Siemens SINUMERIK 840Di sl Programming Manual page 276

Feedrate Control and Spindle Motion
7.1 Feedrate (G93, G94, G95 or F..., FGROUP, FGREF)
Traverse rotary axes with path velocity F, FGREF
For machining operations, in which the tool or the workpiece or both are moved by a rotary
axis, the effective machining feedrate is to be interpreted as a path feed in the usual way by
reference to the F value. This requires the specification of an effective radius (reference
radius) FGREF for each of the rotary axes involved.
The unit of the reference radius depends on the G70/G71/G700/G710 setting.
All axes involved must be included in the FGROUP command, as before, in order to be
evaluated in the calculation of the path feed.
In order to ensure compatibility with the behavior with no FGREF programming, the factor 1
degree = 1mm is activated on system powerup and RESET. This corresponds to a reference
radius of FGREF=360 mm/(2π)=57.296 mm.
Note
This default setting is independent of the active basic system MD 10240:
SCALING_SYSTEM_IS_METRIC and of the currently active inch/metric G code.
Special situations: With the following programming:
N100 FGROUP(X,Y,Z,A)
N110 G1 G91 A10 F100
N120 G1 G91 A10 X0.0001 F100
the F value programmed in N110 is evaluated as a rotary axis feedrate in deg/min, while the
feedrate weighting in N120 is either 100 inch/min or 100 mm/min depending on the currently
active inch/metric setting.
276
F
F'
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
Fundamentals