Author Topic: Warco WM 250 Gone paws up! (Read 22280 times)

johnthefish · « **on:** January 14, 2012, 03:56:42 PM »

Hi everyone,
Bought this variable speed lathe 2 years ago and thought I'd got a good un.... Although I've been in this hobby for years I haven't done much lately due to other commitments. It has only done about an hours running from new. Thought it was about time I got stuck into a project and started to make a boring head. I had noticed the lowest speed had crept up gradually from 50 rpm to about 120 rpm ? Half way through an operation it wouldn't restart, only showed "0" on the readout. No bangs or funny smells,just no go.

I've read through similar threads but after loads of good advice the problem hasn't been resolved (unless i missed it). I'm not looking forward to gazing at the innards because i'm not good at experimenting with things electrical.

No one's mentioned an inverter .. http://www.ebay.co.uk/itm/HP-MOTOR-1HP-DIGITAL-INVERTER-PACKAGE-REMOTE-POD-MYFORD-BOXFORD-LATHE-/380402141319?pt=UK_BOI_Industrial_Automation_Control_ET&hash=

A bit pricey but would sort the problem,wouldn't it ?

Hope someone has a simple (read cheap) answer because its gone awfully quiet here,just when I was getting going again.

Thanks, John

Jonny · « **Reply #1 on:** January 14, 2012, 05:00:59 PM »

Does the spindle start when giving it a spin?

johnthefish · « **Reply #2 on:** January 14, 2012, 05:36:22 PM »

Jonny, yes it does. Just been out to try it. Took 2 or 3 spins by hand,and off it went.

Thank you very much. Starts every time now (without spinning by hand). The lowest speed is still high though.Seems you might have an idea what is wrong with it..capacitor? As if I would know

raynerd · « **Reply #3 on:** January 14, 2012, 07:47:55 PM »

Sounds very much like if it was a cap start the cap has gone!! Glad it is now working for you
Chris

andyf · « **Reply #4 on:** January 14, 2012, 07:53:11 PM »

Hi John,

Is the lathe a variable speed model (or would it be, if it was working properly)? If so, an inverter won't help, because the motor is probably DC.

I have a Warco WM180, which might be the smaller version of yours, and that came with variable speed, using a DC motor controlled by "Pulse Width Modulation" provided by a Chinese clone (from "Best Controls" in China or Taiwan) of of a well-known US circuit board from KB Electronics.

If yours is variable speed, the problem may well lie in the control circuitry. That can be fixed or replaced; if you prefer the latter then a new control board can be obtained, either from Warco or elsewhere. "Elsewhere" might be better, because the original US version is obtainable in the UK for about 80 quid.

Andy.

modeng200023 · « **Reply #5 on:** January 15, 2012, 02:30:03 AM »

I had a similar speed problem with my WM180. The speed on the low setting was higher than it should be.

After poking around and finding nothing wrong I concluded that it was due the speed control potentiometer setting. Sometimes if the control has not been used for a while the contact between the wiper and the track can become unreliable. If this is the case, rotating the control several times may cure the problem especially if you can spray the resistance track with a contact cleaner such as Electrolube.

My machine gets used about once a week and I have had no further unwanted speed changes.

Hope this helps,
John

Jasonb · « **Reply #6 on:** January 15, 2012, 03:00:37 AM »

Have a look at the brushes, one of mine (WM280)wore more than another which caused running problems.

The Inverter is another option but you will also need to use it in conjunction with a new motor, several matched sets available. and you would gett better low speed torque into teh bargain.

Anzaniste · « **Reply #7 on:** January 15, 2012, 03:28:09 AM »

If its only a couple of years old I would be inclined to refer the problem back to Warco and see what they have to say.

johnthefish · « **Reply #8 on:** January 15, 2012, 05:17:18 AM »

Thank you all for taking the time to find a solution to the problem. The lathe is variable speed and I believe, as you say it has a DC motor.
I think Warco are good at flogging machines but not so good when it comes to sorting problems out. I did email them several times with a query when I first got it and never did get a reply. I'm not complaining though,I bought it at a show and he knocked £150 off as soon as I showed a bit of interest. Buying a replacement board from doesn't seem an option if they only last an hour or two.
Assuming that's my problem, the KB electronics replacement looks good. Had a look at their website http://www.axiscontrols.co.uk/shop/kbic-range/39.aspx Is it one of these that I want ???
If this is a simple swap, then I think I could manage that ok.

