06-18-2013: 2 hrs
Time to countersink the holes on the canopy. I read about what to use for countersinking. the zero flute 100degree countersunk bit is the best. However, I only have 82degree bit. The I read other article that as long as the hole is not enlarged, a standard countersunk bit should be fine because the hole can provide enough support so chattering won't happen (thus cracking the canopy). So, I just used standard 3 flute countersunk bit. I used rivet and dimpled sheet metal as guide for countersinking depth. This went well, not cracked holes, and the cutting surface looks smooth, no sign of chattering. I then enlarged all the holes to 5/32" using unibit.
I need to adjust the frame as well because when trial fitting the frame and canopy to fuselage, the canopy won't move smoothly. After some measurement, I realized that the canopy expanded the frame almost 1" total. I called Vans today about the frame re-adjustment after drilling canopy to frames. They said it is ok as long as the canopy is off the frame when adjusting the frame. Following is the measurements:
Before adjustment:
Distance between roller (center to center) without canopy: 41-1/2"
Distance between roller (center to center) with canopy: 42-1/2"
After adjustment"
Distance between rail track (center to center): 41-5/8"
Distance between roller (center to center) without canopy: 40-13/16"
Distance between roller (center to center) with canopy: 41-6/8"
I will trial fit again to see if additional adjustment is needed.
