HEIDENHAIN CNC Pilot 4290 - Manual (Page 200)

4 DIN PLUS 188
For machining the rear face with the Y axis, deactivate arc
conversion (G30 H2) and reactivate it for turning and other
operations in the YZ plane (surface view) (G30 H1).
4.18 Notes and Examples
Programming
When programming a contour on the rear face, be
sure to consider the orientation of the XK axis (or X
axis) and rotational direction of arcs.
Insofar as you use drilling and milling cycles, there are
no special aspects to rear-face machining, since
these cycles refer to predefined contours.
For rear-face machining with the basic commands
G100..G103 (or G0..G3, G12.. G13 for the Y axis), the
same conditions as for rear-face contours apply.
Turning
The expert programs contain converting and mirroring
functions.The following principle applies for rear-face
machining (2nd setup):
■ + direction: Program a positive value to depart
the workpiece
■ – direction: Program a negative value to
approach the workpiece
■ G2/G12: Circular arc ”clockwise”
■ G3/G13: Circular arc ”counterclockwise”
Full-surface machining with counterspindle
G30: The expert program activates the mirroring of
the Z axis and the conversion of the arcs (G2, G3, ..).
The arcs must be converted for turning operations
and machining with the C axis.
G121: The expert program shifts the contour and
mirrors the coordinate system (Z axis). Further
programming of G121 is normally not required for
machining the rear face after rechucking.
Full-surface machining with single spindle
G30: Normally not required
G121: The expert program mirrors the contour. Further
programming of G121 is normally not required for
machining the rear face after rechucking.
Working without expert programs
If you do not use the expert programs or the
converting and mirroring functions, the following
principle applies:
■ + direction: Program a positive value to move
away from the spindle
■ – direction: Program a negative value to
approach the spindle
■ G2/G12: Circular arc ”clockwise”
■ G3/G13: Circular arc ”counterclockwise”