Cheap Emergency Stop

Thought I'd post this up for anyone who's thinking of one but concerned about the cost:

Details below but pic of my completed cable:

http://img227.imageshack.us/img227/4887/cimg0113nf8.jpg


My local electrical wholesaler wanted £37.50 + VAT (sales tax) just for an emergency stop switch.

Bit of hunting around and I got an Italian made switch off ebay complete with casing - brand new and CE compliant for £11.00 from an electrical retailer. From a local shop (bit like Maplins) a replacement plug for the one Laserworld soldered internally for £1, 50p for 2 grommets and £7.50 for 15 (generous) metres of 2 core cable (believe me its generous with the switch in the dining room at the back of the house right by the back window, it goes across the dining room, out through the kitchen, down the hall, up the stairs, across the landing, into the front bedroom and still has slack to plug into the laser in there!!!!! I haven't measured it but in a sizeable 3 bed house, thats a generous 15m!

Total cost: £20 for the lot.

nice going

can u give us links for the parts/suppliers

:)

very nice! good find!

Quote:

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Originally Posted by majorlee

nice going

can u give us links for the parts/suppliers

:)

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Emergency Stop Button: http://cgi.ebay.co.uk/Enclosed-Emerg...d=p3911.c0.m14


9 pin Projector plug (actually some type of pc plug I think - to fit Laserworld RS - other manufacturers may use other plugs): http://www.bardwells.co.uk/detail.as...%26maxprice%3D

Projector plug casing: http://www.bardwells.co.uk/detail.as...%26maxprice%3D

(Sorry guys looks like you have to buy them in twos online but only cheap anyway - less than £1 even for 2)

Can't find the grommets online but if buying other stuff, I'm sure they'd supply them if asked. Basically I got one small enough to fit into the neck of the Projector Plug so as to stop rubbing on the cable - sure they could supply if you were to ask. It was a tight squeeze with the strain relief fitted as well (metal clip to stop cable pulling through), but it just fits with a bit of poking with a screwdriver. I actually bought 2 but the emergency stop comes with a rubber grommet pre-fitted.

The grommet itself has a wide groove inset into the side so as to accomodate the case width. I've put a picture up with some other objects to aid scale - for UK buyers there's a penny coin (1p). For overseas buyers not familiar with the 1p, there's a red size bullet connector. The metal end of the male red bullet connector just fits through the central hole of the grommet to give a further idea of size (loose fit).

Grommet:

http://img232.imageshack.us/img232/2444/cimg0117kc7.jpg


Can't see the cable online either but it was a flat black 2 core cable that was a very tight squeeze into the projector plug (really had to twist the ends down with pliers / lose the odd strand). However better than a thinner cable in my opinion as its makes it tougher. I soldered the cable when in place.

The cable is labelled (impressed not stamped) Samson VDE BSS500 HD3VVH2-F and conductor size is labelled as 2 x .075. Its flat black.

I'm sure they will remember what I bought as I told the guy what I wanted it for and 600mw produced some unrepeatebale words and a very worried look on his face! I think they're used to 5mw customers!

For those in the us these are cheap and nice..

Chad

http://web5.automationdirect.com/adc...ations/E22LB2B

thanx for the links - will look into it!

so just thinking about it...

how would you start the laser again? would u need to go to the unit itself? if its installed up high and its in the middle of a gig it might be impossible to get it started again

how does this work exactly?

The laser would start as normal with it fitted.

The emergency stop switch's contacts are NC (normally closed) so when fitted unactivated theres a complete circuit so the laser will start from the key switch as normal. Its exactly the same as putting the standard supplied projector plug in thats got the internally soldered pins.

The only difference is that when the emergency stop switch is pressed the contacts open and break the circuit thus turning the laser off.

You could use it to remotely start the laser but if doing this you might want to fit a small keyswitch into the stop button casing so as to stop anyone from resetting the button whilst you are at the projector. In fact that might not be such a bad idea anyway if you are using it with other people around. All you need to do is put the key switch in line with one of the wires going to the stop switch.

Maplin sell minature key switches for around £2.

Quote:

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Originally Posted by chad

For those in the us these are cheap and nice..

Chad

http://web5.automationdirect.com/adc...ations/E22LB2B

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That switch won't work as it has momentary contacts only ie it doesn't latch so once you release your hand from it, its back live.

UK electrical regs say an emergency stop is not to reactivate whatever it stops unless you activate a seperate reset button - or to that effect anyway :)

Either it be used with a purpose made safety relay or with a standard relay and latch circuit.

The one I've got complies with CE regulations which makes it legal for UK use. To reset it, you have to twist the top in the direction of the arrows and then press. Just pressing doesn't work.

The CE certification only certifies that it has passed it's required specification during it's design and making and not how it is used once sold.
It still has to have a seperate reset control making it not possible for the item it is stopping to start once 'pulled out' or 'twisted' to it's ON state.

