
PROGRAMMING9. SPINDLE SPEED FUNCTION
B–63504EN/01
100
G96 (constant surface speed control command) is a modal G code. After
a G96 command is specified, the program enters the constant surface
speed control mode (G96 mode) and specified S values are assumed as a
surface speed. A G97 command cancels the G96 mode.When constant
surface speed control is applied, a spindle speed higher than the value
specified in G50S_; (maximum spindle speed) is clamped at the
maximum spindle speed. When the power is turned on, the maximum
spindle speed is not yet set and the speed is not clamped.S (surface speed)
commands in the G96 mode are assumed as S = 0 (the surface speed is 0)
until M03 (rotating the spindle in the positive direction) or M04 (rotating
the spindle in the negative direction) appears in the program.
Fig. 9.3 (a) Relation between workpiece radius, spindle speed
and surface speed
The spindle speed (rpm) almost coin-
cides with the surface speed (m/min)
at approx. 160 mm (radius).
To execute the constant surface speed control, it is necessary to set the
work coordinate system , Z axis, (axis to which the constant surface speed
control applies) becomes zero.
X
Z
0
Fig. 9.3 (b) Example of the Workpiece Coordinate
System for Constant Surface Speed Control
Explanations
D Constant surface speed
control command (G96)
D Setting the workpiece
coordinate system for
constant surface speed
control