Thread: e-stop button

I'd be putting it on the active supply line, just make sure you know which one that is.

On the mushroom button, one set of connections is NO, the other NC (you want the NC). You could possibly wire the NO contacts to the reset line on the parallel port, but you'd need to be *very* careful about securing and bundling wires such that if one comes loose it can't move far enough to connect the mains and computer wiring.

I have the diagram from Mach3 but they have limit switches on the diagram, I don't have those YET

e-stop.jpg

It depends on how complex you want to make it. My Carving-CNC 6040 machine has a very simple NC estop button that's wired in series with the active supply to both the spindle and the 24v stepper supply. If something is going wrong, hitting it cuts power to the steppers and spindle, but I don't think Mach 3 would know about it (haven't tested it, so not entirely sure) which would mean it'd continue to work through the G code and thus lose track of the spindle position. That said, even if the estop input to Mach 3 was triggered at the same time, it's still possible the spindle ends up a step or three different to where Mach 3 thinks it is.

The circuits you posted are a bit neater, all the voltages through the estop button and limit switches are low voltage, the mains and Mach 3 estop signal are handled by a dual-pole relay that gets latched by the momentary reset button. However, in the circuit shown, it means the limit switches act just like hitting the estop - you couldn't use them for setting a home position.

So you might want to separate out the limit switches so they can be used as combined home/limit switches. It depends on how disastrous hitting the limit switches is - on my 6040 the stepper just loses steps with no physical implications, on a more powerful machine, I imagine hitting the limits could cause mechanical damage, thus the desire to shut everything down if a limit is hit.

Thank you Rusty.
Mine has only got a small spindle. I am mainly going to use it for engraving and small stuff.
I will leave the limit switches for sometime in the future when I buy a larger spindle.
Just want to halt everything including the spindle, I guess the main thing will be if I break a bit, which is likely when you use tiny bits.
I got the 4th axis but have to work it out first.
So I use the diagram but without the limiters, just connect it to the positive wires from the power switch?
The reset button is a NC after the e-stop?
Cheers
Wolffie

Originally Posted by SAISAY

So I use the diagram but without the limiters, just connect it to the positive wires from the power switch?
The reset button is a NC after the e-stop?

Just to clarify, exactly which parts of those diagrams are you planning to use (all 3 are part of the same circuit)?

That's where I am lost
It looks like they are only low voltage and a relay but if I connect the button directly to the power switch, it will be 220 volts.
As far as I know, the mushroom is for 220 volts?

Originally Posted by SAISAY

Just want to halt everything including the spindle, I guess the main thing will be if I break a bit, which is likely when you use tiny bits.Wolffie

That is when you use the space bar to halt XYZ movement, then use the movement keys to swap the bit over. (After stopping the spindle by using the manual command interface of course).
Then, when you restart (after resetting Z) Mach will ask to return to the position it was at before you stopped it with the space bar.

Saisay

The fact that you are so confused by this indicates that you don't have sufficient knowledge of electronics/electrical to be playing around with it. The mere mention of the possibility of you playing around with the mains to connect up an E-Stop gives me the heebygeebees.

Leave it alone and get someone more knowledgeable to help you before you do the machine, or more importantly, yourself, some damage.

I'm not being nasty here, just concerned!

Originally Posted by Geoff Sims

The fact that you are so confused by this indicates that you don't have sufficient knowledge of electronics/electrical to be playing around with it. The mere mention of the possibility of you playing around with the mains to connect up an E-Stop gives me the heebygeebees.

Yeah, I'm starting to think that too. When someone uses "positive" and "active" interchangeably, while you can probably work out what they meant to say, it's indicative of a lack of proper understanding of what active, neutral and earth are, what MEN is and why it exists, and the relationship between the mains and the extra low voltage wiring within a CNC controller.

Furthermore, assuming that the mushroom switch is rated for mains, and you do need to confirm this, as well as the amps it'll handle, when you rewire the active supply line, you *must* be very careful how the cable is then routed and secured - amply so when dealing with Chinese machines where the enclosure may not be properly earthed, leading to the real possibility that a poorly or unsecured active wire could come loose and make the case live, leading to a potentially lethal shock when touched.

Originally Posted by Geoff Sims

Saisay

The fact that you are so confused by this indicates that you don't have sufficient knowledge of electronics/electrical to be playing around with it. The mere mention of the possibility of you playing around with the mains to connect up an E-Stop gives me the heebygeebees.

Leave it alone and get someone more knowledgeable to help you before you do the machine, or more importantly, yourself, some damage.

I'm not being nasty here, just concerned!

No need to be concerned, I am not confused nor a fool, just wearing both braces and belt, the Mach3 diagram and manual are confusing, on one page they say "do not rely on software e-stop" then on another they want a relay......

I know enough about domestic electrics and mains to wire a whole house but in my time there were no electronics, just a paternal electrician who is probably now wiring up the stars, rest his soul.
I also know not to wire the fan to the light switch and vice versa nor put the light switch on the hinge side behind the door, like the knowledgeable sparky that wired our new house did and then he had the hide to say "wasn't me", resulting in 2 blind plates covering the holes in the wall
Excuse?
We all make mistakes!!!

The main thing is that I do not want to muck around with relays, can't see the point and I want to make sure I don't need one.

I know absolutely zilch about Mach3, the Shark does not use it.

So far, I haven't got past reading the manual, let alone starting up the machine.

Originally Posted by RustyArc

Yeah, I'm starting to think that too. When someone uses "positive" and "active" interchangeably, while you can probably work out what they meant to say, it's indicative of a lack of proper understanding of what active, neutral and earth are, what MEN is and why it exists, and the relationship between the mains and the extra low voltage wiring within a CNC controller.
Not lack of understanding, just translating from a language other than English and yes, I have no idea what MEN is, only what men are.

Furthermore, assuming that the mushroom switch is rated for mains, and you do need to confirm this, as well as the amps it'll handle (on the Shark it is connected directly to the mains) , when you rewire the active supply line, you *must* be very careful how the cable is then routed and secured - amply so when dealing with Chinese machines where the enclosure may not be properly earthed, leading to the real possibility that a poorly or unsecured active wire could come loose and make the case live, leading to a potentially lethal shock when touched.

Only fools rush in, others ask questions and check, check and doublecheck.
Sorry I had to ask on the forum, nobody around here to ask, I do not live in a city, I live in the boonies.

Hi Saisay ... Do you have the schematic of the system you wish to connect the stop button to ?

Is it the one above ?

Greg

No, that is a page in the Mach3 installation manual Page 4-24

Hi saisay
Stay away from the high voltage side of things. A simple circuit for all that you need to do is here.
I know that it isn't specific to your breakout board etc but it doesn't need to be.
The circuit in the Mach3 manual is very complicated.