I removed the canopy frame and started taking out the avionics. I still need to trim and install the ribs that tie the instrument panel to the subpanel, so I spent a little time determining how to do that. I also tidied up the wiring harness on the right side. After the panel comes out, it won’t go back in until the cabin area is painted and the panel is painted and labeled.
I drilled the mounting holes in the UHMW block and countersunk them for AN509-10R18 screws (which probably have to be replaced by R19 screws).
I then drilled a 0.130″ hole for a MS24665–359 cotter pin. This seems rather thick, but if the main canopy latch fails, the all of the force trying to pull the canopy open is carried in shear by this cotter pin.
Afterward, I drilled and installed the block to the canopy frame. I’ll install the cotter pin for good once I’ve painted everything.
The canopy safety latch pivots in a UHMW block and is used as a secondary latch in case the primary canopy latches pop open. It’s also used to prop the canopy open by resting the longer flange on top of the roll bar. The problem is that because the latch is free to rotate, vibration can cause it to spin around and not stay where you put it. Worse, there has been at least one case where someone shut their canopy and the safety latch pivoted and caught under the roll bar, preventing them from opening the canopy. There are a couple of approaches that builders have used to prevent this. One is to simply squeeze the tube that passes through the UHMW block too increase the friction. Another is to allow the safety latch to slide up and down in the UHMW block with a spring to keep it up. The pilot would then need to pull it down to pivot it under the roll bar. For various reasons, I didn’t like either of these approaches. I ended up deciding to modify the latch so that there are detents when rotating (one in each of the latched and unlatched positions). I stopped by the TechShop and used their milling machine to machine some grooves into the shaft.
I repeated the work from last night on the right side of the canopy frame.
I pulled the canopy off so that I can finish up the canopy frame.
I drilled out the canopy attach lug and frame for some AN3 bolts. Afterward, I drilled the remaining holes out to #30.
