From what many builders say, the canopy can be one of the hardest parts of the kit. A survey on VAF showed about 1/4 to 1/3 ended up with a crack in their canopy. I plan to glue my canopy on using Sikaflex instead of using the screws to avoid this problem.
Total Construction Time: 66 hours and counting
April 5, 2008 (2 hours)
Measured and drilled the pilot holes in the aft canopy deck for the bolts that will hold the roll bar in place. There are four little pieces that fit under the canopy deck to provide a flat surface for the nuts and washers under the longeron and canopy deck. I trimmed them to size and radiused the edge per the plans, then positioned and drilled the matching pilot holes.
April 6, 2008 (2 hours)
The plans call for the outside edge of the rollbar bottom plate to be inset 7/32" from the outside edge of the aft canopy deck. I found mine to be too wide by about 3/16". The instructions say you can just put one end of the rollbar on the floor and lean on the other end to bend it to the right width. Yeah right.
I put a ratchet strap across the ends and pulled it as tight as I could. Still no luck, it just sprang back to the same width. Finally I took a steel rod and used it like a turnbuckle to tighted the straps even more. I marked the compressed width on my table each time, then released it and checked. It wasn't until I had put enough tension to bring the ends in about 5" before the rollbar maintained the right width when released. I was getting pretty concerned about my ratchet straps breaking, but it held. The steel rod I was using got loose one, giving me a nice bruise on my hand, so I put on gloves after that. I also drilled the holes in the four little clips to final size.
April 7, 2008 (1 hour)
Clamped the roll bar in position and backdrilled the bolt holes up through the bottom of the canopy decks. Then I enlarged the holes to final size.
April 9, 2008 (1 hour)
Inserted the bolts and found that I had to file a little off a couple of the clips to get them to fit right. Then I went ahead and tightened up the bolts so I can check that the rollbar is perpendicular to the canopy deck. Looks very close, but I may add a very thin shim and see where I end up. The picture shows the clips from the bottom. The forward ones are easy to install, but the aft ones are rather difficult as you can tell.
April 12, 2008 (3 hours)
I put a couple of 0.020" shims to cant the rollbar forward and it came out just about perfect. Aaron helped me as I cut the roll bar brace to length and drilled the bolts holes for it. Then we assembled the canopy frame roller assembies and cut the left and right canopy tracks to length.
April 13, 2008 (3 hours)
This morning I marked and drilled the screw holes in the left and right canopy tracks. After dinner I worked on getting the rear slider block drilled just right through the back of the canopy frame. There were a few rivet holes at the top center of the bulkhead at the baggage wall that I hadn't yet riveted so I dimpled and riveted them. Finally I dug out the two parts that make up the rear slider track for the canopy and started marking where the bolt and screw holes go.
April 14, 2008 (2 hours)
Drilled the holes in the thicker slider track strip. Next I bent the two parts to match the template in the drawings and each other, then match drilled the two together. The rivets get double countersunk so the heads on the bottom are flush. I shot some primer on the two mating surfaces and then riveted them together. You can see the track taped to the top of the fuselage below. While it's finally warming up here, it will be a long time before it's warm enough to work on the canopy itself, so I decided it's time to jump back to finish up the wing bottom skins.
June 1, 2008 (2 hours)
Now that the wings are done and back off, and temps are getting into the 70's and 80's, it's time to get back to the canopy. Spent time checking the fit of the canopy frame. Finally figured out how the fit along the side tubes is supposed to work. I trimmed a little off the bottom of one of the front tubes so the square tube was at least at the same height on both sides. Then bent the forward bow outward slightly to get the right width.
June 2, 2008 (2 hours)
Spent quite a bit of time trying to see how the canopy frame needs to fit. Did a little bit of bending, not much. Also trimmed the oval cutout from the rear of the right roller track.
June 3, 2008 (1 hour)
Trimmed the oval cutout from the rear of the left roller track. I also noticed that the top bar of the canopy frame leaned a little to the right, so I bent it slightly by hanging it sideways on my bench and standing on the center bar.
June 7, 2008 (1 hour)
Drilled the front hole in the canopy tracks to the canopy decks to maintain the correct spacing at the front bow. Use a heavy rubber mallet to add a slight bit of bend in the left side tube so that it matches the bend of the sideskins. Luckily the right side matched very well.
