Emergency cut-off switch Jet1221

[DAL1957]

I recently upgraded from my Carbatec Pro Midi (Woodfast) lathe to the Jet 1221 as I wanted the electronic speed control. One thing I noticed with the change was that the Carbatec lathe had a larger on/off switch in a more prominent position, and hence, easier to quickly hit in the event of an emergency. The Jet 1221 has a much smaller switch in a much lower position and not easy to find when in a hurry.

I decided that I needed a larger switch and decided to make one myself.

I purchased a suitable cut-off switch from eBay, and cut a short extension lead in half for the cable. I also purchased a couple of rare-earth magnets from eBay. Then with a half hour to spare I put all the bits together, and using some hot glue I locked the cables in place.

The result is a large movable magnetic switch that's easy to find when in a hurry to shut down the lathe.

It was an easy project, but one I would suggest only be carried out if you are confident in working with mains powered devices.


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[BobL]

9/10 for initiative but I have a few issues with the implementation

1) the mains cable fixing to the box could be improved using a proper pair of cable glands especially considering it is a movable control and it makes it much easier to change and repair if needed.

437080

2) not real happy about the loose cable on the floor. At a minimum the incoming cable to the E switch should be hard anchored to the machine at least at one point before the switch
3) Not that happy that the E switch can be moved.
It's fine to have a movable on/off switch (I have some myself) but for E switches I reckon it's better to have them fixed in the same spot on a machine.
That way when you are pinned on the machine in a way you can't see it, you know where it is and are not feeling about for where it might be.
If you have multiples of similar machines its a good idea to have them all in the same approximate location so you don't get confuses as to where they might be when the emergency arises,

[DAL1957]

Thanks for your input BobL.

I would tend to agree with you in saying that the movable magnetic switch should really be left in one fixed location so that you always know where it is in an emergency rather than "Now where did I put it today". The idea of my magnetic switch was to actually place it in one location (just near and above the existing switch - as in the last picture) and pretty well leave it there as it offers easy access from both the front of the lathe and the end.

I see a lot of the bigger machines come with these movable magnetic switches.

There are probably better ways to lock down the cable as you suggest, but all I had on hand was a not glue gun, and those cables will never be going anywhere (which I guess includes if they ever need replacing or fixing).

I guess I should look at hard anchoring the cable to the machine as well, a good thought. At the moment the cables run out the back with the shorter one having the lathe plugged into it and the longer length running to the power point. I'll get out some large cable ties and lock it in place.

However, it is a lot better than the switch fitted to the Jet.

[smiife]

I see the need for the extra switch , but do you not think it would
be better on the other end of the lathe ? I have mine on the right
side and is easy accessed , also you are not in the line of fire
when turning on and off , with unbalanced pieces you can stand
back and test run first !:o..........also , in case of emergency I hit
mine with my leg /hip or bum whichever is closest:U

[BobL]

It depends what you are use to and whether you are right or left handed.
Your fastest reaction time will be with whichever handed you are and provided that hand is of course free.
I like hip/thigh switches because they usually can still be accessed if not hands are occupied or pinned.

[DAL1957]

It's a hard one to decide. Being right handed I naturally favour that hand, and being on the right it will be near the existing switch and speed controller, so keeping everything in one place. However, having had my Carbatec (Woodfast 305) for a while I got used to the switch being on the upper left. I think I'll go with the right hand side and just retrain myself. And being on the right means it will be closer when I am down near the end hollowing out a bowl.

[smiife]

I thought your switch was on the headstock end !:doh:

[DAL1957]

I thought your switch was on the headstock end !:doh:


It's movable, mounted with magnets. I have yet to finally decide, though as mentioned above, I am leaning towards the right hand side.

[KBs PensNmore]

And being on the right means it will be closer when I am down near the end hollowing out a bowl.

I have a Symtec lathe that has the emergency stop button on the LHS, and I find it a b****y pain, my hip/butt keeps hitting it when I'm turning.:~
Kryn

[Old Croc]

There are probably better ways to lock down the cable as you suggest, but all I had on hand was a not glue gun, and those cables will never be going anywhere (which I guess includes if they ever need replacing or fixing).

If you go to the big green shed, in the electrical section you will find the cord grip entry fittings you require. They come in 3 or 4 sizes, about $1.60 each.
Rgds,
Crocy.

[Skew ChiDAMN!!]

What a timely thread! I've been considering doing similar to my old gal; one of the last Oz-made Woodfasts.

It came from a time where if you asked about an emergency stop you'd hear in reply "A what-switch?" Currently it just has a black, flat rocker-style toggle switch mounted directly onto the black motor. Not easy to find at the best of times. :rolleyes:

Because of the length of the bed I'd need an emergency at either end or, my preference, a hip switch.

I'm reluctant to drill any holes in the bed or frame until I know everything is correct so I've been thinking about making a bracket that will clamp under the ways, allowing me to centrally mount an emergency stop with the front of the case flush to the bed front.

Then hotmelt gluing a couple of hinges at thge same height to each leg, allowing me hang a slat over the switch, effectively making it a hip/thigh cutoff.

Hotmelt, so I can remove/adjust everything until I'm confident it will work every time. No point doing it otherwise. Then I'll think about permanent fixtures.

Can anyone see any potential issues with this approach? I have the clearance under the ways, I think, although it would be yet another site for shavings to build up...

