Started working on the F-721B canopy decks. These were drilled earlier to the longeron after it had been bent and now needs some more modification to fit with the F-757-S plate.
First I modified the F-757-S as per the plan DWG25 for a sliding canopy. The part comes without the cutout so you need to mark the dimensions on the plate and then make a 2 inch radius cut out on the inside corner.
Best is to draw a line in the length direction to mark the 1" 13/32 mark.
The 2 inch radius will not extend to the side so it's hard to estimate that your radius doesn't pass the 1"13/32 mark.
I used a fly cutter in the bench drill and aligned the extend of the knife to the 2" 3/8 mark and then aligned the piece so that the other part of the radius didn't pass the 1" 13/32 line.
Worked fine and just needed to grind away the last bit on the front to make it straight. Worked fine.
The next step is quite complicated as well. You need to cut a sleeve in the canopy deck between two marked points. This is where the F-757 will slide in.
It sounds simple but cutting a straight line with a dremel tool and a cutting disc is always a challenge for me.
I scratched my head for a while and then decided to clamp a wood block on the canopy deck in order to guide the disc while cutting.
This worked very well. Just slide the front of the cutting bit against the wood and keep the dremel level. This ensures a straight and quite clean cut that doesn't take away too much material.
This is how the cut looks like. Uncleaned directly after the cut.
And here it is after cleaning it up with some key files and sanding paper.
Then did the same for the one on the pilot side.
Installed it on the canoe.
At first, the F-757 wouldn't fit very nicely in the longeron. I rounded the top edge as the manual suggests and now have a good flat mating connection of the F-757-S to the longeron.
The forward side also butt's nicely in the longeron. Ready to drill, but that's for the next session.