HEIDENHAIN TNC 620 (340 56x-02) Cycle programming - Manual (Page 328)

328 Touch Probe Cycles: Automatic Datum Setting
15.6 D
A
TUM FR
OM INSIDE OF CIR
C
LE (Cy
c
le 412, DIN/ISO: G412)
15.6 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 The TNC positions the touch probe to the starting point 1 at rapid
traverse (value from FMAX column) following the positioning logic
(see “Executing touch probe cycles” on page 283). 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
probes the first touch point 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 “Saving the calculated datum”
on page 312) 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.
X
Y
1
2
4
3
Parameter number Meaning
Q151 Actual value of center in reference axis
Q152 Actual value of center in minor axis
Q153 Actual value of diameter