The Resonator

[cork sniffer]

Cheers FW. I'm also looking at those burrs on the spider cone where the four holes are drilled; still can't work out why they are there if not used.

Remove the burrs to allow the cone to sit flat, don't screw it in, allow the string pressure to hold it.

[FrankenWashie]

Remove the burrs to allow the cone to sit flat, don't screw it in, allow the string pressure to hold it.

Yep, I used a small flat diamond file to flatten those off and get it sitting right.