Thanks Rock. You also have the knowledge that your turntable will work in temperatures as low as -55C! That Mobil 1 0W40 has a pour point of lower than -55C!
Salut, Bob P. |
Quincy, I think that you mean a 0W30, not 30W. What you really want to use is not a multigrade, but a straight SAE 5 weight, if you can find it. However, if using a multi-grade (this sounds like an car oil commercial!), use Mobil 1 5W20. At any rate, all engine oils are overkill - even olive oil will do, just have to change it every 6 months or so as it will get rancid!
Bob P. |
Sean, regarding WD-40, I hear you!
With respect, Bob P. |
A light sewing machine oil is all that is required.
Of course, I know that someone is going to start hearing differences in the sound of the oils, probably because the different viscosity oils will have differing damping and resonances on the speed of the table and vibrations cause by the slightly wobbling spindle. (All tongue in check, of course!).
Bob P. |
Sean,
About "too heavy a lubricant being detrimental and increasing drag". The short answer is Yes! If the lubricant is too heavy and not pumpable, i.e. grease, it might not be possible for it to penetrate into the surfaces interface. Depending on the load on the bearing, however, a lighter lubricant might not be capable of supporting that load and we are back to direct contact of surfaces. I think, however, that grease would also be perfectly alright for lubrication in a turntable, but the drag on the drive system might be compromised.
As to the "goal of a lubricant", the main reason for lubricants is to SAVE the mating surfaces from WEAR, not to necessarily save the energy necessary to turn the spindle in the bearing. The best way to reduce the wear on the bearing is to reduce the friction between the surfaces, either by introducing a substance that fills the small microscopic bumps and ridges in both surfaces, effectively "smoothing" the surfaces, or by introducing an intermediate substance between the surfaces, thus protecting the surfaces from wear. In the first case greases, solids (graphite) and oils can be used. In the second case, various fluids are used, including air.
I am not sure about your other query about making the slipperiest substance "known" to man more slippery?
Once two bearing surfaces are protected from wear, the job of lubrication is done. The increased drag etc. is not relevant to the lubrication, but might be important for other reasons.
Back to the original arguement. First, The fact that a turntable turns longer with a particular lubricant in it is no indicator of lubricating "goodness". Second, for the purposes of lubricating our turntables, any motor oil is overkill. As I facetiously said, olive oil might very well serve the purpose of reducing wear in the spindle bearing. You might want, however, to use motor oils because there are many different viscosities available and you might want to play with those to determine if some "sound" better than others.
I shall stick to light "sewing machine" oil for my Oracle Alex III, (13 yrs old) but I am tempted to add graphite to the oil, just to see if I can "hear" the difference. It might even make a long term difference to the life of the bearing.!
Regards, Bob P. |
Semi, your choice of the Teflon based grease seems judicious. There is no advantage in the Lithuim based grease, except if you expect to encounter water! It is good, however, if you want to grease your car window lift mechanism!
The only comment that I could have about the inverted bearing, is that, ironically, the load on that type of bearing is lower than on the straight vertical journal bearing, where all (well, most) of the load is on the tip and therefore could use a thinner lubricant, but as you have pointed out, what's to keep it there?.
Bob P. |
Semi, when discussing the lighter load on the inverted bearing, I meant that lighter lubricant can be used, but one needs to find a way of keeping it at the bearing. My previous message might have been misleading.
Bob P. |
Sean, I have already conceded the last word to you!
Why are you restating things that I have already elucidated and then claiming that you were correct all the time?
You don't know the exact formula for that lubricant but I do! In fact one of the components, the didecyl adipate dimer ester (we abreviated to DIDA) was one of the many lubricant bases that we (BASF) made for Castrol.
I have nothing more to add that would help you in understanding the facts of lubricating systems and lubricants themselves.
Respectfully, Bob P. |
Then, Sean, I suggest that you put Teflon in the bearing, if you want the slipperiest substance known to man. If you were refering to Mobil 1 as the slipperiest substance, then you are incorrect. Using Teflon, I think that you will find that the surfaces that bear the load will wear out more quickly than using a grease or oil, because the teflon cannot handle that load!
BTW, friction and wear aren't substances that can be "transmitted" as you put it. Its not like vibrations!
At any rate, you can have the last word if you must, but I shall remain with my recommendation of a simple machine oil.
With respect, Bob P. |
Rockvirgo, how did you ensure that all of the previous oil was completely removed before trying the next oil? Iso-propyl alcohol is not a good solvent for lubricating oils.
Bob P. |
Sean, and this is my last word on this subject, my initial foray into this subject was to state that just because a turntable turns longer using a specific lubricant does not mean that that lubricant is superior to another lubricant as you stated.
The rest of the issues brought forward had nothing to do with that original statement and therefore I did not comment on those.
Let's leave it at that!
Regards, Bob P. |
Rockvirgo, yes to a point. But for this "shearing" action to be of benefit, the lubricant has to be strong enough to handle the load imposed on it by the two mating surfaces so that the surfaces DO NOT touch, but are in fact sparated by a continually shearing liquid. That is why water is not a very good lubricant, even at medium low loads. That is why a minimum viscosity is necessary for a lubricant to be successful.
Also, synthetics, as you have pointed out, have long straight chain molecules as opposed to the conventional oils which have a mixture of ring and branched chain along with some long chain molecules. Its not so much the molecules breaking up that is the "shearing" as it is the separate molecules moving against each other. Long or straight chains tend to slip by each other more easily than branched chains. |
Sean,
I agree to a point about your saying different oils should be verified, but one oil that was not checked was olive oil!
You might be surprised to find that it allows the platter to turn even longer than the motor oil.
BTW, longer turning time does not indicate that the lubrication is better, just that viscosity of the lubricant is lower therefore allowing more shearing of the lubricant itself which puts less drag on revolving spindle.
In fact too low a viscosity could be bad, since the lubricant barrier formed between the metal parts would break down and then we would have metal touching metal and increased wear. The platter, however, might turn for much longer, since the actual friction of metal to metal (sometimes ceramic) surfaces might be lower than with the lubricant between them.
Motor oils are for much harder lubricating conditions than a "babbit" bearing, which a turntable bearing is basically. That is why I said that motor oil is over kill. For lubricating a simple spindle, a light machine oil is all that is needed and while I might have been facetious in saying that olive oil would be just as good, I am sure that that is true! Try it, you might like it! (Pun intended).
Salut, Bob P.
PS. As a professional Chemical Engineer and having managed synthetic lubricant plants for several years, I am quite sure of my views on the subject of lubricants and their applications. |
