HEIDENHAIN TNC 620 (340 56x-01) - Manual (Page 154)

154
6.3 Cont
our Appr
oac
h
and Depar
tur
e
Approaching on a circular path with tangential
connection: APPR CT
The tool moves on a straight line from the starting point P
S
to an
auxiliary point P
H
. It then moves to the first contour point P
A
following
a circular arc that is tangential to the first contour element.
The arc from P
H
to P
A
is determined through the radius R and 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
S
.
 Initiate the dialog with the APPR/DEP key and APPR CT soft key:
 Coordinates of the first contour point P
A
 Radius R of the circular arc
„ 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 from the workpiece
side:
Enter R as a negative value.
 Center angle CCA of the arc
„ CCA can be entered only as a positive value.
„ Maximum input value 360°
 Radius compensation RR/RL for machining
Example NC blocks
X
Y
10
20
PA
RR
PS
R0
PH
RR
40 10
CCA=
180°
R10
35
20
7 L X+40 Y+10 RO FMAX M3 Approach P
S
without radius compensation
8 APPR CT X+10 Y+20 Z-10 CCA180 R+10 RR F100 P
A
with radius comp. RR, radius R=10
9 L X+20 Y+35 End point of the first contour element
10 L ... Next contour element