HEIDENHAIN TNC 426B (280 472) Touch Probe Cycles - Manual (Page 64)

52 3 Touch Probe Cycles for Automatic Workpiece Inspection
3.2 A
u
to
matic D
at
u
m Set
ting
DATUM FROM OUTSIDE OF CORNER
(touch probe cycle 414, ISO: G414)
Touch probe cycle 414 finds the intersection of two lines and defines
it as the datum. If desired, the TNC can also enter the intersection into
a datum table.
1 Following the positioning logic (see “Running touch probe cycles”
on page 7), the TNC positions the touch probe at rapid traverse
(value from MP6150 or MP6361) to the first touch point
1 (see
figure at upper right). The TNC offsets the touch probe by the
safety clearance in the direction opposite the respective traverse
direction.
2 Then the touch probe moves to the entered measuring height and
probes the first touch point at the probing feed rate (MP6120 or
MP6360). The TNC derives the probing direction automatically
from the programmed 3rd measuring point.
3 Then the touch probe moves to the next starting position 2 and
probes the second position.
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
sets the datum at the intersection of the measured lines, or enters
its coordinates in the active datum table.
1 2
4
3
3
1
1
3 3
1
1
3
The TNC always measures the first line in the direction of
the minor axis of the working plane.
Before programming, note the following:
By defining the position of the measuring points 1 and 3
you also determine the corner at which the TNC sets the
datum (see figure at right and table at lower right).
Before a cycle definition you must have programmed a
tool call to define the touch probe axis.
Corner Condition X Condition Y
A X1 greater than X3 Y1 less than Y3
B X1 less than X3 Y1 less than Y3
C X1 less than X3 Y1 greater than Y3
D X1 greater than X3 Y1 greater than Y3