Important Positions For Approach And Departure - HEIDENHAIN TNC 640 User Manual

Programming Contours | Approaching and departing a contour

Important positions for approach and departure

Starting point P
S
You program this position in the block before the APPR block.
P lies outside the contour and is approached without radius
S
compensation (G40).
Auxiliary point P
H
Some of the paths for approach and departure go through
an auxiliary point P that the control calculates from your
H
input in the APPR or DEP block. The control moves from the
current position to the auxiliary point P
programmed. If you have programmed G00 (positioning at
rapid traverse) in the last positioning block before the approach
function, the control also approaches the auxiliary point P
rapid traverse
First contour point P
A
You program the first contour point P
The last contour point P
function. If the APPR block also includes the Z coordinate, the
control moves the tool simultaneously to the first contour point
P .
A
End point P
N
The position P lies outside of the contour and results from
N
your input in the DEP block. If the DEP block also includes the
Z coordinate, the control moves the tool simultaneously to the
end point P .
N
Abbreviation
APPR
DEP
L
C
T
N
Danger of collision!
The control does not automatically check whether collisions
can occur between the tool and the workpiece. Incorrect pre-
positioning and incorrect auxiliary points P
contour damage. There is danger of collision during the approach
movement!
Program a suitable pre-position
Check the auxiliary point P
with the aid of the graphic simulation
HEIDENHAIN | TNC 640 | ISO Programming User's Manual | 10/2017
at the feed rate last
H
and last contour point P
E
in the APPR block.
A
can be programmed with any path
E
Meaning
Approach
Departure
Line
Circle
Tangential (smooth connection)
Normal (perpendicular)
NOTICE
can also lead to
H
, the sequence and the contour
H
at
H
7
R0=G40; RL=G41; RR=G42
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