401 bearing issues

[Daniel Quinn]

I'm of the view that this forum needs more humour , It is more often than not a little literal .

[Nick]

That may be the case, but IMO humor != passive aggression

[izzy wizzy]

There is no universal lubricant for bearings. There are so many factors to consider. And as we're talking such super fine tolerances in our measuring machine here, a little (that's a technical term BTW) can make a significant difference.

The advice from someone who has experience with a particular bearing's application might be a whole lot more useful than a general "if it works for this, it will be good there too".

[Daniel Quinn]

In this thread I'm playing devil's advocate to spark debate in a humours manner in the hope we all might learn something new .

Alas your post is rhetoric.

[Cressy Snr]

What’s rhetoric when it’s at home eh?
These bloody elite metropolitan intellectuals and their long words, trying to look clever. I don’t know what this country’s coming to. Use plain English I say.

[izzy wizzy]

Some bearing lubes are meant to provide some drag for the motor to pull against. Some, to fill the gaps in a not so precise bearing. Spin time might not be a measure of goodness in the overall design.

My TT bearing and similar designs can use air tool oil. It's a pain but if you can bothered to experiment there might be a "best" lube for you. OTOH, I'd rather take advice on what's good, having done the "try this" for a bit.

On a tight tolerance bearing, it can take many hours for the bearing to seat after an oil change, usually overnight worked. A thrust plate change, same time frame.

[pre65]

In this thread I'm playing devil's advocate to spark debate in a humours manner in the hope we all might learn something new .

Alas your post is rhetoric.

I'm all for a bit of humour myself, but in the right place.

Your "so called" attempt at humour (in this case) has backfired.

[Nick]

In this thread I'm playing devil's advocate to spark debate in a humours manner in the hope we all might learn something new .

Again, you seem to be objecting about what you originally didn't post. If you had first posted

It will take of lot of convincing that differing lubricants used in bearings are audible or in any way offer an advantage .

I would agree, you are playing devil's advocate etc. But you only posted that suggesting it was in some way equivalent to what you first posted

Max , you worry about motor oil viscosity and I'll worry about my gait

I fail to see the connection. It was the first post I was suggesting was unnecessary, no matter how much you seem to want to make it about the other post.

The fact is that Max's comment was very valid, the expected operating conditions for motor oil are very different from that of a turntable bearing, so when you suggest that "if its good enough for a engine", it may not be a valid comparison to make.

[Daniel Quinn]

How do you think the operating conditions of a bearing and an engine differ and how is that difference relevant.

My thinking is that differences in temperature aren't relevant . The temperature between ball and thrust pad is sufficient for motor oil to be beneficial .

And pre , thanks for giving me your opinion if you don't mind I'll continue to ignore it , however please feel free to offer your opinions again , somebody might be interested .

[Nick]

How do you think the operating conditions of a bearing and an engine differ and how is that difference relevant.

Well, ignoring the biggest difference, other things I can think of is the relative speed of the moving parts, the variation in pressure between the parts, the presence of pollutants both soluble and non soluble in the oil, and the existence of a circulating system to pump the oil at pressure to where its needed.

I am sure there are many other factors that are involved in engine oil design that are not applicable to a turntable bearing.

But above all, the fact that one is designed to operate at above 90C and specifically note viscosity changes between winter starting conditions and normal operating temperature.

My thinking is that differences in temperature aren't relevant

This is a claim that I feel would require some justification.

[pre65]

On an engine, the oil has to perform in different ways, for example, the requirements for plain bearings (big ends and main bearings) are different to shear loads on camshafts and tappets and also the much greater heat.

It's difficult to answer your question in a simplistic way.

[pre65]

And pre , thanks for giving me your opinion if you don't mind I'll continue to ignore it , however please feel free to offer your opinions again , somebody might be interested .

As you please, but the fact you replied means you aren't ignoring me.

[Daniel Quinn]

The motor engine will clearly have moving parts that are somewhat faster , but deos that mean the oil is not appropriate for slower speeds .

I would hazard a guess that nobody actually knows and nobody as tested it , it is hifi afterall .

But I bet those who pay a fortune for a peppet of snake oil can tell the difference

[Nick]

The motor engine will clearly have moving parts that are somewhat faster , but deos that mean the oil is not appropriate for slower speeds .

I don't know either way and neither do you.

I would hazard a guess that nobody actually knows and nobody as tested it , it is hifi afterall .

I also don't know, but I expect someone has done more testing than you seem to have done (none, just going by hunches).

But I bet those who pay a fortune for a peppet of snake oil can tell the difference

Maybe, but it sounds like both you and they may both be suffering from conformance bias. Theirs that if its expensive it must be better, yours that if its expensive it must be a conn, and that your feelings are valid as evidence.

All I can say is that the original suggestion of oil designed for room temperature slow moving parts sounds like a better match than that designed for high temperature fast moving parts. It also seems that slideway oil is available for similar cost to 5W-40 engine oil.

[rowuk]

The motor engine will clearly have moving parts that are somewhat faster , but deos that mean the oil is not appropriate for slower speeds .

I would hazard a guess that nobody actually knows and nobody as tested it , it is hifi afterall .

But I bet those who pay a fortune for a peppet of snake oil can tell the difference

Actually, this IS tested and results in the oils rating. For those needing to be spoonfed:
https://penriteoil.com.au/knowledge-cen ... cosity/180
Do not confuse the first chart which describes the maximum range of temperature useable with the viscosity (a chart lower on the page) at a given temperature. Here we can plainly see that motor oil when cold is simply too thick for record deck bearings.

In an internal combustion engine, we have the high operating temperature (compared to a platter bearing), forced lubrication, petrol and exhaust effects as well as a huge speed difference.