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Charly07/10/2012 10:38:14
21 forum posts
6 photos

Me again,

At the moment I have a straight connection from the motor to the plug, but would obviously prefer to have an on/off switch. Can I buy any type or what should I look out for? There is one going on ebay at the moment.

Thanks

Charlene

Les Jones 107/10/2012 11:07:05
2292 forum posts
159 photos

Hi Charlene,
A switch similar to THIS ONE will provide basic switchin an a no volt release function. (This means the motor will not start up when the lathe is plugged in or after a mains failure.) This type will not provide any overload protection for the motor. For that you need a direct online starter. This must be rated to match the current drawn by the motor. Here is an example of a direct online starter.

Les.

Charly07/10/2012 11:18:01
21 forum posts
6 photos

Thanks Les, I suppose it would be better to get the direct online starter - I guess the overload protection would be there to protect the motor? My motor states 3.7 Amps.

Charlene

maurice bennie07/10/2012 11:48:20
164 forum posts
1 photos

Hi Charlene .Most workshop tools are switched using a device with a "panic " button,I think most people would advize using one ,much safer.

maurice

Charly07/10/2012 13:01:44
21 forum posts
6 photos
Posted by maurice bennie on 07/10/2012 11:48:20:

Hi Charlene .Most workshop tools are switched using a device with a "panic " button,I think most people would advize using one ,much safer.

maurice

Hi Maurice,

I agree with you totally, but I went and bought a DOL switch and they didn't have any with the big panic buttons, although this one has the stop button protruding, so when I hit it - if I can find it - it should work. I'm just in quite a rush to see and hear how it runs, because I think the motor was bought on the cheap and just thrown in to be able to up the price on the lathe. The lathe is in a bad state, but I will replace the parts as I go along. I just want one to work on for the moment.

Charly07/10/2012 13:04:37
21 forum posts
6 photos

Hi guys,

This is the switch I got. My motor states 0.5hp and 3.7A, so I reckoned this one should be capable of doing the job. I can go and exchange it if I need to.

Charlene

013.jpg

012.jpg

Les Jones 107/10/2012 15:21:54
2292 forum posts
159 photos

Hi Charlene,
You were quick going out to buy a starter. From the picture it looks like the one you bought is rated at 12 amps. This will not protect your motor. One with 4 or 5 amp rating would be better. It should be possible to fit an external emergency stop button by connecting it in series with the internal stop button. Interlocks on the chuck guard and belt cover can be added in the same way.

Note added. While looking for information on the starter in your picture I found that it does not have any thermal overload protection. The company do make thermal overload relays to go with this starter but I do not know if these fit inside the starter or inside a separate box.

Les.

Edited By Les Jones 1 on 07/10/2012 15:44:39

Charly07/10/2012 16:38:01
21 forum posts
6 photos

Thanks for that Les. Yes, I had to go and buy some extractors, so I thought while I was at it I might buy one, but unfortunately the wrong one. Maybe I should just order the one in your link from Machine Mart. I think I will do the external emergency stop button as you suggest as well.

Charlene

NJH07/10/2012 17:49:53
avatar
2314 forum posts
139 photos

Hi Charlene

What Les says is quite right but the most important part of the starter is that it is NVR i.e. when the mains go off for any reason the switch trips out and the machine will not start again when the mains are restored. That way you get to keep all your fingers etc. when the power suddenly comes back and you have chosen that time to do the annual clean-up on your lathe. Protection for motor - nice- but penalty for not having it is the price of a new motor should the overload happen. Stop switch ( or to give it a more suitable name - Panic Button.) Big and easily accessible so you can't miss it when all goes pear shaped - yes good idea but you may be very careful of course! It is likely that the starter switch you have can be wired for a remote Stop button- if so just providing a big red "STOP" button in a suitable position and wiring it in might be the cheapest option unless you can change the one you have bought.

Cheers

Norman

Edited By NJH on 07/10/2012 17:55:30

Charly07/10/2012 20:27:24
21 forum posts
6 photos

Hi Norman,

Yes I made sure I could return that starter before I bought it. I have 30 days, so it will go back ASAP. I would take the meaning of NVR to be that it opens the contacts until you physically pull it out again to close it so that power is restored only when you decide it to be?

Thanks

Mike Poole07/10/2012 21:11:45
avatar
3676 forum posts
82 photos

hi Charlene,

The starter you have purchased should be suitable for your motor, the overload unit is an optional item and will fit inside the enclosure. Toolstation sell these starters and the overload units, their part number for the overload is 44178 to suit your motor. They also sell mushroom head buttons for remote stops. The stop button on the starter is raised and the start button is flush so a panic fumble for the stop should find it even with out looking. The siteing of the starter should be considered for ease of use and so you will not be in line with the chuck on start up , if the work should leave the chuck for any reason it could hit you. The figures quoted on your starter are the ratings of the contactor and as it is rated up to 4hp is quite ok for a smaller load. The overload is the important item for motor protection and they should be adjusted to suit your motor the unit mentioned has a range from 2.8A to 4.2A and usually they are set to the lower value when you get it out of the box. If not set to 3.7A you may have nuisance tripping. if the overload ever trips do not be tempted to turn up the overload, you either are oveloading the motor or you have a fault, turning up the setting will eventually result in smoke and be expensive.