[Skew ChiDAMN!!]

Oops! Sorry, I got carried away with my own agenda. :doh:

Dalboy, I meant to ask if there was any reason you ran two leads to the stop switch? From the pix it looks like some of that wiring is redundant and you could've used a single lead, one wire to the switch, one wire back. Any jiggery-pokery could've been done at the take-off point.

I'm probably wrong, but it'd make everything simpler and cleaner...

[BobL]

. . . .Dalboy, I meant to ask if there was any reason you ran two leads to the stop switch? From the pix it looks like some of that wiring is redundant and you could've used a single lead, one wire to the switch, one wire back. Any jiggery-pokery could've been done at the take-off point.

I have used a single lead on my MW lathe however using a 3 core (N/A/E) cable means only the active (or even less safely, the neutral) being deactivated whereas I believe it is considered best practice to cut both the A and N on any switch especially on a safety switch. I note that Dalboys switch does have the connections to cater for both wires this but it looks like he has only switched A and not the N.

Since doing my MW lathe I have used the double wire, with both A and N deactivation method, on all my machines

If you want to use one cable, a 4 core plus earth can be used but it the requires some sort of splitter further back to get the wires out that need to connect to the mains and those that head off to the motor.

It would be interesting to get a qualified sparkies comment on this.

RE: Movable E-switch. I would favour two switches over a movable one. The time you take flailing around for the switch that is not at the position you thought it was can be significant in overall injuries.

[Skew ChiDAMN!!]

I note that Dalboys switch does have the connections to cater for both wires this but it looks like he has only switched A and not the N.

Yes. Both A & N should be switched if possible, I didn't pay attention to the switch itself. On closer look it also looks like one of his leads is the power cord. I'd assumed that he'd simply used the back of the existing on/off switch as a take-off point/splitter. It's logically the same circuit, but a different physical layout.

(I had a stupidly early morning and it shows. :B)


If you want to use one cable, a 4 core plus earth can be used but it the requires some sort of splitter further back to get the wires out that need to connect to the mains and those that head off to the motor.

This is what I'd be doing. My motor has an external terminal box so I'd retain the existing power lead and simply add another terminal block to reroute the lead to the E/S and back to the pre-existing circuit.

[BobL]

Yes. Both A & N should be switched if possible, I didn't pay attention to the switch itself. On closer look it also looks like one of his leads is the power cord. I'd assumed that he'd simply used the back of the existing on/off switch as a take-off point/splitter. It's logically the same circuit, but a different physical layout.

(I had a stupidly early morning and it shows. :B)



This is what I'd be doing. My motor has an external terminal box so I'd retain the existing power lead and simply add another terminal block to reroute the lead to the E/S and back to the pre-existing circuit.

Sounds good.

[DAL1957]

It might have been nice to have cut both the active and neutral lines but the switch only has the 2 contacts (single pole) and so can switch only one line. Electrically it would not matter if you switched one or both, either way the power is cut. It would only be important if for instance the neutral and active lines were the wrong way round (though that said you still would cut the power).

The reason I have 2 lines going into the switch was to simplify the system for connecting to. Any other way would have meant accessing the existing switch and electrics. I took a short extension cord and cut it in two, with either end retaining the original plug and socket. Then I connected it as seen in the first 2 pictures. What I am left with is effectively an extension cord with a switch in the middle - just plug the lathe into the socket and plug the plug into the power point - simple and easily removed later if I want to use it on another machine, without any modifications to the lathe.

I suppose you could always have two emergency switches in series with one at either end, and rig up some sort of beam across the lathe that you could bump stop.

David.

[BobL]

It might have been nice to have cut both the active and neutral lines but the switch only has the 2 contacts (single pole) and so can switch only one line. Electrically it would not matter if you switched one or both, either way the power is cut. It would only be important if for instance the neutral and active lines were the wrong way round (though that said you still would cut the power).

Sure it would cut the flow of power to the machine but the machine itself would still be energised because the active is still attached to the machine. If someone were to work on that machine without disconnecting the mains plug because they assumed the machine was off then they could run into problems.

If the neutral is not attached then that also tells me it's not a "no volt "switch. It might be a latching switch which is better than nothing but it is better to use a no volt switch since that prevents machine reactivation when the power restarts after a power failure.

[Colin62]

The switch on the lathe is a no volt switch, so if you kill the power to it using the kill switch, it will isolate the lathe, and not restart it until you turn it back on manually. It will also disconnect both live and neutral, because the lathe’s switch is two pole.

[DAL1957]

The fitted Emergency Switch is a locking type, push in to lock a shut down, rotate the knob to unlock. And as mentioned above, the fitted Jet switch is the No Volt Type which will need to be turned back on after a power interruption, as well as the Emergency Switch. So a double shut off.

[Paul39]

Skew,

Computer hard drives have two magnets in them that stick to steel & cast iron so well they must be pried off.

My 20 inch swing Woodfast came with an E stop switch on a magnet which I keep on the tailstock. The aftermarket DC variable drive has on - off and speed control on the cabinet below the headstock. Too far away if things get funny while hollowing a bowl.

E stop in the photo is probably under the shavings, not much use that way.

[BobL]

E stop in the photo is probably under the shavings, not much use that way.

Looks like you could use some dust extraction?