I also drove out to see Pete Howell's canopy to better understand how the canopy frame fits when gluing the canopy. Later in the evening Aaron and I stopped by Paul Winkel's house to check out his RV-7 under construction. He's doing a really nice job with his whole plane.
June 8, 2008 (2 hours)
Had a little time trying to do some initial bending of the frame to align the side tubes to be 1/16" inset from the side skins.
June 9, 2008 (6 hours)
Spent a couple of hours after work bending the rear canopy bows. They seemed close, but whenever I bent them in one spot the frame bowed out somewhere else. As I was thinking of hanging it up for the evening we had an issue at work that ended up with me on a conference call until 2 a.m. I basically spent most of this time with the phone on mute and trying to tweak the frame. Multiple times I got it really close, but even small bends were throwing it off elsewhere.
June 10, 2008 (2 hours)
Finally decided to take Pete's advise to cut the rear canopy bow at each side. One side moved a little, but the other side sprung about 3-4" outward when I finished the cut. Now I was finally able to put the bends I needed in without causing problems elsewhere. I should have started with these cuts first.
June 11, 2008 (1 hour)
Spent a little time trimming a little length on the cut ends to get things lined up just right. Perhaps another hour or so of tweaking and it should be good.
June 13, 2008 (4 hours)
Took just a little off each rear bow and got them to fit really nicely. Then I started my first cuts of the plexiglass canopy. I'm using a dremel tool with a plastic cutting disk which seems to work really nice. I cut all four edges off the canopy sides and then sanded them smooth. Had to put the canopy up on the fuselage to see how it looked.
June 14, 2008 (2 hours)
Spent some time checking the fit of the canopy to the frame. After drawing a centerline down the middle of the canopy, I put the canopy upside down on a sheet of plywood and positioned the frame to get a nice fit. I marked where the handle will go and then got to work drilling an 11/32" hole for the handle.
June 15, 2008 (3 hours)
Spent a lot of time messing with my dremel tool, which was working pretty intermittently, finally replacing the brushes to get it to run right. I marked a cut line 1 inch aft of the rear canopy bows then trimmed away the excess. I also cut away the plastic sheet from along where the canopy frame will attach. I finally decided it was time to make the "BIG CUT". I carefully drew a line 1/16" forward of the front bow, then overlaid it with yellow electrical tape, which made it really easy to see. Cutting it was pretty anti-climactic, and I ended up with a pretty nice straight edge. I sanded the cut edge all the way down to 600 grit then had to place it back on the fuse just to see it. It's nice to have that behind me.
June 16, 2008 (1 hour)
I brought my canopy frame over to RV-6A pilot Alex Peterson's house this evening. He was kind enough to weld up the two aft bows where I cut them - Thanks Alex! Later in the evening I filed off the excess weld material. Progress continues.
June 17, 2008 (2 hours)
This evening I put the canopy on the frame and marked a line on the plexiglass 9/32" above the top of the side tubes. This will be where I trim the sides of the canopy where it attaches to the side skirts. I then put the canopy aside and used sandpaper to roughen the whole canopy frame, then painted it with satin black spray paint. Before painting I ran tape along the frame where it meets the canopy to allow the Sikaflex adhesive to bond straight to the powdercoat instead of an additional layer of paint.
June 18, 2008 (1 hour)
Trimmed the bottom sides of the canopy where I had marked them yesterday. Perhaps an hour of prep work to finish and I'll be ready to Sika my canopy to the frame.
June 20, 2008 (1 hour)
Double-checked the fit of the canopy to the square tubes and decided to trim another 1/8" off one of the sides. After that I sanded all the edges of the canopy down to 600 grit sandpaper to make sure I had no nicks or scratches.
June 21, 2008 (2 hours)
Today I used my compressor to blow as much of the dust and plexiglass particles off the canopy. Then I positioned the frame and tan electrical tape along all the edges. Next I roughened the surfaces to get Sika with a scotchbrite pad. I also did some deburring of the side skirt parts.
June 22, 2008 (3 hours)
Tracy helped me to Sikaflex the frame to the canopy. First I cleaned the frame and canopy with the Sika 226 cleaner, followed by priming with the Sika 209N primer. After letting it dry for 20 minutes, I added the rubber hose spacers spaced about 5-6" apart and refit the frame to the canopy. While my frame is just the right width for the rollers to sit in the middle of the track, the plexiglass will make it bow outward. I measured that the frame bows outward about 1/2" with the plexi clamped in place, so I used a couple of aluminum rulers clamped across the top of the frame to hold it about 1/2" narrower than the final width I want. Hopefully once I'm done it will spring back so that the rollers are centered on the tracks.
