The Coolant output is primarily used to control chip-evacuation, dust-extraction or cutting fluid systems, but can also be creatively repurposed for other switching requirements.

It can be controlled with M-Codes:

• M8 = On
• M9 = Off

• Max Current: 3A
• Voltage: 24v (Same as Input voltage)
• Suitable for inductive loads

You can use the Coolant output to switch any other 24v device as well, as an example, you can connect your OpenBuilds Spindle LED Ring as shown to put it under M-Code control (for example if you want a Job to turn the LED ring on at the start and off at the end, you can add an M8 to the header and an M9 to the footer of your g-code)

You can use our IoT Relay Power Strip to control a Vacuum for dust extraction. Also checkout our Dust Shoe

Note: Even if you already have an IoT for your spindle, we recommend a second one for the Vacuum, as they are high current draw appliances and can overload the IoT relay if used with a spindle, and having a separate control signal for the Vacuum is a big bonus too.

You can switch 24v Solenoids using the Coolant output. Typically you'd use this configuration in-line between an Air-compressor and a Nozzle pointed at the endmill. Compressed air blowing on the endmill will help evacuate chips from the cut, and keep the endmill cool