HEIDENHAIN TNC 640 (34059x-05) Cycle programming - Manual (Page 512)

Touch Probe Cycles: Automatic Datum Setting
15.12 DATUM AT CENTER OF 4 HOLES (Cycle 418, DIN/ISO: G418)
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TNC 640 | User's Manual Cycle Programming | 1/2015
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 444) 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 472). 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
Please note while programming:
Danger of collision!
If you set a datum (Q303 = 0) with the touch probe
cycle and also use probe in TS axis (Q381 = 1), then
no coordinate transformation must be active.
Before a cycle definition you must have programmed
a tool call to define the touch probe axis.