More Riveting Canopy Frame – 4 hrs

Saturday Jun 23, 2012

Last night after work and this afternoon I worked on the riveting of the canopy frame. With the exception of one rivet, this thing is done. Some of the rivets were tough to shoot and it helped to have Denise drive the gun on a few while I bucked.

The reinforcement kit is installed also as you can see in this view.

I put it back on the fuselage afterward to check how it fits. Overall, not too bad. I have no complaints on the left side at all. The right side has about 1/8 inch gap between the C-702 skin and the forward fuselage skin. I can play with that a little bit more but if all else fails I can fill it when I do the fiberglass work on the C-702 skin.

Here is a close up of the left side. Nice.

Here is the right side. That gap measures 1/8 inch at the very bottom.

Painted Canopy Frame Parts – 5 hrs

Sunday Jun 17, 2012

The epoxy was good and hard this morning where I tacked the shims to the canopy frame so I used my hole deburring bit to countersink the holes in the shims. These are ready to receive the dimples in the C-702 skin.

Next I riveted the canopy bow frame to the canopy frame side rails. My daughter Jennifer was in the garage keeping me company while I did this.

ThenI prepared the spray gun and painted all the parts of the canopy frame that will be visible inside the fuselage. This took a while but all you can see here is the end result. All these parts are done and the paint is dry to the touch but still curing.

With that done I directed my attention to the forward fuselage structure, and in particular the canopy latch mechanism. I had this installed loosely for a while but now it was time to do it for real. I decided to install the cotter pins in the linkage now knowing that they will be in the way when I finally rivet the skin over this. My plan is to use a few CherryMax rivets to replace those that are really hard to get at with the linkage installed. I think that will be better than trying to install all these cotter pins upside down with my head under the instrument panel.

For the record, here is a shot of the right hinge pin showing the cotter pin installed and the hinge block screws torqued (no torque stripe on self-locking nuts).

Made and Drilled Brace Clasps – 1.5 hrs

Monday Jun 11, 2012

I thought last night that I had finished fitting the reinforcement kit parts to the canopy frame but I later realized that I still needed to make and fit the six clasps. These are little oval tabs that tie the different sections of the outboard braces together. So I made the six parts out of scrap .032 sheet.

The instructions say to hold the clasps in place and match drill. That sounded like an invitation for the drill to drift so instead I aligned each one by hand and marked one hole location with a sharpie. Then I removed the clasp, marked the location with a spring punch, drilled the hole, and clecoed the clasp to the brace through that one hole. I could then use a cleco clamp to hold the clasp in alignment as I drilled the next hole. That worked really well.

Finished Drilling Reinforcement Braces- 4 hrs

Sunday June 10, 2012

Continuing on with the reinforcement kit for the canopy frame very early this morning I marked bend lines on the flanges of the side braces and bent the tabs to the approximate angle required. Then I placed the center brace on the frame, aligned it 1 inch from either gooseneck bracket and aligned the holes with the centerline I marked previously on the weldment flange. Drilling the holes along the was flange simple. Then I fit the side braces by hand, pressing it firmly in place to get the position right. I had to trim a little bit off the outermost tabs that mate to the inside of the weldment to get the tabs to sit flush. Then I match drilled the holes along the weldment flange making sure the forward tabs were aligned to the centerline.

I too a break to go to church and spend some time with the family and came back to this task in the evening. I wanted to make sure I did not twist the canopy frame while match drilling the aft tab holes to the C-702 skin so I decided to put the frame back on the fuselage to make sure everything was true before drilling. So I just jumped in the pilot seat and drilled the holes while pressing up lightly on the braces. I could drill all but the outboard four holes on each side in this configuration.

I don’t know why but I kinda like this picture with the frame lifted.

Then I took the frame back off the fuselage and finished drilling the outboard four holes on each side.

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.