Thanks! One question though; how do you ensure that the tool doesn't move side way while cutting?
The idea, I think, is that you screw that bolt down sufficiently hard that the cutter simply cannot move, except under exceptional forces - which you shouldn't encounter as you'll stall the lathe first.
The one issue I have with Bernd's setup as pictured (although I appreciate it's only an example), is that the bulk of the hold-down force will be over the bar to the left of the strap piece, and not over the cutter... Ideally, you want the bolt as close to the cutter as possible. If you're worried about movement, add a second clamp on the other side for extra stabilty, a bit like the attached C-o-C drawing.