clarke cl 250 lathe and milling head

[Danny SmithParticipant @dannysmith56242]

Hi,I’ve just joined this forum after purchasing a used Clarke cl 250 lathe with milling attachment.
I’m having problems firing this thing up.I purchased it as a non runner.After getting the multi meter out,,I found the on/off speed control pot was shot.so I have replaced this along with the 4amp fuse.when I turn the lathe on,the overload (orange light) illuminates and nothing happens.After a few minutes it blows the 4amp fuse.I’m no expert when it comes to electronics and I’m only familiar with the basics.does anyone have any ideas What else I need to check? All help appreciated.

Regards Danny.

[Danny SmithParticipant @dannysmith56242]

[Neil WyattModerator @neilwyatt]

Have you checked the lathe and motor will turn freely? It may be worn out brushes, more likely than a shorted motor.

If the mechanicals turn freely and the motor isn't shot (it should run slowly on a car battery if you disconnect it from the lathe), then the control board may be shot. See if you can see any obvious signs of burnt out components.

Contact Clarke or Machine Mart for spares, or you could fit a C1 board from Arc Euro http://www.arceurotrade.co.uk/Catalogue/Machine-Spares/C1-Lathe-Spares I think Warco a, Chester and Axminster all sell versions of this machine as well. Not cheap, sadly – so do test the motor first.

Neil

[Danny SmithParticipant @dannysmith56242]

Thanks for your reply Neil.I have checked the motor brushes and they are hardly worn.The pulley is a little notchy when rotated by hand.I have tried the motor on a 12v motorcycle battery with no response.I’ve had all the electronics out of the lathe,when I soldered in the new speed pot.The board looked immaculate.All tracks fine.I’m thinking maybe the fwd/rev switch could be wired up wrongly? I don’t have a decent wiring diagram to check this out.

Danny.

[John RuddParticipant @johnrudd16576]

Test the control system with a 100w light bulb in place of the motor…..

[Les Jones 1Participant @lesjones1]

Hi Danny,
From your last post it sounds like the motor is faulty. Connect your multimeter to the motor wires to check the resistance between them. Note the resistance with the motor shaft position moved a few degrees at a time until you have rotated 360 degrees. The idea is to see if the resistance between all opposite commutator pairs is the same. I would expect you to get a reading of between 5 and 10 ohms. Only use the readings when the motor is stopped as the motor will generate a voltage while moving it between positions. If you get high resistance reading then measure the resistance directly on the commutator between segments spaced 180 degrees. If you then get the correct readings then there is a fault between the motor wires and the brushes. Or the brushes are not making contact with the commutator. I have just confirmed that an 180 volt 850 watt permanent magnet motor rated at 5000 RPM rotates OK on 12 volts.

Les.

[Danny SmithParticipant @dannysmith56242]

Thank you John and les,I will try your suggestions later today.My motor is a zyt-150 150w 240v dc 2000 rpm.
If the motor is at fault,can it be repaired?luckily I have the same motor on the miller.so I may be able to compare the two.

Thanks again
Danny.

[John RuddParticipant @johnrudd16576]

Danny,

yes the motor can be repaired but the cost makes it uneconomical….best bite the bullet and buy a replacement..

Arc list the ZYT 150 at around £95….

[Pat BraveryParticipant @patbravery]

Hi Danny, You say that the on/off pot is shot, remember that the on/off is different in that when you switch it on you are breaking the circuit. I think that it is called make to break type. It is not how you would expect the on/off to work. I got caught out on my CL300 some years ago. Good luck with it. Pat

[Danny SmithParticipant @dannysmith56242]

Thanks for your help guys.The pcb is shot.I’ve ordered a 240vac to 180vdc motor contrroller.which has on/off and speed pot.so I’ll need to incorporate a motor reverse switch and lathe/mill selection switch.hopefully won’t be to difficult.Should be able to get this lathe working.

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