Finishing Kit

July 23, 2011

Canopy Frame Fitting - continued - 10.0 hrs.

I had a HUGE day today. With the aft canopy frame and the side rails pretty much fitted and ready to go, it's time to finish up the attachment of the WD-725 side rails to the forward canopy frame assembly. This has been bugging me for some time. Here's why. Here's the direct quote from the instructions: "The fwd ends of the WD-725 canopy side rails may need to be adjusted/modified where they mate to the WD-716. Squeeze the upper bend with flush sets in a rivet squeezer and then finish the adjustment with a hand seamer. The goal is to get a smooth transition from the WD-725, rolling inboard to the WD-716."

I've searched a lot of websites to see how other builders with tip-ups have done this, and it only adds to my confusion. A lot of guys straighten out the tab on the WD-716 a little bit and move on. But it clearly says that it's the WD-725 side rails that need the work! I can't find anyone who has some accurate proper documentation on this step. So, being very fortunate to live close to the factory, I thought I'd get it straight from the horses mouth. So I drove down to Vans yesterday afternoon. I needed to pick up a few things anyway, but my main mission was to go out to the hanger and take a look at the factorys' RV-7A and take some notes on how they did it. I was hoping that I might even run into one of the experts to ask some questions if necessary. Boy, am I glad I did it! My timing was perfect. When I got there, the guys were out fueling the planes and getting them ready to blast off to Oshkosh the next morning. Had I waited any longer, they would have been gone for the trip and my work would have been put on hold here, and my visit would have been much less productive.

I walked around and looked things over and sat in the 7A for quite a while and took a ton of pictures of all sorts of details regarding the canopy. Here's the bottom line with the WD-725. When the light was just right, I could clearly see what they had done to modify the part. Here's a picture. Now I was anxious to get home and get mine done.

My granddaughter Maya came along for the ride, and we had a wonderful visit. She's never been to the factory before. At my prompting, she was on her best behavior, asking politely if she could sit in the airplane. The guys at Vans were very nice to her, and she played it to the max. She wanted to sit in every airplane in the fleet! Here she is in the RV-12. She also spent time in the RV-10, and the RV-7A.

My little future pilot, perhaps? She really enjoyed sitting here for a long time while I was taking pictures, dreaming about flying up there with the clouds.

Some day, she'll be able to go for a ride in one of these wonderful machines. With her momma's permission, of course. Anyway, we had a great time and I got answers to my questions. Back home, I got out my squeezer and started working on these parts. First, work on straightening out the joggle:

After numerous trials on and off the plane, here's the final result. Straightening out the upper joggle for just a couple inches and giving it just a slight inward bend gives it all it needs. The picture doesn't show it, but the tab on the forward weldment now mates with this part very well.

While I was at Vans, I picked up a pair of new C-613's and a new F-704 splice plate. Then, I match-drilled the new ones to the old ones. You can see the new one clecoed to the WD-725 on the left, and the old one with the red dot on it. The red dot is where the #40 hole from the skin would have to be drilled, so you can see that it's too close to the hole specified in the plans. So on the new part, I left that hole undrilled for now. I'll match drill it when the skin is on and keep this one hole #40 size. I did the same thing for the one on the other side.

With everything drilled, deburred, and countersunk, I spot-primed the parts where they mate and riveted the C-613's to the WD-725's

Then, back in the plane for final fitting and drilling to the forward canopy frame assembly. Here they're drilled to #40 for now:

Here's a shot from the outside, showing where I match-drilled through the existing hole where the skin goes on, through the C-613.

With the front of the canopy frame all drilled & clecoed, the only thing left is final fitting and drilling the aft flanges of the WD-725's to the F-631A's. You clamp the side skins onto the side rails and use scraps of .032 or whatever to make sure it's flush with the sides of the fuselage. I clamped everything together like this, and when it looked good, I saw my other problem. There was a gap at the aft end between the flange on the WD-725 side rail and the F-631A of about 1/8". I had known a while back that this was the case, and so I examined the factory RV-7A carefully on my visit yesterday to see how they did theirs. I noticed that the gap between the F-631A and the aft canopy frame roll bar got bigger as you go from the top down the sides to the bottom of the canopy. So they obviously had a gap here, too, when they assembled theirs. But apparently it doesn't matter. I realized that the 13/16" shims that I cut for clamping the assembly to the roll bar should have been 7/8" all along, just like the plans recommend. So I cut new ones 7/8" thick, and it reduced the gap to a little less than 1/16".

For drilling the flanges to the ribs, I loosened the clamp and inserted some shims until the gap was closed. After checking everything once more, I drilled the flange pilot holes to the rib.

Here's the left side, all drilled, clamps removed. I think I ended up with a perfectly acceptable gap between the canopy frame and the roll bar, very similar to what I saw on the factory's 7A. It's about 3/8".

Wow, what a day. I haven't been this productive in a long time. It really feels good to have these issues solved and this much progress made.

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