Another RV-12 builder in captivity …. Trapped until all the upper holes in the C-1202 canopy skirts are drilled into the canopy with a #30 plexiglass bit.
Canopy frame with canopy after the great escape from captivity.
Once the upper row of holes in the C-1202 canopy skirts were match drilled into the canopy with a #30 plexiglass bit, the canopy is to be removed for deburring and to have ALL the holes enlarged to #27.
Mike holding the canopy as I enlarging all the previously drilled #30 holes in the canopy using a #27 plexiglass drill bit.
CAUTION: Enlarging the holes in the canopy from #30 to #27 was risky. The drill bit wants to catch and RAPIDLY pull itself into the plexigless … not good. The first hole ended up with a small chip on the back side … fortunately it is in the bottom of the hole so if it cracks in the future it should migrate out of sight. Quickly learned to slow the drill down to a couple of hundred RPM and SLOWLY place the spinning drill onto the plexiglass and let it work itself into the plexiglass. And even that was difficult to control without the bit wanting to bite and quickly pull itself into the plexiglass.
If doing it over again, I would have NOT followed Van’s plans to drill #30 holes first. Instead, I would have drilled the aft canopy frame bow and the upper row of holes in the canopy skirts using a #27 plexiglass bit from the get go. These holes receive #8 screws, so the canopy frame’s aft bow and the holes through the canopy skirts and attach angles all need to go to #27 anyway in order to accept the #8 hardware. This would avoid the drill bit catching while trying to enlarge the plexiglass from #30 to #27 because the plexiglass drill bit does not pull when drilling a fresh hole. (Of course, the holes in the forward bow on the canopy frame need to be left at #30 since they receive rivets so one would only need to worry about enlarging those corresponding holes in the canopy as opposed to every hole).
After all the holes in the canopy have been enlarged to #27, the holes corresponding with the forward bow need to be machine countersunk for the AACQ4-4 rivets that will be used to rivet the canopy onto the canopy frame’s forward bow.
Machine countersinking the forward holes in the canopy for the flush rivets that will secure it onto the forward bow of the canopy frame.
With the canopy now ready for permanent instillation, the canopy latch receives attention. A hole needs to be drilled into the end of theC-656 handle and then the handle is mated with the WD-1218 canopy latch and drilled to #19.
Drilling the #30 hole in the C-656 latch handle.
With the C-656 latch handle mated to the WD-1218 canopy latch, the assembly is drilled to #30 then the holes in the WD-1218 canopy latch are enlarged to #19 along with just the outer portion of the C-656 handle. The inner portion of the handle is not drilled to #19, but does need to be tapped for 8-32 threads.
Match drilling the WD-1218 canopy latch to the C-656 handle.
Tapping the inner portion of the C-656 handle for 8-32 threads.
The last items worked on for the day were the two C-1207 guide blocks. The guide blocks are slotted and will receive a tab riveted onto the canopy frame to assure proper canopy alignment when the canopy frame is in the closed position. The blocks have two screw holes which require machine countersinking to accept a #8 screw. After the blocks are countersunk the screw holes are tapped for 8-32 threads.
Machine countersinking the screw holes in the C-1207 guide block for a #8 screw.
Tapping the guide block’s screw holes for 8-32 threads.
Installing a C-1207 guide block on the right side of the fuselage.