Siemens SINUMERIK 808D ADVANCED Programming And Operating Manual page 183

Note
To be able to use this cycle, a speed-controlled spindle with position measuring system is required.
Sequence
Position reached prior to cycle start:
Starting position is any position from which the programmed thread starting point + run-in path can be approached without
collision.
The cycle creates the following sequence of motions:
● Approach of the starting point determined in the cycle at the beginning of the run-in path for the first thread turn with G0
● Infeed for roughing according to the infeed type defined under VARI.
● Thread cutting is repeated according to the programmed number of roughing cuts.
● The finishing allowance is removed in the following step with G33.
● This step is repeated according to the number of idle passes.
● The whole sequence of motions is repeated for each further thread turn.
Explanation of the parameters
DM1 and DM2 (diameter)
Use this parameter to define the thread diameter of starting and end point of the thread. In the case of internal threads, this
is the tap-hole diameter.
Interrelation SPL, FPL, APP and ROP (starting, end point, run-in and run-out path)
See the following illustration for the parameters for CYCLE99:
The programmed starting point (SPL) or end point (FPL) constitutes the original starting point of the thread. The starting
point used in the cycles, however, is the starting point brought forward by the run-in path APP.
The run-out path (Cut out) begins before the programmed end point FPL. It brings the end position of thread forward so that
the end of cut out is equal FPL.
Interrelation TDEP, FAL, NRC and NID (thread depth, finishing allowance, number of cuts)
The programmed finishing allowance acts paraxially and is subtracted from the specified thread depth TDEP; the remainder
is divided into roughing cuts.
The cycle will calculate the individual infeed depth automatically, depending on the VARI parameter.
Programming and Operating Manual (Turning)
183
6FC5398-5DP10-0BA2, 06/2015