MadModder
Gallery, Projects and General => How do I?? => Topic started by: Stilldrillin on May 17, 2011, 09:05:31 AM
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Hi Chaps!
My Chester 7 x 12 has very occasionally flashed, from the motor area..... But, kept on running. :scratch:
Fitted new brushes..... No difference!
Yesterday, waiting for instructions. Speed control off. Direction switch, forward. It took off at top revs, in reverse! :bugeye:
Stopped it, using the direction switch. Tried it again. It produced a beautiful flash from the motor area, and died...... :zap:
Today, I've stripped and cleaned out the motor. Replaced the blown plug fuse. No joy....... :scratch:
Working in from the plug, is this plastic box. It is inside the motor enclosure......
(http://i110.photobucket.com/albums/n95/Dayjo/P5170005.jpg)
Guess this is the culprit......
(http://i110.photobucket.com/albums/n95/Dayjo/P5170006-1.jpg)
It is mounted on this face, protected only by a sheet of mica (or similar).
Power reaches the l/h connetor block. But not the r/h one. (There's power in the middle, I inadvertently touched the pcb)! :palm:
Guess it's a transformer?
(http://i110.photobucket.com/albums/n95/Dayjo/P5170008.jpg)
Anyone any ideas or guidance? Where do I get another?
Thanks in advance....... :thumbup:
David D
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It's the supression board.
Some capacitors, resistors and a choke ( the copper wirey bit )
Parts a commonly available, repaired several.
Give the values off the parts ...
Dave BC
Another shufti ...
Don't look like any of the components are shot, probably just visited blast fire and destruction on the PCB traces.
You can, at a push, run without it. :thumbup:
Wait !! Don't !! It looks like the line trace is burnt. Maybe you have a short on the controller board :(
Can you see anywhere where it has shorted through the insulator sheet ???
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Dave SD
Where is that connected ??
On the machine mains input ( usual ).
Or between the controller and the motor ??? ( can't imagine this on a DC motor, not with those mains colours ?? but, Chinky device, who knows )
Dave BC
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Dave.
Mains input J1. Out, to machine J2.....
I'll see if I can find any blast damage......
David D
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Dave
Looks like the line trace has carried a lot of current out to the rest of the machine circuitry ... which is why it's got that incinerated look.
I would suspect that's just a symptom, the real cause lies further on, ie, maybe a MOSFET blown or summat ??
You say the motor revved up then snuffed it ??
Well, the motor does what the controller wants. If a MOSFET goes short, it will dump current into the motor unrestricted. The motor will zoom away ..
Until a fuse goes pop or some other protection device trips ..
That line trace appears to have acted as a fuse, and failed. :(
Don't think that's the real problem though.
Dave BC
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I was going to ask, if I solder a wire along the bottom run of blown copper.......
(http://i110.photobucket.com/albums/n95/Dayjo/P5170011.jpg)
But, MOSFETS and things have now lost me...... :scratch: ::)
Guess I need an Electrician....... :(
David D
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Yes, you can.
But don't solder wire across the 4 ( 2 either side ) that connect to the 'doughnut with copper wires'
Those should not be there .. as you can see, only where the copper trace is showing having burnt off the conformal coating green stuff..
What is the wattage of the motor??
My WM16 is 600W. I use a 5A in the plug and a 6A slo-blo in the machine fuseholder. But the controller is a bit different. SCR's not MOSFET's.
I would make sure you have a 5A in the plug top, and check what fuse is in the machine. Seems like a lot of damage for a probably simple fault.
IF the MOSFET(s) have gone pop, it should have opened the machine fuse and that's it. All that grief seems very odd.
If that's the input filter, it's dragged a hell of a lot of current from the mains to blow the trace.
Dave BC
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That's a very strange looking bit of damage... normally with burning like that to the bottom of the board, you'd expect to see a blown component and - at the very least - heat damage to the top of the board. On the other hand, the neutral wire on the input side looks like the insulation has melted back, which implies great heat; yet the output wires all look fine; i.e. the heat problem was contained within the circuit you've pictured.
One way to test this theory would be to bypass the board, and put a very low value fuse in the plug (3 amp tops). It's possible that a 3A fuse wouldn't survive a normal startup, but it should be enough to check that any ancillary functions (DRO, lamp) are still working. If your speed controller allows you to do a slow motor speed start, then you could try firing it up; if it runs away before blowing the fuse then the problem is in the controller board, and the hot suppressor circuit is a symptom rather than the cause.
However, my money would still be on the suppressor circuit: A) it's the source of the white smoke (burnt board), and B) the output wires don't show the heat damage that the input wires do. Assuming, that is, that I've got the board the right way around (the choke being the furthest part from the plug). If it's the other way around, then the problem is definitely deeper into the machine...
