To Grease or to Oil, that is the question.

Evening all,

I know that a light oil such as Nuto 32 should be used (or is recommended) on the headstock bearings on the Myford ML7 range.

I have just picked up an ML8 wood turning lathe, quite old, and the gent I purchased it from had always used grease on the bearings.

Now the instruction sheets for the ML8 are quite specific, in fact it is highlighted, that "ON NO ACCOUNT IS GREASE TO BE USED" on the bearings.

Now this ML8 must have been going for "Donkey's years" however long that may be with grease in the bearings and correctly adjusted, the bearings show no sign of play.

Are there any Tribology experts out there who may shed a little light as to why Myford were adamant about this point?

Len. P.

Grease doesn't flush out any nasties from the bearing shells, oil does

edit: non expert btw

Edited By Ady1 on 03/07/2013 19:44:46

Bearings is odd things... I used grease on the roller bearings I fitted to my mini lathe and mill. They are about the same size (or bigger) as those fitted to vans with over 4-tonne loaded weight, and they can do 200,000 miles + subject to a static load of nearly a tonne for up to 20 years and shock loads of GOKW when being driven before they give out.

Neil

Oil - nuff said!

The Southbend/Boxford book " know your lathe" page 18 item 1

"HEADSTOCK SPINDLE BEARINGS These are grease packed and rquire a small amount (1cc apporx) every 3 to 6 months."
...................................................
So it depends on the lathe

Oil is used to reduce friction/drag relative to grease for higher speed spindles and lower friction/drag reduces self heating of the bearing. Therefore with many bearings including car wheels it is often advised not to overdo the amount of grease to avoid overheating though to some extent it is self regulating as the hot grease runs out.
It is also often considered to be bad practice to clean a bearing of all oil with solvent and 'play' with it by whizzing it up with an air line. Equally too thin an oil relative to the loading is probably unwise.

A compromise perhaps - petroleum jelly (vaseline) is recommended for the GA high speed engraver spindle.

Hi Len

The bearings in the headstock of a Myford ML8 are Angular Contact ball bearings.

The ML7 metal lathe are tapered White Metal Bushes Oil Lubricated .

The reason that "ON NO ACCOUNT IS GREASE TO BE USED" is that there appears to be no seals fitted to the spindle bearings.

The use of grease in the bearings has probably done very little harm to the bearings.

The only problem that MAY arise when greased is used on constant use on high speed when the bearing could run HOT.

If you are unsure a "Strip and Clean" will help with any doubts.

An excellent site for infomation is at

http://www.lathes.co.uk/MYFORDWOOD/

The tricky bit is to adjust the bearings with no play and no excessive preload.

Eric

It doesn't really matter as long as there is some form of lubricant applied

the choice is usually decided upon the allowed working tolerances, oil can get where grease can't

but at normal running temperatures both will get there.

Grease has a longer lasting effect but is prone to clogging

oil is less lasting but keeps the bearings free of contamination

you pays your money you takes your choice.

Dear Merrymiller, My Twopence worth as a wood mainly turner.ML8 headbearing are exposed to contamination by wood dust,an abrasive, crud forming ball flattening (bearing that is) contaminant, hence they are specified to operate on the total loss principle with a low viscosity oil SAE 32 which helpfully runs out of the bearing housings carrying with it the aforementioned undesireables.Spare yourself the acedemic agonising,these bearings are massive and operate at nowhere near their design maxima,lubricate them with ATF and top them up when you feel they need it and they will last another 50 yrs. Using grease may well be technically OK, but in this application you run the risk of killing them with retained contaminants.Most important of all do not adjust them too tight,assuming you are not a cyborg, finger and thumb pressure gently applied to the adjustment collar to arrive at a no end float position will be fine, remember its a wood lathe and you hold the tooling in your delicate fingers, its not an uber rigid, CNC, mega speed, carbide muncher. Happy turning, it's addictive

regards Paul

Edited By Paul Barter on 04/07/2013 18:14:45

Edited By Paul Barter on 04/07/2013 18:15:21

The hand book for my Taiwanese BH 1324 lathe says Tellus27 (shell Tonna 27) oil for the head stock, taper roller bearings. The apron uses Tellus 32 oil. It says lubricate the change gears with thick oil, or grease once a day, I'm trying Catapillar cam lobe oil on the gears at the moment, its thick and sticky.

I note in the South Bend book "How to Run a Lathe" they suggest S.A.E. No. 10 engine oil, or a good grade of machine oil, do not excede 500rpm until the lathe is run in.

I can't see how problems would arise with unselaed roller bearings and grease. Surely any excess grease will exit through the ends of the bearing within a few hundred revolutions?

In a mini lathe there is no way to oil the bearing without some degree of dis-assembly.

Althougha mini lathe is supposedly designed to go up to 2000 rpm, I can't remember using mine above 1000rpm which is about the same as a car doing 60 mph.

Neil

Ball bearings don't need much in the way of lubrication by either grease or oil, because the only parts that rub are the cages against the balls and the lips of any seals that may be fitted.

It's similar for taper roller bearings, except they have a little end thrust along their rollers which is provided by the flange on the inner race and acts to stop them coming apart in use.

Given the option, I'd happily use grease on rolling bearings in preference to oil provided I was sure it couldn't be washed out or contaminated or something, although oil would be my first choice for plain bearings under most circumstances.

Martin.

By 1981 my version from our old friends MAP it has moved to SAE 20.

> Given the option, I'd happily use grease on rolling bearings in preference to oil provided I was sure it couldn't be washed out or contaminated or something

In a mini lathe the bearings are recessed into the head by about 8mm and shielded by plastic covers.

Neil

My South Bend book was printed in 1941, the 40th edition, first printed in 1907. Ian S C

Oldvelo, Eric,

As a matter of fact, Myford ML7 bearings are plain parallel white metal bearings and NOT tapered. All end thrust is handled by a separate thrust bearing.

Edited By KWIL on 08/07/2013 10:44:11

"As a matter of fact, Myford ML7 bearings are plain parallel white metal bearings and NOT tapered. All end thrust is handled by a separate thrust bearing."

Thanks KWIL I got it wrong

I stand corrected for my error on the headstock bearings on a ML7 headstock bearings.

It is good to see someone who takes the time to read all the posting before making comment.

Eric