Special Functions - Siemens SINUMERIK 802D sl Programming And Operating Manual

3.5

Special functions

3.5.1 Constant cutting rate: G96, G97
Requirement
A controlled spindle must be present.
Functionality
With activated G96 function, the spindle speed is adapted to the currently machined work-
piece diameter (transverse axis) such that a programmed cutting rate S remains constant on
the tool edge:
Spindle speed times diameter = constant.
The S word is evaluated as the cutting rate as of the block with G96. G96 is modally effective
until cancellation by another G function of the group (G94, G95, G97).
Programming
G96 S... LIMS=... F...
G97
I
LIMS=
F
Remark:
If G94 was previously active instead of G95, an appropriate F value must be programmed!
Rapid traverse
With rapid traverse G0, there is no change in speed.
Exception: If the contour is approached at rapid traverse and the next block contains an in-
terpolation type G1 or G2, G3, CIP, CT (contour block), then the speed for the contour block
is applied already in the approach block with G0.
Upper speed limit LIMS=
During machining from large to small diameters, the spindle speed can increase significantly.
In this case, it is recommended the upper spindle speed limitation LIMS=... . LIMS is only ef-
fective with G96 and G97.
By programming LIMS=..., the value entered into the setting data (SD 43230:
SPIND_MAX_VELO_LIMS) is overwritten. This SD takes effect when LIMS is not written.
The upper limit speed programmed with G26 or defined via machine data cannot be over-
written with LIMS=.
Grinding
Programming and Operating manual, 06/2006, 6FC5398-4CP10-0BA0
; Constant cutting speed ON
; Constant cutting speed OFF
; Cutting rate in m/min.
; Upper limit speed of the spindle with G96, G97 effec-
tive
; Feedrate in mm/rev. as with G95
Programming
3.5 Special functions
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