Prusa MK3s Misumi Bearings and Rods Upgrade
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- Опубликовано: 9 июл 2024
- See how you I replaced linear bearings and rods(shafts) on my Prusa MK3s with higher quality Misumi parts.
I've attempted to cut some corners and remove minimum amount of parts just so I can get to the bearings and rods.
I'll try to show everything in detail but I will also show mistakes that I made. So please watch video in its entirety first. Also to save some time I do not go into details on how to re-assemble everything. You can either follow disassembly instructions in reverse or go check official prusa assembly manual for guidance.
Here's list of parts you will need:
(6x) LMU8 Bearings (a.k.a. bushings) (buy 10 if you plan to upgrade Z axis)
(2x) SFJ8-370 Linear Shafts (rods) for X-axis (370 mm)
(2x) SFJ8-330 Linear Shafts (rods) for Y-axis (330 mm)
Lithium Grease (amzn.to/2WyEffv)
Greasing Cap: www.thingiverse.com/thing:112...
99.9 Isopropyl Aclohol
Thin Zip-Ties
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Much thanks for this video, I was surprised to see that as of writing this, Prusa still has no official guide on how to take apart your printer to re-pack/grease your bearings. Good to visually see someone doing the procedure first, many thanks!
Glad you found it helpful, thanks a lot for letting me know! :)
at last someone who actually shows the faults he makes.... good video. big ups
One thing that everyone seems to be missing or forgetting. When you install the linear bearings, whenever 2 bearings are on a single rod, it is really important that you make absolutely sure the 2 bearings are "out of sync", so the bearings do not roll over the same part of the rail as the other bearing. If you don't do this the rails will wear out faster...
That's a really great idea! It never even occurred to me, thanks! Bur realistically chances of bearing rows aligning exactly when installed blindly are very very small...
I dont think everyeon is missing this since it is explained multiple times in the assbely guide. My is still loud as hell.
stumbled on this video because I have to do the same thing on my Mk3s. This was super helpful, thanks!
Hey man, just wanted to drop you a line or two because I struggled to do my bearing change because it seemed too much to disassemble and it is all overwhelming because you get frightened to break a running printer. I stumbled over your video und it was about the only one with good instructions and so well made, that I found my courage again and made the re-assembling today. I did some different steps but I wanted to let you know that your video inspires people out there to not give up. Cheers to you, for filming your work and making it possible for others to get inspired by it. Thank you very much..!
Wow thanks for the kind words! Comments like this make all the effort worth it's time! Thank you!
Thank you for a great video, followed this today and got my rods and bearings updated after one or more bearings failed and got some grooves in my x-axis rods. Cheers!
Changed my damaged X-Axis rods today, thanks to your video managed to get it done in under an hour. Thanks dude.
You are an unsung hero my man! Very happy to have found these clear instructions and I'm now ready to start the upgrade on my printer! Thanks so much
Super helpful to see it done before I attempt! just got my mk3s and the Y axis bearings are chattering! great vid, and remember, always be careful cutting zip ties :D
Excellent video. Thanks for making and sharing this!
Thank you for a very thorough video!
Great video! I am just about to do this when my order arrives. Also a reminder to grease everything.
I’ve been having the same issue with grinding and shifting layer prints as well. My rods now have grooves cut in them and I temporarily fixed it enough to get printing again by spinning the rod about 10 degrees. I’ll definitely have to rebuild and will follow your process to upgrade at the same time.
Great video!
Very helpful, thanks.
Great video. Thank you.
I had exactly the same issues with X-axis rods/bearings. Good to hear that I'm not the only one :)
So it's been 6 months since I made the video, and now my rods(bearings?) crapped out on me :( I'm getting loud crunchy sounds and rods have deep grooves worn out... I think I used wrong Misumi Rods (SFJ8 vs PSFJ8) or didn't lubricate them correctly (I was a tiny bit skeptical about those 3D printed greasing caps. I just ordered another set and will do a follow up video.
@@madeinbasement Sorry to hear that. I am about to change the x-axis rods/bearing for the third time soon. Also considering the Misumi ones, I will be grateful for your follow up video. There is an upgrade with linear rails, maybe I will give it a go:
www.prusaprinters.org/pl/prints/16838-prusa-mk3-mk3s-x-axis-linear-rail-guide-upgrade-up
For me it is kinda strange, the rails should last longer. I am not sure what is the cause, but I was doing the lubrication procedure as in Prusa guide here help.prusa3d.com/en/guide/printer-maintenance-tips_23200/ and the problem persists. Maybe the balls of all three bearings should be right on the top of the rod.
