Maintenance and replace? rods barrings
just wondering as i am thinking of replacing my barring with new ones
where can i get some good new barrings which you all have good experience with?
I also have uneven ubolts where do you guys get accurate ubolts or any good alternative to it?
also i am thinking of getting new Lube for the rods what are some good ones? is ptfe a good idea to get in the lube? i was looking at the following links to get some new lube but if there is better option let me know?
https://www.super-lube.com/multi-purpose-synthetic-grease-with-syncolon-ptfe
i was also wondering if i am lubing the rods correctly on the following link it says "Using your finger or the towel spread the paste around the diameter", by diameter they dont mean around the whole rod just in the general area diameter of where you droped the grease, like maby 10-20mm area and not the whole rod all over?
https://manual.prusa3d.com/Guide/Printer+maintenance+tips/1437?lang=en
RE: Maintenance and replace? rods barrings
The entire rod length needs lubrication - and the bearings will spread it evenly when moving the axis back and forth. Wipe off the excess that collects at the ends of the rods and at the bearing seals.
The bearings are usually lubricated with #2 white lithium grease before they are installed on to the rods. The bearings have grease seals to keep the grease inside the bearings. Superlube 21030 is another alternative.
If your printer is fairly new, the bearings are probably still serviceable. You can pull the moving parts and add grease then reassemble. Or, without disassembly, you can use light machine oil (like 3-in-1) or even motor oil in a pinch - add a few drops on each rod both sides of the bearings, and then work it into and past the seals into the bearings by moving the axis back and forth.
You don't want to apply so much the oil drips off, but a light sheen is expected. As you apply oil to dry rods, you can feel when the oil gets into the bearings and begins reducing friction.
Unless you know your bearings are worn out, there's no need to replace them.
The U-bolts are fine for what they do, just don't over tighten them. As an alternative, there are Y-Axis bearing holders you can print and use instead of the U-bolts: Thingiverse has several types you can download.
RE: Maintenance and replace? rods barrings
Thingiverse also has a nice bearing lub cap for the Superlube tube - and a cap for the cap.
https://www.thingiverse.com/thing:1128781
This assures that the grease is pressed into the bearings.
RE: Maintenance and replace? rods barrings
And with that you can end up forcing too much grease into your bearings stopping them from recirculating, you want a thin smear not pack every last bit of space full of grease.
It will work for a bit, as the bearings slide along the rod, but eventually you may end up scoring the rod.
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.
RE: Maintenance and replace? rods barrings
I used a large diameter hypodermic ... and I don't think you can pack too much grease in. Sort of like car wheel bearings, the race packed nearly full is good. Space for thermal expansion of air once inserted, but that's about it. When I packed my last set of Misumi bearings, the rods pushed quite a bit of the grease out, leaving the bearing and raceways filled. You need to consider the bearings roll on the rod and on the bearing race and grease needs to be packed inside the bearing retainer, too.
RE: Maintenance and replace? rods barrings
The entire rod length needs lubrication - and the bearings will spread it evenly when moving the axis back and forth.
ya that what i wanted to make sure, that you just put it around the diameter of the rod where you droped the grease, then move your axis back and forth to get it on rest of the rod, but not spreed the grease through the entire rod around the full diameter of the full rod.
That being said i had greased the rods around 2 months ago but now i checked with my fingers and i cant get any grease on my fingers from the rod is that normal after some time of printing do the rods become dry and but the barrings still hold the grease, is that how it works? or should the rods be slightly greased at all times including the barrings??
I also remember when i did my first self test after assembling the kit and also running the wizard setup from the LCD the "Belt tension" number i got were higher but now even though i tighten my belts and loosen them at there max/low levels i cant seem to get those higher numbers??
RE: Maintenance and replace? rods barrings
This may need some discussion.
My rods are clean and dry - and I will keep them that way.
My bearings are packed with grease, and the seals keep it there.
The bit of grease that leaks out gets pushed to the rod ends - where I keep it wiped off.
No grease - or oil - on my rods. I am not fond of those picking up dust and grit.
Not to mention - get those on the screwed rods and you will dissolve your Delrin trapezoidal nuts.
RE: Maintenance and replace? rods barrings
RM - we agree 100%. I don't grease the rods ... the grease is needed inside the bearings and seals. The rods will have a film of lubricant that's left behind as the bearings move along, but it is a film, not a coating. And the excess that leaks past the seals and builds up at the rod ends should be removed from time to time.
