Machine Safety ?

[TrickyCNC]

It soon becomes apparent, that this simple X Y and Z moving axis thing you've just put together, is actually a very powerfull machine !

If you got any body parts trapped at the end of travel, they would break ! Those small motors are quite torquey !

Also, it wasn't untill after a few runs, that I realised, this is still a router , and I should be using my safety glasses when I'm near / watching it ! I probably should have my ear defenders on too

Also, changing bits ... with my router (or TS etc), I make sure it's unplugged, and I can see the plug is not plugged in, before changing bits / blades. With the CNC, it's not so easy to do that. Do you trust the spindle power control of the program, that it wont start spinning somehow when doing a manual tool change ?

How do you guys treat your machine safety wise ?

Any tips ?

Anything else to watch out for, that you might forget about as a newbie ?

Cheers
Rich

[ger21]

I've seen a table saw turn on without touching the switch, and have always unplugged ever since, even with the CNC.

However, once I added the Super PID, I no longer had the option of unplugging.
When I added the Super-PID, I left the stock on/off switch on my router, and I always turn it off when changing bits. This at least gives me a little extra safety, as both the PC would have to turn on the router when it's not supposed to, and the switch would have to fail for it to turn on when changing tools.
Be aware that if the router is controlled by the PC, that a PC crash can cause the router to turn on. Even if a momentary power loss causes the PC to reboot, the router can come on. I've seen it happen with mine.

You can always mount a plug near the router on your gantry or somewhere else so you can still unplug it.
On my next router, I plan on having a separate big red button just for tool changes, mounted near my tool change location.

Glasses and ear protection are for wimps, btw.

[DonFrambach]

My machine is small so it was easy for me to build a case around it which contains dust and noise. The case also protects me. The case is closed when the machine is running and I start my machine from a keypad mounted externally. (the E-stop is down at waist level not shown in this photo). My router is directly controlled by Mach 3 but I put a switch in series with the motor so I can be certain it is turned off for bit changes, etc. Here's some photos:

[louieatienza]

It's fun to watch the machine go, even close up, but anything can go wrong - an axis runs away due to electical fault or bad code, you crash your tool, dust... Never ever put your face near the router to see what you're cutting!

Gerry I hear you about the switches. The problem is the switches can go bad at any time and let juice into the wires. Instead of cutting my router wire for the SuperPID I used a heavy duty extension cord, ran from outlet to the SuperPID, and tool the other end and ran it out. This way I can unplug the router when I need to safely...

[vid1900]

I have a second circuit breaker for my spindle next to the machine, it ALWAYS gets thrown before I change a bit.

I also press the Estop switch to make sure the motors don't try anything funny should they somehow get triggered.

I have an Estop on every side of the gantry and at the end of the table where the keyboard is. Can't be too careful.

[PaulRowntree]

I have a second circuit breaker for my spindle next to the machine, it ALWAYS gets thrown before I change a bit.

I also press the Estop switch to make sure the motors don't try anything funny should they somehow get triggered.

I have an Estop on every side of the gantry and at the end of the table where the keyboard is. Can't be too careful.

I never thought about it, but this puts my X-Y chain based machine at a safety disadvantage : pressing Estop kills power to the motors, so my gantry and gantry carriage freewheel quite easily. As a result, I can never Estop to change bits or I will loose my (0,0) reference.
Another reason to add and use homing switches.
Cheers!

[JerryBurks]

I am not concerned about the spindle because the torque of the high frequency spindle is almost nothing at standstill and ramps up over 8 seconds. The steppers could surely do serious damage but at least I don't depend on a Windows PC to make sure it does not move. The Planet-CNC USB controller is stand-alone. Not that the microcontroller firmware could not go haywire but I tend to believe it is less likely than a big office operating system.

[vid1900]

I never thought about it, but this puts my X-Y chain based machine at a safety disadvantage : pressing Estop kills power to the motors, so my gantry and gantry carriage freewheel quite easily. As a result, I can never Estop to change bits or I will loose my (0,0) reference.
Another reason to add and use homing switches.
Cheers!

If you can't Estop, you could use a locking pin lever (or just a dropped in bolt through a hole) to hold the gantry in the home position while you change bits.

The sound of a stepper vibrating against a dead stop is scary, but not as scary as the machine crushing your finger.

[Woodbutcher-59]

I have seen power tools turn on by themselves 3 times over the past 25 yrs.

I don't change any kind of blade or bit without pulling the plug.

Even cordless tools can bite you if your not alert.

My CNC router has a switch for the VFD power. I always turn it off for bit changes, but I gotta admit I've forgotten to power it back up a few times and then started a program only to realize the spindle isn't gonna start.

Then its a race for the Estop before the bit reaches the workpiece....

AND I still have all my fingers....

Jeff

[ssutton]

I always use the power switch on the router and turn it off when changing bits. I always check the switch at every machine start by starting the router with mach and then switching it off manually to check the switch. Eye protection and ear protection is a must......even if I am a wimp according to Gerry. I have e stops on every axis and over travel limits.

Scott

[louieatienza]

I've snapped 1/4" bits clean off the router crashing during rapids... and this was BEFORE I switched from 24V to 48V and doubled my rapids. So I make sure I don't wear any loose clothing or put myself in aposition where I may be trapped when working on the machine, unless it's off.

[Al_The_Man]

I am not concerned about the spindle because the torque of the high frequency spindle is almost nothing at standstill and ramps up over 8 seconds.

That does not apply to a Universal/series motor router etc, the torque is maximum at zero RPM.
This is one main reason your car starter is a series motor.
As to E-stop, unfortunately it seems alot of folks use a separate plug to feed the router/spindle, by rights and according to code, there should be a disconnect in the form of a power relay or contactor to drop the power off to the spindle what an E-stop occurs, this can easily be done when a central enclosure is used for all the machine equipment, if you by-pass the rules then don't be surprised when the odd ball conditions happen.
Al.