Mill and lathe motor upgrades

[Ramon WilsonParticipant @ramonwilson3]

Hi,

Recently Peter Gain posted on this section a thread on ‘Electric Motor Noise’.

 

This came at a very opportune time for me as I was literally just in the throes of considering to fit an ‘inverter control’ drive to my lathe. My oft mentioned friend John had recently fitted a Newton Tesla drive to his S7 and very impressive it was too – this was the first time I had seen such a set up running and the smoothness, relative quietness and controlability was very convincing.

 

Not unnaturally Peters concerns raised several of my own and I spent some time talking to the various suppliers of such units. I was particularly concerned not to end up with something noisier than the original single phase Myford supplied motor.

 

A couple of years ago I had need to replace a one and a half HP French made single phase motor. The extortionate cost of rewiring this, as a direct replacement was not available, soon became apparent. After a Google search I settled on an Italian made motor from a company called Electric Motors 2 Go. This motor was inexpensive, a third of the cost of rewiring and has proved to be a very good alternative.

 

I decided in the end then to purchase, from this same company, not only a motor for the lathe, which it turns out, to be of Indian manufacture but another Italian one of different design for the Mill . A call to Newton Tesla confirmed that one inverter could be used for either mill or lathe and a suitable socket and separate plugs supplied.

 

I have just finished replacing the motors and wiring the NT controls and inverter all in. The wiring was very straightforward and the whole thing works perfectly. Just as Peter commented the lathe motor does have a very slight whine to it at the top of the range but overall it’s a big improvement on what was there before. This is not to undermine anything that Peter has said, indeed we have been exchanging emails on the subject for some time and his experiences on the Indian made motors particularly has been very helpful and timely. It has to be said that the overall quality of the Indian motor in no way matches that of the Italian one. In fact the foot mount was loose because the screws were bottoming out in blind holes but it was short work to put that right. I’ll let you know if they vibrate loose – yes they are fitted with stud lock!

 

The Italian motor on the mill is just superb. So quiet that the bearings in the ballrace on the intermediate pulley can be heard rolling. Perhaps a few words and pics of the mill is worth another thread as quite a bit of work has been done to it since first purchased to improve it

 

I have often looked at the various adverts for this modification to equipment and wondered if it was all a bit uneccessary but can already see this is one of those things that I “should have done it years ago”.

 

All in all then a very worthwhile exercise.

 

Hope this is of interest to someone – more on the mill a bit later.

 

Regards – Ramon

 

 

Edited By Ramon Wilson on 20/02/2011 21:08:07

[Ramon WilsonParticipant @ramonwilson3]

[Peter GainParticipant @petergain89847]

Like Ramon, I decided to replace the single ph motor on my Myford Super7 with a 3ph one. As the machine has a clutch I wished to leave the motor running between operations & while “miking” etc. The existing motor produced more noise than I cared for.

I obtained a conversion set from one of the advertisers in ME. The motor was an Indian made product. To me it seemed too noisy & emitted an unpleasant high pitched whine.

The supplier exchanged it for another. This was just as bad & was returned. A 3^rd one produced the same unfortunate noise. To his credit, the supplier gave me a full refund for the price of the motor. I retained the inverter & remote pendant.

Some surfing & e-mails revealed that these Indian motors are imported by at least 2 different companies. One, Massey-Coldbeck, supplies them branded as Greaves-Crompton & are marked “Made in India”. This was the first motor I tried. Another importer brands them as “BFM” (Beatson Fans & Motors), they are not marked with the country of manufacture.

 

Surfing showed that good quality FHP electric motors emit between 47dB(A) & 50 dB(A) on no load at 1mtr. Testing the supplied Indian motors the average noise was recorded as 56dB(A) to 58d(BA), on no load at 1mtr.

Massey-Coldbeck stated that they have supplied over 3000 of these motors with very little adverse feedback. It transpires that many of them are used to drive extract fans in chip fryers in fast food outlets. Not surprising that noise complaints do not feature.