Adding oil or grease to the rods is a makeshift-after-the-fact attempt to get some lubrication inside the bearings when a person did not properly lube them at install. Prusa is doing customers a disservice by say their bearings are lubricated. They only have a preserving shipping oil just like all the other bearings you buy. And I'll continue with this position until I see something in writing from the bearing manufacturer that the oil as shipped is proper lubrication for intended installation and final use (I say this because my Prusa bearings had machining grit inside them and they ground on the rods like sand paper until I replaced them).
RE: Maintenance and replace? rods barrings
interesting... so lets say if i wanted to figure out if my barrings had enough grease should i just more my axis back and forth a few times and see if i get grease film on the rods to make sure the barrings have enough grease, i followed the instructions on how to grease your rods from prusa but now i am wondering if i gave it enough or some of it got dried inside the barrings but idk??
RE: Maintenance and replace? rods barrings
There is at least one good article on how to grease your bearings, but unless you soaked them in alcohol to remove the old stuff and packed them with the appropriate grease - you did not grease your bearings. Redo it at an appropriate interval for your use.
RE: Maintenance and replace? rods barrings
this one?
RE: Maintenance and replace? rods barrings
also just remembered that some of the barrings were bone dry from the inside when i assembled my kit and i put those barrings on the Y-Carriage and i lubed the y axes only because the other 2 axis barrings were lubed and i did not lube up the X or Z, oddly i am getting lot of Y-crashes odd?
RE: Maintenance and replace? rods barrings
@mop - there is no right answer to what you are asking. There are hundreds of videos on packing bearings with grease. Most are for car wheel bearings, but the principle is the same: the bearings have cavities that need to be filled with grease that is in contact with the rolling balls and races. Seals keep the grease in, any dirt out. As the seals wipe the metal surfaces they move on, a film remains because the surface and the seal aren't perfect.
If you did not fill the bearings with grease before you inserted the rods, you probably do not have enough grease in them as recommended by most bearing companies. If you didn't pack the bearings before installation, apply some grease on the rods, move the axes back and forth several times, then wipe off the excess grease, and call it good enough. Do this grease application every month or two and remember to pack the bearings when you have an opportunity to tear things down.
On the other hand, remember: others have reported they get great service life without adding any grease or oil at all.
RE: Maintenance and replace? rods barrings
As for U-Bolt options: when I do my next rebuild I'm trying something like the first holders here:
https://www.thingiverse.com/thing:3009203
and these look interesting but require finesse to use properly
https://www.thingiverse.com/thing:2969556
RE: Maintenance and replace? rods barrings
this one?
I certainly like that one. Read both the article and the comments.
Whether you agree with it or not - it gives some useful background information.
RE: Maintenance and replace? rods barrings
On the other hand, remember: others have reported they get great service life without adding any grease or oil at all.
i applied the grease after installation to Y did not apply any thing to rods for X and Z since the barrings seemed greased, also i could not find how ofter i should be using the grease for maintenance but 1-2mo seems like the last time i greased my barrings also my belt/barrings tension # was higher back then vs now but your saying not every one has the issue of having to grease the barrings interesting....
i might have to see if using the grease only on my Y works or not to help with crashes and maby get higher barring load number.
As for U-Bolt options: when I do my next rebuild I'm trying something like the first holders here:
https://www.thingiverse.com/thing:3009203
and these look interesting but require finesse to use properly
intresting.... i may have to try the first link and if/when i tare down my printer and not have to deal with the U-bolt nightmare.
RE: Maintenance and replace? rods barrings
this one?
I certainly like that one. Read both the article and the comments.
Whether you agree with it or not - it gives some useful background information.
ya i did want to completely soak the barrings in IPA and apply a different grease and see if that produced some improvements. At some point or when or if i remove parts from my machine.
RE: Maintenance and replace? rods barrings
This is a good clip for the Mk3 or Mk3s.
Just use screws long enough to just start to poke out of the hole when screwed in from above, just tighten the clip up against the frame and thats it, no overtightening and holds the bearings securely.
I printed these 10 months ago from PETG and they have been perfect.
https://www.thingiverse.com/thing:2830466
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.