HEIDENHAIN TNC 320 (340 551-02) - Manual (Page 125)

HEIDENHAIN TNC 320 125
6.3 Cont
our Appr
oac
h
and Depar
tur
e
Approaching on a circular arc with tangential
connection from a straight line to the contour:
APPR LCT
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
on a
circular arc. The feed rate programmed in the APPR block is in effect.
The arc is connected tangentially both to the line P
S
–P
H
as well as to
the first contour element. Once these lines are known, the radius then
suffices to completely define the tool path.
8 Use any path function to approach the starting point P
S
.
8 Initiate the dialog with the APPR/DEP key and APPR LCT soft key:
8 Coordinates of the first contour point P
A
8 Radius R of the circular arc. Enter R as a positive value.
8 Radius compensation RR/RL for machining
Example NC blocks
Departing on a straight line with tangential
connection: DEP LT
The tool moves on a straight line from the last contour point P
E
to the
end point P
N
. The line lies on the extension of the last contour
element. P
N
is separated from P
E
by the distance LEN.
8 Program the last contour element with the end point P
E
and radius
compensation.
8 Initiate the dialog with the APPR/DEP key and DEP LT soft key:
8 LEN: Enter the distance from the last contour element
P
E
to the end point P
N
.
Example NC blocks
X
Y
10
20
P
A
RR
P
S
R0
P
H
RR
RR
40 10
R10
35
20
7 L X+40 Y+10 RO FMAX M3 Approach P
S
without radius compensation
8 APPR LCT X+10 Y+20 Z-10 R10 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
X
Y
20
P
E
RR
P
N
R0
RR
12.5
23 L Y+20 RR F100 Last contour element: P
E
with radius compensation
24 DEP LT LEN12.5 F100 Depart contour by LEN=12.5 mm
25 L Z+100 FMAX M2 Retract in Z, return to block 1, end program