Mike

NJH07/10/2012 21:12:29
avatar
2314 forum posts
139 photos

Hi again Charlene

I think NVR means " No Volt Release

This type of switch is essentially a relay. The "Start" button operates the relay which then holds in via the current flowing through its coil. Another pair of contacts connect the mains supply through to the motor. The supply to the motor is disconnected by disconnecting the supply to the relay coil either by pressing the "Stop" button ( the normal way) or because the mains supply has failed. In either case the relay releases and the circuit path to the motor is broken until the mains is restored AND the "Start" button is again pressed.

You could exchange the starter for one of the correct rating as advised by Les. It is also worth seeing if they can supply a switch with a big "STOP" button built in. They are available - I have one on my mill.

You can just see it on the right in this picture - conveniently placed next to my knee when I am working on the machine!  ( Click on photo to enlarge)

untitled.jpg

Cheers

Norman

Edited By NJH on 07/10/2012 21:13:08

PS. Or go with Mike's suggestion and see if they do a remote "Stop" but this will require wiring etc.

Edited By NJH on 07/10/2012 21:18:38

Edited By NJH on 07/10/2012 21:21:34

Mike Poole07/10/2012 21:28:22
avatar
3676 forum posts
82 photos

Hi Charlene/Norman

The remote stop for knee or foot operation is a good idea, Colchester had a foot stop/brake on some lathes, very nice to use. A foot stop on a pillar drill I would consider essential especially if like me you don't always bolt the vice down, a jam up can be very difficult to let go of to hit the stop with your hand.

Mike

Charly07/10/2012 21:54:00
21 forum posts
6 photos

Hi Michael,

I was going to take that one back, but if you say it will do then I'm glad. I could just go and buy the Thermal Overload Relay extra. I realised the stop button is raised on the box, not sure whether i will still need a remote one then. I will need someone to assist me in the wiring, because the insides don't look like anything I've seen before, lol.

014.jpg

Les Jones 108/10/2012 08:33:01
2292 forum posts
159 photos

Hi Charlene,
Now that Mike has confirmed that the thermal overload unit fits inside the starter I think buying one from Toolstation is the best option. (I had originally assumed that you live in France from your name and the fact that you do not have a profile.) The Toolstation stop button (17283) looks ideal. Don't forget to buy cable glands for where the cable enters the starter and stop button. (Item 25329 on page 390 if you get them from toolstation.) The advantage of this unit over the Machine Mart one is that if you ever need to use it with a different size motor you just need to replace the thermal overload relay. You could just wire it up as it is for now and add the thermal overload and stop button at a later date. (I do not have thermal overloads on my lathe or drill.) It could be argued that as you will always be by the lathe that you would probably notice if the motor slowed down or stopped due to an overload.

Les.

Cornish Jack08/10/2012 12:09:11
1228 forum posts
172 photos

NJH -

Norman, totally OT, but where exactly do you do your workshop activities??? Obviously not in that demonstration hall in your photo - or is that your dining room ( eating off the floor, of course!!!)winkcheeky I was teetering on the edge of taking an (out of focus) piccy of my shambles for another current thread but I'm not sure that I shall ever venture into it again. Such exquisite squeaky cleanliness is very disheartening to we mortals!crying 2

Rgds

Bill

KWIL08/10/2012 12:36:05
3681 forum posts
70 photos

It is a Palace of Engineering, not for working in!

John Stevenson08/10/2012 12:47:58
avatar
5068 forum posts
3 photos

Best place for on Estop on a milling or drilling machine is forehead hight.

That way when you get dragged in you belt the E stop with your forhead and both hands are free to hold onto whatever is most valuable. smiley

Charly08/10/2012 12:55:35
21 forum posts
6 photos
Posted by KWIL on 08/10/2012 12:36:05:

It is a Palace of Engineering, not for working in!

I agree with that!

Thanks for your input Les. Strange, but this morning while I was having a coffee at work I looked at one of the switch boxes there and the cable gland and couldn't remember what it was called! Thanks for that! Yes, maybe I will leave the thermal overload for now. Should be able to react when I hear the motor is suffering - shouldn't happen to me in any case.

I know it's only 2 or 3 wires, but I have no idea how to wire it up! No instructions with the switch as well.

I will update my profile as well smiley

Charly08/10/2012 12:59:59
21 forum posts
6 photos
Posted by John Stevenson on 08/10/2012 12:47:58:

Best place for on Estop on a milling or drilling machine is forehead hight.

That way when you get dragged in you belt the E stop with your forhead and both hands are free to hold onto whatever is most valuable. smiley

Very good idea John, but unfortunately I don't have that option.

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