Hard to explain - tomorrow I will bring my reg's book home from work and quote you what I am trying to say out of it.

RGB, yep Thanks I posted the wrong one.

http://web1.automationdirect.com/adc...tions/E22LPB2B

OR

http://web1.automationdirect.com/adc...ons/E22JLB2N8B


Those should work better

chad

Quote:

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Originally Posted by chad

RGB, yep Thanks I posted the wrong one.

http://web1.automationdirect.com/adc/Shopping/Catalog/Pushbuttons_-z-_Switches_-z-_Indicators/Eaton_Cutler-Hammer_22mm_(E22_Series)/Emergency_Stop_-z-_Mushroom_Pushbuttons_-a-_Stations/E22LPB2B

OR

http://web1.automationdirect.com/adc/Shopping/Catalog/Pushbuttons_-z-_Switches_-z-_Indicators/Eaton_Cutler-Hammer_22mm_(E22_Series)/Emergency_Stop_-z-_Mushroom_Pushbuttons_-a-_Stations/E22JLB2N8B


Those should work better

chad

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http://web1.automationdirect.com/ima...e22jlb2n8b.jpg

I priced something like this at Platt Electric out here in Oregon and they quoted me $115! (they had to build it out of 3 different parts, but still!)

Thanks for the link. $25 is very feasible.

-Jonathan

this has the button and key all in one.. kind of a cool feature!

http://cgi.ebay.com/Waterproof-EMERG...2em118Q2el1247

Ok following some suggestions, I've now added a key switch. Can't say its great quality, but it does the job - £2.49 from Maplin.

Joined in with Silver Solder.

http://img218.imageshack.us/img218/971/cimg0139fs2.jpg

http://img216.imageshack.us/img216/6947/cimg0138cm9.jpg

Keyswitched Estop switch in Uk - £16

http://www.toolstation.com/search.html?searchstr=78083

PAUL

Looks like a good find.

Quote:

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Originally Posted by smogthemog

UK electrical regs say an emergency stop is not to reactivate whatever it stops unless you activate a separate reset button - or to that effect anyway :)

Either it be used with a purpose made safety relay or with a standard relay and latch circuit.

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Jim

Would I be complying with UK regs if both my lasers and PM25 desk got power via one of these E-stops as the desk needs a pin code on power up before the desk and lasers can be used again preventing the system restarting once the E-stop is released.

Carl

You really need a small contactor in there to as the switches are usually only rated at quite low currents.

Here is mine:

EDIT - Forgot the fuses on the diag...... DOH!

Revised drawing:-

Sorry :)

Not exactly as per my build but it will work a treat. I used one contactor contact and one fuse holder for two of the plug sockets and the other two are seperated.

Cheers Jim
just what I'm looking for really rather than just relying on the pin code on the desk.

Thanks for the diagram. I take it the button below the E-stop is the reset for the relays.

Edit : Just realized that is the lamp under the E-stop.

Carl

Yeah, it's the lamp, just to show you the contactor is on. The key switch is spring return so just a quick 'flick to the right' (RockyHPShow :)) and it's on. Hit the E-stop and it goes off and will only come back on again when the E-stop has been pulled out and you turn the spring return key switch again.
You could alternatively replace the key switch with a push button but I fitted a key switch for extra safety.

Jim

The key switch would be the only option for me. I like the scenes of authority over the system.:)

How much am I looking at to put a box like that together. CPC is just up the road from my house. Very handy.

Carl

Quote:

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Originally Posted by smogthemog

The key switch is spring return so just a quick 'flick to the right' (RockyHPShow :)) and it's on.

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Er... That would be a JUMP to the LEFT, and then a STEP to the RIGHT. (Virgin!) :p

Adam

I used to have a nice E-Stop key switch from a semiconductor manufacturing machine and I threw it away because I never thought I would use it. -Sigh-.

Jim

Can you confirm in the diagram what the item labeled C1 next to the lamp is. I'm thinking capacitor. If so what value is it.

Quote:

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Originally Posted by Carl B

The key switch would be the only option for me. I like the scenes of authority over the system.:)

How much am I looking at to put a box like that together. CPC is just up the road from my house. Very handy.

Carl

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If your projector has an emergency stop connection built in its easier and cheaper to use that connection as I've done as then you're dealing with low voltage / current.

If not, then you're only option is to go down Smogs route which is to interrupt the power supply. However, here because you're dealing with mains voltage and current at whatever level the projector draws, the components are going to be more expensive as they'll be higher rated. I see also Smogs gone down the RCD circuit breaker route, presumably to offer additional protection to his sockets in venues where circuit breakers aren't fitted as standard.

C1 is a 20A contactor - a high power relay with a 230vAC energising coil

RGBlaserfan

Interrupting the mains is my only option as I built the projectors my self and regrettably the more expensive option but I can't do much about that.

Jim

Thanks for clearing up my confusion. So use to thinking items on a circuit diagram with a C against it as a capacitor.

Carl