wing. Julie stuck around a while and helped me set up the plumb bobs and Mason’s line. The sweep is now within 1/16″. Excellent. After she left, I messed around with the incidence a bit. I had to lift the rear spar of the right wing a tiny bit, but the left wing was right on. Using the digital level, everything was within 0.1 degree. Wing twist appeared to be absolutely zero.
I’m still not entirely sure where the level and 3″ block are supposed to be positioned on the wing. Should the level be right on the front edge of the main wing skin, or just forward of that? Should the block sit in the middle of the rear spar or at the aft edge of the spar? I think as long as I’m consistent across both wings, it doesn’t matter too much.
The rear spars are clamped and ready to drill. That was a good spot to stop and think about it overnight. I’m also going to bring down an analog level. I think they can actually be more accurate than the digital level.
Great progress tonight. Thanks Julie. Just a little drilling here and there and the wings will be ready to be permanently mounted. And then it’ll be time to fire up the windmill. Can’t wait.