Question about lubricants for linear rail.  

RE: Question about lubricants for linear rail.

Subscribing because the called-for lubricant isn't available from Prusa right now.

RE: Question about lubricants for linear rail.

Linear rail should be lubricated with Microlube GL 261. It's sold by many shops.

According to maintenance guide the linear rail should be lubricated every 3-6 months. So it makes sense to buy the correct lubricant for that purpose.

RE: Question about lubricants for linear rail.

I wouldn't use it. The linear rail is one of the main moving parts with massive accelerations and speeds and quite some pressure.

The Klüber GL-261 is quite an expensive, special grease for extreme cases.
Using some other grease/oil bears the risk of the additives reacting and clogging, resolving etc.

In theory, any "extreme speeds+pressure" specialized Lithium Soap, mineral oil based grease would be fine, but I wouldn't risk it.
Annoyingly, you can only buy the 40 g version of the Klüber grease and Prusa sells the 20 g version, which would be sufficient and not as expensive.

Anyway, I'd ask the Prusa Support or buy the Klüber grease somewhere else.

"Similar" greases are often about 10€ for 400 g and I doubt that they have the same quality/specifications at 1/10th of the price.
But if you want to risk it, I'd recommend to buy some premium Lithium soap, mineral oil based grease and a syringe.

RE: Question about lubricants for linear rail.

I'm mostly asking to know if what i have is the same thing, seeing as when i was assembling the core one, the residue on the rail felt like the singer machine oil (can also be used on guns).

If the things i have are not suitable, of course i'll be getting a new lubricant.

RE: Question about lubricants for linear rail.

I was wondering myself, why the lubrication set is grease, but the residue the manual tells you to wipe off seems to be oil...

I wouldn't put anything on the rail, that doesn't list "Lithium soap, mineral oil based grease". Your oil sounds great, but I can't find specifications.

Same for the other stuff, you listed. I really dislike, when manufacturers don't list this kind of information and it basically comes down to "Our stuff is great, trust me bro". 

Off-topic, but maybe helpful overall: the absolute best grease I've ever came across, is Liqui Moly "Winch Grease". NOT the "boat grease".

The Winch Grease is a Calcium based grease, which is mechanically as good as Lithium soap grease, but isn't aggressive to rubber, plastic etc. and it has PTFE additives as backup dry-lubrication. It's for fast movements and high pressure. And it's white and won't look nasty over time. 

Only downside is that it's kinda expensive and that it separates very slightly at the opening of the tube. Basically you get the grease and a little drop of oil, that you have to mix back in or wipe off. 

In my experience, it doesn't after applying it. I've used it for everything over the last 3 years (doors, simracing pedals, bike parts, locks etc). Greased things once, never had to do again.

I don't know, why Liqui Moly isn't promoting it with a better selling name. From what I've read from engineers and experienced myself, it's advanced premium grease for basically everything. A Winch at sea gets tortured. What works for it, works for almost everything. 

I'm just not sure if it's a good idea to mix it with the stuff already on the linear rail.. But my rail is doing some "bubbling" sounds that I'm not confident to put off as "normal", so I might test the Winch Grease. 

RE: Question about lubricants for linear rail.

Posted by: @george-4

I'm mostly asking to know if what i have is the same thing, seeing as when i was assembling the core one, the residue on the rail felt like the singer machine oil (can also be used on guns).

You need to use grease, not oil. The oil that was on the rail when shipped was for corrosion protection during storage and shipping, and should be wiped off (as per the assembly instructions).

The fact that the standard grease included with the kit should not be used is not due to its consistency, I believe, but due to the fact that it does not play nice with some plastic parts in the THK bearings.

RE:

Thanks Jürgen, I forgot about the corrosion protection oil. Makes sense, ofc.

Also: Please ignore what I said about maybe using the Winch Grease for the linear rail. Yes, it's superb grease, but it's quite thick and sticky. Perfect for doors, pedals etc., but not for small ball bearings. You also, apparently, don't want PTFE "pieces" in a small ball bearing. It's more for sliding connections. It would probably be great for the Z-leadscrews. 

Anyway, I've just ordered a 40 g tube Klüber GL-261 at "Pneumatik Shop24" for 21€ and will report back about viscosity etc., compared to the Y-bearing Prusa grease.

One thing I didn't check, but stumbled upon during further research: the Klüber grease is specified for up to 130°C, the EP-2 grease, recommended by Voron (not sure if still is), doesn't like to work above 60°C.

