9 contour train (cycle 25, din/iso: g125), Cycle run, Please note while programming – HEIDENHAIN TNC 640 (34059x-01) Cycle programming User Manual
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Fixed Cycles: Contour Pocket
7.
9 CONT
OUR TRAIN (Cy
c
le 25, DIN/ISO: G125)
7.9 CONTOUR TRAIN (Cycle 25,
DIN/ISO: G125)
Cycle run
In conjunction with Cycle 14 CONTOUR GEOMETRY, this cycle 
facilitates the machining of open and closed contours. 
Cycle 25 CONTOUR TRAIN offers considerable advantages over 
machining a contour using positioning blocks:
The TNC monitors the operation to prevent undercuts and surface 
blemishes. It is recommended that you run a graphic simulation of 
the contour before execution.
If the radius of the selected tool is too large, the corners of the 
contour may have to be reworked.
The contour can be machined throughout by up-cut or by climb 
milling. The type of milling even remains effective when the 
contours are mirrored.
The tool can traverse back and forth for milling in several infeeds: 
This results in faster machining.
Allowance values can be entered in order to perform repeated 
rough-milling and finish-milling operations.
Please note while programming:
Y
X
Z
The algebraic sign for the cycle parameter DEPTH 
determines the working direction. If you program 
DEPTH=0, the cycle will not be executed.
The TNC takes only the first label of Cycle 14 CONTOUR 
GEOMETRY into account.
The memory capacity for programming an SL cycle is 
limited. You can program up to 16384 contour elements in 
one SL cycle.
Cycle 20 CONTOUR DATA is not required.
The miscellaneous functions M109 and M110 are not 
effective when machining a contour with Cycle 25.
Danger of collision!
To avoid collisions,
Do not program positions in incremental dimensions 
immediately after Cycle 25 since they are referenced to 
the position of the tool at the end of the cycle.
Move the tool to defined (absolute) positions in all main 
axes, since the position of the tool at the end of the 
cycle is not identical to the position of the tool at the 
start of the cycle. 
