Looking for recomendations.

This topic has 9 replies, 5 voices, and was last updated 19 October 2020 at 19:07 by Samsaranda.

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18 October 2020 at 16:48 #502032
David Richardson 3
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@davidrichardson3
Afternoon all.

Hope everyone is well. (especially in these weird times) I'm not sure of its just me but now more than ever i'm so tempted to retreat into the shed and stay there untill Covid buggers off.

one problem however.

i have a clarke CL250m and the overload light is on. its had a new circuit board and the motor is fine. i think ive bench tested all of he switches and wires in there for continuity etc, but it still wont run. I'm at the limit of my technical knowledge WRT this. I'm based just outside of manchester at the moment; and wondered if anyone knows of any repair shops out there who could look at this for me? ive tried googling "tool repairs" etc but not had much look.

i'd be greatfull for any recomendations that any of you fine people have.

Thanks in advance

David
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18 October 2020 at 16:48 #33702
David Richardson 3
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@davidrichardson3
I need a repair doing
18 October 2020 at 17:10 #502034
John Rudd
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@johnrudd16576
David,

A bit more info please….

What model speed controller is it? For a CL250 its likely to be an FC250, can you confirm model number plz.

How was the motor tested? Ideally it should be bench tested on a DC power supply and run up to its max speed. Any arcing/sparking at the commutator needs to be checked…..Shorted comm segments/worn brushes etc…

Has the speed pot switch been tested? The contacts on the rear should close at minimum speed ( turned fully anti clockwise to off ) and be open at any other pot setting.

Edited By John Rudd on 18/10/2020 17:11:05
19 October 2020 at 13:01 #502143
David Richardson 3
Participant
@davidrichardson3
Good Afternoon John.

thanks for the reply. I'll try to answer as best as i can; but as mentioned i'm getting near the limits of my electrical knowledge. the lathe has a SIEG-FC150BJSMD board in it; and that's new.

The Motor, was tested on a friends DC power supply, it span up and the brushes are good (not new but they still have life in them) we tested the other motor on the Mill as well and that was good as well.

regarding your questions about the other switches; they havent been tested but i'm not really sure how to to be honest, which is why i was thinking its about time to send it out to someone who knows what theyre doing,

Thanks

David
19 October 2020 at 13:17 #502145
John Rudd
Participant
@johnrudd16576
David,

The switches need checking with a dvm on its Ohms ranges or with a continuity tester….( battery bulb and bits of wire should suffice….)

Manchester is a bit far for me…(Newcastle…) otherwise I'd look at it for you…

Test the switches then come back and we'll go from there..
19 October 2020 at 14:41 #502157
An Other
Participant
@another21905
Hello, David,

So far you only seem to have concentrated on the motor, and you seem to have confirmed that it is OK. You can test the control board by connecting a 100W filament type light bulb in place of the motor. When you you turn the speed control, the brilliance should change. If it remains at full brilliance, or is off, then the chances are that the output devices on the control board are defective (I call them devices, because no-one on this forum, as usual, seems to agree what they are – to me, they are power MOSFETS. On most of the FC250 boards I have repaired they have been either 2SK790's or IRLZ44N. The 2SK790 seems to be fitted to older boards, and the IRLZ44N to the newer boards – they can still be obtained. I am not sure which devices(s) are used on the board you have – there are many versions of these controllers, but in general the output devices have been the same whatever the board.
19 October 2020 at 14:52 #502160
John Rudd
Participant
@johnrudd16576
While I do not profess to be an expert in repairing the electronics for mini mills/lathes and larger DC motored machines, I am comfortable with the experience and knowledge I have in expediting repairs…

Even though the replacement board is new, until the wiring/switches etc test out ok and the 'overload lamp' issue is resolved, the board test at the moment will not work…..

Edited By John Rudd on 19/10/2020 14:58:55
19 October 2020 at 17:36 #502185
An Other
Participant
@another21905
I was going to reply to the last post – but there really seems no point.
19 October 2020 at 18:34 #502194
Thomas Cooksley
Participant
@thomascooksley79020
Hi everyone, just a thought: it's not something simple like the chuck guard not being closed? or if the motor runs OK on the bench is the lathe seized or tight to turn? Tom
19 October 2020 at 19:07 #502198
Samsaranda
Participant
@samsaranda
On my Warco lathe I once had a problem with the chuck guard, the micro switch was not operating, it Had moved slightly and this stopped it operating correctly, once adjusted normal service was resumed and has worked every time in the years since then.
Dave W
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