Siemens SINUMERIK 840Di sl - Page 311

Feedrate Control and Spindle Motion
7.11 Constant cutting rate (G96/G961/G962, G97/G971/G972, G973, LIMS, SCC[AX])
Fundamentals
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
311
Rapid traverse G0
With rapid traverse G0, there is no change in speed. Exception: if the contour is approached
in rapid traverse and the next NC block contains a G1, G2, G3 … path command, the speed
is adjusted in the G0 approach block for the next path command.
Axis replacement of the assigned channel axis
The reference axis property for G96/G961/G962 is always assigned to a geometry axis. In
the event of an axis replacement involving the assigned channel axis, the reference axis
property for G96/G961/G962 is retained in the old channel.
A geo-axis replacement will not affect how the geometry axis is assigned to the constant
cutting rate. If the TCP reference position for G96/G961/G962 is affected by a geo-axis
replacement, the spindle will attain the new speed via a ramp.
If no new channel axis is assigned as a result of a geo-axis replacement, e.g., GEOAX(0, X),
the spindle speed will be frozen in accordance with G97.
Examples of GEOAX geo-axis replacement with reference-axis assignments using SCC
Example 1
N05 G95 F0.1
N10 GEOAX(1, X1)
;Channel axis X1 becomes first geo axis
N20 SCC[X]
;First geo axis (X) becomes reference axis for G96/G961/G962
N30 GEOAX(1, X2)
;Channel axis X2 becomes first geo axis
N40 G96 M3 S20
;Reference axis for G96 is channel axis X2
Example 2
N05 G95 F0.1
N10 GEOAX(1, X1)
;Channel axis X1 becomes first geo axis
N20 SCC[X1]
;X1 and implicitly first geo axis (X) becomes reference axis
;for G96/G961/G962
N30 GEOAX(1, X2)
;Channel axis X2 becomes first geo axis
N40 G96 M3 S20
;Reference axis for G96 is X2 or X, no alarm
Example 3
N05 G95 F0.1
N10 GEOAX(1, X2)
;Channel axis X2 becomes first geo axis
N20 SCC[X1]
;X1 is not a geo axis, compensation-block alarm 14850
Example 4
N05 G0 Z50
N10 X35 Y30
N15 SCC[X]
;Reference axis for G96/G961/G962 is X
N20 G96 M3 S20
;Constant cutting rate at 10 mm/min ON
N25 G1 F1.5 X20
;Face cutting in X at 1.5 mm/rev
N30 G0 Z51
N35 SCC[Y]
;Reference axis for G96 is Y, reduction in spindle speed (Y30)
N40 G1 F1.2 Y25
;Face cutting in Y at 1.2 mm/rev
References
/FB1/Function Manual Basic Functions; Transverse Axes (P1) and Feedrates (V1).