Chester Conquest lathe just gone 'pop' !

Hi All , Just been taking about 30 thou cut on my conquest and there was a pop and the machine stopped with a blown fuse on the control panel (5A Fuse). I have replaced the fuse but it blew again immediately. Just wondering if anyone has knowledge of these lathe electrics. Is it likely that the motors burnt out or perhaps the triacs ? How do i test it ?

Any help appreciated

Chris.

Hi Chris,

I think your lathe is the same as the Clarke CL300 lathe. There have been several threads on this forum dealing with motor / speed controller problems. If you type in CL300 in the Google search box at the top of this forum page you should find them. I think the speed controller is a FC250 (Or FC250J) If you do a search for this you should find the schematic fot it.

Les.

Edited By Les Jones 1 on 09/04/2012 17:03:40

Hi , The speed controller is made by KB Electronics in America and is the model KBLC-240D. I have removed the circuit board from the lathe and after examining it i have found that one of the power diodes has 'blown'. Apparantly these (or an alternative part) are available so i'm going to have a go at replacing this one component and hope for the best.I'll post the result as hopefully this will help someone else

Chris

Hi Chris,

I have just had a look for the scematic for the KBLC-240 but the best Ican find is here. It is very poor quality.

I have now found this better schenatic.

Les.

Edited By Les Jones 1 on 09/04/2012 18:28:53

Hi Les

Thats excellent info , many thanks. Hopefully after replacing the blown diode i'll be up and running. Going to my local electronic component shop tommorow and i'll give it a go and report back.

Once again , thanks for taking the time and effort to help - its much appreciated.

Chris.

Les, I think the poor quality one is for an earlier version of the KBIC/KBLC (they are essentially the same) series, when all the components had leads. Even though the modern KBIC 240 I bought a few years back has many surface mount components, a copy of that diagram was in the manual, though it has since been dropped.

There are differences between the circuit in the old diagram and the one in your second link , which was drawn up by Pat Darragh to go in the files of the Yahoo 7x12 Group. Pat kindly allowed me to reproduce it on my website, together with his components list, parts placement photo and diagram for the auxiliary board, so it would be available to folk who aren't members of that group.

I did manage to locate a couple of suppliers for the power diodes - D8020L rather than D8010L, but that just means they are rated at 20A rather than 10A, which might make them last a bit longer: < http://parts.digikey.co.uk/1/1/264192-rectifier-800v-20a-220-d8020l.html > . They charge a lot for shipping, though the diodes are not expensive at about £2 each.
and < http://www.dalbani.co.uk/catalogue/product_details.php?id=34855 >. I don't know how much they charge for shipping, because you have to register on the site before ordering.

There are bound to be equivalents available, of course.

Andyf

Edited By Andyf on 12/04/2012 22:13:13

Hi Andyf,

Farnell also stock the D8020L. That diode is also used on the speed controller in the Seig X3 mill. I had to trace out the schemaitic for this controller as I could not find it on the web. If you are interested in that schematic it is on my website. You are welcome to put it on your website or use it in any other way.

Les.

Les, like Pat D, you must be blessed with infinite patience to chase down all those PCB tracks!

Thanks for the offer, but I shan't take you up on it, not wanting to put too much on my website about machines I don't own. But I'm a member of the Yahoo X Series Mills Group and Madmodder, so I've bookmarked your web pages in case queries about the X3 circuitry are raised on either of those forums.

For completeness, you didn't make a note of any identifying marks etched con to the PCB, did you? Sieg seem to change the boards in their products every now and again.

Regards,

Andyf

Hi Andyf,

The information on the X3 cotroller together with information on the way the motor failed on my X3 is also in the file section of the X series mills group under "X3 motor ans controller." I have photographs of the component side of the X3 board and scans in high resolution of the underside which I used to help me trace the schematic. If you would like a copy PM me with an email address to send them to.

Les.