@@madeinbasement I just checked on caribou3d.com they are using PSFJ:
caribou3d.com/en/module/iqitsearch/searchiqit?fc=module&module=iqitsearch&controller=searchiqit&s=rod
@@medyk3D I don't know... This post forum.prusaprinters.org/forum/original-prusa-i3-mk3s-mk3-improvements-archive/misumi-replacement-rods-and-bearings/ mentions that G6 tolerance (which is less precise than H5) is recommended to be used with Misumi bearings. I'm not sure if that makes a difference. But I strongly suspect greasing caps. Previously with my MK2.5s I used different greasing adapters that seem to pack more grease inside bearings. I don't remember exactly, it was similar to this one: www.thingiverse.com/thing:3440524
@@madeinbasement You can contact with caribou3d for advice about rods/bearings. Last time I put lots of grease inside the bearings. Now I have grooves again.
I checked my Instagram: the orignal ones lasted for 833 meters of filament/117days of printing. Now I am at 20km/176days and should change them again. From mail from Prusa one should clean and lube "every couple hundred hours" so I do it every month.
help.prusa3d.com/en/guide/printer-maintenance-tips_23200?lang=en
Options are:
- design flaw
- material flaw (is there anything better than misumi)
- wrong maintance (well rather not)
- wrong grease (possible I am using www.cx80.pl/en/products/greases-cx80/cx80-lithium-grease-detail.html)
- wrong assembly (maybe)
any other ideas?
I hate RUclips video intros - this one rocks!
Thank you for this!
Hello! Just a suggestion that I will make, make sure that if your bearings are already lubed that you clean out as much of the previous lube as possible. It makes the whole process much less messy and in my experience reduces noise
great video, thanks
I had issues with layer shifts too at one point and what helped was to tighten the screw (see it at 2:20 in the video) so one of them is flush with the flat side of the stepper shaft. That one was loose for some reason and caused the pulley to move back and forth. After tightening, that was gone. Something to look out for :-D
Ok but at 2:20 you are seeing b-roll footage from another printer :)
I just tried to grease the Y-axis bearings on my 2-month old Prusa MK3/S by following your video. Two worked great after, but the third was already damaged. I don't understand how Prusa actually thinks corrosion inhibitor is a functional lubricant. I already have the grease and cap, so I'll have a full set of Misumi bearings and rods ordered soon. Thanks for the informative video.
My Mk3S+ (fitted with Misumi Bearings) started making grinding noises after about 20 hours of printing. I found a 120mm long score in one of the X-axis rod which had been cut by the bearing.
After some research on Prusa forum and over the web I discovered that the 'oil' that many bearings ship with is highly unsuitable for general lubrication, it's in fact a corrosion inhibitor; this is confirmed by the Misumi datasheet us.misumi-ec.com/pdf/fa/2012/p1_0265.pdf.
The anti-rust oil should be removed by degreasing the bearings in Isopropyl Alcohol (in ultrasonic bath even better), then packed with suitable grease. Many users on Prusa forum recommend either lithium grease or alternatively synthetic grease with PTFE like Super Lube. Misumi recommend specifically 'Lithium soap based grease'.
Prusa's assembly instructions do not tell you to degrease and regrease with a proper lubricant, it seems they believe the corrosion inhibitor is fine. In mine and many other's experience it might suffice for a short while, then one day find your bearings seize and grind.
Anyways, nice video and thank you. I followed along to service my X and Y bearings.
Yes you are correct. It's shame they don't admit this fact about packing oil... I'm still learning btw, lithium grease might not be the best option in long run due to high viscosity. They say "Zeller Gmelin Divinol Lithogrease 000-150 is better for this, and I just received a big bottle to try it out. I'm also trying to some plastic bushings too. Will try to make a video out of it :)
@@madeinbasement Just received my Prusa MK3S+, linear bearings sound very loud, therefore I ordered 1000 ml Divinol Lithogrease 000/150. I'm curious whether the linear bearings run better with it. The size of 1000 ml is unfortunately much too big and so the price of 20 € is more than decent.