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I am 99.99 % sure its the suppressor circuit as AdeV said disconnect it and join the wires colour for colour with a small say 3 to 5 amp fuse in the plug top , you will disrupt the tellys :)
the damage looks to me as to swarf ingress as you have had flash overs in the past , as other have said there is no component damage compared to the board side
Stuart
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hope you get it sorted!
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Thanks for your thoughts, Chaps! :thumbup:
Working downwards, from my last pic.....
Dave.
Motor is 400 watts. 5A machine fuse, (which didn't blow). 13A plug fuse, as delivered, (which did blow).......
Will swap the plug fuse for 5A, when sorted......
Ade.
Neutral wire undamaged, except where all wires have been screwed up, to fit in the nil available space at each end.....
I've cleaned out the motor, (lot of oily brush powder), and fine emeried the dirty commutator. New brushes......
The belt is not fitted yet. Should ease test start up......
Stuart.
No swarf, as such. Just oily film.....
Jim.
Thanks Mate!
While I'm here..... I need the correct brushes. The new ones are only 8mm wide, need 10mm x 4.5mm, with eared brasses.
Saw an addy, some time ago with pics & sizes of the various types available..... Anyone else know what I'm on about? :scratch:
David D
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David, there's a troubleshooting guide at http://littlemachineshop.com/Reference/DriveTroubleshooting.pdf , from which it looks likely that the mosfets on the speed control board are prime suspects. If the suppressor is on the input side of the speed contro board, it is hard to imagine that a suppressor fault could cause the motor to run flat out. In any case, the nature of a suppressor is such that a fault on it would be unlikely to increase motor speed.
Odd, though, that it ran at full speed in reverse, when the switch iwas set to forward.
Andy
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Dave
Brushes ?? Are the brushes in that Warco motor I gave you the same size ????
BC
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David
If the machine fuse did not blow but the 13 a plug top one did , then I would plump for the board that you have shown and not the control pcb
as I said ditch it and join the wires up and try , it don't go now so you cannot make it wosera :)
I have spent the greater part of my working life refilling electrical with magic smoke ( not done so for 15 years but spent 37 years at it )
my guess as to the reversal is that it faulted to earth and applied a voltage across the controller
Stuart
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Hi David
the damaged PCB is a mains filter
and you should be able to test the speed control board without the filter
first test it without the motor connected and a 60W to 100W GLS bulb in series with the live supply
to limit any possible fault current
the bulb needs to be a have a tungstan filament (eco bulbs don't work for this test)
if the bulb only glows dimly and not full brightness
retest without the bulb ,but now with the motor connected
as I can't download the manual for your machine
what speed control pcb do you have ???
John
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Hi Chaps! Thanks for caring..... :thumbup:
Andy.
Thanks for the guide.... Lots of self help info there.
Dave.
"Your" Warco brushes are 8mm wide, the same as the Arc Euro ones I have fitted.
Stuart.
If anyone can make it worse, I'm sure I can!
John.
I've got a 60watt test bulb, somewhere......
Can't help you over the speed control pcb. All I know, it's Chester's original. (American?).
Kenneth.
Thanks for the part no. and agreement with the consensus of opinion.
Can't do anything until tomorrow afternoon. Then I'll give it a try, as instructed.
Household/ workshop wiring, I can manage.....
But when I come across pretty little coloured bits inside smoking boxes..... I'm completely smockravelled.... ::)
David D
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Dave SD
Somewhere in my shitpile stock of spares, I have a fair number of motor brushes.
Will have a shufti tomorrow.
Are they just black carbon things, or are they copper impregnated. ?? Usually obvious, they look coppery :lol:
I may have some larger ones, easy to reduce them with some open coat garnet paper or similar.
Mucky job ... :( but done it before ...
Dave BC
EDIT Mine is similar to this ...
http://kbelectronics.com/manuals/kbic.pdf
Have a look elsewhere on their site. You may well have a KB controller if it's US origin, see if you can spot the one you have.
Just remembered, I have a KBLC240D .. see attached
Off to ZZZZZZZZ's
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Are they just black carbon things, or are they copper impregnated. ?? Usually obvious, they look coppery :lol:
I thought they were, but it seems some Chinese companies are making copper-impregnated brushes; so it may be so.
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Hi Dave ,
I think you have had a short circuit from earth to the filter or the wiring to the speed control
but just incase , I've just had a look through my collection of manuals and circuit diagrams
and found a low res copy of the KBIC circuit and manuals inc .circuit of the KBPB and KBET controllers
they may help if your controller is faulty ?
it looks like they should take little current so with the series connected lamp
and no motor connected , the lamp should be dim at most ,if not out
John
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Wow, there sure are a lot of people here to help you, David. All I can see is the smoke got out and black stuff got in.