A company trading as “Electric Motors2Go” offer 3ph FHP motors which they claim are “made in European community”. But the illustration clearly shows a BFM branded product which has been confirmed by BFM as being made in India. I e-mailed Tony, the owner/manager of Electric Motors2Go pointing out the obvious discrepancy & asked for his comments. He declined to answer. (From 1^st of March advertising on the internet will be subject to control by the Advertising Standards Authority).

I gave up trying to source a new motor made EU/USA/Australia. (So far as I can ascertain there are no motors made in the UK). I finally obtained a second hand motor from Myford. It is a well made Brook Crompton Parkinson (Hawker Siddeley) product supplied in the maker’s original box. It was made in Doncaster before the Tyco take over & is built up to a specification rather that being made down to a price to suit the accountants. When running it has that indefinable quality purr rather than a harsh grating noise. The average sound level produced is 47dB(A).

Ramon refers to the high quality of the Italian made motor. Unfortunately, there does not seem to be an easy way to mount a metric motor onto a Myford.

I accept that I may be too fussy & make too much of the noise level, others may be more tolerant. But to fit a cheap motor to a Myford is analogous to installing a Ford diesel engine into a classic Rolls-Royce.

Regards, Peter Gain.

[KWILParticipant @kwil]

No problem with a Metric motor on a Myford S7. I use an ABB motor and only had to open out the pulley to the 19mm shaft size. Some inverters can cause a whine, but you can adjust a part of the S/W setup to minimise this.

[Roderick JenkinsParticipant @roderickjenkins93242]

I’ve just replaced the motor on my S7 with a package from Transwave which includes a BFM motor (3/4 HP). Much smoother and quieter than before, the old (original) motor started clicking after about 5 minutes – very irritating. I did have an issue with the inverter, the earth leakage on the filter tripped the 30mA RCD on the house supply but an upgrade to an unfiltered jaguar inverter (slightly more expensive) soon sorted this out. Transwave were very pleasant to deal with, the new inverter was sent overnight with instructions to send the original back when everything was satisfactory. Recommended.

 

Rod

[Peter GainParticipant @petergain89847]

Hi Kwil,

I played with the software but still found it impossible to prevent the whine from the Indian motors.

 

Wish I had known that a metric motor will fit a Myford. Would have saved me much time trying to find a good quality motor. Ramon reports that his Italian metric motor is very smooth & quiet.

 

Peter Gain.

[Ramon WilsonParticipant @ramonwilson3]

Hi Peter Kwil et al,

 

Just to reiterate really that the BFM motor lived up to Peters assessment. Actually before I ordered the motors I did consider fitting the Italian type to the Myford but just didn’t want to have to mess about making an extension to the Myford mounting plate then trying to bolt it in in situ. As it turns out the two feet held on by two cap heads on the Italian motors could easily be replaced by two made from a couple of blocks of ally to suit the Myford plate. Hindsight eh? – wonderful

 

Had I have known that I would have definitely prefered to have gone down that route.

Having said that it is not that the noise from the BFM is obtrusive (except at the top end) but that the Italian has all the appearances of a much better produced item. Time will tell on that one.

 

I would just like to add that personally I have found Tony at Electric Motors 2Go very helpful, patient and informative each time I have had dealings with him. On both occasions items ordered have arrived with 24hrs too. No connection just satisfied.

 

Regards – Ramon

 

PS Peter – yes they are mine – check the IC threads on here

Edited By Ramon Wilson on 22/02/2011 21:54:32

[joegibParticipant @joegib]

I’d like to underline Kwil’s caution about investigating VFD software adjustments before jumping to the conclusion that unacceptable motor noise is down to motor deficiencies.

I decided to convert my lathe/mill to VFD/3 Phase operation 2 years ago and I ended up with:

(a) 2 x VFD units — Telemecanique plus Allen Bradley,

(b) 3 x 3-Phase motors — 1 Taiwanese, 1 ‘EU’ (country N/K) and 1 Italian.