Once I had it all clamped into position, I used a caulking gun to fill the gap with the Sika 295UV adhesive. Tracy came behind me and used popsicle sticks to smooth the adhesive a little better. I managed to use pretty much a full tube on this first pass, leaving the adhesive just a little short of the spacers to make sure I can pull them out later. I'll let this cure for at least three days before I loosen any of the clamps. Once it's all set up I can pull the spacers out then fill the gaps as well as add a smoother coat along all the rest of the joints.
June 25, 2008
With three days of curing done I decided to take the clamps off and see how my gluing job came out. I was surprised that I ended up with the frame about 3/8" too wide at the front even though I clamped the frame about a half inch narrower than the final width I needed. The aft width of the frame came out almost perfect. It wasn't too hard to bend the front frame in the additional 3/8" I needed and now the rollers are centered in the tracks perfectly. While you couldn't do this with a drilled canopy frame, with Sika I had no problems doing this. I'm really pleased with how this is coming out.
June 27, 2008 (1 hour)
Measured and drilled out the 10 1-1/4" lightening holes in each of the canopy skirt braces.
June 28, 2008 (3 hours)
Today Aaron and I went out to Crystal airport for the VAF MN Wing picnic. Had a good time chatting with all the other RV'ers there. Between the morning and the evening I managed to get a few other things done. I deburred the lightening holes I made yesterday using a scotchbrite wheel in my die grinder. I spent a little time checking the location of the track on each side and then drilled #40 holes to the canopy deck to set their final position. I also decided to do the same with the rear canopy track, getting it positioned just right and then drilling it to the aft fuselage. I then drilled the 1/4" hole in the forward end of the track and also the baggage wall bulkhead and installed the threaded rod that supports the forward end of the track. Finally I decided to finally drill out the six AN470 rivets just aft of the canopy decks, countersink them, then replace them with AN426 rivets. These need to be flush as there's a support bracket that will be mounted on top of the longeron right there.
June 29, 2008 (4 hours)
Did lots of messing around today without a lot of progress. I had to make of the rear delrin blocks a little thinner as it was too wide for the bracket. Then I marked and drilled the holes across the top of the canopy side skirt braces and cut the bottoms of the circles I had made. This will allow it to follow the curvature of the side bows. Later I cut the canopy side skirts, laid out all the holes and drilled them. I spent time also trying to verify how it will all fit on the sides of the canopy.
June 30, 2008 (1 hour)
I finally decided I should have measured a little more carefully on the hole spacing where the side skirt attaches to the brace pieces. Each hole is just a little shy of 1/32" too far apart, meaning I'm off by about a 1/2" by the time I get to the end of the row of rivets. I decided I'm going to make replacement side skirts using the aft skirt material. I plan to make the aft skirts out of fiberglass anyways. So to get at least something done today I drilled the canopy skirt braces to the side bows of the canopy frame.
July 1, 2008 (1 hour)
This evening I made new side skirt pieces and deburred them.
July 2, 2008 (2 hours)
Decided I needed to get the rear frame blocks mounted before I worked on the skirts more. Drilled the holes to #40 in the U-brackets and then to the longerons. Then I got to work drilling the holes in the plastic blocks. This is a little tricky as the hole needs to be positioned at just the right point on the rear of the block, then gets drilled at a 23 degree angle downwards and 5 degrees inwards. Spent a lot of time getting them just right. Once I was done the pins on the canopy frame slide into them just right.
July 3, 2008 (1 hour)
Tonight I enlarged the U-brackets to #12 for the AN3 bolts. I noticed that I didn't quite have the full 1/16" gap from the canopy frame to the side skins, so I adjusted what I could as I drilled these holes. I was still slightly off by just under 0.025", so I positioned the canopy frame with the right alignment, then drilled the screw holes through the U-bracket and plastic block. When I was done I had the alignment right on.
July 4, 2008 (3 hour)
Before the neighborhood picnic started, I spent time double checking the fit of the side skirts. I laid out new hole patterns, drilled them, then went ahead and drilled them to the canopy frame.
For those following my progress, I'm jumping around a lot, including work on the Upper Fuselage & Cabin as well as the Electrical System.