Canopy frame hinge points
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.