That's it for my diagnostic genius. Good luck getting it fixed up! Sneaky stuff, that 'tricity.
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David D,
I was probably wrong to refer you to the Little Machine Shop troubleshooting guide, which deals with the Chinese-made control boards for Sieg minilathes, utilising mosfets rather than SCRs.
If your lathe is the Chester Conquest shown on their website, it is from the "Real Bull" factory (like the mini-lathes supplied by Amadeal) and is described as having a US control board. That will probably be a KBLC version of one of the KB Electronics' standard KBIC modules, and Dave BC has referred you to their online manual . The KBLC boards are specials supplied to manufacturers, but I believe the only difference between them and the standard KBICs is the rating of the power diodes and SCRs.
Should it transpire (after testing without the filter board in circuit) that the speed control board is fubar and has to be replaced, use a KBIC-240 board with the appropriate “plug-in horsepower resistor” for your motor. Chester’s website says 400W, or a bit over 0.5 HP, and it is no doubt 180VDC. KB’s online manual shows the part number for a 0.75 HP resistor to be 9840.
But even if the magic smoke has left the speed control board, it may be repairable – see http://andysmachines.weebly.com/variable-speed-controls.html , which also tells yopu how to find UK suppliers. As I say there, I have the circuit schematics and parts list which KB have now unsportingly removed from the manual, so if you need them, give me a shout.
Andy
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Mornin Chaps.
It's only 06.50 or so, and me brain's hurting already...... :palm:
My total understanding of leccy, is on a par with Dean's. :scratch:
This afternoon, I'll bypass the gubbins, and switch on with fingers crossed...... :zap:
THEN, I/ we'll proceed..... Or not! ::)
Dave.
The brushes are black carbon. Cross section 10mm x 4.5mm. :thumbup:
David D
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David
as I am not to far away from you I will ensure that I have my tin foil hat on this afternoon along with welding googles when I look towards your neck of the woods in case a mushroom shaped cloud appears :zap: :) :) :) :) :)
hope it just the add on board
Stuart
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:lol: :lol:
Nice one Stuart! :thumbup:
Should I warn the neighbours? :D
David D
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HI I can never figer out electricity to me its all a black art
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To add my tupence to this I'd say the filter board arching is a symptom and not the cause of the problem. It certainly isn't going to make the motor go backwards at full speed. If a track is burnt through nothing will run, if C1 or C2 (the one on the live side) is shorted the mains fuse will go and then nothing will run. If C1 or C2 have failed open you'll only get noise on your TV.
If its the brushes then maybe its a back EMF that caused the spark on the filter board and has also progressively trashed the speed controller eventually leading to a catastrophic failure causing the motor to run backwards for a while and then it got totaled.
Look for similar arching on the speed controller, evidence of arching on the brushes and commutator. If you find problems fix them all otherwise you'll be back here.
Apologies if I've repeated what has been said before but my money is on the filter being a red herring.
Pete
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I have the circuit schematics and parts list which KB have now unsportingly removed from the manual, so if you need them, give me a shout.
Andy
I have the parts list and circuit archived if anyone else needs them, give me a shout.........
Dont by pass the board, connecting the motor direct to the mains!!! it is a dc motor with a permanent magnet field....Quite different to a drill motor...
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John its not the controller board is just a mains filter to filter out the odd order harmonics generated by the switching pulse width controller , the controller board is bigger and has mosfets on it the board in question ha only passive parts on it a couple od c's and a choke
note the colour of the cables and number of them,, live ,neutral and earth no othe connections for speed pot emergency stop etc
Stuart
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Well.... I fitted 3a fuse in plug. (I've got plenty)!
Couldn't find me 60watt test lamp. So, I just wired it together with junction block, and no blackened gubbins......
I switched on. Released emergency switch lock. Selected forward (probably). The motor spun up for 1 second. POP! :zap:
Plug fuse blown......
Hadn't seen a flash. So, I repeated with lights out. POP! :zap:
Flashed inside the motor.
So, I went out for a walk........ :thumbup:
David D
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Dave SD
If you can get it to me tomorrow, I'll have a look.
I have a Variac + Bridge rectifier so we can verify the motor itself.
Got dozens of fuses, so that's no problem.
Can you give a pic of the controller board, I have some S8020L SCR's from when mine did the 'phttts' on me. I think :scratch:
If it's the one with SCR's ..
EDIT ................. YES, I HAVE 4 of the little blighters :thumbup:
Anyone know what MOSFETS are in t'other sort. Got loads of them too, just no idea what they are.