To keep it brief I’ll just say that bench testing any combination of these units resulted in the motor emitting a high-pitched penetrating whine that was (to me) intolerable for normal operation. I thought I’d bought a set of white elephants!

On investigating further (and with some help from another forum) I discovered that VFDs have a characteristic electronic operating frequency normally set at 2 or 4KHz by default. Commonly, however, certain (most?) VFD/motor combinations can excite accoustic resonances in the motor windings/laminations, leading to the high-pitched whine I mentioned earlier (these frequencies are well within the human hearing range, of course). Fortunately, though, most modern VFDs of any quality have software controls that allow you to change the unit’s operating frequency from 2/4KHz through 8/10/12/16Khz to ‘tune out’ the whine (in reality, the whine is still there but you’ve set it to a level above the human hearing threshold). For this old geezer 10KHz does the job.

On doing fresh bench testing after adjusting the operating frequencies I was happy to find that now, any combination of my VFDs/motors was relatively quiet, certainly very acceptable. All that remained was normal motor ‘hum’, some ball bearing noise and the ‘whirr’ of the VFD cooling fan, the latter being the noisiest component!

So, if you encounter this problem, don’t immediately start running around changing motors as I did! Check out the capabilities of your VFD first. Sadly, the manuals seem to be aimed at commissioning engineers, not home workers, and their terminology varies as between units. Persevere, though, and if you need help, post a query here or other ME sites.

Joe

Edited By joegib on 23/02/2011 11:35:36

[John CoatesParticipant @johncoates48577]

I converted my 1947 Barker lathe to 3 phase with an inverter and remote control unti from Direct Drives and a motor from Inverterdrives. Much quieter than the old speed wheels and now have a speed range from 24 rpm up to 1200 which is about the limit I would subject 60 yr old bearings to.

 

All in it cost £160 to change which includes all the cabling which was ends from local electrical factor. Beware as screened cable for the conection from inverter to motor can cost £17/metre

 

Emboldened I am now doing my Chester Champion mill. Bought a Mitsubishi inverter from some new dealer on eBay and got it for a song and the motor again from Inverterdrives. This cost me £119 as I alrerady had the cabling from the lathe conversion. This should hopefully all be up and runing by the weekend.

 

All the lathe took was an adapter plate making from 10mm plate to move the motor back (shorter spindle length) and up. The old cone pulley wheel was replaced with a single drive puley with a replaceable centre boss. The mill has required a spacer fabricating because the spindle on the old motor was much longer and without the spacer the cone pulley cannot clear the mounting housing. But that is work in hand and soon I shall be enjoying variable speed on the mill as well which was much higher rated to start with (up to 1640 rpm)

 

John

[KWILParticipant @kwil]

John,

 

I do not know where you got those prices from, Multi Core SY Screened cable is up to around £5 per metre depends on size and no of cores.

[John CoatesParticipant @johncoates48577]

Posted by KWIL on 23/02/2011 12:25:17:

I do not know where you got those prices from, Multi Core SY Screened cable is up to around £5 per metre depends on size and no of cores.

 

Hi kwil

 

From the invoice which showed list price as £1700 for a 100m roll. Mine was shown as “odd end” and they charged me about £4 for 6m so I got it cheap. The list price must be what they charge “professionals” on proper building jobs not some numpty who comes in off the street on the scrounge!

 

[KWILParticipant @kwil]

Look at TLC-Direct for prices, usual disclaimer.

[joegibParticipant @joegib]

Further to my earlier post, I googled ElectricMotors2Go to see what the ‘Indian’ motors Peter Gain referred to looked like. This brought up a series of Ebay links and on clicking one, I was led to the Ebay shop of ‘goldcresttechnologies’ (this is evidently their Ebay ‘handle’). This was a surprise because this was the firm from whom I bought the motor I referred to as ‘EU (country N/K)’ in my earlier post. The motor I bought is this:

Motor

 

But the motor actually supplied differed somewhat from the artwork in that the paint finish was light grey rather than creamy white and the terminal box was a conventional square diecast affair rather than the elongated (plastic?) box shown in the illustration. So, it’s possible that both Peter and I bought motors from the same product range, albeit of different power ratings.

