I have been doing a little research on lubricating linear rails and all I found out is it a hot mess of disinformation.
Some say oil but vary on viscosity and it doesn’t last very long requiring re-lubing which can be difficult on a 3D printer since the rail carriages are tucked away under things.
Some say grease but what kind? It does last a lot longer between lubing so that is a plus. Most seem to recommend Superlube synthetic grease with PTFE (Teflon) but every decent rail manufacturer says not to use additives including PTFE. Other go with Lithium grease. All these greases have a NLGI grade of 2 but again you are not suppose to use more then a grade 1 (lower viscosity the lower the number). NLGI grade 1 grease seems to be a real unicorn, almost non existent to us mere mortals. Thicker grease can cause problems with the movement of the balls, they jam in the grease and get dragged along instead of rolling.
There doesn’t seem to be a simple unified answer that doesn’t contravene some specification or other. Just to make things better, most grease doesn’t even list the NLGI grade on the packages or websites, finding info is a real…
Any ideas?
I dont have any useful info to add to this yet, but am just getting into linear rails for my next printer.
I opted to get some Mobilux EP2 grease for some Honey Badger rails i also purchased from Fabreeko.
Off hand i dont know the specs of this grease but i too heard about avoiding superlube and ptfe additives. I would guess the end answer is 2 parts. 1 being what is ideally recommended for longevity, and 2 what would be ideal for a 3d printer at say stock accelerations/weights/temperatures.
If i find out anything while i wait for the rest of my printer to ship ill add it here too + sources.
Since my rails are the $25 not the $400 rails maybe I need not care about it so much. I don’t know why having Teflon in grease would be so bad, others don’t seem to care. Maybe this is a good time to follow the Lemmings.
I have used both thicker and thinner greases,
For my V0 that I did I used a thinner grease which I knew would have to be checked/ re-applied more often than a thicker grease. But since the printer was moving faster (40-50k accell at 500-800mm/s) I didn’t want a thicker lubricant adding extra resistance to the rails. I ended up using some thin bike lube I had laying around because it was thick and was not harmful to plastics (which make up a solid portion of that machine).
For most of my other linear rail machines I used superlube teflon lube, I have never really had any issues with it, and I usually have to re-apply around every 8 months to a year. Seems to have done the trick so far!
Matt
How do you re-lube the rails without tearing the printer apart?
I have a big jar of Lithium grease so I may just go with that or Superlube ($$$$$) or the Permatex equivalent (slightly less $$$$$) or oil. Decisions, decisions, decisions.
Oh woe is me.
If I remember correctly, a syringe of the lubricant of choice, with a thin needle to stick into the carriage is the recommended way.
1 Like
The larger sized carriages have a port for injecting lube but the smaller ones like the MGN12 don’t.
I use super lube on mine and they have been running good for over a year now!
Usually I just spread some over the rails, try to coat all the rail except under the carriage with a thin layer. Then I write a macro to move each axis up and down at a decently rapid speed, I will usually make it move up and down around 100 times or so on each axis and by that time all the grease should have done its magic!
I ordered another set of rails for the Z axis today, might as well screw up everything all at once.
2 Likes
Personally I think cleaning the gunge is more important that what kind of lube. I use a pure 99% IPA to remove all the buildup on the rails, Then once clean I use a thin PTFE (Super lube) to coat the rails to protect them and a small dab of paste type (also super lube) to work into the bearings. I do cleaning relate every 10KG of filament. It is the easiest for me to keep track of print time. My printers are all enclosed so environmental dust is not a huge factor if it is ut in the open more often might be needed.
2 Likes
Great point, forgot to mention this! Every linear rail that I buy spends a night in the drunk tank (basin filled with isopropyl alcohol), then in the morning I scrub everything off the rails and give it a re-lubrication.
I will expand on your point a bit in case anyone comes to this thread in the future. The big reason for this is that the factories where these things are being produced overseas are not always the cleanest environment, so often times you will have metal dust or shavings etc. on the rails which can be very bad for the longevity of the rail. Bathing it in the IPA helps to get rid of all of the crap that has formed on the rails and gives you a nice clean fresh start.
And always be sure to be careful when removing the carriage off of the linear rail as you don’t want to loose the ball bearings inside the carriage. Some linear rails come with a removal tool, but you can also print one out. (something like this)
1 Like
Do you remove the carriages or clean them in place?
I bought mine, in two orders, from OUYZGIA a made up AMAZON retailer name (to avoid some Amazon rules etc.) but I am somewhat impressed considering they are not expensive slides. Out of the packaging, that was quite good, the carriage slide well, frequently they don’t, there is no noticeable wobble or shimmy on the rails, a common complaint and even under a load, my finger pressing down hard, they still slide nicely. Compared to some that frequently have bad reviews these seem OK. I will be cleaning and lubing them before use.
They do seem to be better then the usual questionable cheaper Chinese rails. Time will tell.
No I leave them. Getting them on and off you can drop bearings out I just move them out of the way. Grime at least to me it worse than anything. I don’t want to use too much as it holds dirt. I just use a light coating so it keeps rust away and a small amount to reduce friction on the bearings.
I take it on a case by case basis, if the rail looks really dirty or I see a lot of grime when washing it off I will take the carriage off, if you use the tool to do it you can usually do it safely without using ball bearings. Just take it slow and careful.
If the rail seems generally clean then there is no real point in taking the carriage off!
1 Like