HEIDENHAIN TNC 620 User Manual page 248

6
Programming contours
6.3 Approaching and departing a contour
Approaching on a circular path with tangential
connection: APPR CT
The tool moves on a straight line from the starting point P
auxiliary point P . It then moves from PH to the first contour point
H
PA following a circular arc that is tangential to the first contour
element.
The arc from P to P
H
the center angle CCA. The direction of rotation of the circular arc
is automatically derived from the tool path for the first contour
element.
Use any path function to approach the starting point P
Initiate the dialog with the APPR DEP key and APPR CT soft key
Coordinates of the first contour point P
Radius R of the circular arc
Center angle CCA of the arc
Radius compensation G41/G42 for machining
Example NC blocks
N70 G00 X+40 Y+10 G40 M3*
N80 APPR CT X+10 Y+20 Z-10 CCA180 R+10 G42 F100*
N90 G01 X+20 Y+35*
N100 G01 ...*
248
is determined through the radius R and
A
If the tool should approach the workpiece in the
direction defined by the radius compensation:
Enter R as a positive value
If the tool should approach the workpiece
opposite to the radius compensation: Enter R
as a negative value.
CCA can be entered only as a positive value.
Maximum input value 360°
to an
S
.
S
A
Approach PS without radius compensation
PA with radius comp. G42, radius R=10
End point of the first contour element
Next contour element
HEIDENHAIN | TNC 620 | ISO Programming User's Manual | 9/2016
R0=G40; RL=G41; RR=G42