Finishing Kit

July 6, 2011

Canopy Frame Fitting - continued - 4.5 hrs.

Today I tackled the flange-bending and fluting for the other F-631A canopy frame rib. Fortunately, this one went a lot faster and easier than the first one. Nevertheless, I spent a couple hours with it to get it to a satisfactory point. Then, I taped the wood shims on them and clamped them to the aft canopy frame in the fuselage for fitting. The top ends needed to be filed a bit to adjust the angles so they fit closely together. I also spent time laying out and drilling all the holes in the splice plates, starting with the C-704. UPDATE: There are two holes you don't want to drill a pilot hole for just yet. The middle hole on the right and on the left. This is because it's very close to the tooling hole in the F-631A. Read ahead for my explanation of what happened. I had to replace this part and do it over.

I also laid out and drilled #40 pilot holes in the C-613 splice plates. UPDATE: There's one hole you don't want to drill a pilot hole for just yet, in each of the C-613's. Read ahead for my explanation of what happened. Next, I drilled the C-704 to the left side F-631A curved rib. I drilled these to #40 for now. I'll wait for the 4 circled holes that will hold the UHMW block for the canopy handle.

Then I realized that you can't drill the other half with this clamped in place on the plane, obviously, since it faces aft and it's up against the aft frame. I can't cleco this to the outside of the curved rib for drilling the other half either. The reason is, the flange sticks out aftward, and you can't cleco it in place on the other side. So I followed my friend Mike Bullocks method and fab'd a duplicate temporary plate out of some scrap .032 to use for drilling the other side. I drilled it to the C-704 so the holes are identical. Here it is, clecoed in place on the forward face of the left F-631A. This should work perfectly for drilling the other side, once they are fitted in place. Then, the C-704 should fit perfectly inside on both halves, for final drilling to #30.

With this plate ready to go, and the top ends of these parts filed so the angle matches and they meet pretty well, I taped the shims inside and clamped them to the aft canopy frame.

The plans call for shims that are 7/8" thick, but I did what I see a lot of builders doing and made mine 13/16" instead. This gives about a 1/4" gap between them and the aft canopy frame. UPDATE: This was a mistake! It led to a gap between them and the flange on the WD-725 and I had to remake them. Just follow the plans. I also used 3 on each side instead of two. This just makes everything fit a little better, I think. I put the seatbacks in, to make sure there are no clearance issues. I'm happy with how this is coming together. I took special care with a straightedge to check a lot of points along the curve to make sure the fit of these parts matches the aft canopy frame as good as possible, and to double-check the 92.5° bend I put on the flanges. This turned out to be a smart move. Eyeballing this isn't good enough. I ended up making a lot of slight adjustments, continuing to use the straightedge, to get it placed as accurately as I can. I tweaked the bend angle of the flange in a few spots, too. I think this is good to go. With that done, I clecoed the temporary splice plate in place on the left side.

Next, I laid out and drilled all the pilot holes in the WD-725 side rails. I drilled them to #40 for now. Then I put the 1/8" shims in place for the trial fit of the WD-725's and laid them in place. I need to study some more about how to fit the forward ends of these to the forward canopy frame, but I feel like some real progress is being made here.

You can see that I have the temporary splice plate clecoed in place above, between the two F-631's at the top. I think I'm ready to go ahead and drill this, at least to #40. I don't see how I could make any adjustments that would make it fit any better than it already does.

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