HEIDENHAIN TNC 620 User Manual page 528

14
Manual Operation and Setup
14.10 Datum setting with a 3-D touch probe
Circle center as datum
With this function, you can set the datum at the center of bore
holes, circular pockets, cylinders, studs, circular islands, etc.
Inside circle:
The TNC probes the inside wall of a circle in all four coordinate axis
directions.
For incomplete circles (circular arcs) you can choose the
appropriate probing direction.
Position the touch probe approximately in the
center of the circle
Select the touch probe function: Press the
PROBING CC soft key
Select the soft key for the desired probing
direction
Probe: Press the NC START key. The touch probe
probes the inside wall of the circle in the selected
direction. Repeat this process. After the third
probing operation, you can have the TNC calculate
the center (four touch points are recommended)
Terminate the probing procedure and switch to the
evaluation menu: Press the EVALUATE soft key
Datum: Enter both coordinates of the center of the
circle in the menu window, confirm with the SET
DATUM soft key or write values to a table
Further Information:
from the touch probe cycles to a datum table,
page 511
Further Information:
from the touch probe cycles to the preset table,
page 512
Terminate the probe function by pressing the END
soft key
The TNC needs only three touch points to calculate
outside or inside circles, e.g. for circle segments.
More precise results are obtained if you measure
circles using four touch points, however. You should
always preposition the touch probe in the center, or
as close to the center as possible.
528
Writing measured values
Writing measured values
HEIDENHAIN | TNC 620 | Conversational Programming User's Manual | 10/2015