HEIDENHAIN TNC 320 (340 55x-03) Touch Probe Cycles - Manual (Page 114)

114
3.3 A
u
to
matic W
o
rk
piece Measur
ement
MEASURE HOLE (touch probe cycle 421,
DIN/ISO: G421)
Touch probe cycle 421 measures the center and diameter of a hole (or
circular pocket). If you define the corresponding tolerance values in
the cycle, the TNC makes a nominal-to-actual value comparison and
saves the deviation value in system parameters.
1 The TNC positions the touch probe at rapid traverse (value from
FMAX column) following the positioning logic (see “Running touch
probe cycles” on page 21) to the starting point
1 . The TNC
calculates the probe starting 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
saves the actual values and the deviations in the following Q
parameters:
X
Y
1
2
3
4
Parameter number Meaning
Q151 Actual value of center in reference axis
Q152 Actual value of center in minor axis
Q153 Actual value of diameter
Q161 Deviation from center of reference axis
Q162 Deviation from center of minor axis
Q163 Deviation from diameter
Before programming, note the following
Before a cycle definition you must have programmed a
tool call to define the touch probe axis.