HEIDENHAIN iTNC 530 (340 49x-04) - Manual (Page 242)

242 6 Programming: Programming Contours
6.3 Cont
our Appr
oac
h
and Depar
tur
e
6.3 Contour Approach and Departure
Overview: Types of paths for contour approach
and departure
The functions for contour approach APPR and departure DEP are
activated with the APPR/DEP key. You can then select the desired
path function with the corresponding soft key:
Approaching and departing a helix
The tool approaches and departs a helix on its extension by moving in
a circular arc that connects tangentially to the contour. You program
helical approach and departure with the APPR CT and DEP CT
functions.
Important positions for approach and departure
„ Starting point P
S
You program this position in the block before the APPR block. Ps lies
outside the contour and is approached without radius compensation
(R0).
„ Auxiliary point P
H
Some of the paths for approach and departure go through an
auxiliary point P
H
that the TNC calculates from your input in the
APPR or DEP block. The TNC moves from the current position to the
auxiliary point P
H
at the feed rate last programmed.
„ First contour point P
A
and last contour point P
E
You program the first contour point P
A
in the APPR block. The last
contour point P
E
can be programmed with any path function. If the
APPR block also contains a Z axis coordinate, the TNC will first move
the tool to P
H
in the working plane, and then move it to the entered
depth in the tool axis.
„ End point P
N
The position P
N
lies outside of the contour and results from your
input in the DEP block. If the DEP block also contains a Z axis
coordinate, the TNC will first move the tool to P
H
in the working
plane, and then move it to the entered height in the tool axis.
Function Approach Departure
Straight line with tangential connection
Straight line perpendicular to a contour
point
Circular arc with tangential connection
Circular arc with tangential connection
to the contour. Approach and departure
to an auxiliary point outside the contour
on a tangentially connecting line.
P
H
RL
P
S R0
P
A
RL P
E RL
RL
RL
P
N
R0