It may be I have a suitable substitute.
Dave BC
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time to get a new motor then
A point before you spend :( :( :( :( dis the motor from the control board and replace it with a 100 watt lamp BC or GS your choice make sure its a 220 volt one not 110 one( we used to have at Stanton Iron works 25 v, 50 v, 110 v and 240 volt lamps all in normal BC :doh:) then try to power up you should be able to see the result of the speed pot in how bright the lamp is , if it goes full on or not on you need a new pcb ark euro do do spare ones , but beware duff motor could release the magic smoke for a new board and visa versa
may be useful http://www.repaircontrol.com/FinalTest/FCSeriesPreInstallation.pdf
http://www.repaircontrol.com
Stuart
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Dave.
Is this what yer after?
(http://i110.photobucket.com/albums/n95/Dayjo/P5180002.jpg)
Commutator looks a bit grotty. Seeing as it's only done 2 seconds work....... :scratch:
(http://i110.photobucket.com/albums/n95/Dayjo/P5180006-1.jpg)
Hmmm......
Stuart. I think this is where I hand over to a Higher Authority...... :thumbup:
David D
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Hi Dave
Seen worse comms ....
Any type numbers on the components screwed on th LH side ??
5 of them, metal tabs capscrewed onto the heatsink ??
Will be on the black bit under the screws ( M3 ??? )
Looks a bit like mine, not sure ??
Dave BC
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David D no problems it take a real man to call for higher help
good luck with it Dave BC
If all else fails this may help http://www.amadeal.co.uk/acatalog/KB_Mini_Lathe_Speed_Controller_Circuit_Board.html
http://www.littlemachineshop.com/Reference/DriveTroubleshooting.pdf
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Hi Dave SD ,
the pictures are interesting
your lathe looks like this one :--- http://www.cnczone.com/forums/mini_lathe/125585-wiring_parts.html
the motor does not look too bad , as Dave BC said
one way to test it is to apply a low voltage AC across the commutator (with the armature out of the motor )
then measure the voltage between adjacent segments ,it should be all the same
a shorted turn or an open circuit will result a marked difference
If the problem is the control board
first check the 3 diodes and 2 thyristors (scr's) on the heatsink are not short circuit
and then 275V varistor MOV1 and the capacitor across it C20? , they are both directly across the mains supply
John
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Dave.
Top three are numbered, D8010L
Bottom two are, A69108
Is this pic any help?
(http://i110.photobucket.com/albums/n95/Dayjo/P5180008-1.jpg)
David D
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John.
I appreciate you trying to educate me..... But!
Where do I get low voltage AC from? :scratch:
The control board instructions are beyond me........ ::)
Seriously out of my depth now! :bang:
David D
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Nearly same as mine, I have the bits ... dunno about the technology ???
@John
When the one on my WM16 was visited by blast, fire, pestilence and a general all-over immolation. The varistor, X-cap and the diodes were all intact.
They're still in there.
Both SCR's were s/cct, hence the aggro.
Just replaced those ..
@ Dave SD
Low voltage AC is the forte of a Variac ... Variable Transformer ...
I think that A69108 number was non-findable, maybe it's an in-house P/N ??
Dave BC
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Hi Dave ,
I assume you will be working with Dave BC
the safest way is with a step down transformer ,to limit the current to about 1/2 to 1A
to make the voltage between segments large enough to measure , about 0.2V
and not two bulbs connected to the mains as I did as an apprentice at Pilkinton's , about 1974 ( before H&S)
If the board is the problem we will need the circuit from Andyf
John
PS Dave bc just seen your post , yes they could be in house numbers
any component in the controlled bridge rectifier that goes short circuit will take the other one with it , sooner or later
even if only one looks faulty I'd change both
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Hi John
I have I-limited DC anyway ... Trouble with Variacs, being Auto, never quite sure which may be the hot end.
No doubt would be fairly briskly enlightened with fingers poked in eh ??
Dave BC
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Hi Dave ,
the armature test is with a AC voltage to check for shorted turns , the transformer action of the armature windings
make them show up better than with DC
yes with a variac transformer you will need a step down / isolating transformer as well
John
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we used to use a small transformer with the lams cut open normally called a growler from the noise it made when you found the shorted turn, did not work on the 100 plus hp dc motor I used to rewind though, as the turn was a loop of copper tape 1/2 X 3/32 the other name is not politically correct now a days
otherwise it was drop tested with 2 vdc from a mg set ( we used welder cable to carry the juice )
David D did you get my pm about the amadeal board being the same as yours
Stuart
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Gottit Stewart.... Thanks! :thumbup:
Wish I'd got the vaguest idea what you lot were talking about........ :palm:
David D
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Maybe we shared a common tutor ???