The Core One probably isn't used much at higher chamber temps than that, but it's nice to know, that the lubricant of the linear rail could take 130°C without issues.

I'm curious about what's the Prusa grease.. Since I've got 40 g of the Klüber, I'm tempted to use it for the Y-bearings and see, if they become quieter. 

RE: Question about lubricants for linear rail.

Grease? ah. I don't suppose superlube is appropriate either though. It's PTFE based. I'm trying to see my options as prusa is out of the appropriate lube, and amazon won't ship it here.

RE: Question about lubricants for linear rail.

Posted by: @george-4

Grease? ah. I don't suppose superlube is appropriate either though. It's PTFE based. I'm trying to see my options as prusa is out of the appropriate lube, and amazon won't ship it here.

Where are you living? Maybe Prusa Support can tell you an alternative?

About grease vs. oil:
Viscosity at 100°C:
Klüber GL261 = 20 mm²/s
SAE 5W-30 engine oil = 9-12.5 mm²/s

Viscosity at 40°C:
Klüber GL261 = 290 mm²/s
LM Winch Grease = 380 mm²/s

Seems like the Klüber grease for the linear rail is some form of slightly liquid grease.
ChatGPT and Google are no real help to find an alternative, I tried..

RE: Question about lubricants for linear rail.

i'm in cyprus. And i just checked again, it seems that its just amazon.com that doesn't ship. amazon.de says that it delivers to my place, but it doesn't show the Klüber GL261.

When i put MICROLUBE GL 261 in amazon.de, the superlube that i have pops up, along with liqui moly that you mentioned earlier.

RE: Question about lubricants for linear rail.

Do you know any shops, for which it's "normal business" to ship to Cyprus without high shipping costs? 

From what I've read in one of the Voron threads, you "just" need an anti-corrosion, semi-high-pressure, non-anti-water, low viscosity grease. And it should be ptfe free, silicone free and temperature rated to 120°C+.

To mix well with the Klüber GL-261, Lithium soap, mineral oil might be preferred, but in theory, full synthetic, calcium soap grease might be better.

Mobilux EP2 has all that, but isn't great at above 60°C. Finding the right grease (alternative) is  real pain..

I would google for alternatives to the EP2 grease, try to find a shop that ships to you without paying a lot extra and then look for data sheets. 

RE: Question about lubricants for linear rail.

Found a premium grease, that seems better on paper and might be easier to get for you:

https://www.triaxlubricants.com/products/triax-atlas-600-grease-full-synthetic?variant=43803289714863

At 40°C, it's 180 vs the 290 of the Klüber GL-261 and at 100°C it's 19.6 vs the 20 of the Klüber. So quite close overall, but thinner at PLA temperatures. Datasheet says it's working up to over 200°C, so not issues at maximum Core One chamber temperature.

Synthetic Calcium grease and has the same NLGI-2 class, as the EB2 grease recommended by Voron. 

RE:

For what it's worth, another post from me, sorry.. If anyone has more knowledge, please correct me!

After another hour of research (I was curious to learn about this and my linear rail is doing some "clicking noise"):

1. Normally, linear rails are lubricated with massively thinner grease, almost oil-like or even oil. The balls in the bearings are quite small, so a normal, thicker grease will seem to make it very smooth, but in reality, the balls will be sliding, instead of rolling, leading to lot of different issues, long term.
   Also, to not make them just slide around, it's important to have a consistent, slight friction. So no PTFE additives.
2. HIWIN, another linear rail manufacturer that's used for Vorons etc. has its own greases. The high speed grease "hiwin G04" has a viscosity of just 25 cSt (mm²/s) at 40°C, compared to the 290 mm²/s of the Klüber GL-261.
3. The THK greases are Lithium or Urea based. I hope there's THK Lithium-based grease in the pre-greased and pre-assembled linear rails, that we get from Prusa. Otherwise, selling the Lithium-based Klüber grease wouldn't be great, since you shouldn't really mix Urea-based grease with Lithium-bases greases. Anyway, the Lithium-based THK greases have viscosities of 100 and 170 cSt at 40°C. The "better" Urea-based greases are more like 25 cSt at 40°C.
4. ChatGPT, not as a reliable information, but it, suggests a range of 30-60 cSt at 40°C for the 20-600 mm/s, that I gave it, which makes sense, when looking at other greases for linear rails or high-speed leadscrews.
5. The clicking noise is NORMAL. The XL rails do it too. The Core One rails might not do it from the get go, because Prusa uses too thick grease and the balls won't roll at first. I'm wondering, why the support is telling people to grease their X-axis', when getting told about the little clicking noises.
6. We shouldn't need to lubricate the linear rails for at least 200 km. My printer states 31.7 km at 12 days, 20 hours of printing time. So since the clicking noise is normal and I'm far away from needing to lubricate, I won't buy any grease soon.

