HEIDENHAIN TNC 620 User Manual page 505

14.6 Datum setting without a 3-D touch
probe
Note
When you set a datum, you set the TNC display to the coordinates
of a known workpiece position.
All manual probe functions are available with a 3-D
touch probe.
Further Information:
probe (option number 17), page 526
Preparation
Clamp and align the workpiece
Insert the zero tool with known radius into the spindle
Ensure that the TNC is showing the actual positions
Datum setting with an end mill
Protective measure
If the surface of the workpiece must not be
scratched, you can lay a metal shim of known
thickness d on it. You then enter a value that is
greater than the desired preset by the value d.
Select the Manual operation mode
Move the tool slowly until it touches (scratches)
the workpiece surface
Select the axis
Z
DATUM SETTING Z=
Zero tool in spindle axis: Set the display to a
known workpiece position (e.g. 0) or enter the
thickness d of the shim. In the tool axis, offset the
tool radius
Repeat the process for the remaining axes.
If the tool in the tool axis has already been set, set the display of
the tool axis to the length L of the tool or enter the sum Z=L+d.
The TNC automatically saves the datum set with the
axis keys in line 0 of the preset table.
HEIDENHAIN | TNC 620 | Conversational Programming User's Manual | 10/2015
Datum setting without a 3-D touch probe 14.6
Datum setting with a 3-D touch
14
505