Siemens Sinumerik 840D Thread Cutting Cycle CYCLE97

With Sinumerik 840D Thread Cutting Cycle CYCLE97 cylindrical and tapered outside and inside threads with constant pitch in longitudinal or face machining can be machined. The thread can be single or multiple. With multiple threads, the individual thread turns are machined one after the other.

Infeed is automatic. You can select either constant infeed per cut or constant cross-section
of cut.

Right-hand or left hand thread is determined by the direction of rotation of the spindle which
must be programmed prior to the cycle start.

Neither feedrate nor spindle override have any effect in thread travel blocks. The spindle override must not be changed during thread machining.

Contents

Sinumerik CYCLE97 Format
Sinumerik CYCLE97 Parameters Explanation

Sinumerik CYCLE97 Format

CYCLE97 (PIT, MPIT, SPL, FPL, DM1, DM2, APP, ROP, TDEP, FAL, IANG, NSP, NRC, NID, VARI, NUMT, _VRT)

Sinumerik CYCLE97 Parameters Explanation

Siemens Sinumerik 840D Thread Cutting Cycle CYCLE97

PIT (Thread Pitch)

Thread pitch as a value (enter without sign). The thread pitch is an axis-parallel value and is specified without sign.

MPIT (Thread Pitch as Thread Size)

Thread pitch as thread size. To produce metric cylindrical threads, it is also possible to specify the thread start as a thread size via the

parameter MPIT (M3 to M60)

SPL (Thread Starting Point Longitudinal)

Thread starting point in the longitudinal axis

FPL (Thread End Point Longitudinal)

Thread end point in the longitudinal axis

DM1 (Thread Start Diameter)

Thread diameter at the starting point

DM2 (Thread End Diameter)

Thread diameter at the end point

APP (Run-In Path)

Run-in path (enter without sign)

ROP (Run-Out Path)

Run-out path (enter without sign)

TDEP (Thread Depth)

Thread depth (enter without sign)

FAL (Finishing Allowance)

Finishing allowance (enter without sign). The finishing allowance FAL is removed after roughing in one step.

IANG (Infeed Angle)

Infeed angle (“+” for flank infeed at the flank) (“–” for alternating flank infeed)

If you wish to infeed at a right angle to the cutting direction in the thread, the value of this parameter must be set to zero.
In other words, the parameter can also be omitted from the parameter list, since in this case, it is automatically loaded with zero by default.

If you wish to infeed along the flanks, the absolute value of this parameter may amount maximally to the half of the flank angle of the tool.

NSP (Starting Point Offset)

Starting point offset for the first thread turn (enter without sign). With this parameter, you can program the angular value that defines the point of the first cut of the first thread start on the circumference of the turned part. This is a starting point offset.

The parameter can assume values between 0.0001 and +359.9999 degrees.

If no starting point offset is specified or the parameter is omitted from the parameter list, the first thread turn automatically starts at the zero-degree mark.

NRC (Number of Roughing Cuts)

Number of roughing cuts (enter without sign)

NID (Number of Idle Cuts)

Number of idle passes (enter without sign)

VARI (Machining Type)

Definition of the machining type for the thread (1 … 4)
With the VARI parameter, you define if machining is to be internal or external.
With which technology the infeed will be machined during roughing.

The VARI parameter can assume values between 1 and 4 with the following meaning:
1 = External Constant infeed
2 = Internal Constant infeed
3 = External Constant cutting cross-section
4 = Internal Constant cutting cross-section

NUMT (Number of Thread Turns)

Number of thread turns (enter without sign).

You specify the number of thread starts for a multiple thread with the NUMT parameter.

For a single-turn thread, the parameter must be assigned zero or can be dropped completely in the parameter list.
The thread turns are distributed equally over the circumference of the turned part;

the first thread turn is determined by the NSP parameter.

_VRT (Retraction Distance)

Variable retraction distance based on initial diameter, incremental (enter without sign).

When _VRT = 0 (parameter not programmed), the retraction path is 1 mm.

The retraction path is always measured according to the programmed system of units, inch or metric.