HEIDENHAIN ND 730 v.1 - Manual (Page 5)

Fundamentals
5
Cross slide, saddle and top slide
On conventional lathes, the tool is mounted on a slide that moves in
the direction of the X axis (the cross slide) and in the direction of the Z
axis (the saddle).
Most lathes have a top slide above the saddle. The top slide moves in
Z axis direction and is designated Zo.
Z
Z
O
X
+Z
+X
+Z
O