Does rail grease type actually matter?

[RhyminGarFunkle]

Obviously lubrication is important, but is it really crucial to use a specific formulation? Everywhere I've looked says to use white lithium grease for the linear rails, but I've never actually seen anyone explain why that in particular over other kinds of grease.

I'm getting ready to build my first Voron, and my inclination is just to use the same stuff I use on motorcycle bearings and axles, Bel-Ray waterproof grease - if it's good enough for thousands of miles at 60+ MPH, surely it's good enough for the 1-3 MPH my printer rails will be moving at? I've considered that grease made for parts that move at 65+ MPH might be too thick for the much slower printer parts, but I use the same grease on the triple-tree bearings (where the front fork and handlebars meet the frame of the bike) which move much more slowly and in a limited range, and it works great there too.

Is there a reason for white lithium grease specifically, or is that just kind of what everyone says to use because if you say, "Most anything will work" someone will end up slathering their rails in Crisco?

 

[fionoz]

Don't slather your rails in anything PLEASE. There are way too many factors to consider.
I wouldn't recommend white lithium grease either.

Just buy some ep2. It's pretty cheap.

If you can't get that, or have some really cheap rails that you just want to get working, use white lithium.

 

[RhyminGarFunkle]

Okay, buy why EP 2? Why not lithium or aluminum/barium complex grease (like the Bel-Ray I brought up)? What makes one type of grease best for this particular application, and other types completely unsuitable?

 

[NoGuru]

Okay, buy why EP 2? Why not lithium or aluminum/barium complex grease (like the Bel-Ray I brought up)? What makes one type of grease best for this particular application, and other types completely unsuitable?

It's simple. It comes down to what is required from the parts and motion system.

Would you put 0W-30 in your motor cycle? Probably not since that is intended for colder temps. So some Grease is better at doing a certain job better then others.

So the EP2 is recommend based on longevity, viscosity, and chemical resistance. Sure you can use other grease but you might have to re-apply it more often.

 

[RhyminGarFunkle]

So the EP2 is recommend based on longevity, viscosity, and chemical resistance. Sure you can use other grease but you might have to re-apply it more often.

That's what I'm asking, what about those properties make it a good choice? For example, many (seemingly) knowledgeable people recommend oiling rails instead of greasing them, because with thick grease the balls can't roll across the rails, so they instead slide which increases friction and wear over time. The downside of oiling is that it definitely needs to be reapplied more frequently. When I compare the data sheets of the EP2 to the Bel-Ray, one of the few major differences is the Bel-Ray is significantly less viscous (but still plenty thick to stay in place). Wouldn't this decreased viscosity be a plus, allowing for easier rolling without needing be reapplied as frequently as oil? Why or why not?

I'm not trying to be difficult about this, and I'm certainly not trying to say, "My grease is a better choice than what everyone else has successfully used for years." But all of the info I see about grease selection - including in this thread - basically comes down to, "Use this because it works well." I want to know why it works well, and why alternatives work less well.

 

[Dave]

There are a ton of opinions on grease, and most of them are just opinions. We have lots of data that EP2 works well in printers with lower chamber temps, but we also know that if you get above about 60 degrees C, then EP2 will fail prematurely. One of the Voron Crew members who runs a print farm is evaluating higher temp greases so that we can make a better recommendations. I’m currently testing Valvoline Cerulean, and others are looking at Mobilith high temp formulations. I still want to test out Red and Tacky in a hot chamber, but haven't yet.

What you want to avoid is greases with solid additives like molybdenum disulfide or Teflon. Will they work? Sure! But they aren’t optimized for use with bearings. You want an Extreme Pressure (EP) grease for that. Plus, the solids aren’t great for many bearings. They are really intended for sliding, not rolling interfaces.

In general, any EP2 grease will work for most printers. We recommend the mobilux just because it’s available and because we know it works. It’s DEFINITELY NOT optimized for higher temps, and I can personally verify that it fails prematurely with 70 C chamber temps. So, do you need to panic? Not really. Just lube and clean more often. For a legacy, Mobilux EP2 will work perfectly for a long time. For a Doom Cube running at 75 C, it will fail at the Tap after a few dozen hours (if you are running Tap).

So, what about a recommendation? I can say is that the Valvoline Cerulean grease has been pretty good for me for a few dozen hours with no problems yet. It’s about $8 for a full sized tube, so the cost is pretty cheap. The Mobilith is a synthetic that will probably hold up at high temp better. The Mobilith is probably a better bet, but is a whopping $20 for a giant tube. (So expensive!!! ) We (Voron Crew) may be making a change to the official recommendation at some point, but for now, we still recommend Mobilux EP2 for most printers with chamber temps below 60 C.

 

[Yaaj]

I use Kluber NBU15 because I have some left after a milling machine spindle rebuild. Barium soap, synthetic, low viscosity. Max temp 130°C, dropping point 220°C. Very easy to apply with a syringe.
Probably overkill. IIRC it was hyped for printer leadscrews like 5-10 years ago, and was available from eBay in Europe at this time (50g tubes).
I wouldn't use a waterproof grease. They tend to be extremely sticky.

