New MK3s incoming! Some questions
Hi all,
In a few days i will receive my Mk3s kit (my first 3d printer) and i am glad to finally become part of the users' community (a community that has helped me a lot since last year, with answers to all of my questions that led me to buying the Mk3s, many thanks again!).
I was wondering if i should get any special grease added to bearings etc prior to assembly or if they are good to go from the box. Lithium grease perhaps? I am asking this since if i am not mistaken, sometime ago, i have read a few threads on this and i am a bit on the fence on what i should do.
For the assembly itself, i ll consult the online manual and the related comments. If i am not mistaken based on some comments, i must pay attention to the squareness of the x-y plane, and sequential tightening of the assembly's corners (the general concept if i got it right).
Hopefully i wont have to ask questions on the assembly (given how well written the manual is).
Any specific areas/points i should be aware of as a new user, apart from what the manual says? (I have been reading this forum for more than a year, covering many aspects, i am just trying to double check if i missed something, which can happen, as one enthusiastically awaits for the new printer 🙂 ).
Thank you very much for your time and replies
RE: New MK3s incoming! Some questions
Squaring the frame was the one place in the build where I had issues. I probably disassembled and reassembled the frame a half-dozen times or more before I got it to the point where I felt it was "close enough". Actually wore out the heads on a couple of the screws I did it so many times. Hopefully yours will go smoother, and there are some tips in the comments in the online manual to deal with issues if you do run into them. In my experience the kit was fun to build, and the manual is indeed excellent.
Greasing the bearings was something I wasn't aware of when I built my kit. If I had it to do over again, I would have done so. There is a thread over in the "user modifications" section where people are discussing the right type of grease to use. Might be worth a visit if you are considering greasing the bearings.
Scott
RE: New MK3s incoming! Some questions
I think mixing lubricants in the bearings is frowned upon. I'd build the kit as is. (Online guide & read the comments is recommended). A few months down the road you can do maintenance and clean the bearings and re-grease them (there's a "Super Lube" header you can print specially for LM8UU bearings and instructions are here)
RE: New MK3s incoming! Some questions
Gerry and Scott many thanks.
I will pay attention to the x-y plane construction.
As for the bearings, ok i will build as is, and follow the instructions in the link provided, to clean/lubricate the bearings during the first maintenance.
RE: New MK3s incoming! Some questions
Just a quick follow-up, i did read about the light oil that the bearings have from the factory. Can't i add more of this? I got some light machine oil (for model railroads , motorized models etc.).
RE: New MK3s incoming! Some questions
I think mixing lubricants in the bearings is frowned upon. I'd build the kit as is. (Online guide & read the comments is recommended). A few months down the road you can do maintenance and clean the bearings and re-grease them (there's a "Super Lube" header you can print specially for LM8UU bearings and instructions are here)
You're right that mixing random greases is not a good idea and may have unintended effects, like clogging the bearing.
However ...
The preservation oil that bearings are shipped in is a mineral oil and is designed to be compatible with mineral oil based greases. If a lithium soap mineral oil grease is used, the oil doesn't require removing. Even SuperLube, despite being synthetic is, according to the manufacturer, compatible with mineral oils and specified not to require washing the mineral oil out before applying.
RE: New MK3s incoming! Some questions
So, the WD40 lithium grease i suppose is fine to be added to the bearings before 1st installation (during assembly), without the need to de-grease the bearings from the factory oil?
RE: New MK3s incoming! Some questions
If you're referring to the WD-40 Specialist Protective White Lithium Grease, then that's totally inappropriate for any kind of ball bearings. After the petroleum solvent evaporates, it creates a thick super viscous film of basically pure lithium soap. It'd freeze the balls in the bearings in place.
RE: New MK3s incoming! Some questions
I am glad that i asked beforehand. Does the same apply with all similar grease/lubricants in spray form? I also saw one by Bison and a few from Wurth.
What i have available in my workbench is light machine oil (for model railroad gears/bearings etc...by Faller) and some sort of grease made by Viessmann (model railroad company).
RE: New MK3s incoming! Some questions
I am glad that i asked beforehand. Does the same apply with all similar grease/lubricants in spray form? I also saw one by Bison and a few from Wurth.
All the "White Lithium Grease" lubricants have this problem. Once they dry, they are butter-like, not liquid at all. There are other types, primarily sold as penetrants, but also marketed for lubrication, like WD-40 classic which have the opposite problem - they're too light and displace any old oils and evaporate soon, leaving the bearings entirely dry. Then there are silicone oils/greases in spray and those aren't great either. They tend to accumulate dust and get sticky.
In general, spray-on lubricants are better to be avoided for bearing greasing.
What i have available in my workbench is light machine oil (for model railroad gears/bearings etc...by Faller) and some sort of grease made by Viessmann (model railroad company).
You will not do wrong with light machine oil. But it'll not be a huge improvement compared to the conservation oil the bearings come soaked in. Oil is what delivers the lubrication in greases, the main issue with it is that it needs to be replenished regularly as it easily seeps out without the thickening agent in the grease.
I couldn't find the specs on the Viessmann 6857, it looks like it could be OK, but the manufacturer says 'high viscosity', which wouldn't be great. As greases go, the bearings need an easy flowing, low-viscosity one.
RE: New MK3s incoming! Some questions
Hm, i guess the Faller oil is the safe bet. The only grease i could find locally by checking shops online are one by an italian brand (saratoga) and one French (Facom), lithium (not spray) . The Italian one mentions it is specifically for bearings (high speed applications, NLGI class 2). The Viessmann oil (you got the number right), has no specs on the label, consistency-wise i would say possibly NLGI 1 to 2. It does not move if i tilt the contained upside/down.
RE: New MK3s incoming! Some questions
You can use a NLGI 1-2 lithium grease if you're careful and after greasing make sure that there isn't too much of it and that each of the rows of balls in the bearing is still able to roll properly when on a rod. NLGI 0 or less is better, but not easy to buy.
But the oil is indeed the safe choice.
RE: New MK3s incoming! Some questions
What I used on my bearings during my first PM tear-down (I was also applying the MK3S mod at the same time) is Superlube silicone grease with PTFE (Amazon link only for reference, not an affiliate link). I soaked my X and Y bearings (couldn't get the Z bearings out) in 90% IPA with occasional shaking to try to remove the original oil. After they dried I used this nozzle from Thingiverse to pack the grease into the bearings (lining up the rows of ball bearings with the openings of the nozzle and squeezing until some grease leaked out the end). I packed the Z bearings in situ, hopefully if the grease and the oil aren't compatible, the light load those bearing get won't cause an issue. Before this I was getting black residue on my lower X axis rod, no residue after the PM.
I can't say if I did the "right" thing for my machine, but it hasn't seized up on me yet... (Fingers crossed)
See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs
RE: New MK3s incoming! Some questions
Thank you for the info/help. I ll check the bearings movement during installation and add machine oil or the light grease that i got.