HEIDENHAIN TNC 640, User Manual, Page: 297 / 948

Programming Contours | Approaching and departing a contour
7
HEIDENHAIN | TNC 640 | Conversational Programming User's Manual | 10/2017
297
Departing on a circular path with tangential
connection:
DEP CT
The tool moves on a circular arc from the last contour point P
E
to
the end point P
N
. The circular arc connects tangentially to the last
contour element.
Program the last contour element with the end point P
E
and
radius compensation
Initiate the dialog with the
APPR DEP
key and
DEP CT
soft key
Center angle
CCA
of the arc
Radius R of the circular arc
If the tool should depart the workpiece
in the direction opposite to the radius
compensation: Enter R as a positive value.
If the tool should depart the workpiece
in the direction
opposite to the radius
compensation: Enter R as a negative value.
Example
23 L Y+20 RR F100
Last contour element: PE with radius compensation
24 DEP CT CCA 180 R+8 F100
Center angle=180°, arc radius=8 mm
25 L Z+100 FMAX M2
Retract in Z, return to block 1, end program
Departing on a circular arc tangentially connecting the
contour and a straight line: DEP LCT
The tool moves on a circular arc from the last contour point P
S
to
an auxiliary point P
H
. It then moves on a straight line to the end
point P
N
. The arc is tangentially connected both to the last contour
element and to the line from P
H
to P
N
. Once these lines are known,
the radius R suffices to unambiguously define the tool path.
Program the last contour element with the end point P
E
and
radius compensation
Initiate the dialog with the
APPR/DEP
key and
DEP LCT
soft key
Enter the coordinates of the end point P
N
Radius R of the circular arc. Enter R as a positive
value
Example
23 L Y+20 RR F100
Last contour element: PE with radius compensation
24 DEP LCT X+10 Y+12 R+8 F100
Coordinates PN, arc radius=8 mm
25 L Z+100 FMAX M2
Retract in Z, return to block 1, end program