HEIDENHAIN TNC 426, User Manual

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222 8 Programming: Cycles
8.3 Cy
cles f
o
r Dr
illing, T
a
pping and Thr
ead Milling
U Angle for spindle orientation Q336 (absolute
value): Angle at which the TNC positions the tool
before it is plunged into or retracted from the bore
hole.
UNIVERSAL PECKING (Cycle 205)
1 The TNC positions the tool in the tool axis at rapid traverse FMAX
to the programmed setup clearance above the workpiece surface.
2 The tool drills to the first plunging depth at the programmed feed
rate F.
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 setup clearance and
then at FMAX to the entered starting position above the first
plunging depth.
4 The tool then advances with another infeed at the programmed
feed rate. If programmed, the plunging depth is decreased after
each infeed by the decrement.
5 The TNC repeats this process (2 to 4) until the programmed total
hole depth is reached.
6 The tool remains at the hole bottom — if programmed — for the
entered dwell time to cut free, and then retracts to set-up
clearance at the retraction feed rate. and — if programmed — to
the 2nd set-up clearance with FMAX.
Before programming, note the following:
Program a positioning block for the starting point (hole
center) in the working plane with radius compensation R0.
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program DEPTH
= 0, the cycle will not be executed.