HEIDENHAIN iTNC 530 (340 49x-02) ISO programming - Manual (Page 306)

306 8 Programming: Cycles
8.3 Cy
cles f
o
r Dr
illing, T
a
pping and Thr
ead Milling
THREAD DRILLING/MILLING (Cycle G264)
1 The TNC positions the tool in the tool axis at rapid traverse to the
input set-up clearance above the workpiece surface.
Drilling
2 The tool drills to the first plunging depth at the programmed feed
rate for plunging.
3 If you have programmed chip breaking, the tool then retracts by
the entered retraction value. If you are working without chip
breaking, the tool is moved at rapid traverse to set-up clearance
and then at rapid traverse to the entered starting position above
the first plunging depth.
4 The tool then advances with another infeed at the programmed
feed rate.
5 The TNC repeats this process (2 to 4) until the programmed total
hole depth is reached.
Countersinking at front
6 The tool moves at the feed rate for pre-positioning to the sinking
depth at front.
7 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.
8 The tool then moves in a semicircle to the hole center.