Anyone using relays or sensors with Arduino for CNC safety?

[Lt_Dhuran]

I’ve been playing around with Arduino safety systems for my garage CNC like i added a temp sensor and current monitor tied to a relay that cuts power if anything goes out of range. Works surprisingly well for short jobs, though I’m still refining the thresholds. Thinking about adding a smoke detector input next just in case something goes wrong during longer runs. Anyone else experimenting with this kind of setup? I’d love to compare notes on the wiring or any libraries you’re using for quick response times.

 

[Jessica_Albert]

Cool idea, but I’d be careful trusting Arduino timing for “safety” stuff. It’s fine for alerts, not so much for emergency cutoffs. If you’re gonna let it kill power, at least run it through a solid-state relay with isolation and a hardware failsafe.

 

[IVGrbn]

I’ve been playing around with Arduino safety systems for my garage CNC like i added a temp sensor and current monitor tied to a relay that cuts power if anything goes out of range. Works surprisingly well for short jobs, though I’m still refining the thresholds. Thinking about adding a smoke detector input next just in case something goes wrong during longer runs. Anyone else experimenting with this kind of setup? I’d love to compare notes on the wiring or any libraries you’re using for quick response times.

That's a smart safety approach! Using an Arduino with temperature and current monitoring to trigger a relay kill switch is great but I have to agree with @Jessica_Albert about critical timing. It's better to let the Arduino be one of many inputs that can break the coil power to your main contactor, alongside your physical E-stop and limit switch chain. Make sure your mechanical relay is rated for the inductive load of your motors, or use a faster Solid State Relay with proper isolation. You won't need a specific library for speed. Just keep the main loop tight! Direct port manipulation would be the fastest way to read inputs if you're chasing microseconds. Good luck with the thresholds!