HEIDENHAIN TNC 640 (34059x-04) Cycle programming - Manual (Page 119)

THREAD MILLING/COUNTERSINKING (Cycle 263, DIN/ISO:G263) 4.7
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TNC 640 | User's Manual Cycle Programming | 3/2014
119
4.7 THREAD MILLING/COUNTERSINKING
(Cycle 263, DIN/ISO:G263)
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
2 The tool moves at the feed rate for pre-positioning to the
countersinking depth minus the set-up clearance, and then at
the feed rate for countersinking to the countersinking depth.
3 If a safety clearance to the side has been entered, the TNC
immediately positions the tool at the feed rate for pre-
positioning to the countersinking depth.
4 Then, depending on the available space, the TNC makes a
tangential approach to the core diameter, either tangentially
from the center or with a pre-positioning move to the side, and
follows a circular path.
Countersinking at front
5 The tool moves at the feed rate for pre-positioning to the sinking
depth at front.
6 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.
7 The tool then moves in a semicircle to the hole center.
Thread milling
8 The TNC moves the tool at the programmed feed rate for pre-
positioning to the starting plane for the thread. The starting
plane is determined from the thread pitch and the type of
milling (climb or up-cut).
9 Then the tool moves tangentially on a helical path to the thread
diameter and mills the thread with a 360° helical motion.
10 After that the tool departs the contour tangentially and returns
to the starting point in the working plane.
11 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.