Student switchgear

Help, anyone know where to get replacement switchgear like this?. The lid on the box says Craig and Derricot type CLS. UT

Hi Bernard

Is that the fwd/rev switch operated by an apron lever ?

Emgee

No it’s the off/on operated by the large lever

Could you tell us what the problem is with it, please? It' looks such a simple and accessible mechanism that it may be repairable if a direct replacement is not available.

BTW, Craig and Derricot are still in business, although yet another British company that has been taken over by a foreign concern, but can be found at https://craigandderricott.co.uk/  They may be able to help with either a direct replacement or an equivalent component.

Edited By Chris Crew on 29/08/2021 01:24:46

The contacts are burnt out so badly that the overcenter eye on one side of the switch has disappeared, this held one end of of the spring that makes the switch operate quickly. The spring is hanging down off the leg that is not as badly damaged. There are one or two of their switches on our favourite auction site although different shape and size, maybe the internals are the same and switch could be rebuilt in its old casing. Have now found contact details thankyou and will be ringing them Tuesday so job will have to sit in the chuck for a week or so.

Is it, or has it been converted to single phase? The wiring in the box is somewhat non-standard (Colchester did not use plastic chocolate blocks).

You may be able to use the mechanical parts of the switch to operate a microswitch (even maybe a reed switch) that controls a relay/contactor to switch the power.

With an external device to do the switching, you only need one pole of the switch in your photo to be functional: the contactor it controls will switch two or three poles if required.

The mechanical action occurs from the top, with the plunger moving up and down. Weld or glue or sellotape something like one of these under the plunger: https://www.switchelectronics.co.uk/push-button-plunger-limit-switch-spdt-16a

Yes was 3 phase about 30 years ago it’s an ex university machine. Was converted to single phase for me so it’s not done too badly.

Craig and derricot washed their hands of me said they didn’t make it any more sorry(that overused word again) and didn’t offer an alternative either or a company likely to help. Found Bernstein’s on the net very helpful with a suggestion and would be better to buy it from an agent, which was local. This is when it goes bad ,ring them with part no say they will ring back but don’t, ring the next day same thing 3rd day I visit them and ask how things are going and why no return calls and they mumble about minimum order costs, so I suggested that was my decision to make. Left them with a flea in the ear and ordered and paid for it from the manufacturers in 15 mins. Will post more when arrives and it is fitted, cross fingers.

Sad to say, Bernard, that kind of response seems to be quite common these days.

Hope you get sorted out OK, could be a nice machine when you get it running.

Just an update lathe operational again just got to tidy wiring and refit tinware and gear cover and we are good to go.The switch came from Bernstein if any body else needs to do the same job. It is a bit different but just needs a 3mm mounting plate and adjustments to the spacer thickness so not too difficult in the end.

Are you using it to switch the motor directly or via a contactor?

If is is switching direct, please consider what follows:-

The spec. for the switch here:

https://www.wolfautomation.com/limit-switch-plunger-snap-action-1nc-1no/

Datasheet here:

https://www.galco.com/techdoc/bnst/608.7352.002_dat.pdf

says it is rated for 10A, so that would be about 3HP at 230v single phase.

For a Student-sized lathe, that rating looks to me to be a little low.

No it’s via a contractor in the front plate