HEIDENHAIN TNC 640 (34059x-05) Cycle programming - Manual (Page 128)

Fixed Cycles: Tapping / Thread Milling
4.9 HELICAL THREAD DRILLING/MILLING (Cycle 265, DIN/ISO: G265)
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TNC 640 | User's Manual Cycle Programming | 1/2015
4.9 HELICAL THREAD DRILLING/
MILLING (Cycle 265, DIN/ISO: G265)
Cycle run
1 The TNC positions the tool in the tool axis at rapid traverse
FMAX to the entered set-up clearance above the workpiece
surface.
Countersinking at front
2 If countersinking occurs before thread milling, the tool moves
at the feed rate for countersinking to the sinking depth at front.
If countersinking occurs after thread milling, the TNC moves
the tool to the countersinking depth at the feed rate for pre-
positioning.
3 The TNC positions the tool without compensation from the
center on a semicircle to the offset at front, and then follows a
circular path at the feed rate for countersinking.
4 The tool then moves in a semicircle to the hole center.
Thread milling
5 The tool moves at the programmed feed rate for pre-positioning
to the starting plane for the thread.
6 The tool then approaches the thread diameter tangentially in a
helical movement.
7 The tool moves on a continuous helical downward path until it
reaches the thread depth.
8 After that the tool departs the contour tangentially and returns
to the starting point in the working plane.
9 At the end of the cycle, the TNC retracts the tool in rapid
traverse to setup clearance or, if programmed, to the 2nd setup
clearance.