Noisy WM250V Lathe

I thought it better to start a new thread although a similar one started on 4th November on a similar topic. Its nice to know I'm not alone.

I bought my WM250V (variable speed, powered cross feed) in October last year. Very soon after initial use it started to make an odd noise. I immediately stopped what I was working on, phoned Warco whose workshop guy said it shouldn't make that noise. Yes it was okay to continue to use. Warco would arrange collection back to their workshop. By agreement the lathe was collected in March but at their workshop no problem. I visited and agreed despite my best efforts the noise could not be initiated. The lathe was eventually returned in September.

Needless to say the noise has immediately returned. It seems to me to be some sort of electical resonance. It does not always occur, but sometimes does on start up. It is usually initiated by vibration, intermitent cuts on steel being the worst offender but parting off 1" steel is also a good bet.

The immediate cure seems to be switch off/on. Doesn't always work. Sometimes using the emergency stop button works together with on/off at the mains.

I have tried alternative electrical supply, sometimes works sometimes not.

I am in contact with Warco who say their Technical Department are looking into it.

Having read the other thread there is some ideas to try, but all mean partial disassembly which I m loathe to do. I think it's Warco's problem and don't want to invalidate any warranty.

Any advice or similar experieneces out there.

I can sympathise with the service department, I repair gas boilers for a living, and you wouldn't believe the amount of jobs I go to where the customer reports a 'funny noise' or intermittent fault, neither of which ever occur while I'm stood in front of the flipping thing. You can only fix a fault if you can find it. Noises are especially hard to diagnose unless you actually hear them, a description of a noise from the customer is normally nigh on useless as everyone interprets noises differently.

i would suggest that you make a video next time it occurs, send it to Warco and maybe post up here as well.

Thanks Alan, I also have sympathy with service departments and I have no real problem with the way Warco are dealing with it.

I have video'd the noise and sent it to Warco, I had hoped to link the video to this post but could not find a way to do so.

Bruno,

Hopefully they'll recognize what it is, three points i'd like to suggest, if it's a gear operated machine then switching to belts helps to reduce noise considerably.

number two, it could be what it's mounted on that's contributing to the noise, a solid wooden bench (preferably (i would) raise on box section steel too) helps to dampen vibration and reduce unnecessary noise,

Noise is unfortunately a fact of machining, my lathe is what i'd call quiet for a machine and that's just under ordinary human speaking volume, i'm sure you know that as you're talking about an odd noise rather than noise in general, but i just thought i'd point that out.

I'm thinking this could also be down to the motor, DC motors in general can make a bit of a whining sound at high speed, this could be a warning sign actually, i'd make sure you check the brushes if it is a DC motor. 

Michael W

Edited By Michael Walters on 14/11/2016 09:05:25

Bruno

You will probably have to host it somewhere like youtube and then provide a link.

would be interesting to hear the noise.

Noise seems to affect a lot of us in work - my problem is Customers reporting noisy hard discs!

You haven't any description - Rattle, click, whirr, whine, whistle, buzz etc are all good words. Sometimes pressing on different parts of the machine and seeing the effect is an indication.

I'm suspecting, based on almost no information, is the electronic speed control. What happens as you slightly adjust the speed when it is making the noise?

Bruno - I have the old style WM250 V-F with the DC motor controlled by a speed control board and although I have had various problems with it, a noise such as you describe has not been one of them.

My guess is that you have one of the late model lathes with the inverter style control and that your noise problem might be unique to this later model.

As to what is causing it I don't know. A suggestion though - if the motor is fitted with carbon brushes, have you checked them for wear?

Rik

What sort of noise is it, where is it coming from and how is the lathe mounted?

It may be specific to your own style of working or a tool you are using rather than the lathe or its mounting. Strange noises are not unusual if a tool is not able to work properly, and if you can speed up or slow down the speed or feed rate you should be able to stop it.

Neil

Yes a recording of the noise would be useful. Our machines are capable of a full symphony of noises

Edited By Bruno Taylor on 15/11/2016 07:40:04

That sounds like the motor cooling fan, mine makes a bit of a noise but more airflow than anything. Yours sounds like the fan is either badly mounted or the bearings are failing in the fan.

It's also possible that it is the fan in the inverter that is causing the noise

If you remove the louvred panel on the back of the headstock, the inverter is behind, the fan is positioned below that ,to cool the motor at lower speeds.

Edited By Graeme W on 15/11/2016 07:37:39

Edited By Graeme W on 15/11/2016 07:39:16

It looks to me like it was making the noise with the motor stopped. The chuck was not rotating. If you had removed the belt you should have given that information. If it is making the noise when the moror is stopped you should have stated this in the first post and passed that information to Warco when you reported the fault. People need accurate information to try to diagnose a fault..

Les.

I would check that none of the wiring is hitting either the motor cooling fan or the vfd fan. It's not exactly tidy in there!

John

Edited By Journeyman on 15/11/2016 09:49:26

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Good grief ... Do they really ship them like that ?

MichaelG.

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P.S. ... I agree with Graeme W ...  That sounds like the motor cooling fan ... badly mounted

Edited By Michael Gilligan on 15/11/2016 09:43:35

Edited By Michael Gilligan on 15/11/2016 09:45:29

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... and the display is reading Zero.

Could we have a little more background detail please, Bruno

MichaelG.

It sounds like a fan problem to me too. I'd be most suspicious of the computer cooling type fan immediately under the VFD. One of those wires may be too close to the fan. Try gently moving the wires to make sure they are all well clear. Guessing again, it may be that using the lathe sometimes sets up a mode of vibration that twangs the wire.

My experience is of similar fans failing in computer servers. On these the problem was usually the bearings. They can make odd noises, but not - in my limited hands-off experience - quite like your example.

I don't think it helps in this case, but this paper on VFD vibration is 'quite interesting'.

Dave

Apparently so! It's not mine, I have the older WM 250, but I just happened to be reading a post on MYCNCUK and this picture was there of a brand new lathe being unboxed. I edited the photo to credit the source. I can't see it in the photo but I assume the cooling fan is somewhere at the bottom of the cabinet.

John

It's the fan on the back of the drive motor.

The cooling fan has it's own motor to keep the drive motor cool while running slowly, mine does it sometimes after a heavy cut causes vibration. Probably caused by cheap bearings with too much clearance.

Steve

Flippin 'eck looks like a right rats nest in there, is there actually a fan in there?. Not being electrickery minded at all, apart from Ohms Law & installing extra sockets etc, sounds like an electrikery problem to me, reminds me of the buzzing sounds when mains power was applied to HV buss bars on electrical system on GE gas turbines after overhaul... electrical frequency / resonance?

​George.

Seems like Steve provided your answer whilst I was one finger typing my comment.

G