It was -2 c this morning so will have a look later at the brushes and pot,switches etc later.

Thanks again,will keep you updated..John

andyf · « **Reply #9 on:** January 15, 2012, 05:48:19 AM »

Hi John,

Those are the ones. If you do end up having to buy a new control board, the KBIC 240 (230V mains input) should do the trick. You probably won't want to bother with the KBIC 240D's dual voltage (115 or 230V) mains input. You will need to know the horsepower of your motor so you can get the appropriate "horsepower resistor" with the board. The HP can be worked out from the wattage of the motor; 746W = 1HP. Warco list the current model as 900W, which would be 1.2HP.

But check everything else first. If low speed is too high, you may be able to use the KBIC manual to identify the min and max preset resistors on the board, and set the min one a bit lower. This can interact with the max speed, so a bit of to-ing and fro-ing may be required. It's a good idea to mark the present positions of the two presets before you start twiddling.

Beware of

. Unplug the lathe each time you twiddle, and don't go near the control board if you test the speed with the board exposed.

Andy

John Rudd · « **Reply #10 on:** January 15, 2012, 07:36:21 AM »

JTF,

I have the KB documentation for these boards,pm me your email and I'll forward you a copy if you want them.

You can test the board by replacing the motor with a 100watt lamp bulb, the bulb will go from off to full brightness if the board is ok...Chanes are the speed pot is probably the first I'd suspect as the boards,imho, seem fairly reliable( I have one in my Chester mill that has been going for the last 6 years without any issue....other than the pot going west!)....either way the boards are repairable

as they use off the shelf components and there's nothing special about any of them..

Jonny · « **Reply #11 on:** January 15, 2012, 09:11:53 AM »

John the amount of chinese motorised things i have come across that need a push start is unreal and nothing to do with control board/s.
Change the caps.

andyf · « **Reply #12 on:** January 15, 2012, 09:29:57 AM »

Johnny, I'm happy to be corrected if I'm wrong, but if you are referring to start and run capacitors, I don't think permanent magnet DC motors have them. Mine don't, anyway.

Andy

John Rudd · « **Reply #13 on:** January 15, 2012, 12:45:50 PM »

According to the Warco website, the WM250 is a variable speed machine...

So it either has a multiphase motor with a vfd ( which I doubt...) or else it has the usual brushed motor with an electronic speed controller of the pwm variety....No start/run caps in sight....

Unless, JTF can tell us anything different after embracing the cold air...

It could be a clockwork motor......with a broken spring

.....

johnthefish · « **Reply #14 on:** January 15, 2012, 01:09:09 PM »

Andy, Thanks for the heads up on the type of board to replace mine (should it need replacing).

I've been in the workshop today and run it without any load. Started and ran ok for about a minute, but then started hunting and "jiggering",making the gear train rattle like mad.

As modeng200023 sugested I worked the pot and reverse switch for a while and that worked a treat til I put my 2 1/2" dia stock back in. It did a 2mm cut ok but then started the jiggers again...So back to square one.

The lathe is very close to the wall so I will have to pull it out to get at the circuit board and to check the brushes.

John Rudds offer of the KB info sounds useful and I will certainly take him up on it.
That might be useful to my son who is an electrician.Problem is he works away and not due back for a week or two.

John, just about to post this when I was alerted to your latest post. It is variable speed, but don't know it its VFD or PWM ... She might have PMT, that would explain it all

Thanks for all your help .. John

Jasonb · « **Reply #15 on:** January 15, 2012, 02:26:04 PM »

By "Jiggering" do you mean the motor was cutting on/off as thats exactly what I had as soon as any load was applied, this is what a cooked brush looks like. starts to ware and spark, sparks make it hot and melt the spring which makes it spark more and so on.

J

johnthefish · « **Reply #16 on:** January 15, 2012, 03:22:35 PM »

Yes. Cutting on and off very quickly and then slowing down and back up again. No torque at all at low speed. I have a look at those first as that is something I will be able to see rather than components that look the same to me,dead or alive.
At work all day tomorrow so hopefully will get the lathe pulled out in the evening and have a look.

Pete. · « **Reply #17 on:** January 15, 2012, 04:33:54 PM »

That brush on the right has got hot and unsoldered the braid causing the motor current to flow through the spring, heating it up and causing it to lose it's springyness. We get that a lot on our brushed motors at work.