Mine was Prof. Stanley Unwin ... :palm:
Dave BC
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As part go my apprenticeship I had to spend a year in the armature/stator winding dept at Stanton and Staveley ltd at its Stanton works so it was big old dc stuff for me :) john Swift just triggered a long lost memory from when I was 17 65 now though :)
so not so much as a unwind moment but trade talk
Stuart
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Dave BC,
Got your message. The schematics should be in your email inbox by now.
Andy
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Hi Stuart
happy days !
I'm not sure how we survived the apprenticeship (your just 9 years older than me )
first weeks with the sparkes , worked on live mains circuits in a mixing room
sprayed trichloroethleyn at motors to degrease them ( and my hands!!!!)
all good fun that I expect todays trainees don't have today
later on followed my chosen career
worked in the drawing office on diagrams that I followed in R & D next door
to make part of the non contact measuring equipment to measure the thickness of the glass at the "UK5" float glass plant
a laser beam scanned across the glass
the reflection off the upper and lower surfaces was detected with a photo multiplier
then its just a matter of calculating the thickness
during this time at Cowley hill works ,had the fun of fixing the B&W cameras that looked into the glass furnace
they didn't work for long when the cooling water supply failed
for now we'll have to wait to see how the tests go on the motor and controller
John
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Thank you all, for your input. It's very much appreciated! :thumbup:
Just arranged a visit to Dave Bluechip's, for Friday morning. :smart: :zap:
Then, we'll see what's what, possibly...... :D
David D
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Chin up lad .... as Wallace sez to Grommit ....
Look a bit positive ... :thumbup:
Friday 13th was last week ..... er ... I think it was anyway ...
Dave BC
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John
yes live working was the norm then , trice for degreasing yep , dis boards with no cover on the live bit and at 550 vac :zap:
we used to clean the DC 220 vdc bus bars live bare hands :zap: , open front slate switch panels and open frame rotary converters
later I spent the latter 30 years working for a bank looking after the engineering for the computer centre at Kegworth , retrained in diesel fitting , air control systems ,BAS and later BAS system programming
Now do nowt only play in WS as I need wheels to get
David D
going to Dave BC's by ek thou is gerrin a bit close , I will hey to get a thicker tin hat :) :) :) :)
Stuart
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John
yes live working was the norm then , trice for degreasing yep , dis boards with no cover on the live bit and at 550 vac :zap:
we used to clean the DC 220 vdc bus bars live bare hands :zap: , open front slate switch panels and open frame rotary converters
later I spent the latter 30 years working for a bank looking after the engineering for the computer centre at Kegworth , retrained in diesel fitting , air control systems ,BAS and later BAS system programming
Now do nowt only play in WS as I need wheels to get
David D
going to Dave BC's by ek thou is gerrin a bit close , I will hey to get a thicker tin hat :) :) :) :)
Stuart
Tin Hats are no 'kin good ... if I were you, I'd get some Blast Doors fitted ... :lol:
BTW I went to Kegworth from 1987 - 1995 .. I don't recognise your name though.
Maybe you weren't in the Oddies Luncheon Club ??
Dave BC
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Small world
I was In the engineering dept that door on the left when you when in the staff entrance
we were shift 'C" ran parallel with "Dork"
my fitter spent most of his spare time perched on the end of the bar in the oddies ( Ron ) doing crosswords with his cash on the bar
you would remember the New Inn and the Cap and Stocking then
Stuart Hardy
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Stuart
Know the room. Been in there for odd reasons.
My hang out was on the Mezzanine floor, with the ... er ... whatever they did/or were ... :scratch:
Never went in the other pubs, seem to remember a fairly edible steak pie/chips in the Oddies.
I worked for Masstor Systems Inc. Our kit was where you went in the main systems hall.
3 pairs of somewhat anonymous white boxes, with vertical windows where you could watch the accessor nipping up and down.
( if you were desparate for something to do )
I would probably recognise faces, can't remember names too well.
For some reason I can remember Noel, one of the sleuths on the gate .. dunno why.
Dave BC
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I Think I have you but not sure
they were the octagonal boxes with the carts stored around the walls pretty nifty bit of kit
faces well not much of mine can be seen , full set and glasses
yes Noel and the crew at the gate house Len and John as well
Stuart
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I Think I have you but not sure
they were the octagonal boxes with the carts stored around the walls pretty nifty bit of kit
faces well not much of mine can be seen , full set and glasses
yes Noel and the crew at the gate house Len and John as well
Stuart
Nope, wrong ones. They were the StorageTek Silos. With a telly on the things.
