Canopy

Work has been keeping me busy in the evenings the last few weeks, but last night I was able to spend some time in the garage. I trimmed the canopy sides to get it to sit flush with the canopy rails, and to sit down correctly on the forward canopy frame skin. I used a combination of a diamond blade on the jug saw, a sanding block, and a burred edge on a small steel ruler to cut, sand and scrape the edges. It wasn’t my favorite thing to do, as the canopy is bulky, flimsy and awkward, but it came out ok. Most of these edges will be hidden by skins and fairing, so the straightness of these edges wasn’t critical.

Over the course of the last week I have been making progress on fitting the canopy to the canopy frame. I marked out the amount that needed to be trimmed from the aft edge and then cut it using a jigsaw with a diamond blade. The blade melted it’s way through the canopy without any problems. With the cutting done I scraped the edge with a thin piece of metal to smooth out and round the edges.

Today I installed the finished canopy frame onto the fuselage and checked all the clearances. I was relieved, but not surprised, to see that the frame fit very well and had not discernible twist. The only real issue is the gap between the cockpit rail and the bottom of the canopy rail. For some reason the canopy rail is not completely flat, and the gap along the rail is not uniform. At either end it’s about 1/16 and in the middle it’s 1/8, and it’s the same on each side of the canopy.

It’s annoying because the skin will also be bowed and have the same gap when the canopy is closed. I pinged Vans, but there’s not much I can do at this point. I may try to make a new skin for each side to ensure the gap is uniform, but I’ll hold off until I’m completely done with the canopy.

Tonight I finished installing the canopy latch system. This will help position the canopy frame while I fit the canopy. Everything fit fairly easily and the whole system works well.

Over the last two evenings I finished riveting the canopy frame together. For forward section went together ok, and I was frequently checking the twist as I riveted. There were a couple of interesting rivets, but generally it was fairly easy. I was able to fairly quickly rivet on the side rails and the aft frame. Once done I couldn’t resist setting the canopy on top to see how it looked.

Tonight I finished riveting all of the holes common to the canopy skin and under structure. It took a while but it was easy work. Setting the structure on it’s side I could easily reach both sides and control the riveting easily.

Tonight I worked on riveting the forward section of the canopy frame. I was careful to check for twist throughout the process, and occasionally manipulated the frame to correct any error.

Today I countersunk the base of the forward canopy frame. It’s weird that the plans have you do this step now, vs doing it before it’s riveted to the frame. There are clearly some out-of-step issues with the plans in the canopy frame section, but I’m hoping it will still work out ok.

Tonight I riveted a lot of the canopy frame skin to the sub structure. It was fairly fast and easy going, and everything turned out well.

Over the course of the last week my Dad and I installed the rear window. There is some trimming to do first, which we did with a jig saw and a diamond blade. This was a good setup as it was accurate, square and it melted nicely through the material. With the notes cut, then filed and scraped to final dimensions, the process of drilling the canopy starts. With one person holding a black of wood to back up the Perspex, and the other one drilling, we were able to drill all of the holes without trouble. The forward edge is a little different, as the drill needs to be lined up and square to drill through into the roll bar. The holes are the final sized and tapped. My dad did an excellent job and the finished window fits perfectly!