Four Mini-Projects – 8 hrs

Saturday June 9, 2012

I think I finally decided what to do with the canopy release mechanism. I’m going to make a short handle that will extend just aft of the subpanel so I can release the pins when the canopy is tilted up. That will be useful during the remainder of the build phase and when I finally paint the airplane. It obviously won’t serve as an emergency canopy ejector but that’s OK by me. Seems like almost nobody installs this with the handle poking through the instrument panel.

So this morning I installed the crank arm on the mechanism. I aligned it so the arm was fully aft when the pins were retracted and drilled a hole large enough for a #8 screw. While I was at it I made some final modifications to make the mechanism work smoothly, trimming a little here and there to eliminate rubbing.

My friend Ron came by this morning and we worked on the doubler strips for the rear window screws. We unclecoed the top skin and laid it out on the bench and used it as a template to make strips out of .025 thick aluminum scrap left over from the wing walk doubler. Since there are 15 holes on each side of the fuselage I made three strips on each side that each cover 5 holes. It was helpful to have an extra set of hands to trim and match drill these pieces.

Another item on my list was to make bumper stops for the canopy frame to keep it from shifting too far forward under the influence of the lift struts. A very good set of instructs can be found at this site: http://rvbuildershotline.com/articles/2008/frame_brace/ so I will only summarize

Following those instructions I used a scrap piece of angle which I drilled to the longeron just ahead of the subpanel. You can see my rough-out sketch on the angle for the final shape.

I drilled a1/4 inch hole through the subpanel and the angle for a 1/4 inch carriage bolt that is 2-1/2 inches long. Then I cleaned up the shape of the bracket with the band saw, belt sander, and scotchbrite wheel.

Here is a view from the aft side showing the head of the carriage bolt which is dome shaped. I also made a mirror image copy of this for the right side. Now I just need to prime the brackets and rivet them on. I’ll set the fore/aft position of the stops later when I put the canopy frame back on.

Next up on the “to do” list is to install the canopy frame reinforcement kit. This requires a homemade tool to bend the edges of the lightening holes in the reinforcement plates. I used some hardwood scrap and made the tool you see below. The first one broke because the grain of the wood was running in the high stress direciont, so I made a second copy with the grain running parallel with the slot. That worked fine.

I removed the rough edges on the parts and created the raised inner lip on the lightening holes as you can see in this photo. It was easier than I expected, working in small steps to gradually increase the angle of the lip to about 20 degrees. This photo shows two of the three plates.