So I just cancelled my order for the Klüber grease and won't lubricate my linear rail for a few months.

But when I'll do it, I definitely won't buy the Prusa lubrication set. Instead, I'll take out the linear rail, clean it and put some better suited grease in it.

I'm really wondering about the Klüber grease... The Core One has quite some issues, so I don't know how much I can trust the official lubrication set or should research for a better grease.
290 mm²/s at 40°C for the Klüber GL-261 seems like quite a bad choice. It's not like the Nextruder weights 15 kg.. And I mostly just have 25-30°C chamber temperature.

Alternatives:
- SKF LGHP 2: Mineral oil, Urea thickener, NLGI 2-3, -40° to +150°C, viscosity 10.5-96 mm²/s (100° and 40°C), smallest package about 20€ /400 g.

- Klüber Isoflex Topas NCA 52: Synthetic oil, Calcium thickener, no NLGI, but the datasheet mentions high pressure and linear rails. -50° to 130°C, viscosity 5.9-31 mm²/s, about 15€/50 g.

- Hiwin G04: organic Ester oil, Lithium thickener, NLGI 2, -35 to 120°C, viscosity at 40°C = 25 cSt, about 15€/11.5 g.

- THK AFA/AFG: Synthetic oil, Urea thickener, no NLGI, but THK only produces linear rails etc. and the datasheet mentiones linear rails, so should be fine. -45° to 160°C, viscosity at 40°C = 25 mm²/s, about 25€/70 g (or 17€ from AliExpress, since THK sits in Tokyo).

- NSK LR3: Synthetic oil, Lithium thickener, no NLGI, but for medium loads and high speeds. -30 to 130°C, viscosity at 40°C = 29 mm²/s, about 15€ from AliExpress.

RE: Question about lubricants for linear rail.

I was able to find this one in amazon.de and it ships here!

Posted by: @raaz-2

Found a premium grease, that seems better on paper and might be easier to get for you:

https://www.triaxlubricants.com/products/triax-atlas-600-grease-full-synthetic?variant=43803289714863

At 40°C, it's 180 vs the 290 of the Klüber GL-261 and at 100°C it's 19.6 vs the 20 of the Klüber. So quite close overall, but thinner at PLA temperatures. Datasheet says it's working up to over 200°C, so not issues at maximum Core One chamber temperature.

Synthetic Calcium grease and has the same NLGI-2 class, as the EB2 grease recommended by Voron. 

RE: Question about lubricants for linear rail.

I was able to find this one in amazon.de and it ships here!

Nice! And definitely an "okay" grease, compared to what Prusa sells. But maybe check, if you could easily buy one of the greases from my last post. They should be better. 

Just to be sure: do you actually need to lubricate the rail? If your print statistics doesn't show 200+ km for the X-Axis, you really shouldn't need it. The clicking is normal, louder squealing/grinding/etc. is not, of course. 

RE:

Another grease: i use it for rods and also my bearings.  Kärcher 6.964-092.0 Fett, flüssig, 50 ml  . its -40 - 180 °  celsius and. its viskosity is quite high. so more like "thick oil"

When i swapped my bearings on the mk4, i tried different greases/options (Dry, WD40,Prusa, Superlube and Kärcher)

 I have the feeling, that the balls in the bearings , packed with the prusa grease, have no chance to roll and rotate. 

(dry or wd40 was best, but noisy 🙂 )   Superlube was better but still too thick for my taste.

So i went for the "Kärcher-Lube the Last 3years.

I will see, how it compares to the Klüber-lube.  (conversion kit arrives satturday 👍 )

RE: Question about lubricants for linear rail.

I don't need it now, i just wanted to be ready, i'm only halfway. I just got in the lubrication rabbit hole 😆 

Posted by: @raaz-2

I was able to find this one in amazon.de and it ships here!

Nice! And definitely an "okay" grease, compared to what Prusa sells. But maybe check, if you could easily buy one of the greases from my last post. They should be better. 

