Replaced Y and X Axis bearings
After 19 months of printing the Mini started to be too noisy and I figured the bearings needed to be replaced. Replaced them with Ruthex Drylin RJ4JP-01-08 bearings on both the Y and X axis. For the Y axis I used the excellent Prusa Mini Y-Axis Bearing Holders from Jose Tinman (see Prusaprinters.org). I cleaned all the rods with rubbing alcohol to remove any grease. The X-Axis end was updated to R8 as recommended by Prusa. Both jobs were very straightforward and easy following the Prusa Mini support instructions. What a difference these new bearings make - the Mini is like a different machine!. A highly recommended (minor) upgrade.
Original Prusa Mini 03/20 PINDAR Misumi Bearings
performance
How is the resistance to movement with the Ruthex Drylin versus the stock?
question
These bearings need to be lubed too, right?
[Mini+] [MK3S+BEAR]
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These bearings need to be lubed too, right?
I really don't think so, from what i understand you keep them dry, they have there own lube built into the material they are made from.
Dry
Yes, running them dry. Some say to prepare the rods with PTFE but I decided to go it without.
Original Prusa Mini 03/20 PINDAR Misumi Bearings
R8 X-Axis
R8?
The X-Axis end was updated to R8 as recommended by Prusa different machine!.
MINI+ with FW:4.3.3, Bondtech IFS Extruder, drilled out PC4-M8 couplers, 1 piece Capricorn bowden.
R8
Yes, R8. Check the github…..
Original Prusa Mini 03/20 PINDAR Misumi Bearings
Might try on X-Axis
I am replacing the clone heatsink with an original Prusa one, so may go with these on the X-Axis (since it will be apart anyway.)
Play
Is there any play between bearing and rod?
X-Axis bearings
I have been researching these. Seems you have to have some kind of bearing enclosure (ideally metal) around the bearing for it to work within its design characteristics. I think what the OP has used (stock holders on the X-axis and the printed holders for Y-axis) is sufficient, but not metal. The U-Brackets will not work properly from what I understand, but based on reviews, makes sense.
I still haven't taken apart hot end yet, but will shortly. I am going to put these on the X-Axis. From there, I may do the Y-Axis depending on how X-Axis goes.
Reasoning for all of this? None. Using decent bearings that were cleaned and properly lubricated during assembly and the printer is pretty quiet. The reason, however, I got the clone, was to experiment with things like this. I will definitely report my findings when complete.
Sticktion
Ahh, these pop up from time to time when somebody "discovers" them, and most of the time reaction and recommendation is not very favorable 😆
Take this as a word of mouth as I personally don't have experience with Igus bushings and have to rely on information from 3D printer communities: these bushings show something that's called static friction. They require higher force to start moving, which can cause some issues like sensorless homing errors, skipped steps or artefacting. While printer is moving constantly, it is actually changing direction all the time and it may be presenting itself there.
Example, which is about linear rails from Igus instead of bushings - but given history I'd trust devs in that community as they (usually) do their homework when it comes to stuff they recommend using. First printers way back when were designed to use Igus bushings with linear rods, but it was very quickly decided to move away from it as it was not suitable for this use-case.
But hey, if it works for you, by all means use it 👍 Metal linear rods with ball bearings will always be louder, there's not much which can be done about that.
RE:
Well, all of the above are valuable remarks. After a while the Drylins stopped working well: on the Z-axis play between the bearings and the rod became evident with poor printing results and the X-axis started to squeak. Not wanting to take half measure I tasked Prusa to sent out to me a full set of Linear MISUMI LMU8 bearings and a grease kit on top. Oh and a set of the new clips for the X-axis. Greased the bearings and installed them and not looking back at all! Massively improved the print quality and very happy. So, after the Drylin experiment I would suggest these are not a great replacement for regular bearings. Thanks all for your comments!
Original Prusa Mini 03/20 PINDAR Misumi Bearings
RE: Replaced Y and X Axis bearings
Thank you for reporting your experience
[Mini+] [MK3S+BEAR]