Divinol Lithogrease 000/150, with the viscosity and appearance of egg yolk, seems to be working quite well and the bearings are much quieter. Dosing is still difficult. I feel like I'm using way too much. I will write to the German manufacturer for a recommendation. Long-term experiences follow.
Excellent video, exactly what I needed. How are the bearings and new rods from Misumi holding up for you? Change in print quality? Worth the purchase? Thank you.
Did you ever figure out what the nut was for that fell out at 11:42?
It looks like your x axis belt is rubbing against the x motor mount. Maybe that’s why you are seeing layer shifts? That’s what happened to mine and I simply pushed the belt pulley further inwards
I think the bearing will grind if they've no preload. They just slide instead of rolling. I've some cheap from import and they don't roll and leave marks, unless you push them harder against the rod. Your opinion?
Very curious how long it took you to do the replacement? Really appreciate you making this video as it is very helpful and I’m dreading having to do this on my MK3. My bearings on the x axis make a cracking noise when x axis is moved all the way to the right. :(
Not that long. Probably about an hour or so...
I am your 1000th subscriber thanks to my lil nerd brother!!! GME!!!!
WOW it’s hard to believe I’m at 1K! Thank you so much! :)
why not truning the rods 10 Degress and make the bearing slide on the un grooved surface ?
that way you save the rod and use it for more cycles
Sure if that works for you why not? I figured since I'm disassembling printer I might as well replace rods...
At 2:00 I noticed the gap between the x motor and x belt pulley seems way to large you should only have about a 0.2 mm gap. Take a pice of paper fold it in half, loosen the x axis pulley grub screws, place the paper between the motor and the pulley and push the pulley against the motor with the paper in between. Once you can't push any further remove the paper and retighten the grub screws.
Thanks will do!
I just upgraded mine from MK3 to MK3S and it has helped a little with quality, which was already very good. I just would like to know if the investment is worth it. Did the quality of your prints improve?
Quality was already great so no I didn't expect quality improvements with this upgrade. It did improve reliability, eliminated layer shifts and I don't have to grease rails for a while (I had to do it almost after every print before).
Thanks for this great video. btw, where did you bought the MISUMI bearings and rods please?
us.misumi-ec.com/
@@madeinbasement Thx
Hey mate, very informative video! Am trying to purchase them off misumi themselves. Mind sharing what the options/ customisation you choose on the rods with the misumi site? (Induction hardened/ shaft tolerance/ how to choose surface finish)
Thanks in advance!
any success? I see this was from a year ago, but Misumi has one complicated-ass site!
If my rods are okay, can I just replace the bearings? My Y axis just started making a cracking noises but I see no damage to the rods.
Yes I think it should be just fine
Do you have a link to the bearing grease cap stl file?
Ah yes, sorry forgot to put link in the description. Here it is: www.thingiverse.com/thing:1128781
Haha... I appreciate this video existing, but man what a train wreck. Sorry you had to deal with a second disassembly/reassembly and cut wire. Maybe you can spare some others that pain. I'm degreasing and lubing my bearings today due to increased friction on the X and Y axis. Really wish Prusa recommended doing this on initial assembly...
LOL yeah I wanted to show everything including my failures so you can learn from my mistakes. But yeah it could've gone better. It's super hard to do this these assemblies on camera, as you have to constantly make sure you not blocking the view so a lot of the operations I had to do kind of blind, by looking at the monitor :) I totally cut that zip tie by touch without seeing it, and of course snipped wire :(
Polish your rods and use Krytox 204 grease.
Can swear that that last sentance came from red alert.
but original part of prusa is Misumi?
EDIT: It appears Prusa now includes Misumi bearings! I just got latest MK3S+ and it came with Misumi parts
you forgot the links to ALL of the misumi parts.
Sorry to tell you but at 2:04 you can clearly see that the X pulley is no placed correctly on the stepper rod and the belt is grinding against the plastic part, maybe that is why you had layer shift in X direction.
You are correct, but this is video from another printer (MK2.5s) which btw runs great :) I noticed black flakes from belt rubbing but honestly didn't spend too much time trying to adjust it as it doesn't affect prints. I will next time I work on that print (I plan to upgrade extruder to full Bondtech)
This really shouldn’t be necessary if the printer was assembled properly to start with. My Mk3s has done almost 1000 hours now, with no issues.
Upgrades that make no improvement whatsoever...