HEIDENHAIN TNC 320 (77185x-01) Cycle programming - Manual (Page 354)

Touch Probe Cycles: Automatic Datum Setting
15.12 DATUM AT CENTER OF 4 HOLES (Cycle 418, DIN/ISO: G418)
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TNC 320 | User's Manual Cycle Programming | 3/2014
15.12 DATUM AT CENTER OF 4 HOLES (Cycle
418, DIN/ISO: G418)
Cycle run
Touch Probe Cycle 418 calculates the intersection of the lines
connecting opposite holes and sets the datum at the intersection.
If desired, the TNC can also enter the intersection into a datum
table or 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 286) to the center of the
first hole
1 .
2 Then the probe moves to the entered measuring height and
probes four points to find the first hole center.
3 The touch probe returns to the clearance height and then to the
position entered as center of the second hole 2 .
4 The TNC moves the touch probe to the entered measuring
height and probes four points to find the second hole center.
5 The TNC repeats steps 3 and 4 for holes 3 and 4 .
6 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 314). The TNC
calculates the datum as the intersection of the lines connecting
the centers of holes
1 / 3 and 2 / 4 and saves the actual values in
the Q parameters listed below.
7 If desired, the TNC subsequently measures the datum in the
touch probe axis in a separate probing.
Parameter number Meaning
Q151 Actual value of intersection point in
reference axis
Q152 Actual value of intersection point in
minor axis