Hi All , Many thanks for all the help and advice. I have replaced the D8010L Diode that was blown and now the lathe is back in action. As a precaution i have ordered some spare diodes as they are hard to come by and delivery from digi-key e.t.c. is expensive. If anyone needs any diodes let me know.

Thanks again everyone

Chris.

Hi.

Although not a failur Mine is the same lathe and although the controler has not blown it seams to have develooped a small problem. When powering the lathe on with the speed dial at the off position the lathe starts. however it speeds up and slows down with the turning of said knob but still will not switch off unless I either flick the F/R toggle switch or hit the stop button. The only thing was it worked when last used a few months ago.. Im just wondering could it be suffering from damp or anything like that. Ov not had much chance to have a play with it as yet so other than iv said I dont know. Im hopeing more use will make it work its way out of the problem but till then has anyone else had anything like this?

regs Osh

Hi Osh,

Somewhere on this forum is some advice on adjusting teh preset variable resistors (carefully) to solve this problem. Don't just twiddkle at random or you could end up with a blown board or motor and remeber it is very live & dangerous in there!

Neil

Oshb5 , At what speed does the lathe turn when the rotary speed pot is set to zero ? If it turns very slowly (probably accompanied by a 'buzzing sound from the motor) it sounds like the 'min speed' potentiometer on the circuit board needs turning down (anticlockwise) very slightly.

As mentioned take great care if you attempt this , let me know how you get on

Chris.

My Dad's Conquest has developed a weird speed controller problem. He went into the workshop one morning and the spindle was just rotating slowly, and he could only switch it off at the mains. I assumed the pot was faulty (it's a double switch type) through some failure of the switch contacts.

I've just checked the pot and it's fine. So doesn't seem much point fitting the new one!

Appreciate some clues as to what to look for. He has this five or more years now, I seem to remember the Ad boasting "American controller electronics" or some such. The board is similar to, but different from, the that in Les' link above. It has no branding on the component side of the board.

Any ideas of what to look for appreciated.

Steve

Had another word with him, apparently when he tried controlling the speed, it then went flat out and he could only stop it by switching it off at he mains... as per previous post the pot seems fine.

Hi Steve,
Without a schematic of the board do not think it is possible to diagnose the fault. The only thing I can say is that I do not think it is a fault in the power control devices (SCR's Triac, Mosfets etc.) as these tend to fail to a shorted condition which would mean that the motor either ran at full speed all the time or the fuses blew. If you trace out the schematic of the board I will try to work out what may be causing these symptoms.

Les.

Any hints for a Fanuc spindle drive... mines also gone pop...£4500 for " new" drive if available ...

(a06b-6059-h002)...

Re: Chester lathe, I think you would be very lucky to get away with a single diode/component.

You need to check all the semiconductors for short circuit, at least. You can source all your components on good old ebay, no minimum order charges etc.

Can you rule your motor out? It may have a leak to earth.

Good luck!

Thanks for the kind offer Les, but I doubt I'll be able to trace out the board. He did say when he subsequently tried to use it it did go to full speed and could not be controlled. Dad (82) isn't in a rush (he has his Grandad's Brittania set up for rush jobs...) so I'll try and get hold of the schematic and see if I can find the board on Google to give me a clue.

I'll let you know what I find.

Any hints for a Fanuc spindle drive... mines also gone pop...£4500 for " new" drive if available ...

Try Lektronix for a repair, or UK Automation for refurb, NOS or S/H with warranty.

The most expesive repairs I have had from Lektronix have been circa £1400 + Vat for Siemens 611 36/47Kw E/R modules & a 130A spindle main spindle drive module (30Kw motor). Small (circa 3Nm) Fanuc AC servo drives have been around £400. Their repairs are warranted for 12 months. A warranted used 36/47 E/R module from UK Automation was around the same - there are 3 machines at work that use these damned things & it pays to have a spare to keep the machines running while the inevitable "blown" one is repaired (again !).

Lektronix offer a free collection service & no obligation quote. No connection with the company other than as a satisfied customer.

HTH

Nigel B.