Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 412)

Axis Motion
Chapter 12
12-40
If your cylindrical grinding machine uses the S--word to control wheel
spindle speed, then CSS (programmed with a G96) is available when
dressing the grinding wheel and when grinding the part. RPM spindle
speed mode (programmed with a G97) is also available for the wheel
spindle.
Machines that fall into this category typically have manual or PAL
controlled part spindles. Part spindle speeds are changed through a manual
gear change, a speed selection switch or special M codes. Much of this is
dependent on your control’s AMP configuration and PAL program. Refer
to the documentation prepared by your system installer for details.
Important: Constant Surface Speed (CSS) is applied only to the spindle
that is controlled with the programmed S--word.
The format for the G96 command is:
G96 L__S__;
Where : Is :
L specifies whether CSS is in per minute or per second mode. L1 specifies per
second mode. L0 specifies per minute mode. If L is not programmed the control
uses the default mode defined in AMP by your system installer.
S specifies the constant surface speed in meters or feet per second (L1) or per
minute (L0).
When using CSS during wheel dressing, the wheel spindle typically is
selected as the CSS axis. CSS axis selection is described on page 12-45.
Grinding wheel surface speeds relative to a stationary wheel dresser should
be based on the specifications of the wheel and the wheel dresser. Enter
this surface speed in the G96 block using the S parameter as described
below.
Use the following equation to determine grinding wheel speed in RPM
when CSS is active. This equation is for reference only. The value
obtained here is calculated automatically by the control and there is no
need to program it.
(S
program
)(K)
N
w
= (--------------)
D
w
Where : Is :
N
w
Speed of grinding wheel (rpm) 1
S
program
Surface speed programmed in the G96 block (m/min or feet/min) 1
K Constant 318.31 (1000/
π
) for metric system or 3.8197 (12/
π
) for inch system
D
w
Diameter at which wheel is being dressed (mm or inch)
1 if using units of seconds, make sure all S and N values are entered in seconds
12.5.4
Cylindrical Grinder,
S- word for Wheel Speed