# G4003G Emergency Stop/Reset Switch



## abrace (Jan 27, 2017)

All,

           I am still new to this machining thing. Whenever I am playing around with the work, or the chuck, I like to have the lathe shutoff for safety and not rely on the little handle on the carriage. I therefore push in the reset/E Stop button to kill power.

           This button is cheap, and sometimes I have to fiddle with it to get it to pop back out and restore power. Seems like a momentary button would be a good plan wired in series with the E-Stop to save the life of that switch. Seems like the lathe uses a magnetic starter, or something similar, so one power is cut to it for even a few milliseconds it won't resume even after power is restored. Seems like a momentary switch would do the trick.

           Any thoughts? Has anyone else done this?

---Aaron


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## Cobra (Jan 28, 2017)

Rather than a momentary switch, I would replace the Chinese switch with one from Digi-Key.
From their list you can select one that would be a direct replacement of the original.
http://www.digikey.ca/products/en/s...t=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25


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## rgray (Jan 28, 2017)

I have a M1112 shop fox that is the spittin image of a g4003g. My stop switch rotates clockwise to turn on and pushes straight in to stop.
I also turn it on and off frequently. I figure no use running the contactor if not using the lathe. If I'm at the lathe I never use it so I probably use it less than you.
Did they go with a cheaper switch?
I think your idea is correct and a better switch would be easy to adapt. I'm no electrician but it makes sense to me that it is already relayed as turning on the e-switch does not turn on the lathe power till the start button is pressed. So the momentary should work.
Hopefully someone with more electrical savvy will chime in on that.


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## abrace (Jan 28, 2017)

Yes, it is a push in and twist clockwise to release. The twist clockwise operation is what doesn't work well. Sometimes I have to twist it back counter clockwise a little to get it to pop out. Very flimsy.


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## higgite (Jan 28, 2017)

I agree 100% with Cobra. If you replace the switch, do so with the same type of switch that locks open to kill the control circuit and requires a deliberate secondary action, like twisting the knob, to enable the lathe again, not a momentary button. The idea behind the e-stop switch is to lock out all control power until you deliberately reset it, so if you accidentally hit the control handle on the carriage, nothing happens. Or, if the switch on the control handle fails to stop the lathe, the e-stop is there to stop the machine and prevent it from restarting. If you plan to replace the e-stop switch with a momentary button, pushing the button will stop the machine just like the e-stop switch does, but releasing the button "resets" it immediately, just like turning the knob on an e-stop switch and if the control handle is in the "on" position or if the switch that the handle operates is still stuck "on", the lathe will take off again as soon as you release the button. You might as well just leave the existing switch in the "on" position and never touch it again. My 2 cents, fwiw.

Tom

ETA: Sorry, I misread the OP. Thought he wanted to replace the e-stop switch with a momentary button. My bad. I see his intent now. I still tend to agree with Cobra, though, to just replace the existing e-stop switch with a higher quality one.


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## rgray (Jan 28, 2017)

higgite said:


> If you plan to replace the e-stop switch with a momentary button, pushing the button will stop the machine just like the e-stop switch does, but releasing the button "resets" it immediately, just like turning the knob on an e-stop switch and if the control handle is in the "on" position or if the switch that the handle operates is still stuck "on", the lathe will take off again as soon as you release the button



Correct me if I'm confused. If you hit a momentary stop switch the lathe stops just like the e-stop button. Then you must push the start button to turn it back on. It will not come back on by itself when releasing the momentary I don't believe.
There is 1 level of safety removed there but not to bad.


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## abrace (Jan 28, 2017)

I must not have been clear in my initial post. I am not looking at removing the e-stop and replacing it. I am looking at adding a new momentary switch in series with the E-Stop. I would leave the E-Stop intact and functional.

Second, with the E-Stop, when you 'release it', power is still not restored to the lathe. You then have to push the momentary 'power' button to power it up.

So, to be clear, today assuming I have the carriage switch down and the chuck spinning, I press the e-stop and the lathe stops. When I release the E-stop the lathe is STILL stopped. I then have to press the momentary 'power on' button to have it resume. Therefore it seems to operate with a magnetic starter, latching contactor, or similar item that causes the lathe to stop if power is interrupted and stay stopped even when power is restored. This is a basic safety feature on large equipment. Therefore I am looking for this momentary switch to do just that. Interrupt power for a second to cause the contactor to release and power to be off.

Additionally I could make it a non momentary switch as well I suppose, but regardless, I hope this clarifies the situation and what I am looking to do.


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## abrace (Jan 28, 2017)

rgray said:


> Correct me if I'm confused. If you hit a momentary stop switch the lathe stops just like the e-stop button. Then you must push the start button to turn it back on. It will not come back on by itself when releasing the momentary I don't believe.
> There is 1 level of safety removed there but not to bad.



I don't think you are confused. I believe that is exactly how it would happen. I could just put a normal switch versus a momentary and probably accomplish the same thing.

It just seems silly to be using the e-stop button for chuck changeouts, tool changeouts, and inserting the work. Other equipment I am used to has a momentary Start button, a momentary Stop Button, and a latching E-Stop. The G4003G only seems to have 2 of the three.


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## Cobra (Jan 28, 2017)

The G4003G or the G0750G have the same panel.  The e-stop button is just that.
On reset, you need to press the Power Start button that activates a relay to provide power to the motor circuit.
My feeling was that rather than adding another switch, I would think it better to replace the non-functioning E-stop switch with a new switch of better quality to have ongoing life.


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## abrace (Jan 28, 2017)

Cobra said:


> My feeling was that rather than adding another switch, I would think it better to replace the non-functioning E-stop switch with a new switch of better quality to have ongoing life.



I will pull the panel sometime this weekend and take a peek and see what Digikey has that will fit. Even if I add another switch, it still makes sense to have a top quality E-Stop switch versus that PoS Grizzly gave me.


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## mksj (Jan 28, 2017)

I would look at something like the IDEC E-Stops, they are rated for something like 1 million cycles, wear out the machine before you wear out the button. I have been using them in a lot of different systems very smooth and durable, I replace all the cheap switches that come stock with these machines. These are for a 22 mm hole, no light. I normally do not push the E-Stop in unless I am changing chucks, but better to be safe than sorry.

Idec - AVW411-R E-Stop, 22mm, Pushlock Turn Reset, 40mm Mushroom, 1NC/1NO, Red
https://www.wolfautomation.com/e-stop-22mm-pushlock-turn-reset-40mm-mushroom-18436


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