Please note while programming – HEIDENHAIN TNC 640 (34059x-01) Cycle programming User Manual
Page 121

HEIDENHAIN TNC 640
121
4.1
0
OUTSIDE THREAD MILLING (Cy
c
le 267
, DIN/ISO: G267)
Please note while programming:
Program a positioning block for the starting point (stud 
center) in the working plane with radius compensation R0.
The offset required before countersinking at the front 
should be determined ahead of time. You must enter the 
value from the center of the stud to the center of the tool 
(uncorrected value).
The algebraic sign of the cycle parameters depth of thread 
or sinking depth at front determines the working direction. 
The working direction is defined in the following 
sequence:
1st: Depth of thread
2nd: Depth at front
If you program a depth parameter to be 0, the TNC does 
not execute that step.
The algebraic sign for the cycle parameter thread depth 
determines the working direction.
Danger of collision!
Use the machine parameter displayDepthErr to define 
whether, if a positive depth is entered, the TNC should 
output an error message (on) or not (off).
Keep in mind that the TNC reverses the calculation for pre-
positioning when a positive depth is entered. This 
means that the tool moves at rapid traverse in the tool axis 
to set-up clearance below the workpiece surface!
