Bearing Oil for your turntable?

[arcorob]

Lini..I respect that

Rob: I don't concur, 'cause sewing machine oil usually has a pretty low viscosity - quite a good bit lower than the Renotac 342/343 oils used by Dual, so I would be worried about the long term effects a too light oil might cause...

Greetings from Munich!

Manfred / lini

I respect what you say and you are probably right in the end. But I use sewing machine oil for a reason. It is a light machine oil, and yes, lower viscosity. But many small motor will have a small hole and stamped - Use 2 drops of light machine oil.

Similarly, I consider this to be a light machine oil situation for several reasons.

1) The object is to lubricate the moving parts and prevent friction. That is accomplished
2) Higher viscosity means higher drag - A turntable motor just doesn't have that kind of torque to effectively use 30w oil
3) Higher drag can have the opposite effect in making the motor work harder to maintain speed
4) Motor oil with higher viscosity tends to gum over time as it ages..sweing machine oil can be there for 50 years and not turn to goo

Anyway, like I say, you may be perfectly correct and I worry about nothing ...but I prefer my method

You know, have not seen you around much...how are you ?

 

[totem]

Over the years many TT manufactures have used various
bearing designs and tolerances that are tied to a specific range of acceptable lubrication viscosity's.

Therefor no single oil or viscosity should be considered universal unless applied to
a specific set of requirements.

 

[marcmorin]

I respect what you say and you are probably right in the end. But I use sewing machine oil for a reason. It is a light machine oil, and yes, lower viscosity. But many small motor will have a small hole and stamped - Use 2 drops of light machine oil.

Similarly, I consider this to be a light machine oil situation for several reasons.

1) The object is to lubricate the moving parts and prevent friction. That is accomplished
2) Higher viscosity means higher drag - A turntable motor just doesn't have that kind of torque to effectively use 30w oil
3) Higher drag can have the opposite effect in making the motor work harder to maintain speed
4) Motor oil with higher viscosity tends to gum over time as it ages..sweing machine oil can be there for 50 years and not turn to goo

Anyway, like I say, you may be perfectly correct and I worry about nothing ...but I prefer my method

You know, have not seen you around much...how are you ?

Folks.........viscosity and lubricity are not the same thing.
Viscosity refers to how sticky something is. Granted, an oil cannot lubricate if its not there. A general rule on Lubricity and Viscosity is the higher the viscosity, the lower the lubricity. Going by automotive standards for a viscosity rating is almost irrelevant in the bearing dynamics of a shaft running in a hole @33.3RPM. The only place where any EP additive to any oil matters is at the point of thrust. The best known EP additive is molybdenum due to its natural ability to slip at pressure as high as 550,000 PSI.
The film strength of an oil in a bearing sleeve is more determined on the surface finish of the shaft and sleeve. The film strength of an oil at point of thrust is determined first by finish, second by the hydocarbon chain.
Automotive oil lubricity is designed to be at its peak at 165deg F. Standard refined motor oil loses 50% lubricity at 210 deg, and then halves every 10 deg rise in temperature. Synthetics (depending on manufacturer) retain lubricty at higher temps than standard oils, but do not have any lubricity advantage at room temperatures under the standards they were designed for.