Siemens SINUMERIK 840D Programming Manual page 254

Turning Cycles
4
4.8 Thread chaining – CYCLE98
In a second method, the total thread depth is divided
into constant infeed depths. The cross-section of cut
gets larger from cut to cut. However, if the values for
the thread depth are small, this method can create
better cutting conditions.
The final machining allowance FAL is removed in
one cut after roughing. After this, the noncuts
programmed under parameter NID are executed.
IANG (infeed angle)
With parameter IANG you define the infeed angle. If
infeed is to be performed at right angles to the
cutting direction in the thread this parameter must be
assigned the value zero. I.e., this parameter can
also be omitted from the parameter list as it is then
automatically assigned the default value zero. If
infeed is to be performed along the flank, the
absolute value of this parameter must be no more
than half the flank angle of the tool.
The sign entered for this parameter defines how this
infeed is performed. If a positive value is entered,
infeed is always performed on the same flank, if a
negative value is entered, infeed is performed
alternately on both flanks. The infeed type on both
flanks alternately can only be used for cylindrical
threads. However, if a negative value is assigned to
parameter IANG for a tapered thread, the cycle
automatically performs a flank infeed along one
flank.
4-254
IANG<=
Infeed along
one flank
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide, Cycles (PGZ) - 04.00 Edition
03.96
08.97
4
ε
ε
ε
2
Infeed on
alternate flanks
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