andresteare wrote: 27 Apr 2021, 19:04
Nek, you did a lot of research, testing, had great results and added a lot of value to this conversation, you proposed a good solution and that's great, we all appreciate it.
However the more solutions are proposed the better this research gets, all input is welcomed. Unfortunately till we have an actual chemist, specifically trybologist we can't call an ultimate solution or what specific specs determine exactly what we are looking for, we still have to look for a solution that is widely available, 767-477 is a solution, but getting OKS is hard if you don't live in Germany. And for god sake are we really fighting over a frigging switch lube?.
Of course you are right. I got worked up these days by all these unprovoked attacks (check my previous post) which made me easily triggered and I misunderstood a simple phrase. Anyway lets move on, it doesn't worth it, lets forget about it.
Now let's get back to the research, after checking multiple PAO greases (I literally downloaded and checked all TDS for PAO greases availabe un DuPont database, also on Chevron and Exxonmobile) it makes a lot of sense when it comes to dampening effects cause a really low viscosity solution wouldn't dampen an object so it is indeed needed for scratchy objects.
But I'm not really sure if it's THAT important when comes to lubrication, using the word lubrication as to say it makes a very slippery layer between objects that makes contacting objects go slide with less surface resistance. Viscosity is:
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness"
but I'm not sure if that related to Friction coefficient. This doubt came to me after noting that I was able to find literally just 1 fluid with matching viscosity in Exxon and nothing in dupont, which doesn't makes sense, some company as big as DuPont surely have a solution targeting whatever application OKS-477 is aimed for. So for now I know that NLGI (consistensy) is important, Penetration and viscosity migh be really relevant, viscosity and base oil are important to determine if you can mix two lubricants. If anyone is 100% sure of what property is most important for "friction coefficient" it would be highly appreciated.
The only PAO based solutions that get closer to the Viscosity of OKS-477 make no mention of the NLGI grade so we have no idea if they're too thin to be mixed with Nyogel and I didn't find them any non-bulk way to buy them, by the way the formulas that match OKS-477 viscosity and base oil are
Synfluid® mPAO 150 cSt from Chevron and
SpectraSyn Elite 150 cst from Exxonmobil (they are probably the same thing).
All inputs are welcomed
Let me say that your post was such a refreshing change. Finally someone that actually cares about this and wants to do actual research. You can be sure that I will help you as much as I can.
Now about the PAO greases: some weeks ago, I too, had contacted via email several US chemical companies including chemco and chevron IIRC, if they have something similar to OKS 477 (gave all of them the TDS). This was to help someone else (ZedTheMan member), that lives in the US to find something equivalent to it. But disappointingly all of them replied that they do not.
I am amazed as you are, I though that those companies could and would produce anything. However I concluded that they probably don't have a product that is mass produced with these properties, but if you go and order as industrial customer I'm sure they will produce anything you want.
Anyway, I contacted OKS and asked where someone can buy OKS 477 in the US and they pointed me to a US distributor which even gave me an oficial price quote. Sadly, they take orders of 10 items or more, so despite not being terribly expensive (I am looking at you NG 744VH), it is prohibitive for one person. ZedTheMan that wants to get hold of one, said that he would look around if there is interest to make a group buy. Maybe you should get in touch with him and maybe others and put this in motion? Apart from that, I am willing to actually send you a small quantity (no charge of course) via mail if you want to try it.
Apart from that, here is what I know so far: Viscosity of the base oil is by far the most important factor for lubricants which makes a lube to actually lubricate and work or not. This is what every tribology article that I read, have stated and emphasized. Next comes the Thickener (for greases) and its properties, like its penetration (that which NLGI refers to as consistency). The thickener acts as a sponge, holding the oil inside it and when it gets pressured, it releases it and then it reabsorbs it. It also plays a role in how well the grease will stay put on the surfaces, under various conditions and that it will not deteriorate with time (oil separation) and, as with the base oil itself, how compatible it is with the surfaces (e.g., it is plastics safe, or corossion preventing, or low electrical resistance etc).
But the number one thing that is needed to get right first, is the viscosity of the base oil. It must be viscous enough for the use case at hand, that will keep the sliding/rolling surfaces from ever touching eachother.
The whole point of lubrication is these two things:
1. keep the surfaces from
ever getting in contact at all times
2. have those surfaces slide
on the base oil, as fast and as effortlessly as possible (to minimize energy and maximize output)
So for the #1, the oil
must, as it is released from the thickener, gets in between the surfaces and fills in all their microasperities, forming a thin film that separates completely the two surfaces and prevent them from ever getting in contact, at all times. For if the surfaces do get in contact at any point, then horrible friction between them occurs, and they slow down, wasting energy and lowering their output. And on top of that, they actually scratch each other and that deteriorates them in time, in many ways.
Now what causes the surfaces to get in contact? The Load applied to them, i.e., the pressure they get from either gravity or from something else, that pushes them together. In some use cases a very light viscosity oil would be enough, because they may have almost no load between the surfaces, so it suffices to use a base oil, being just enough lightly viscous that will keep the surfaces separate while they slide
on the oil as fast as possible.
On other cases though, the Load could be very high, e.g., big heavy crates sliding on a floor, so a "light" oil will not be able to stay between them and will spread and just drop out. So for these, the oil must be much more viscous, which means stronger, heavier and more difficult to penetrate and spread apart. So as the load goes up, the higher the viscosity of the oil is must be.
The rest of the properties are secondary and complimentary at best, they are there for other reasons, besides the actual lubrication job. They are there to prevent for instance, the corrossion or oxidation of the surfaces in time, or to make the thickener stay put better under specific conditions (humidity, temperature etc), and for other reasons, "unrelated" to the main function of the lubricant itself.
About the Coefficient of Friction that you mention, yes it is important, however not anywhere near as important as the #1 thing above. It is related to the #2 actually. The CoF just gives you a ballpark number, of how much effort and energy it will take to move around (slide) the surfaces, (0.1 CoF simply means, that it will take about 10% of the Load/weight, in push force to make them move and slide, 0.2 takes about 20% and so on). However, this is important after the #1 is fulfilled, because if #1 is not fulfilled, then it doesn't matter what ever CoF the lube is rated at, the lube will simply not work and the surfaces will touch and rub each other, sending the CoF right down the drain.
What I am trying to say here, is that the CoF is not as relevant for switches as you might think it is. You can control the force of the switch just by the spring used, you don't really care if the CoF of the lube is 0.1 or 0.01, all you want is to to make the switch have a particular pressing force e.g., 50g. So a lube with 0.1 CoF, will just need a
stronger lighter spring, where a lube with 0.01 will need a
lighter stronger spring (updated because I got those two backwards). It's not a big deal, you can't make it work as intended using these other methods.
These are the basics that I know of. I too would like a real tribologist to come and give us his or her input, but as far as I know, those fundamentals are the consensus of all and no one doubts them. It is all the secondary stuff that makes tribology so complicated, but we can almost ignore most of them once we have the basics nailed down.
my two cents and sorry for making this last fuzz.
to restore alps to its original greatness. 