Mine ran parallel to the 'main drag'. Come through the doors, walk straight on, on your immediate left.
Table near them with the printers etc. on.
Going a bit :offtopic: :offtopic: aren't we ??
Dave BC
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Off topic?
Are we?
What was the topic? :scratch:
What are you all talking about?
I'd join in..... If I understood....... ::)
:lol: :lol:
David D
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What are you all talking about?
David D
Ooops, we appear to have struck a snag ...
We were rather hoping you might know :scratch:
That's it then ... anybody got a 'Plan B' ???
Dave BC
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Plan B
What the **** was plan A :wack:
DaveH
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Dave
Errrr ... not sure .. I think we're going round in circles ... :bang:
Maybe Plan A was really Plan Z from last time around ??
Time for my afternoon nap
Dave BC
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Plan B? :scratch:
Well..... Mebbe! ::)
Something in the transmission has made a strange noise, for a while now........
Re assembling the motor, I noticed a clean/ polished line around the inside of the housing, in line with the plastic cooling fan.
Closer inspection showed a blade cracked 3/4 the way through, able to swing outward under centrifugal force. Also a small corner missing from another blade...... :doh:
Stuart's Amadeal link took me to the correct motor....... And the board to match......
If Dave can fix the old board, I will have a spare. Which, of course will never be needed...... :thumbup:
David D
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Hi Dave D and Dave BC ,
just incase you didn't look at all of the cnczone link
I've added the circuit I traced for of the small pcb with the blue relay
hope the tests go well tomorrow
John
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John.
Thank you!
I did have a look..... Then me brain started overloading again........ ::)
The motor and board are on their way from Amadeal. I will take advice before installing em.
I can repair the blown copper trace with a soldered wire.
I'm meeting Dave BC at a local show, next weekend. He can have the board to play with then....... :thumbup:
At the moment, I'm hopeful I can cope with a simple unplug/ replug....... Mebbe! :palm:
David D
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David
just swap the wires one at a time and you will be fine
Stuart
John Swift
on the first pic shown by David all I see is three cap's a R and an inductor the big yell thing is marked c3 with the blue ones c1 ,c2 I do not see any relays on that particular board
Stuart
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John Swift
on the first pic shown by David all I see is three cap's a R and an inductor the big yell thing is marked c3 with the blue ones c1 ,c2 I do not see any relays on that particular board
Stuart
Ohhh....... Stuart!!
Pleese........ Don't start all that, all over again! (http://freesmileyface.net/smiley/confused/confused-8.gif) (http://freesmileyface.net)
David D........ (http://freesmileyface.net/smiley/others/others-249.gif) (http://freesmileyface.net)
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Hi Dave ,
add a lable/ marker to one of the red wires that connect to the control pcb
then take a photo or make a note
changing the wires over one by one is a very good idea
but you need to have a plan B if some wires come off by accident ( been their :lol: )
PS just spotted the cable ties your photo on page 3 gives all the detail you need
PPS using your photo just added your wire colours to a diagram of the control
not sure of order of mains wires but ties help to get them right
Hi Stuart ,
the relay board is in the control box with the speed control PCB
the relay circuit could be use full while fault finding
since it is an interlock for the power and switches the 27 ohm braking resistor
the damaged filter PCB is in a plastic box hidden by the motor cover at the rear of the machine
John
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I've just soldered in, a length of wire.
Not a pretty site, but neither am I........ ::)
(http://i110.photobucket.com/albums/n95/Dayjo/P5220007-1.jpg)
I've now got continuity down all 3 strips, (including the blob, top right). But nowt across. :thumbup:
David D
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Hi Dave ,
I'd clean as much of the black deposit of between the live and earth tracks as possible
sooner or later the current will track across
I can't see a connection between the small capacitor and the live track
John
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Point take over black deposit, John.
Small capacitor? There is continuity to my wire, from the top right solder blob, as the copper is sound between it and resistor blob.
I thought also routing through capacitor would be belt & braces.......
David D
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Still here......
I mostly use brake/ clutch cleaner spray. But, it wouldn't touch the black deposit! Thinners did the job! :thumbup:
I've taped the loose mica cover to the pcb, and assembled with new grommets into the plastic box housing, and machine cover.
Got continuity from each plug pin (l, n, e) to the appropriate component in the control box.... With no crossover.
Just need a parcel to arrive from Amadeal now. Sigh...... ::)
David D
P.S.
When it arrives.....
Am I safe to fit motor and board...... And just switch on????
