For CNC machines equipped with a remote activated spindle, the M03 M-Command will activate the spindle in the clockwise direction. For CNC machines with a pulse width modulated (PWM) spindle, an additional parameter will set the speed, typically calculated in RPM.
For spindles with a slow spin up time, it is crucial to place a G04 dwell command after the spindle start to ensure it has enough time to get up to full speed.
Standard Format: M03 S00000
The S parameter represents the desired speed. Omit the S command if there is no PWM spindle available, it is not required.
In this example, the spindle will be turned on, run for 10 seconds and then turn off with command M05.
M03 G04 P10.000 M05
For spindles with a PWM speed control, this example will turn the spindle on and set the speed to 12000 rpm. A G04 dwell command is added to ensure it gets up to speed.
M03 S12000 G04 P5.000