Siemens SINUMERIK 840D Programming Manual page 318

4
Turning Cycles
4.8 Thread chaining – CYCLE98
Description of parameters
PO1 and DM1 (starting point and diameter)
With these parameters you define the original starting
point of the thread chain. The starting point calculated
by the cycle that is approached at the beginning with
G0 is the length of the arc-in section in front of the
programmed starting point (starting point A).
PO2, DM2 and PO3, DM3 (intermediate point and
diameter)
With these parameters you define two intermediate
points in the thread.
PO4 and DM4 (endpoint and diameter)
The original end point of the thread is programmed
under parameters PO4 and DM4.
With an inside thread, DM1...DM4 corresponds to the tap
hole diameter.
Connection between APP and ROP (arc-in, arc-out
sections)
The starting point used in the cycle is the starting point
brought forward by the arc-in section APP and, in the same
way, the end point is the programmed end point brought
back by the arc-out section ROP.
The starting point defined by the cycle always lies
1mm outside the programmed thread diameter in the facing
axis. This retraction plane is automatically generated by the
control.
Connection between TDEP, FAL, NRC and NID (thread
depth, final machining allowance, number of rough cuts
and noncuts)
The programmed final machining allowance is subtracted
from the defined thread depth TDEP and the remainder
divided into rough cuts. The cycle automatically calculates
the individual actual infeed depths depending on the
parameter VARI. The thread depth to be machined is divided
into infeeds with the same cross-section of cut so that the
cutting pressure remains constant for all rough cuts. Infeed
is then performed with differing values for the infeed depth.
4-318
X
P04 P03
PP3 PP2
ROP
SINUMERIK 840D/840Di/810D Programming Guide Cycles (PGZ) – 11.02 Edition
4
03.96
P02 P01
PP1
DM3=DM4
DM2
DM1
APP
Z
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