Universal (ish) Arduino grbl opto-coupler interface also works with logic-level pwm In adding an alternative cutter drive motor (‘spindle’) to an existing cnc machine, an electrically isolated pwm to ...

The machine uses a ‘grbl’ controller, which has an Arduino-based circuit that includes multiple outputs, including a powerful 24V pwm signal that is generally used to drive a 60-80W spindle motor.

There’s extensive documentation, GRBL settings, and more pictures in their GitHub repo, too – in case you have a similar CNC and would like to learn about upgrading its controller board!

There’s extensive documentation, GRBL settings, and more pictures in their GitHub repo, too – in case you have a similar CNC and would like to learn about upgrading its controller board!