eliot d
So you know about finance math? I once asked a sophisticated banker to explain derivatives to me. Well, I asked for it! It was more complex than fancy number theory! (I was really sorry I asked him.)

By the way, I thought your idea of putting tape over the mouth of the dai and rotating like a windshield wiper was interesting. But I still have some problems even there with getting the right plane(in the math sense) out of the process. But the thought got me thinking about doing it on the lathe. I can see clearly how to get it just right that way, but I don't think I'll try it. It's a case of theory vs practice.

Oh and another thing: you did a really bad thing to me( and maybe some others) when you showed a link to some Japanese woodworker sites. They remind me of stories of Julliard-type pianists on first hearing Vladimir Horowitz.They just gave up and went into accounting or whatever!