 

[vinnycordeiro]

There are a ton of opinions on grease, and most of them are just opinions. We have lots of data that EP2 works well in printers with lower chamber temps, but we also know that if you get above about 60 degrees C, then EP2 will fail prematurely. One of the Voron Crew members who runs a print farm is evaluating higher temp greases so that we can make a better recommendations. I’m currently testing Valvoline Cerulean, and others are looking at Mobilith high temp formulations. I still want to test out Red and Tacky in a hot chamber, but haven't yet.

What you want to avoid is greases with solid additives like molybdenum disulfide or Teflon. Will they work? Sure! But they aren’t optimized for use with bearings. You want an Extreme Pressure (EP) grease for that. Plus, the solids aren’t great for many bearings. They are really intended for sliding, not rolling interfaces.

In general, any EP2 grease will work for most printers. We recommend the mobilux just because it’s available and because we know it works. It’s DEFINITELY NOT optimized for higher temps, and I can personally verify that it fails prematurely with 70 C chamber temps. So, do you need to panic? Not really. Just lube and clean more often. For a legacy, Mobilux EP2 will work perfectly for a long time. For a Doom Cube running at 75 C, it will fail at the Tap after a few dozen hours (if you are running Tap).

So, what about a recommendation? I can say is that the Valvoline Cerulean grease has been pretty good for me for a few dozen hours with no problems yet. It’s about $8 for a full sized tube, so the cost is pretty cheap. The Mobilith is a synthetic that will probably hold up at high temp better. The Mobilith is probably a better bet, but is a whopping $20 for a giant tube. (So expensive!!! ) We (Voron Crew) may be making a change to the official recommendation at some point, but for now, we still recommend Mobilux EP2 for most printers with chamber temps below 60 C.

Also, if we consider Hiwin's recommendations for lubrication, as seen on page 10 of their linear guideway catalog, they recommend:

Linear guideway must be lubricated with the lithium soap based grease before installation. After the linear guideway is installed, we recommend that the guideway be re-lubricated every 100 km. It is possible to carry out the lubrication through the grease nipple. Generally, grease is applied for speeds that do not exceed 60 m/min faster speeds will require high-viscosity oil as a lubricant.
(...)
The recommended viscosity of oil is about 30~150cSt. The standard grease nipple may be replaced by an oil piping joint for oil lubrication. Since oil evaporates quicker than grease, the recommended oil feed rate is approximate 0.3cm3/hr.

 

[3dCase]

As long as I have been a professional machine builder, designer and maintenance engineer, this exact question has never failed to divide the audience to the maximum level. It is virtually the same as starting political or religious conversations on social media.
First thing is, you are lubricating, that is always better then not lubricating. Yes maybe not the ideal stuff but that is not always instantly fatal.
Second question should be "do I need to improve how I lubricate?" And this depends on the situation and what you use right now.
We can talk long and short about these things, but one statement remains always true. If you stick to the manufacturers guidelines you will not need to worry about any warranty implications.
For all else, one simply needs to follow some best practices, and to do those correctly, you need to know about the basics of lubrication. One such is explained in this blog (not affiliated).

The Basics of Industrial Lubricant Selection

There are several factors to consider when selecting the right industrial lubricant. A manufacturer’s recommendation is a great starting point, but it doesn’t have to be the only option. Most manuals are written for ideal conditions, but these guidelines don’t address the real environment in...

blog.chesterton.com

I know their examples are not 3d printers but the principles of lubrication are the same. Read this and I hope it helps you to understand the criteria used for correct lubrication choice and all the other related things such as frequency and quantity.
In the mean time keep doing what you do and keep it clean as well. Those two things will prove a massive boon for the performance of your moving things. Just stay away from obviously wrong things like abrasive solid lubricants or utterly not fit for purpose types such as super high tack high viscosity high temperature high pressure grease for tracked vehicles for instance.

 

[garlicbread]

After stumbling across this thread myself from the UK
I'm currently trying this stuff out

TRIAX ATLAS 600 No 2 - Synthetic High Temp Grease

TRIAX ATLAS 600 Synthetic Grease is a one of a kind ultra high performance synthetic grease designed for virtually all multi-purpose and heavy duty applications in both regular and severe service. This product is built from the ground up with high viscosity base oils and top tier additive...

www.triaxlubricants.co.uk

It appears to have a similar numbers such as viscosity to the mobilux ep2 stuff but uses Calcium Sulfonate Complex instead of Lithium so has higher temperature ratings
(also it's easy to order from amazon uk)
Will see how it turns out.

 

[5twenty]

Yeah, any NLGI 2 is recommended.

"The currently recommended lube for the linear rails is Mobilux EP1 or EP2, or the NLGI equivalents."

