HEIDENHAIN TNC 426 (280 476) User Manual
Page 278
HEIDENHAIN TNC 426, TNC 430
251
8.3 Cy
cles f
o
r Dr
illing, T
a
pping and Thr
ead Milling
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Nominal diameter
Q335: Nominal thread diameter
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Thread pitch
Q239: Pitch of the thread. The algebraic
sign differentiates between right-hand and left-hand
threads:
+= right-hand thread
– = left-hand thread
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Thread depth
Q201 (incremental value): Distance
between workpiece surface and root of thread
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Threads per step
Q355: Number of thread
revolutions by which the tool is offset, see figure at
lower right 0 = one 360° helical path to the depth of
thread
1 = continuous helical path over the entire length of
the thread
>1 = several helical paths with approach and
departure; between them, the TNC offsets the tool by
Q355, multiplied by the pitch
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Feed rate for pre-positioning
Q253: Traversing
speed of the tool when moving in and out of the
workpiece, in mm/min
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Climb or up-cut
Q351: Type of milling operation with
M03
+1 = climb milling
–1 = up-cut milling