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Hello and thanks for the kind words.
I see the problem, there should be 6xM3 machine screws called out as item 14 in the lower right view and then 3xM4 self tapping screws in the upper view attaching the nose cone to the disc. Sorry I made a last minute change and didn't catch this...
Item 3 is a printed part and its the pitch arm (black), no need for anything counter sunk the parts don't overlap at any point.
Item 13 is an interference fit with item 2, its very difficult to install as it needs to be locked in place (I used a battery drill and drove the bolt home). Item 13 will need installing in all 3 positions prior to assembly into the disc (take a look at the picture with all the parts laid out you can see them pre assembled). The pitching of the blade doesn't require assess to the bolt as its all connected to the pitch mechanism so by depressing the piston when tightening the blades you effectively hold the bolt captive. To get the blade tight enough and get the correct pitch I used rubber o-rings so I could compress the ring and get the perfect pitch angle, you could also use washers or even a cut down spring. Its really important not to over pitch the blades as I've set them right on the very edge of stall for maximum lift even 0.5 degrees on a single blade will cause a stall if in doubt under pitch them to start with.
I hope that was clear and helpful.
Have fun, Dan