Just to be sure: do you actually need to lubricate the rail? If your print statistics doesn't show 200+ km for the X-Axis, you really shouldn't need it. The clicking is normal, louder squealing/grinding/etc. is not, of course. 

RE:

Posted by: @raaz-2

For what it's worth, another post from me, sorry.. If anyone has more knowledge, please correct me!

After another hour of research (I was curious to learn about this and my linear rail is doing some "clicking noise"):

1. The clicking noise is NORMAL. The XL rails do it too. The Core One rails might not do it from the get go, because Prusa uses too thick grease and the balls won't roll at first. I'm wondering, why the support is telling people to grease their X-axis', when getting told about the little clicking noises.

 

Nice to hear that the clicking is somewhat normal. It started bothering me since I only noticed it after support chat suggested I use the supplied Prusa lubrication on the linear rail in an attempt to try to reduce loud resonance noise. In my mind my rail sounds worse now (including the clicking) but I'm also trying to convince myself that the edges are covered with some type of "guard" to stop dirt from accumulating in the housing, and simply pushed the grease away - rather than going inside.

RE: Question about lubricants for linear rail.

Another grease: i use it for rods and also my bearings.  Kärcher 6.964-092.0 Fett, flüssig, 50 ml  . its -40 - 180 °  celsius and. its viskosity is quite high. so more like "thick oil"

I've found out, that it's also sold as "Thermoplex ALN VP 2", for which I could find the datasheet.
It's from "LUBCON" and the specs are:
Synthetic oil, Urea thickener, NLGI 00, but Lubcon states high load compatible and especially for gearboxes, -40° to +180°C, viscosity at 40°C = 68 mm²/s, smallest package about 15€ /50 g.

Sounds like a really good and thin, but not "high-speed" kind of thin grease.
The NLGI 00 isn't great, but I really doubt, that the Core One printhead weights enough to need any high pressure specification.

About NLGI: I've found out, that the NLGI grades are just the penetration depths ranges. Apparently, you can combine a thick base oil with less thickener or a thin base oil with more thickener. Resulting in a similar consistency, but very differently behaviour around the tiny balls of a linear rail.
Apparently, the thinner the base oil, the better the grease will "flow", but might be less sticky.

Here are all greases, I've mentioned:

Kärcher/Thermoplex = 430 (mm/10), 68 cSt;

Klüber GL-261 (Prusa Lubrication Set) = 310 (mm/10), 290 cSt;

SKF LGHP 2 = 245 (mm/10), 96 cSt;
Klüber Isoflex Topas NCA 52 = 265 (mm/10), 31 cSt;
Hiwin G04 = NLGI 2 => 265 (mm/10), 25 cSt;
THK AFA/AFC = 285 (mm/10), 25 cSt;
NSK LR3 = 235 (mm/10), 29 cSt;

So although the viscosity of the Kärcher/Thermoplex seems like a good value between the 25 cSt of the Hiwin G04 and the 96 cSt of the SKF LGHP 2, it's a really thin grease without much penetration resistance.
The speeds in a pressure washer pump are probably insanely faster, than the X-axis moves of the Core One and the pump doesn't do a lot of small oscillating moves.

Temperature and viscosity seem great, but I'm not sure how well the Kärcher/Thermoplex works for the Core One.
My guess would be, that the viscosity value & high temperature combination can't provide a great penetration value (NLGI).
The Klüber GL-261 is the thickest of this list, but has the second worst penetration value, quite weird, but probably very sticky at identical consistency.

It probably doesn't matter anyway and if you have the Kärcher grease at hand, just use it. It's still in the perfect ballpark for most of it's specs!
Pretty cool grease, in any case, and widely available in Germany, so thanks for sharing.

 I have the feeling, that the balls in the bearings , packed with the prusa grease, have no chance to roll and rotate. 

I have the same feeling.. The balls in the THK linear rail don't seem much different in size, compared to the bearings of the Y-axis and the "Prusa Grease" doesn't seem thin enough, from what I read and experienced myself.
It might be good enough to prevent wear though. Or maybe the bearings and rods are just way too tough to wear out in a 3D-printer..

Since I basically only print PLA and some PETG, I think I'll get the Klüber Isoflex Topas NCA 52 and use it for the Y-bearing, Z-bearings and linear rail.
It might not be the stickiest, but viscosity and penetration are absolutely spot on for 3D-printers.