HEIDENHAIN TNC 320 (340 55x-03) Touch Probe Cycles - Manual (Page 65)

HEIDENHAIN TNC 320 65
3.2 Pr
eset
ting aut
o
matically
DATUM SLOT CENTER (touch probe Cycle 408,
DIN/ISO: G408)
Touch probe cycle 408 finds the center of a slot 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 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
probes the first touch point at the probing feed rate (column F).
3 Then the touch probe moves either paraxially at the measuring
height or linearly at the clearance height to the next starting point
2 and probes the second touch point.
4 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 64) and saves the actual values in the Q parameters listed
below
5 If desired, the TNC subsequently measures the datum in the touch
probe axis in a separate probing.
X
Y
1
2
Parameter number Meaning
Q166 Actual value of measured slot width
Q157 Actual value of the centerline
Before programming, note the following
To prevent a collision between touch probe and
workpiece, enter a low estimate for the slot width.
If the slot width and the safety clearance do not permit
pre-positioning in the proximity of the touch points, the
TNC always starts probing from the center of the slot. In
this case the touch probe does not return to the clearance
height between the two measuring points.
Before a cycle definition you must have programmed a
tool call to define the touch probe axis.