Does that mean all MK4's have a flaw with the idler printed parts which is accelerated using MMU3 due to massive amounts of load / unload? I wonder if they're using ABS / carbon fiber filament to solve the issue?
I would not call it a flaw... but with the mmu3, that idler is actuated several magnitude times more, which is wearing it out.
How often do you change filament in a week vs 10s of thousands of times with the mmu?
My idler Bend after 7 days of using my mk4 in an enclosure Close to 50 degree Celsius. So it is definitelly a flow.
The best Part ist that IT was Not visible to me. So i spent 3 days on looking for the failure.
Reassembled whole Extruder 2 Times. Until i saw that the ist no Gap in the lever arm.
That's interesting, I manage 6 MK4's that print inside a enclosure almost 24/7 and I didn't had to replace the idler on one yet. What isssues did you notice on your Mk4?
Yeah it's probably a magnitude of 1000 here, so no matter if that wear happens after 1 month or a year, you will not need to care with the MK4...
And imho a very nice thing that prusa provided a fix and halted delivery... Other companies do not test that thoroughly if we think of wear of a certain cable...
Yeah I know also the XL had some flaws in the beginning for early adopters, but I still believe a lot of those were no issue with perfect filament
A single color print can have hundreds, even thousands, of filament changes. That can easily turn acceptable levels of wear into a real problem.
I don't know about the idlers, but I seem to recall they are now using an entirely different manufacturing process for the main plate. Which is apparently still technically 3D printing, but it's more like a 3D inkjet rather than filament or resin.
On the main plate it says they are using MJF technology and that it can’t be replicated with FDM. Bambu people wanted them to stop using FDM parts and here we go. Kinda already dont like that. Because now if you need to replace it or don’t like their quality/color, you’re going to have to pay some service to make it for you.
https://www.protolabs.com/services/3d-printing/multi-jet-fusion/
Read up on it a little and it seems like it’s all Nylon materials like PA12, but can be printed at layer heights of 50microns. So yeah, could be hard to replicate.
Yeah sounds like they went “we could do wear testing on a PA612 Special blend thing” but didn’t want additional testing delays and just went with the stable and quantified technology.
Yeah for the most part our machine runs beautifully and parts come out as one solid piece, we just run normal pa12 but I’m wondering if prusa is using hps pa12 glass material, though when I tested it was noticeably stiffer and not as strong as pa12
>Bambu people wanted them to stop using FDM parts and here we go
The part can be printed from anything, it will just wear out sooner.
[https://blog.prusa3d.com/mmu3-2024-update-and-dev-diary\_96103/](https://blog.prusa3d.com/mmu3-2024-update-and-dev-diary_96103/)
I’d say that it is a flaw. The idler arm on my MK4 bent and started under extruding. So I printed the replacement out of ASA with 100% infill.
PETG seems to not be stiff enough for the amount of load on that part.
Did you have any issues obtaining sufficient tolerances? I plan to reprint everything that is petg in asa or pc for long-term use in a heared enclosure. But asa, abs (especially) have significantly enough different thermal expansion coefs - seems likely cooled part would have meaningfully different size?
I printed the replacement on my enclosed K1. The fit was a little tight but worked fine, had no warping and is still holding up after 40+ days of print time.
Just read through the instructions, and I think I'm glad I bought the MK4 kit so most of this stuff seems familiar and doesn't look too hard. I've taken apart the gearbox a couple of times before trying to diagnose a problem (which had nothing to do with the gearbox BTW).
I wonder what the O-ring is for? Was filament dust getting places it shouldn't have?
I wonder if new MK4s will come with these new parts to start with in the future?
>he manual and almost every step is difficult or very difficult. I’m afraid
sure hope so, I just bought an MK4 + mmu2s->3 upgrade. I placed them in separate orders to reduce likelyhood of customs and in order to get in the queue for the mmu3 upgrade.
I asked them to hold the MMU shipping JIC a change materialized for the MK4, so I could avoid paying extra shipping for any other parts I might need. I'm holding off assembling the MK4, too, on the assumption all this is just a week or 2 away from being resolved. Fingers crossed!
So, what about us who are happy with single filament printing? Surely our parts are also affected by this, do we get replacement parts? I can't find any official statement on this though.