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Just let us know when you switch on :zap: I will call up Ratcliffe and warn them to expect a current surge :) :) :) :) :)
Take some pic of the wiring as has been sated and change only one at once
Stuart
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Hi
If I may chip in, these boards need to be adjusted after instalation. If it is a KB one the manuals are avaleble and explain the procedures.
Abraham
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Thanks Abraham. :thumbup:
It is a KB....... Hmmmm...... :scratch:
I'd have far more confidence, stripping & rebuilding an engine..... Something like a V12 Jaguar....... ::)
David D
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Thanks Abraham. :thumbup:
It is a KB....... Hmmmm...... :scratch:
I'd have far more confidence, stripping & rebuilding an engine..... Something like a V12 Jaguar....... ::)
David D
The KB boards need adjustment ONLY if you are dissatisfied with the factory settings. If adjustment is required the manual has clear instructions, including pictorials, to follow. The main consideration is installing the proper HP resistor for the motor being controlled.
Joe
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Thanks Joe! :thumbup:
They are being supplied as a "pair", so should match without fiddlin'...... Mebbe! ::)
Still no delivery. :scratch: So, I rang a short while ago, and talked to the Boss, Hugh.
Both of his staff are away...... Coping on his own! Parcel's ready! Arranged delivery for Thurs morning......
Possible power dip, in the North East Midlands, Thurs aft...... :zap:
David D
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Well..... Ok......
The parcel arrived a bit late. Managed only to wire and locate motor, and swap boards, before family matters got in the way......
I now have 2 boards, both with orange stickers saying. Plug in horsepower resistor (R21) must be installed for this product to operate.
If that's an instruction to me, I've got a problem..... I can only see R20 and R22, and nothing unplugs..... :scratch:
Is this an instruction to the person who sets up the board, before it comes to me? :scratch:
Confused of Staveley. ::)
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CoS,
See my photo attached........
I have all the documentation pertaining to the KBLC boards including the factory set up for all the preset adjustments if needed.
R21 is annotated on the right hand side in RED, although not very clear.........
(http://i754.photobucket.com/albums/xx182/Chippiejnr/R21.jpg)
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Gottit John! Thank you! :clap:
And..... It does unplug, with a firm pull! :thumbup:
The new board has the same sort of thing, in the same place.......
Guess nothing needs swapping over......
David D
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Gottit John! Thank you! :clap:
And..... It does unplug, with a firm pull! :thumbup:
David D
Glad to have helped someone today.....
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YEEeeeee......... HAAaaaaaarrrrrr!!!!!!! :ddb: :ddb: :ddb: :ddb:
I've got me lathe back! It works! :D
Initial impressions.......
A really good brake...... It never really operated before, especially after fitting a 4" chuck.
No creep.... No hunting.....
Slightly higher revs. Slightly less torque.
I can now hand rotate the chuck, "in reverse". Without it fighting me......
Thank you all, for caring...... :thumbup:
David D
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Hi Dave
thats the result we have been waiting for :D :) :D :) :D
a job well done :beer:
John
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:thumbup: :thumbup: :thumbup:
It would be interesting to know how Dave BC gets on with fixing the old board, if he gets round to it.
Andy
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:thumbup: :thumbup: :thumbup:
It would be interesting to know how Dave BC gets on with fixing the old board, if he gets round to it.
Andy
Picking the dead board up tomorrow at Eastwood AFIAK.
Anyway ....
It's all very well his controller chirping up .... :clap:
My telly now has a 6" x 4" picture ... :( :(
And me toaster is taking 3 hours to dry a slice of bread ...
Dave BC
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good news
its good when a plan comes together with no release of more magic smoke
Andyf I bet its the motor not the board
Stuart
should be over Sat if I can park near enough I can only do about 20 yards
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Mentioning magic smoke........
Was doing a bit of roughing this afternoon......
(http://i110.photobucket.com/albums/n95/Dayjo/P5310002-1.jpg)
Not very big licks......
(http://i110.photobucket.com/albums/n95/Dayjo/P5310006.jpg)
5" dia aluminium castings. 10 thou each pass. Approx 200/ 250rpm.......
(http://i110.photobucket.com/albums/n95/Dayjo/P5310007.jpg)
Had to use a parting tool. All I'd got to pass over the o/d.
Never bogged down/ stalled. Seemed to be machining nicely.......
BUT..... I had that hot paint smell again! Just like a new car exhaust system....... :bang:
The motor was warm, only. Nothing else was hot. Anyone any ideas?
David D
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Hi Dave ,
all being well its just the lacquer on the new motor or the horse power resistor running hot the first time
one thing to look at could be the 1/4" lucar push-on connectors
if the are like the ones on my CL300M lathe they don't grip very well once you disturb them
I replaced them with new ones make from thicker brass
John
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hi im glad my old lathe runs on belts :mmr:
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Pour water all over it, David.
