Spindle oil


What oil are people using to lubricate their spindle bearing?
scottht
Herman: Those are all good points but you're making it far more complex than it really is. The reason that we have different fluids in a car has to do with the materials and applications being used. ATF is different from motor oil because ATF is used as a hydraulic fluid with detergents and lubricants added. It is not exposed to gasoline, anti-freeze, carbon, etc... and the clutch materials inside the transmission are of a different compound than any of the materials used inside of a motor.

The fact of the matter is that it would be hard to improve upon a situation requiring lubrication when you're already using the slipperiest substance known to man. So long as one did not exceed its' thermal limitations, which would be hard to do because of the reduction of heat involved, how could you reduce drag & friction any lower? If this lubricant won't work here, what is it that would allow other lubricants to work better? Neither would be under any pressure other than the weight of the platter on the bearing. On top of that, there's no circulation system involved, so flow time isn't a concern. You basically have a bearing sitting captively in a machined area that needs lubrication. There's nothing high tech or diverse about this application what so ever. Sean
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Sean, I believe it is a bit more complex than just choosing a lubricant based on how slippery it is.

From the Teres website: "The bearing is designed with large amount of surface area to maximize viscous damping. The oil in the bearing exerts a smooth, constant resistance as the platter rotates adding to speed stability." Evidently they want a certain amount of drag. Don't you think the amount of viscous damping is dependent on the type of oil used, and that they chose one to achieve the desired result? If the wonder oil you tout reduces drag to too low a level then the bearing would not be doing what it is intended to do.

Why does VPI recommend lithium grease? Perhaps for the same reason. In any case, it is inconceivable to me that a company such as VPI would recommend lithium grease if a lighter weight oil would be better. Surely they have looked into this a little deeper than your average audiophile and come up with what they feel is the best lubricant for their turntables.

The "slipperiest substance known to man" is not always the best stuff for a particular application.
Herman: Tufoil is basically a combo of specially formulated thicker oil mixed with moly grease that has microscopic particles of PTFE imbedded in it. It is neither as thin as oil nor as thick as grease i.e. it is somewhere in the middle.

As far as counting on the lubricant used to stabilize the speed of the platter and reduce pulsing of the motor by creating drag, that is a piss-poor design. Not only do all lubricants break down over time, but their viscosity varies with both ambient and internal temperatures. As such, i can see the need to use a specific type of lower grade lubricant as a "band aid" IF the product was poorly machined and / or lacking in design integrity ( poor speed regulation / stability ). If a product is truly well designed and well machined, the name of the game for any bearing type device would be the lowest friction possible. Sean
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Sean,

I think that you missed the point about viscous damping. The intent is to compensate for stylus drag. The drag from a stylus is highly variable exerting a very small but non-uniform braking force. The theory behind viscous damping is that applying a highly uniform braking force that is many times greater than stlyus drag will swamp out the effect of the stylus. I can't prove the validity of this theory, but there seems to be a great deal of supporting evidence. The primary evidence is that the vast majority of high-end turntables have bearings with a lot of vicous damping and are decidedly not optimized for low friction.

Variance in viscosity is not an issue for two reasons. 1) Temperatures in a turntable bearing will not change enough to be meaningful. There simply is not enough energy present to affect more than a one or possibly two degree temperature change. 2) The magnitude of drag is relatively unimportant. Any change in drag from temperature will be slow and gradual enough to be irrelevant.

Back to the original thread, my experience is that bearing oil viscosity does make a small difference in sound. My unproven theory is that oil with the higest viscosity that produces laminar (non-turbulent) flow in the bearing will be optimal. Turbulent flow will produce less uniform drag. So the objective is to maximize drag without turbulence. Radial bearing clearance and bearing design both effect flow so the best viscosity will be different for each bearing design.

Beyond viscosity it is difficult to imagine that additives or expensive formulations would be relevant. When it comes to lubrication a turntable bearing is a cake walk. Low temp, low speed, low pressure and clean.