Static Electricity and CNC Machines

What Causes Static?
Think back to science class—remember rubbing a plastic pipe with wool and then using it to attract bits of paper? That’s the same principle behind what happens in your dust collection system. As wood chips and dust are sucked up the hose, they rub against the inside, generating a significant static charge. That charge builds and builds until it finds a path to discharge—hopefully not through your controller.

👉 Watch this video to see it in action

That spark? It’s about 60,000 volts.

Grounding vs. Earthing
Many online guides say you need to ground your dust collection hose—but what they should really say is you need to earth it. While the terms are often used interchangeably, they’re not the same.

• Ground: A circuit reference point, often internal to your device.
• Earth: A physical connection to the ground, like a stake driven into the soil.

Static electricity must go to Earth. If it dumps into the GND of your MASSO system instead, it could travel through your controller and cause major damage.

How to Prevent Static Damage
Here are some key tips to manage static electricity safely:

1. Use the right hose
Cheap hoses often lack proper conductive properties. Look for higher-quality dust collection hoses with a spiral wire built in—that wire can be earthed at both ends.

👉 Here’s a quick video on how to earth the spiral wire

2. Earth your machine frame
Most discharges will target the machine frame, so give the electricity somewhere safe to go. Connect your machine frame to earth via mains earth.

3. DO NOT earth your MASSO power supply negative
To avoid creating ground loops and routing static through your controller:

• It’s OK to connect your machine frame to earth.
• It’s OK for MASSO GND to connect to the machine frame.
• But do not connect MASSO GND directly to earth. That path can let static discharge travel through your controller, causing potential harm.

For best results, follow the grounding/earthing recommendations of:

• Your dust collection system provider
• Your CNC machine manufacturer