# cnc safety features



## TimPa (Jan 4, 2011)

we may have disabled adults operating, or at least nearby the cnc. other than an emergency stop, does anyone recommend any other safety features we can install (light curtains, flashing/warning lights, safety mat, etc.) that you suggest to improve the safety factor of this machine?

thanks


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## kp91 (Sep 10, 2004)

E-stop and eyeballs. The machine should be attended by the operator when running.

The only time you come near the cutter is when changing bits. I use a router for mine, so I use the power switch on top as the secondary means of securing power, besides the software operated router switch.

There are a lot of examples of people who build enclosures around their machines, but that can be impractical.


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## 4DThinker (Feb 16, 2014)

We've got a wide red line painted on the floor around our large multicam CNC, and anyone coming close gets warmed to stay behind that line. If you fear lawsuits then an optical/laser trip zone could be wired as e-stop if the beam is ever broken. The moving gantry is the most dangerous thing, and our Multicam has knocked a student out by making an unexpected fast move while the student was leaning over the bed inspecting the work. 

4D


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## MT Stringer (Aug 15, 2012)

TimPa said:


> we may have disabled adults operating, or at least nearby the cnc. other than an emergency stop, does anyone recommend any other safety features we can install (light curtains, flashing/warning lights, safety mat, etc.) that you suggest to improve the safety factor of this machine?
> 
> thanks


Tim, training would help increase the safety factor. Anyone that is on the floor regularly should receive some kind of training. That might be a standard operating procedure for observers, and another one for operators. And/Or a short video for them to watch explaining how the machines operate and the safety factors that should be adhered to.

Any one else should either not be allowed in close proximity or literally escorted by someone knowledgeable of the machines operation.

Now saying that, that is just my experience from working in a chemical plant for 30+ years. Safety is a big part and training to the inth degree was essential for anyone operating the equipment.

An example for a electrically driven pump:

A procedure for normal start up, normal shutdown, emergency shut down, start up after maintenance work has been preformed, and shut down to prepare for maintenance work to be preformed.

I realize that might be overkill for a CNC machine, but it should give you something to think about...and you are already thinking about safety.

Hope you find this helpful.
Mike


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## BalloonEngineer (Mar 27, 2009)

Assuming you have the space, putting a painted keep out line around the machine for visitors, and requiring training for anyone crossing the line. Oops - didn't notice this was already suggested above. 

One safety feature I added to my machine was a separate power switch for the VFD. I always cut power to the VFD/spindle before bit changes. I can do it without turning off the rest of the CNC so I can do a bit change safely in the middle of a single Gcode file. One of the people in my cnc club has had spindle start during a bit change three times! We think it could be due to static affecting his wireless mouse or keyboard on his control computer.

Please note: switch must be cutting power to the VFD - you cannot put any type of switch between VFD and spindle - it could damage VFD.


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## kp91 (Sep 10, 2004)

BalloonEngineer said:


> . One of the people in my cnc club has had spindle start during a bit change three times! .


I got 31 stitches in my left hand from a router that started on it's own during a bit change. Relying on a single isolation is painful and expensive.

Unplug, disconnect,etc. don't rely on a single switch.


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## RainMan 2.0 (May 6, 2014)

BalloonEngineer said:


> Assuming you have the space, putting a painted keep out line around the machine for visitors, and requiring training for anyone crossing the line. Oops - didn't notice this was already suggested above.
> 
> One safety feature I added to my machine was a separate power switch for the VFD. I always cut power to the VFD/spindle before bit changes. I can do it without turning off the rest of the CNC so I can do a bit change safely in the middle of a single Gcode file. One of the people in my cnc club has had spindle start during a bit change three times! We think it could be due to static affecting his wireless mouse or keyboard on his control computer.
> 
> Please note: switch must be cutting power to the VFD - you cannot put any type of switch between VFD and spindle - it could damage VFD.


Wow , this is a great tip and something I will definitely implement. Thanks for the heads up Richard






kp91 said:


> I got 31 stitches in my left hand from a router that started on it's own during a bit change.


Ouch! This is going to give me nightmares :fie:


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## Tagwatts (Apr 11, 2012)

Because, of my already poor hearing, I make it a practice to wear ear plugs or muffs when using mine. I also insist each person in or near the area have safety glasses. i know these two items should go without saying, but for whatever reason, I am continually reminding people. One more little thing, i allow no one to touch a machine, the project or any part of the wood that is being worked on when the machine is turned on. Only one person is allowed to turn it on and off. Never have two people doing this as it can create a major accident. Yes these are all well known, I am just reminding and hope it may save an incident or accident.


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## tacomamacxtech (Mar 31, 2009)

Tagwatts said:


> Because, of my already poor hearing, I make it a practice to wear ear plugs or muffs when using mine. I also insist each person in or near the area have safety glasses. i know these two items should go without saying, but for whatever reason, I am continually reminding people. One more little thing, i allow no one to touch a machine, the project or any part of the wood that is being worked on when the machine is turned on. Only one person is allowed to turn it on and off. Never have two people doing this as it can create a major accident. Yes these are all well known, I am just reminding and hope it may save an incident or accident.


"anyone coming close gets warmed" What part of them gets "warmed" ? LOL


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## tacomamacxtech (Mar 31, 2009)

4DThinker said:


> We've got a wide red line painted on the floor around our large multicam CNC, and anyone coming close gets warmed to stay behind that line. If you fear lawsuits then an optical/laser trip zone could be wired as e-stop if the beam is ever broken. The moving gantry is the most dangerous thing, and our Multicam has knocked a student out by making an unexpected fast move while the student was leaning over the bed inspecting the work.
> 
> 4D


"anyone coming close gets warmed" What part of them gets "warmed" ? LOL


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## 4DThinker (Feb 16, 2014)

tacomamactech said:


> "anyone coming close gets warmed" What part of them gets "warmed" ? LOL


We swat them with a stick. That warms them up pretty quick.


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## Pro4824 (Oct 17, 2015)

Shopbots yellow people mover bar looks like it might be pretty effective. And easy to fabricate.


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