Siemens SINUMERIK 840D Programming Manual page 126

3
Milling Cycles
3.3 Thread cutting – CYCLE90
Programming example
(thread from bottom to top)
A thread must be cut starting from –20 up to 0 with a
3mm pitch. The retraction plane is at 8.
N10 G17 X100 Y100 S300 M3 T1 D1 F1000
N20 Z8
N30 CYCLE90 (8, -20, 0, 0, 0, 46, 40, 3, 800, 3, 0, 50, 50)
N40 M2
The hole must have at least a depth of –21.5 (half
pitch in excess).
Overshoot in the thread longitudinal direction
For thread milling, the travel-in and travel-out
movements occur along all three axes concerned.
This means that the travel-out movement includes a
further step in the vertical axis, beyond the
programmed thread depth.
The overshoot is calculated:
+
p 2 * WR RDIFF
∆z =
*
4 DIATH
∆ z
Overshoot, internal
p Thread pitch
WR Tool radius
DIATH Outside diameter of the thread
RDIFF Radius difference for travel-out
For inside threads RDIFF = DIATH/2 - WR,
For outside threads RDIFF = DIATH/2 + WR.
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SINUMERIK 840D/840Di/810D Programming Guide Cycles (PGZ) – 11.02 Edition
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12.97
08.97
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