Dave’s RV-7A Building Log

I spent just a little time deburring the cabin frame.

In order to get the canopy frame fit just right, I needed to do some riveting. First, I riveted the angles for the canopy latch handle to the side skin. That wasn’t needed for the canopy frame, but I wanted to get it done. From there, I finally riveted the front canopy decks to the longerons. Using a nice little bucking bar I picked up from Clear Air Tools at the Arlington air show, I was able to get at all but one rivet. And that rivet I could have bucked if I hadn’t riveted in the canopy latch handle first. Oh well.

I put the canopy frame back on the fuselage, this time using a couple of extra clamps to hold the skin tight against the frame. The fit at the longerons could use a little improvement. The frame is a little wide at the front and a little narrow at the back. Also, I would like to have the top of the frame sit a tiny bit higher so the canopy skin will clear the forward top skin when the canopy is opened. I might try to tweak the frame a little bit. I also sighted through the holes in the canopy hinge blocks and they seem to line up nicely with the holes I pre-drilled in the canopy hinge fingers. I’ll drill those as soon as I have the canopy frame fit looking good.

I took the canopy skin off of the frame and did a bunch of deburring. I also did a little bit of filing in a few places where the weld beads were sticking up from the frame. I re-assembled and re-installed the frame and drilled the rib connections at the hinge points. The instructions call for a lot of disassembly, deburring, and re-assembly in this stage. It’s tedious, but I want to make sure the frame fit is as good as possible.

I spent about an hour trying to improve the fit of the canopy skin. I filed down the top flange of the front frame rib, but that didn’t seem to do anything. I also filed down the spacers in the hinge blocks a bit. That allowed the canopy frame to move forward a little bit. However, after reading through all of the canopy info on Dan’s site, it’s not a good idea to make the gap between the two skins too small. He ended up spending a lot of time filing down the skins. I’m going to shoot for a .032 or maybe even a .040 gap. The other thing I read in a few places is that no matter how good the fit is at this stage, after drilling and riveting everything will move and need to be adjusted again. Might as well just get it close and move on.

I positioned the canopy frame as good as it’s going to get at this point. I drilled the splice plate between the two halves of the frame and drilled the two rows of holes that go back from the hinge points.

One thing I noticed is that I didn’t need to file down the slots in the subpanel. Straight out of the box the canopy frame is not completely put together. There are a few joints that aren’t welded so that you can adjust the fit. Well, the hinge point has a tendency to hang down a bit until everything is drilled and clecoed together. Now that it’s all stabilized, there’s plenty of clearance in the slots.

I decided how to proceed with drilling the hinge points. Since I haven’t drilled the 1/4″ hole in the plastic blocks, I had an opportunity to make sure I had good edge distance on the hinge fingers. I started by drilling a #40 hole in the ideal location on the hinge fingers.

Next, I clecoed just the skinny outboard plastic blocks to the 745 ribs. (You can see how I traced the hinge finger onto the block to make sure this was going to work out well.)

And finally, I put the canopy frame in position exactly where I wanted it (.032 spacers between the forward and canopy skins), and drilled the #40 holes I made in the hinge points to the plastic blocks.

I clamped the corresponding large blocks to the skinny blocks and enlarged the holes to #10. The reason I didn’t go to 1/4″ is that I don’t have a 1/4″ angle drill bit. I’m going to drill everything to #10 and then enlarge everything on the bench to 1/4″ as the final step.

From there I assembled the canopy frame back to the fuselage with the hinge point blocks put together and bolted to the two ribs on each side. This is the first time I’ve had the canopy frame installed with the aluminum spacers in place. The gap between the forward top and canopy skins was a little too large, so I need to file down the spacers, the hinge fingers, or a little of both. Once I do that and have the canopy exactly where I want it, I’ll drill the plastic blocks to the hinge fingers with a #10, disassembly everything, and enlarge everything to 1/4″. Hopefully it will work out well.

The fit of the canopy frame overall is quite good right out of the box. I have a little bit of bulging right in the middle third of each side. I think I can take care of that by filing the flange of the front canopy frame rib a little more.

On the sides, the skins are a little bit wide, but I think they will pull in a little bit after riveting. I wish I had some wing nut clecos that would pull down the skin a little better. In any case, it’s probably better to have the canopy skins a tiny bit wider than the side skins rather than the other way around. The pictures are of the front and back of the canopy frame. I have a wood shim at the back to hold the frame where I want it, but I really need to finish up the riveting on the forward canopy decks before I can get the gap correct.

I did a little more work on the canopy frame, mainly trying to figure out exactly how to proceed with drilling the hinge points.

I also painted a bunch of little parts and (hopefully) the remainder of the cabin.

I had a bunch of parts ready for paint and decided I might as well finish painting the last few parts of the cabin that I haven’t done already. I painted the cabin parts before assembly for the most part, but I missed a few parts. I figured out that mineral spirits did a good job of cleaning up the paint without taking off what was already there. I vacuumed, sanded, wiped down, blew out, and generally cleaned everything that I wanted to paint. It’s the first time I’ve had the cabin cleaned out in quite a while.

I also messed around with the forward part of the canopy frame a little bit, enlarging the slots in the subpanel where the hinges go through. There was a little interference that was keeping the frame from sitting down properly.

My order from Van’s arrived containing the UHMW tape I needed for the canopy skin. I deburred the front edge of the skin, cut off a 1/2″ strip of the tape, and carefully applied it to the skin. I clecoed the skin to the forward part of the canopy frame. After making sure everything was lined up, I drilled the skin to the aft tube. I re-clecoed the subpanel area back together, including the forward top skin. Placing the canopy frame assembly on the fuselage, it lined up fairly well. I need to file the slots a little deeper, so the frame can sit down further.

I also spent a few minutes trying to figure out how best to proceed with drilling the hinge point. Since I haven’t drilled the hinge point in the UHMW blocks yet, I could drill a nice centered hole in the canopy hinge arms and then drill that to the blocks.

I disassembled the latch assembly and cleaned the parts for painting. I’ll probably leave the latch itself bare aluminum, but I’m painting the rest of it to match the cockpit.

I received an order of several odd sized drill bits that I needed for various things. That allowed me to attach the knob to the latch.

I’ve had the flap push rods on the bench for quite a while waiting to be tapped. I cut and primed them a while ago when I was finishing up the last few fuselage items. After my tapping session yesterday, I figured I might as well finish them up. I drilled them to size and tapped both ends. They turned out great.

I drilled the forward side skin to the latch assembly, deburred, dimpled, and countersunk as needed.

I also drilled and tapped the ends of the push rod that connects the latch mechanism together. It turns out I read the dimensions wrong and had the push rod way too long. I cut it to the correct length, re-drill, and re-tap the one end. That was a hassle, but it’s better than having it too short.

Of course, I had to test fit everything together and play around with it for a while. It’s very cool to see all of the pivot arms moving back and forth smoothly.