Siemens SINUMERIK 840D Function Manual page 132

V1: Feedrates
5.2 Path feedrate F
Diameter programming and reference axis for several transverse axes in one channel:
One or more transverse axes are permitted and can be activated simultaneously or separately:
● Programming and displaying in the user interface in the diameter
● Assignment of the specified reference axis with SCC[<axis>] for a constant cutting rate
G96, G961, G962
For more information, see Description of Functions "P1: Transverse axes (Page 115)".
Example
S
G96
● Where r = 0.2 m → n = 183.12 rpm
● Where r = 0.1 m → n = 366.24 rpm
⇒ The smaller the workpiece diameter, the higher the speed.
For G96, G961 or G962, a geometry axis must be defined as the transverse axis.
The transverse axis, whose position affects the speed of the mater spindle, is defined using
channel-specific machine data:
MD20100 $MC_DIAMETER_AX_DEF (geometry axis with transverse axis function)
The function G96, G961 or G962 requires that the machine zero and the workpiece zero of the
transverse axis are in the turning center of the spindle.
Constant speed (G97, G971)
G97, G971 deactivates the "Constant cutting rate function" (G96, G961) and saves the last
calculated spindle speed. With G97, the feedrate is interpreted as a revolutional feedrate (as
with G95). When programming G971, linear feedrate is selected (as with G94). The feedrate F
is interpreted in mm/min or inch/min.
When G97, G971 is active, an S value can be reprogrammed to define a new spindle speed.
This will not modify the cutting rate programmed in G96, G961.
132
= 230 m/min
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA