Jones and Shipman 540 tight spindle

[Aris VParticipant @arisv]

Hi Everyone,

 

Quiet newbie here.. I’m hoping to get some help with my JS540 surface grinder. I’m a complete novice with these, having purchased an old (1970s?) and abandoned model which has been left in a corner of a motorcyle workshop for many years.I think it has a plain bearing spindle with an oil tank, and it came without any tools/accessories/manuals etc (but it WAS a bargain!)

After filling it with oil, I had a successful test run – and was pleased to see it cut some metal and the results looked passable. So technically I could say it works.

However, I’ve noticed the machine had a bit of trouble starting – the spindle seems to be very tight when at rest, and the motor barely manages to turn the wheel when under power (once it gets going its OK). I suspect it’s not suposed to be this tight, but have no idea what might be causing this. After a few minutes of running i did not detect any excessive heating, and nothing obvious caught my eye in terms of rubbing, friction or corosion. The fact that the cut was successful also suggests that the bearings are fine, and there’s no noticable play, crunchyness or anything similar…

One thought came to mind whether the spindle bearings could have been over-tightened, so I proceeded to disassemble the spindle, looking for ways to adjust bearing pre-load. I’ve gotten down to the picture below, and realised my spindle does not look at all like the ones in the standard manuals.  What you see sits just behind the taper, with a seal cover removed.

So It is at this point I decided to stop and drop a line here in the hopes of some guidance… Does anyone have a similar machine and some relevant experience?

1. Am I right in thinking that the spindle shouldn’t the “tight” and therefore i have a issue, or is it perhaps how these thigns are designed to run?
2. Could this be cause by an over-tightened bearing, or is that unlikely (and am I asking for trouble disassembling it)?
3. Is there some secret place online I could find more detailed technical drawings of the JS540? all i found so far was operating manuals with very little detail
4. Do people have any other ideas of what could be causing this and what to check?

 

Many thanks,

Aris

 

 

 

 

 

[Mark RandParticipant @markrand96270]

What oil did you use? The specified oil is Mobil Velocite No 6, which is an ISO 10 oil.

Axial clearance, when cold, should be 0.0004″

Running temperature is specified at 60°C !

[MacolmParticipant @macolm]

Is the motor single phase? If so, check the start capacitor.

[Chris CrewParticipant @chriscrew66644]

I had a similar problem on a 1310 cylindrical which also has plain bearings. Although it would start and run for a couple of minutes the wheel would then stall. I was running it at first on a static converter and thought it was some sort of electrical reaction. I then acquired a large rotary converter, more than adequate for the machine but the same thing happened. The wheel is driven by a double belt and pulley and suspected two mismatched belts were pulling against each other so I removed one of them to no avail. I then suspected a faulty motor winding but some elementary checks seemed to rule this out. In desperation I removed the wheel head cover and shimmed the bearing shells by about 0.0015″ and this seems to have cured the problem and doesn’t seem to have affected the operation of the machine. There are no discernable vibration marks on the work and as far as measurable with a micrometer or caliper the accuracy is about 0.0005″ although the machine is calibrated to 0.0002″. I fully accept that what I did to the bearings would give a tool room manager a heart attack but my machine is really only a big toy that sits in my garage being used about twice in a blue moon and I have the pleasure of owning it. It is in really good cosmetic condition for its age, circa 1963, being an ex-college machine bought at an auction in a moment of madness 20 years ago so I just wonder if the previous owners had the same problem so it didn’t get used much. I will of course inform any new owner what has been done when the time comes to sell.

[Aris VParticipant @arisv]

Hi all,

Thanks for the responses, to follow up:

• Oil used was Mobil Velocite No. 3, exactly as stated on the oil box. It is a very thin oil
• It’s a 3ph motor, i think c. 1kw, which runs fine on it’s own.
• The belt drive is a simple flat belt, which is brand new (clearly someone had changed it before i got it)
• With respect to axial play, i can feel none and it does not come through as a problem when grinding. I suppose if it’s over-tightened then the axial play would be even less than 4/10ths, which would confirm it, but my measuring tools aren’t accurate enough to detect it!

The difference to Chris’ situation is that mine runs fine when it gets up to speed – i think if the motor over-powers the resting friction and gets going, then either the spindle friction reduces (maybe oil flow) or it becomes negligable relative to the full speed motor power. Deep grinding slows the wheel down, but it has no problem ramping up again.

To give a sense of the spindle friction – i cannot turn the spindle by hand without a wheel on it; when a wheel is on, i can turn it with with minimal effort, but it will not coast after i release it. surely that’s not how it’s supposed to be right? This remains true when i take off the belt, so it’s not the motor slowing it down…

Bearing mis-alignment is of course possible, but it’s unlikely to have developed on it’s own… in which case it’s either came out of the factory like that (no chance), or someone had replaced them incorrectly..?

I’ll try to release the bearing cap and see what that does – if spindle turns freely then it’s a case of over-tightening, if not then bearings are to blame..

Any other thoughts welcome!

Aris

 

 

 

[John HinkleyParticipant @johnhinkley26699]

Aris,

Have you downloaded the various manuals from the Vintage Machinery website ?  The spares manual linked to has a couple of cross-sectional views of the spindle which might give you a few clues.

John

 

[Maurice Clarke 1Participant @mauriceclarke1]

Manuals & Spare Parts details available here:-
http://www.vintagemachinery.org/mfgindex/detail.aspx?id=10631&tab=3

[gerry maddenParticipant @gerrymadden53711]

I may be wrong, not having fiddled with these plain bearing spindles, but it may be a case of the bearing system being a little too tight. Starting torque is high because of the friction between the contact surfaces. Moving the spindle by hand just isn’t fast enough to allow a hydrodynamic oil film to develop. However let the motor get the spindle speed up and a hydrodynamic oil film is develops allowing the friction to drop right down.

This condition is probably fine whilst you run, but every time you stop and start, the bearings will wear a little more than they should. So if it was mine I would find out how to remove the little bit of ‘nip’ that is creating that initial friction.

Gerry

[Dave SParticipant @daves59043]

Can’t check as I’m away, but from memory my plain bearing 540 will do about 1/4 to 1/2 a rev from a flick by hand on the wheel with the belt on. It’s never felt especially stiff so that’s suspicious.

If you pop the belt does the spindle free run when given a flick over with a wheel on it?

When starting up first thing is to give the wheel a few spins by hand to help get some oil in the bearings.

You can pop the lid without disturbing anything, might be worth a look. The internals are quite simple. Check the chamber looks clean and when the spindle is spun that the oil collector picks some up and dumps it onto the bearing (from memory there is a little trough or similar)

Dave

[Michael GilliganParticipant @michaelgilligan61133]

It’s probably verboten for all sorts of good reasons, but: is there a suitable oil available that incorporates the ‘long-chain molecules’ that were made famous by Castrol GTX ?

It would appear that the machine is crying-out for such.

MichaelG.

.

Edit: __ Way out of my depth here … but this one looks interesting:

https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/6F4DB740253243D8802577960030624C/$File/C-OPTIMOL%20VISCOGEN%20KL%2007-00%20-R03.pdf

[Mark RandParticipant @markrand96270]

My suspicion would be that the bearing needs a good clean. Kerosene/white spirit might be a good start.

[Dave SParticipant @daves59043]

Long chain molecules are not appropriate here.

they are part of a multigrade oil such as is found in car engines. They alter the viscosity of the oil depending on the temperature. IIRC the chains “unroll” when hot, adding viscosity as the base oil thins.

Machine spindles do not have to work over 60 odd degrees of temperature swing (-20 to +40).

For a plain bearing J&S grinding spindle the correct oil is like water in thickness.

Dave

[Dave S]

On Dave S Said:

Long chain molecules are not appropriate here. […]

So I’ve learned something

… that’s good.

MichaelG.

[Author]

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