HEIDENHAIN TNC 620 Programming Station, User Manual

Page: 251 / 695

Approaching and departing a contour 6.3
6
HEIDENHAIN | TNC 620 | ISO Programming User's Manual | 9/2016
251
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.
R0=G40; RL=G41; RR=G42
Example NC blocks
N20 G01 Y+20 G42 F100*
Last contour element: PE with radius compensation
N30 DEP CT CCA 180 R+8 F100*
Center angle=180°, arc radius=8 mm
N40 G00 Z+100 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
E
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
R0=G40; RL=G41; RR=G42
Example NC blocks
N20 G01 Y+20 G42 F100*
Last contour element: PE with radius compensation
N30 DEP LCT X+10 Y+12 R+8 F100*
Coordinates PN, arc radius=8 mm
N40 G00 Z+100 M2*
Retract in Z, return to block 1, end program