Replacement Bearings – Myford ML7 Motor

[Tim EdwardsParticipant @timedwards75903]

Hi all,

Has anyone been able to find suitable replacement bearings for the ML7 fitted with a Crompton Parkinson motor? I thought that there might have been an off-the-shelf oilite bearing that would fit but my local bearing supplier couldn’t find anything in their books.

Any help will be greatly appreciated.

[Tim EdwardsParticipant @timedwards75903]

[noel shelleyParticipant @noelshelley55608]

Do you have dimensions ? Can we have them ? I will try Hayley bearings for you, I do a lot with them. Noel.

[Trevor Drabble 1Participant @trevordrabble1]

Tim , Assuming you are refering to the white metal headstock bearings , have you tried Quillstar in Nottingham? Also do you know a new assembly of hardened spindle and phosphor bronze bushes are available from Myford ?

[roy entwistleParticipant @royentwistle24699]

Going from the thread heading I would assume that the OP meant the motor bearings

Roy

ps. I have been known to be wrong

[V8EngParticipant @v8eng]

It may be worth seeing if there are any electric motor repairers / rewinders in your area and asking them.

[Tim EdwardsParticipant @timedwards75903]

Many thanks for all your responses.

The bearings I am looking for are indeed the white metal bearings from the electric motor.

OD = 20mm, ID = 17mm, Wall = 1.5mm

My local electric motor supplier/repairers happen to be an agent for the now Brook Crompton motors. They told me that they would need to machine some new bearings and possibly machine down the spindle shaft, all at the rather hefty price tag of between £400 – 500 – that's replacement upgraded motor money from what research I have done. So before I dig too deep into my pockets, I want to see if I can just get the bearings myself, either off the shelf or made to measure, as I can do everything else.

If only I had a lathe that worked, I could potentially machine my own

[Brian WoodParticipant @brianwood45127]

Tim,

I suggest you replace the worn bearings with oilite bushes instead. Try Bearing Boys who have a full range in both metric and imperial sizes. http://www.bearingboys.co.uk

Regards Brian

[SillyOldDufferModerator @sillyoldduffer]

Posted by Tim Edwards on 29/06/2023 13:04:05:

…

My local electric motor supplier/repairers happen to be an agent for the now Brook Crompton motors. They told me that they would need to machine some new bearings and possibly machine down the spindle shaft, all at the rather hefty price tag of between £400 – 500 – that's replacement upgraded motor money from what research I have done. …

A glorious opportunity to replace the original mildly unsuitable single-phase motor with a VFD and 3-phase motor. Myford only fitted a single-phase motor because at the time most purchasers were stuck with an ordinary AC domestic supply and DC and 3-phase motor control were impractically expensive. Not an obstacle now. It's not just a new motor, the lathe works better too. (Smoother turning, improved torque, and speed control.)

As far as I know, no-one with a duff motor who upgraded their Myford to 3-phase has ever regretted it.

Dave

Edited By SillyOldDuffer on 29/06/2023 14:29:13

[KWILParticipant @kwil]

I am somewhat sceptical about the motor bearings being white metal (inspite of the infomation stated).

White metal bearings need more than infrequent lubrication and I have not seen a ML7 motor with other than just a hole that endeavours to fill up with swarf.

Am I wrong?

[Dave WoottonParticipant @davewootton]

Myford did indeed supply Crompton 1/2 hp motors for the ML7 with whitemetal bearings, I've not long ago sorted out the centrifugal switch on one, definitely supplied by Myford in the early/mid 60's. Gave it a strip down and dust out and checked the bearings which were whitemetal and despite much use were in good order. I had a later ML7 from the 70's at one time and the Crompton motor on that was fitted with oilite bearings, so both were used at various times. The whitemetal one had flip top oilers and from memory the oilite one had ball oilers.

Dave

Edited By Dave Wootton on 29/06/2023 15:45:20

Edited By Dave Wootton on 29/06/2023 15:46:03

[noel shelleyParticipant @noelshelley55608]

I have just checked with my supplier and 20mm X 16mm is available as an oilite NOT 17mm id. Wisdom is that you do not drill of ream oilite BUT if it gets the motor running it might be worth a try ? Make then of Phos bronze ? White metal could be cast and machined ? Noel.

[Neil AParticipant @neila]

If you machine the bore of an oilite bush the tool must be SHARP. Reaming smears the surface and closes up the porous structure.

Details of recommended cutting speeds and feeds can be obtained from the Oilite.com website.

All sounds an achievable fix for your motor.

Neil

[peak4Participant @peak4]

Tim, if you say where you live approximately, another member may be able to assist.

Bill

[peak4Participant @peak4]

Posted by Tim Edwards on 29/06/2023 13:04:05:

Many thanks for all your responses.

The bearings I am looking for are indeed the white metal bearings from the electric motor.

OD = 20mm, ID = 17mm, Wall = 1.5mm

…………….I want to see if I can just get the bearings myself, either off the shelf or made to measure, as I can do everything else.

If only I had a lathe that worked, I could potentially machine my own

Since you could make the bearings yourself, if you had a working motor, here's an offbeat thought, just to get you up and running.
How about a split bushing?
I've not found any 17mmx20mm, but these are 20x23mm, so the correct wall thickness, just a bit to large.
Since they are split already, take a bit out of the split to change the circumference a little (and hence the diameter) and you might get up and running again.

Bill

[duncan webster 1Participant @duncanwebster1]

Why not remetal the bearings? I did lots when I worked on a narrow gauge railway. If they have only a thin layer of white metal that won't work of course. You could try one of the plastic type, DU or HYEX (I might have remembered that wrong, similar to DU but has oil retaining pockets)

 

Edit, go on the IGUS website, loads of info. I know of one standard gauge steam loco that is successfully using plastic bearings in its big rods, so it's not an outlandish idea

Edited By duncan webster on 30/06/2023 00:55:20

[Alan DonovanParticipant @alandonovan54394]

Hi Tim.

I had the same issue with the nose bearing on my lathe motor, fitted to a Myford. I tried to find an ‘off the shelf’ replacement but was unable to find one. I then took it to my local rewind specialist who then refused to do the job. He doesn’t repair motors with plain bearings.

I was fortunate in that I had access to another lathe, so ended up making one out of phosphor bronze, this included a shallow groove in the bore to aid lubrication.  I bought a suitable reamer to finish the bore, which was a good decision as I had to ream again on assembly as the bore had closed down (as anticipated). That was more than a year ago – so far so good.

Strangely the ‘old’ bearing had an imperial OD and a metric ID (I think it was that way round, memory not as good as it was), so my assumption is that the motor was manufactured at the time when UK industry was transitioning from imperial to metric.

It’s worth a go if you can get access to another lathe.

Alan.

 

Edited By Alan Donovan on 30/06/2023 08:14:02

[Michael GilliganParticipant @michaelgilligan61133]

Tim

Unless I have missed it … we still don’t know roughly where you are

My motor is currently off the lathe … you are welcome to borrow it, short-term, if that would help.

I am in North Wales

MichaelG.

[Author]

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