HEIDENHAIN TNC 640 User Manual page 135

Fixed Cycles: Tapping / Thread Milling | Fundamentals of Thread Milling
Danger of collision!
A collision may occur if, upon tool breakage, you retract the tool
from the hole in the direction of the tool axis only.
Stop the program run if the tool breaks
Change to Positioning with Manual Data Input mode of
operation
First move the tool in a linear movement towards the hole
center
Retract the tool in the tool axis direction
The TNC references the programmed feed rate during
thread milling to the tool cutting edge. Since the TNC,
however, always displays the feed rate relative to the
path of the tool tip, the displayed value does not match
the programmed value.
The machining direction of the thread changes if you
execute a thread milling cycle in connection with Cycle 8
MIRROR IMAGE in only one axis.
HEIDENHAIN | User's manual for cycle programming | 10/2017
NOTICE
4
135