On off switch on lathe

[tombear]

Ok folks , the three coats of yacht varnish having cured we have started reassembling the lathe to the wooden bench after the cleaning of the parts. To access the screws that hold the switch box to the wood I removed the cover and found the earth wires adrift like this

Now there's two things I won't mess with gas and mains electricity. I know too little about either and in this case I can't find a wiring diagram for this make of switch to slavishly copy. A sticker on the side says it is a Crabtree B & BD series. Where should the loose earth wires go or should they be joined to bypass the switch?

Cheers!

Tom

 

[bikething]

They should be bolted to the metal case - it's not clear in the photo but probably the 2 screws at the bottom of the picture.

 

[bopdude]

That's the way I see it as well, it looks like an Earth terminal of sorts, hard to make out.

 

[Macaroon]

Looks to me as if those earths have been joined together and connected to the switchbox itself, as it's metal as well; in principle that's what's required, it's just a matter of how they're mechanically fixed. Have they been connected using the screw that holds the cover onto the switch? That's what the photo would suggest and although it's not a very elegant solution it's electrically correct.

 

[bikething]

Have they been connected using the screw that holds the cover onto the switch? That's what the photo would suggest and although it's not a very elegant solution it's electrically correct.

either that or they were just wedged behind the heads of the screws holding the box to the wood

either way it wouldn't guarantee a good connection.

 

[Dave Budd]

in my experience, the screw to hold the earth wire will be the most inaccessible position in the casing possible! So look for a screw that you can't get to without unpicking everything else or using screwdrivers that bend space and time

 

[sandbender]

Looks to me as if those earths have been joined together and connected to the switchbox itself, as it's metal as well; in principle that's what's required, it's just a matter of how they're mechanically fixed. Have they been connected using the screw that holds the cover onto the switch? That's what the photo would suggest and although it's not a very elegant solution it's electrically correct.

What he said.

If the shroud that covers the the wiring above is metal I'd expect it to be connected to the earth.

The assembly at the bottom of the picture looks like it would accommodate the leftside cable that is in a loop with the right side cable perhaps slipping into a hole that the screw bare down onto. If those two screw points are obviously connected to the metal frame and shroud then that will be your answer.

You should check the integrity of the other connections before replacing the cover, make sure none of them are only being held on by half the strands etc.

 

[tombear]

Cheers! That should do me, I'll sort it and get it all back together when I get home.

i've a few bits of wood suitable for practicing on and it came with a few rounds of wood suitable for doing bowls when I get used to it.

It came with some paper work but not the full manual so I'll have to score one of those. Evidentially you can get a bandsaw that bolts to it, Its not something I could merit getting as a stand alone so ill be looking out for one. Actually there's one on eBay but its a bit rich for my blood this close to Xmas!

Thanks!

tom

 

[sandbender]

If the switch is simply used as a two pole on off (which it appears to be) then you might want to consider picking up a more modern switch from Screw Fix or similar.

Just a thought.

 

[MattF]

I would invest in a modern start stop contactor and overload those were made when Noah was a lad the tops of the contactor become live when the contactor pulls in

 

[topknot]

Its an old 3 phase switch, this is seen on the right side of the pic by L1-L2-L3 . I would get someone who knows what they are doing. L1 is bridge out to L3 in blue/black cable through the switch to C1 which is bridge out to B1 in blue cable.

I can not see a neutral cable in the box?

Topknot

 

[MattF]

The contactor is wired correctly for use with a single phase supply as the load is spread across all the contacts and overload as you are only switching the phase and not the neutral.

 

[Macaroon]

What he said - the thing to ascertain is thet the earth forms a continuous loop to include secure connections to everything metal on the equipment; many of these workshop tools and machines are wired to use domestic single phase supply systems and are quite safe when wired correctly and mechanically sound. The continuity of the earth is very simple to achieve and to test with a basic multi-meter.

 

[tombear]

Cheers for that! It's all reassembled now but before I use it I'll get a mate with a fancy multimeter ( he works installing machines that go beep in a hospital ) to check it over before I use it. I really don't fancy frying myself!

Atb

Tom

 

[Macaroon]

A lovely lathe on what looks like a very good bench - you'll have fun with that, methinks

 

[sandbender]

"...Its an old 3 phase switch, this is seen on the right side of the pic by L1-L2-L3..."

I did see that but as it appeared to be powered by a thirteen amp plug I was presuming only one phase was being switched.

Do check the integrity of all the connections, make sure they are good and tight and that none of the cables are hanging on by only a few strands.

Let us know how you get on.

 

[MattF]

Very nice lathe

 

[tombear]

Cheers! I checked and tightened everything I could get to but ill get my mate to do a proper check.

in the mean time I will sharpen the set of tools ( ones on left here )

I got for a tenner on a boot. There was just a layer of fine rust that needed polishing off but I no doubt took the edges of them.

I've also got the set the wife got me, it was supposed to be the most basic set they did in a plastic wallet but they sent me a much better one

For no reason I can think of. I've only used them a bit on the drill powered B & D job I picked up.

ATB

Tom

 

[tombear]

Well me mates checked it over an okayed it with the caveat that he'd change the switch if it was his and that a new plug was needed as there was a crack in the old rubber one. So with a new one on I had a go!

I'd a old beech rolling pin that had been left on a wet sink draining board and gone black in places so I fitted that and had a go at making a wool winding stick (nostpinne?) for herself.

The lathe was lovely to work with and suprisingly quiet. Ill mount a block for doing a bowl next.

Atb

Tom

 

[grip]

I have the self same lathe they're a good robust unit