HEIDENHAIN TNC 426 (280 476) Pilot - Manual (Page 12)

13
Contour
Approach
and
Departure
Contour Approach and Departure
Starting point P
S
P
S
lies outside of the contour and must be approached without radius
compensation.
Auxiliary point P
H
P
H
lies outside of the contour and is calculated by the TNC.
The tool moves from the starting point P
S
to the auxiliary point
P
H
at the feed rate last programmed feed rate!
First contour point P
A
and last contour point P
E
The first contour point P
A
is programmed in the APPR (approach) block.
The last contour point is programmed as usual.
End point P
N
P
N
lies outside of the contour and results from the DEP (departure)
block. P
N
is automatically approached with R0.
Path Functions for Approach and Departure
Press the soft key with the desired path function:
Straight line with tangential connection
Straight line perpendicular to the
contour point
Circular arc with tangential connection
Straight line segment tangentially con-
nected to the contour through an arc
• Program a radius compensation in the APPR block!
• DEP blocks set the radius compensation to 0!