
B-63943EN-1/02 11.SPINDLE SPEED FUNCTION
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11.6 CONSTANT SURFACE SPEED CONTROL
Overview
When a surface speed (in m/min or feet/min) is specified with an S
code (a numeric value following S), the spindle speed is controlled so
that the surface speed is kept constant with respect to the change in
tool position.
r
Surface speed S=2
π
r
⋅
N
Spindle speed N
Fig. 11.6 (a) Relationship between surface speed and spindle speed
Explanation
Specify constant surface speed control as follows:
G96 S_ (Surface speed m/min (in metirci input)
or feet/min (in inch input))
To cancel constant surface speed control, specify the following:
G97 S_ (Spindle speed min
-1
)
To perform constant surface speed control, the maximum spindle
speed for each gear select signal issued from the PMC side must be set
by parameter No. 3741-3744.
The gear select signal is a 2 bit code signal (GR1, GR2). The
relationship between the signal and gear number is :
GR1 GR2 Gear number
0 0 1
1 0 2
0 1 3
1 1 4*
(* :Gear 4 is available only in the lathe specifications.)