Anybody Thread Whirl on their Swiss machine? I have a Star 32 Lathe and want to thread whirl some taps & screws. I have an attachment with the 3 insert cassette, how does that compare with 6 inserts? Is it worth upgrading to the 6 insert holder? Where do ya get custom formed inserts (for things like bone screws)? Any tips, tricks, tool suppliers, or general info would greatly be appreciated. Thanks