HEIDENHAIN TNC 640 User Manual page 760

17
Calibrating the effective radius and compensating
center misalignment
HEIDENHAIN only gives warranty for the function of the
probing cycles if HEIDENHAIN touch probes are used.
When calibrating the ball-tip radius, the control executes an
automatic probing routine. In the first run the control finds the
midpoint of the calibration ring or stud (approximate measurement)
and positions the touch probe in the center. Then, in the actual
calibration process (fine measurement), the radius of the ball tip
is ascertained. If the touch probe allows probing from opposite
orientations, the center offset is determined during another cycle.
The property of whether or how your touch probe can be oriented
is predefined for HEIDENHAIN touch probes. Other touch probes
are configured by the machine tool builder.
After the touch probe is inserted, it normally needs to be aligned
exactly with the spindle axis. The calibration function can
determine the offset between touch probe axis and spindle axis
by probing from opposite orientations (rotation by 180°) and can
calculate and implement the necessary compensation.
The center offset can be determined only with a suitable
touch probe.
If you want to calibrate using the outside of an object,
you need to preposition the touch probe above the
center of the calibration sphere or calibration pin.
Ensure that the touch points can be approached without
collision.
The calibration routine varies depending on how your touch probe
can be oriented:
No orientation possible, or orientation in only one direction: The
control executes one approximate and one fine measurement,
and then ascertains the effective ball tip radius (column R in
tool.t).
Orientation possible in two directions (e.g. HEIDENHAIN touch
probes with cable): The control executes one approximate
and one fine measurement, rotates the touch probe by 180°,
and then executes another probing routine. The center offset
(CAL_OF in tchprobe.tp) is determined in addition to the radius
by probing from opposite orientations.
Any orientation possible (e.g. HEIDENHAIN touch probes with
infrared transmission): The control executes one approximate
and one fine measurement, rotates the touch probe by 180°,
and then executes another probing routine. The center offset
(CAL_OF in tchprobe.tp) is determined in addition to the radius
by probing from opposite orientations.
760
Manual Operation and Setup | Calibrating 3-D touch probes
HEIDENHAIN | TNC 640 | Conversational Programming User's Manual | 10/2017