Laser Compound-Slide Angle Setting

[Christophe Mineau]

it is a convention that the spindle axis of a machine tool is designated as Z. On a lathe what you have called the X axis should be termed Z and your Y is generally called X. Personally I don't like it but that is the convention and less misunderstandings occur if we all use the same notation.

Thanks Tony for the comment, I learned something, and I changed in the post.
But actually (even if this not why I made this mistake, I must admit), I have a milling head now on this lathe, so for the mill, the Z would really be vertical !