Calibrating A 3-D Touch Probe - HEIDENHAIN iTNC 530 User Manual

14.7 Calibrating a 3-D Touch Probe

Introduction
In order to precisely specify the actual trigger point of a 3-D touch
probe, you must calibrate the touch probe, otherwise the TNC cannot
provide precise measuring results.
Always calibrate a touch probe in the following cases:
Commissioning
Stylus breakage
Stylus exchange
Change in the probe feed rate
Irregularities caused, for example, when the machine
heats up
Change of active tool axis
During calibration, the TNC finds the "effective" length of the stylus
and the "effective" radius of the ball tip. To calibrate the 3-D touch
probe, clamp a ring gauge of known height and known internal radius
to the machine table.
Calibrating the effective length
The effective length of the touch probe is always
referenced to the tool datum. The machine tool builder
usually defines the spindle tip as the tool datum.
U
Set the datum in the spindle axis such that for the machine tool table
Z=0.
U To select the calibration function for the touch probe
length, press the TOUCH PROBE and CAL. L soft
keys. The TNC then displays a menu window with
four input fields.
U Enter the tool axis (with the axis key).
U Datum: Enter the height of the ring gauge.
U The menu items Effective ball radius and Effective
length do not require input.
U Move the touch probe to a position just above the ring
gauge.
U To change the traverse direction (if necessary), press
a soft key or an arrow key.
U To probe the upper surface, press the NC Start button
496 Manual Operation and Setup