On Oct 1, 8:59*pm, "Michael Koblic" wrote:

2) Traditionally the lathe cutting tools are to be positioned "exactly on
centre". What in this context is "exactly"? Is there an accepted tolerance
and if so, what is it? Does this vary with the tool? In which direction is
it better to err?

Thanks

--
Michael Koblic,
Campbell River, BC

If one is turning the exterior of a bar and the cutting tool is on
center or below center, any deflection of the tool brings it away from
the surface being turned. If it is above center any deflection pushes
the tool into the surface being cut. This leads to more deflection
and more digging in.

If you are boring, the situation is reversed. Slightly above deflects
away from the surface. Slightly below and any deflection makes it dig
in.


Dan