HEIDENHAIN TNC 640 (34059x-04) Cycle programming - Manual (Page 454)

Touch Probe Cycles: Automatic Datum Setting
16.6 DATUM FROM INSIDE OF CIRCLE (Cycle 412, DIN/ISO: G412)
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TNC 640 | User's Manual Cycle Programming | 3/2014
16.6 DATUM FROM INSIDE OF CIRCLE
(Cycle 412, DIN/ISO: G412)
Cycle run
Touch Probe Cycle 412 finds the center of a circular pocket (or of a
hole) and defines its center as datum. If desired, the TNC can also
enter the coordinates into a datum table or the preset table.
1 Following the positioning logic, the TNC positions the touch
probe at rapid traverse (value from
FMAX column) (see
"Executing touch probe cycles", page 410) to touch point
1
. The
TNC calculates the touch points from the data in the cycle and
the safety clearance from the
SET_UP column of the touch
probe table.
2 Then the touch probe moves to the entered measuring height
and runs the first probing process at the probing feed rate
(column
F). The TNC derives the probing direction automatically
from the programmed starting angle.
3 Then the touch probe moves in a circular arc either at measuring
height or at clearance height to the next starting point 2 and
probes the second touch point.
4 The TNC positions the probe to starting point 3 and then to
starting point 4 to probe the third and fourth touch points.
5 Finally the TNC returns the touch probe to the clearance height
and processes the determined datum depending on the cycle
parameters Q303 and Q305 (see "Characteristics common to all
touch probe cycles for datum setting", page 438) and saves the
actual values in the Q parameters listed below.
6 If desired, the TNC subsequently measures the datum in the
touch probe axis in a separate probing.
Parameter number Meaning
Q151 Actual value of center in reference
axis
Q152 Actual value of center in minor axis
Q153 Actual value of diameter