 

If that’s right, I’m a bit peeved to have bought an ‘Indian’ motor in the belief it was EU-manufactured. That said, to be fair, I found no perceptible difference in noise levels as between the 3 motors when I carried out my bench tests. In other words the whine emitted by the ‘Indian’ motor disappeared when the VFD frequency was adjusted in the same way it did with the other motors. (I should say that I use a spare bedroom for a workshop and live in a flat so I’m also sensitive about excessive noise).

 

I can only re-iterate my earlier advice — people carrying out these installations need to consider the VFD frequency issue before condemning motors as unsatisfactory.

 

Joe

 

 

[Ramon WilsonParticipant @ramonwilson3]

Joe,

 

The motor you show is what I believe to be of Italian manufacture……….

 

It is the same type as I have purchased for my mill and I’ve just nipped out to the workshop to check.

 

This is the Indian motor now fitted to the Lathe

 

 

Unlike this the Italian motor appears plated with the manufacture

 

The legend reads –

ELECTRO ADDA SpA

CONSTRUZIONI ELETTROMECCANICHE – Italy

 

This motor is without doubt quieter than the Indian one at top revs. I have taken on board your previous post regarding frequency and shall see if I can fathom out the tech talk in the Inverter destructions to see if it can be improved. As I have said though it’s not obtrusive at average speeds just at the top end.

 

Thanks for your advice on the frequency change though – wouldn’t have been aware of the possibilty to improve the noise level else

 

I will post a bit more on the Linley mil tonight and you will see the difference in motors

 

Regards – Ramon

[Keith LongParticipant @keithlong89920]

For interest, those of you that have tried two motors and found one to be quieter than the other, have you noticed whether the frames are aluminium or cast iron?

It seems from reading various adverts that modern small motors have aluminium bodies which will be lighter than the older cast iron ones, and I wonder if this is allowing more noticeable “ringing” of bodies, laminations etc?

As in a lot of our machines mass is definitely desirable to help damp out or suppress vibration.

Keith

[KWILParticipant @kwil]

My European motor by ABB (ASEA BROWN BOVERI) has a aluminium body (thank goodness), but my other 3 machines, all run on their own inverters, 2 have English motors and the 3rd, of USA manufacture, all of these are iron framed, all quiet.

Edited By KWIL on 23/02/2011 19:27:29

[Ramon WilsonParticipant @ramonwilson3]

Hi Keith,

 

The motor above is steelbodied and much heavier than the Italian one which is aluminium as here.

Whilst the Indian one is not excessively noisy this is comparatively very quite and much smoother. If appearance and finish is a judge of quality then this is chalk and cheese – a far better product – but only time will tell

Regards – Ramon

[joegibParticipant @joegib]

Hi Ramon,

 

Thanks for posting pictures of the motors under discussion. I’m pleased to find that the motor supplied by ElectricMotors2Go/Goldcrest is indeed the same as your second picture (the grey model) except that on mine the spec plate was badged ‘Goldcrest’. So it’s Italian rather than Indian! That means 2 of my triplet of motors are ‘good’ Italian models. Viva Italia.

 

If it’s of any help in investigating your VFD’s frequency adjustment facilities, my units refer to the feature as:

 

‘Switching Frequency’ — Telemecanique

 

‘PWM Frequency’ — Allen Bradley

 

If you get stuck post the brand/model of the VFD Newton Tesla supplied and I’m sure someone will be able to help.

 

Joe

[John CoatesParticipant @johncoates48577]

My 3 phase motors are a TEC on the lathe and a Marelli on the mill. Obviously only the TEC is up and running but it is very quiet. As said before the greatest motor noise is the fan!

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