Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 610)

Thread Cutting
Chapter 25
25-10
Example 25.2
Tapered Thread Cutting
Thread lead: .125 threads/mm (8 mm pitch)
Depth of cut: 1 mm (X direction)
Number of cutting passes: 2
N1 M03 S30;
N2 G77 G00 X20. Z4.;
N3 G33 X48. Z-47. F8;
N4 X52 Z-55;
N5 G00 X60.;
N6 Z4.;
N7 X12.;
(second pass)
N8 G33 X40. Z-47.;
N9 X52 Z-55;
N10 G00 X60.;
N11 Z4.;
Figure 25.7
Results of Tapered Thread Cutting Example 25.2
8mm
Z
4 -47 -70
12
40
60
N8
N3 N7
N2
N4
N6 N11
N9
-55
20
Multiple-thread cutting can be programmed by assigning a thread cutting
start shift angle using a Q-word. Omission of a Q-word indicates a shift
angle of 0 (synchronizes at the spindle marker). Entering a Q word will
offset the axis synchronization from the spindle marker position.