Jasonb · « **Reply #18 on:** January 16, 2012, 02:41:58 AM »

No wire is still attached both ends, looks more like a spot weld than soldered.

velocette · « **Reply #19 on:** January 23, 2012, 08:00:25 PM »

Hi Regarding DC motor controllers. One controller I have some experience with is a Minarik MM 23001 Imported from USA To use on a Drill Press.
Here is the Link

http://www.surpluscenter.com/item.asp?item=11-2269&catname=electric

Also 10 X 27 Lathe running on KB Electronics KBCC-225R
or try
http://www.kbelectronics.com/Variable_Speed_DC_Drives/DC_Drives_Chassis.htm

KB Electronics have Manuals on line as PDF Files. These are a great source of information for setting up a DC Controller

Hope this will help Eric

steamman · « **Reply #20 on:** January 24, 2012, 04:58:55 PM »

Hi I have been experimenting with various speed controllers ,Vellemen make a kit for self assembly at about £15 or so comes with easy assembly instructions and can run up to about 5 amps or so .This can be used directly from the mains input and connect your motor to output . If you have any info on the motor of your lathe this will tell you what current you are using and if this kit will be of any use before you buy. If the brushes in the motor are worn or have overheated then it is very likely that the commutator is burnt and requires skimming before you replace brushes always check condition of commutator,if it is to bad to skim you will have to replace the motor Expensive?do look for areplacement motor from other sources to save money Warco are Expensive .Hope this helps

andyf · « **Reply #21 on:** January 24, 2012, 05:20:56 PM »

Hi Steamman,

I don't think the Velleman kit would work with John's existing motor, which is a DC permanent magnet type. According to page 2 of the manual for the Velleman kit, it intended for AC motors only.
http://www.esr.co.uk/manuals/k2636.pdf .

We haven't heard from John for 10 days. I hope he hasn't

himself.

Andy

Swarfing · « **Reply #22 on:** January 24, 2012, 05:46:53 PM »

Would this be any good as cheap replacement?

http://www.ebay.co.uk/itm/220920623651?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

velocette · « **Reply #23 on:** January 24, 2012, 07:32:44 PM »

Hi
BE VERY CAREFUL you could be left with a smoking ruin for a DC Motor Controller

This controller is Probably inadequate

http://www.ebay.co.uk/itm/220920623651?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Detailed technical parameters:
1, Input Voltage: 110V.AC/220V.AC +_ 10% 50/60Hz (worldwide voltage is adapted)
2, output current: 2A, 3A, 4A, 5A (the default maximum 5A)
3, Speed range: 1:10
4, static accuracy: 5%
5, adapter Power: 50W ~ 1000W (110V output maximum 500W, 220V output Maximum 1000W)
6, the armature output voltage: DC0 ~ 110V/220V
7, the excitation output voltage: DC100V-1A/DC200V-1A
8 Dimensions: Length 130mm × width 100mm × 45mm high
9, Connection: terminal type (convenient)

ALWAYS Fit fuses to DC side of controller preferably One on each wire!!!!!

RTFMF

Eric

John Rudd · « **Reply #24 on:** January 25, 2012, 04:11:12 AM »

My personal opinion for the appropriate course of action for JTF to take would be:

a) Contact Warco for a price on supplying the correct speed control board for his machine.Buying one from them would ensure it is a drop in replacement minimising any error in wiring it up assuming he has no or minimal electrical experience...

b)He could purchase a vfd arrangement for £200 from Drives Direct. This option again is not a preferred option as it requires some mechanical work involving removing the oem motor and fitting a new one...The footprint may be different and the shaft could be a different diameter.( I came across all of these pit fall when converting my Chester)

Also there's an element of electrical wiring involved too.

This second option would be an great upgrade for the lathe (imho)

Dave at DD is very helpful in retrofitting their supplied upgrades.

The speed control board referenced to on Ebay would suffice if there is current limiting built into it..but we dont know that, so I would stay away from that one..

Just my 2p....

johnthefish · « **Reply #25 on:** January 26, 2012, 06:29:36 PM »

. Well chaps,I'm overwhelmed by the help and advice given up to now,it is much appreciated.
The problem seems to have gone away now,so I've been quiet for the last few days waiting for it to play up again,but its running ok now.
Kept switching it on for short periods and try to take cuts on a piece of 2 1/2" dia steel, It soon started to run smoother and with more torque. All I can think is that by using it,it warmed things up and probably dried the damp out ??
Anyway should it start messing about again at least I'll have a few solutions to try to get it fixed.
Thanks again. John

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Author Topic: Warco WM 250 Gone paws up! (Read 22280 times)