 

[3dCase]

So, as I use linear bearings and slideways in my work as well, I get the occasional mail from the suppliers. This one is from Tuli, a shop I frequently use for motion technology such as linear bearings. In this blog they show what to do and how to do it with linear bearings. You can also check their other blogs, there is one specifically on Hiwin rails and blocks. In fact there are many nice articles on all of the stuff that is in your 3d printer. bearings, ballscrews, alluminium extrusions, corner plates, DIY laser conversions, routers and tips on how to, like safe removal of bearings, or how to repair your ball screw nut.

How to Grease Linear Bearings - Tuli experience

Want to know how to grease linear bearings? Step-by-step instructions for greasing linear bearings are available in our online shop. Visit us!

www.tuli-shop.com

 

[Ryan_M]

... The Mobilith is a synthetic that will probably hold up at high temp better. The Mobilith is probably a better bet, but is a whopping $20 for a giant tube. (So expensive!!! ) We (Voron Crew) may be making a change to the official recommendation at some point, but for now, we still recommend Mobilux EP2 for most printers with chamber temps below 60 C.

For what I can get easily/locally, the greases you mention are close enough in price to not care. Since I'll probably be on the warmer side I may as well go for the Mobilith but there are multiple SHC # options. Looking at the descriptions it seems SHC 220 would be best, can you confirm?

 

[3dCase]

For what I can get easily/locally, the greases you mention are close enough in price to not care. Since I'll probably be on the warmer side I may as well go for the Mobilith but there are multiple SHC # options. Looking at the descriptions it seems SHC 220 would be best, can you confirm?

Voron is not the producer of the rails. They may have recomendations but the producer will have the final say with regards to what they want you to use. My advise is to look on the producer of rails, Hiwin or equivalent, and see what they say you should use. Then look up equivalent tables of greases to see what you can source locally does or does not comply.
We can talk about lubrication until the cows come home, and unfortunately it always seems to go this way, but its not rocket science.
Follow the manufacturers recommendation( that is not voron), and follow common sense.
Every grease type will be mentioned in equivalent tables so that is where you will find your answers.

 

[5twenty]

After stumbling across this thread myself from the UK
I'm currently trying this stuff out

TRIAX ATLAS 600 No 2 - Synthetic High Temp Grease

TRIAX ATLAS 600 Synthetic Grease is a one of a kind ultra high performance synthetic grease designed for virtually all multi-purpose and heavy duty applications in both regular and severe service. This product is built from the ground up with high viscosity base oils and top tier additive...

www.triaxlubricants.co.uk

It appears to have a similar numbers such as viscosity to the mobilux ep2 stuff but uses Calcium Sulfonate Complex instead of Lithium so has higher temperature ratings
(also it's easy to order from amazon uk)
Will see how it turns out.

I bought some of this, as it seems too cheap not to try, at least.

Will be using it on my next build to test it out, or when I put back together my first 2.4 that I took apart to fix the snapped wires.

 

[YAOG]

Obviously lubrication is important, but is it really crucial to use a specific formulation? Everywhere I've looked says to use white lithium grease for the linear rails, but I've never actually seen anyone explain why that in particular over other kinds of grease.

I'm getting ready to build my first Voron, and my inclination is just to use the same stuff I use on motorcycle bearings and axles, Bel-Ray waterproof grease - if it's good enough for thousands of miles at 60+ MPH, surely it's good enough for the 1-3 MPH my printer rails will be moving at? I've considered that grease made for parts that move at 65+ MPH might be too thick for the much slower printer parts, but I use the same grease on the triple-tree bearings (where the front fork and handlebars meet the frame of the bike) which move much more slowly and in a limited range, and it works great there too.

Is there a reason for white lithium grease specifically, or is that just kind of what everyone says to use because if you say, "Most anything will work" someone will end up slathering their rails in Crisco?

I can't comment on white lithium grease for linear rails from personal experience but as a grease for precision equipment over the years it has proven to be a poor lubricant for precision instruments unless it is cleaned and replaced often. White lithium grease has only a few things going for it, it is cheap, easy to fine and technically it is lubricant. But you know the old saying you get what you pay for?

For a temperature and wear demanding grease look for a pure synthetic base oil grease with moderate to EP rating with an NLGI-1 to 0 and a microscopic pressure additive. The thinner the grease the better it will work up to a point. Lower thickness greases tends to need to be cleared and replaced sooner than slightly thicker grease due to migration and contamination. Look for grease that is not going to drip, melt off of fling off yet stays soft enough to lubricate before the equipment is powered up. Pass on silicone based greases which are great for most rubber and plastic O-rings (other than silicone) as most are not great lubes under pressure and it is impossible to clean a silicone contaminated part.

In truth there is nothing really wrong with white lithium grease or even Crisco as long as you keep up with a very frequent rigorous cleaning and relubing schedule. But you will go through a lot of TIME, solvent, towels and grease. But at least white lithium grease or Crisco is cheap.