:D JUST KIDDING!!!!!
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Hmmm...... Thanks for your replies Chaps! :thumbup:
Dean, I'll save that one for emergency only....... :D
David D
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IMHO its new equipment smell
new computers stink , cars smell nice
Its the lacquer gassing off keep it going and it will get less , you are thinking about it, as you did the work you are waiting for trouble ,
David use it and enjoy it
Stuart
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IMHO its new equipment smell
new computers stink , cars smell nice
Its the lacquer gassing off keep it going and it will get less , you are thinking about it, as you did the work you are waiting for trouble ,
David use it and enjoy it
Stuart
Have to agree with you Stuart..... :thumbup:
BUT! The last motor did the same, at around 6yrs old... (1/3rd the way down page)....... http://madmodder.net/index.php?topic=3555.60
And we all know where that got me........ ::)
David D
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A chap with a small lathe like mine (Warco WM180 - same capacity as a "normal" mini-lathe, but different design and with a 550W motor) advised me that it is unwise to run the motor for more than 30 minutes per hour, particularly on large diameter jobs where low speed and high torque is involved. He burned out both his motor and control board after four hours’ continuous running when reducing a 3” OD steel tube to 2.25”, and boring its ID out from 1” to 2”.
I don't know where he got his duty cycle from; maybe he called Warco to grumble and they told him.
Andy
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The weak point of these wretched controllers, FET or SCR, is this:
When you reduce the motor speed for turning large-ish diameters, you are putting a fair load on the motor, but the fan, miserable at the best of times, is now running slow. Hence reduced air-flow.
So, the poor old ( or new ) motor warms up a bit. Often these motors sit in a semi-enclosed casting. So, they cannot be said to be effectively cooled anyway, as they suck in a good percentage of 'pre-heated' air.
The whole idea of these contraptions is flawed for a machine tool like a lathe. If you reduce the average armature current through a PM motor, by whatever means you choose, you reduce the torque. Just when you need it most.
I had a Warco mini lathe, apparently you could screwcut at some 100 rpm. Well, 100 rpm is a bit fast for most screwcutting. But in any case, the chuck could be stopped quite easily by plonking my hand on it. No chance of screwcutting there . :doh:
Now, I can put my Myford with it's belts and gears, at some 100 rpm, or lower. No way would I grab that chuck, it would probably pull my arm off. And only 1/2HP ! ... but, that 1/2 HP is there all the time.
Work out the torque for yourself ... I'll even do it for you ... for nowt.
Power = torque x rpm. Motor rpm = 1425. 1 hp = 750 Watts ish. Call 1/2 HP 375W.
So, Watts = (Newton metres) x ( rads / seconds).
Motor rpm = 1425
1425 RPM = about 24 rps
24 rps = about 150 rads/ sec
So, Torque = ( 375 / 150 ) = roughly 2.5 Nm.
Multiply by 2.2 and 3.3 to get Ft lbs .... about 18 Ft Lbs.
Lowest backgear is 25 rpm ...
Still have the same 375 watts pushing it round ....
About 2.6 rads/sec. ...
Torque some 145 Nm.
908 Ft Lbs ... getting close to 1/2 foot.ton ...
More than enough to shear anyones nuts eh ???
So, assuming a 375W DC motor on a Chinky Lathe ... that's the same 1/2 HP ..
Your controller get anywhere near 1/2 Ft.Ton at 25 RPM ???
These machines with Electronic motor controllers are not like belt and gear machines.
They simply don't have enough guts.
Electronic circuits are very cheap to produce. Accurate mechanical parts are not.
Looking at the KB controller, I doubt very much if they cost much more then £5 to make.
Even at 1-off retail the parts only add up to about £9, OK, so no PCB counted in at that, but if you buy enough, they're not wildly expensive. Not small ones similar to the KB one anyway.
Not surprised Andyf's friend got that reply from Warco.
I think it is an honest answer.
Not one any supplier would boast about in the sales literature though .. wonder why ???
I hope the maths is OK ... no doubt some one will advise .. :smart:
Dave BC
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:thumbup: :thumbup: :thumbup:
It would be interesting to know how Dave BC gets on with fixing the old board, if he gets round to it.
Andy
For those of you with long memories, who are hanging on for an outcome to this saga. :wave:
A certain electrically orientated young man sent me a pm, t'other week....... (Sorry.... I've been a bit distracted!). ::)
Your speed controller is fixed ...
Snubber capacitor gone pop ....
Had it running today for 2 hrs OK.
I think he's a gem! :D
Thanks Dave! :thumbup:
David D