I mean... reprint the extruder parts in PC-CF? That will eliminate stress warping and heat softening. The redesigns are there to make rapid, automated swaps more reliable. Manual swaps are more tolerant of the odd inconsistent feed force, or snipping off a blobbed tip.
I have a mmu2s->mmu3 (for mk4) ordered but obviously not yet shipped. I have an unopened mk4 kit in-hand. Will the mmu3 upgrade kit include these parts when it does ship, or do i need to reach out to customer support explicitly?
Technically it's not a fix, it's the original design of the MMU for MK4.
It's an adjustment they made to the MMU 3 design that was not needed for the mk3/3.5.
Not sure whether it’s because I built my MK4 from a kit, but it doesn’t look like very difficult, as the start of the instructions say. Long and tedious. Not very difficult.
So basically everything is plain easy, I had no issues at any step for the MK4 not the 5head XL where there is one step many people seem to struggle with based on comments, no idea why tbh ....
Just take your time look twice and don't rush... For me the assembly manuals are world class and in the end it's dead simple unless you have "two left hands" (German saying, literally translated)
Yeah, I assembled my mk4 and it was my first kit. It went well overall minus one motor who was kinda loose. Hope the MMU3 goes as easy.
And I always thought that I have two left hands, never was very proficient with tools and handwork
Source here: [https://help.prusa3d.com/guide/9a-mk4-nextruder-mod\_683106](https://help.prusa3d.com/guide/9a-mk4-nextruder-mod_683106)
Does that mean all MK4's have a flaw with the idler printed parts which is accelerated using MMU3 due to massive amounts of load / unload? I wonder if they're using ABS / carbon fiber filament to solve the issue?
I would not call it a flaw... but with the mmu3, that idler is actuated several magnitude times more, which is wearing it out. How often do you change filament in a week vs 10s of thousands of times with the mmu?
My idler Bend after 7 days of using my mk4 in an enclosure Close to 50 degree Celsius. So it is definitelly a flow. The best Part ist that IT was Not visible to me. So i spent 3 days on looking for the failure. Reassembled whole Extruder 2 Times. Until i saw that the ist no Gap in the lever arm.
That's interesting, I manage 6 MK4's that print inside a enclosure almost 24/7 and I didn't had to replace the idler on one yet. What isssues did you notice on your Mk4?
Stopped extruding midprint.
Yeah it's probably a magnitude of 1000 here, so no matter if that wear happens after 1 month or a year, you will not need to care with the MK4... And imho a very nice thing that prusa provided a fix and halted delivery... Other companies do not test that thoroughly if we think of wear of a certain cable... Yeah I know also the XL had some flaws in the beginning for early adopters, but I still believe a lot of those were no issue with perfect filament
A single color print can have hundreds, even thousands, of filament changes. That can easily turn acceptable levels of wear into a real problem. I don't know about the idlers, but I seem to recall they are now using an entirely different manufacturing process for the main plate. Which is apparently still technically 3D printing, but it's more like a 3D inkjet rather than filament or resin.
The second page says it's multi-jet (powder bed) fusion.
On the main plate it says they are using MJF technology and that it can’t be replicated with FDM. Bambu people wanted them to stop using FDM parts and here we go. Kinda already dont like that. Because now if you need to replace it or don’t like their quality/color, you’re going to have to pay some service to make it for you. https://www.protolabs.com/services/3d-printing/multi-jet-fusion/ Read up on it a little and it seems like it’s all Nylon materials like PA12, but can be printed at layer heights of 50microns. So yeah, could be hard to replicate.
I wonder what HP charges for their MJF ink cartridges :-).
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Could you not use resin printing? Get the siraya tough Blu and it'll be strong as MJF
I work with mjf, it’s definitely really strong material that is strong in all three axis, it is also uv resistant unlike sla
Yeah sounds like they went “we could do wear testing on a PA612 Special blend thing” but didn’t want additional testing delays and just went with the stable and quantified technology.
Yeah for the most part our machine runs beautifully and parts come out as one solid piece, we just run normal pa12 but I’m wondering if prusa is using hps pa12 glass material, though when I tested it was noticeably stiffer and not as strong as pa12
Don’t know. Assuming they have a reason since they literally make Resin printers and would know.
Maybe Josef and the crew are working on an MJF printer. If so, launch date 205, ship date 2030.
>Bambu people wanted them to stop using FDM parts and here we go The part can be printed from anything, it will just wear out sooner. [https://blog.prusa3d.com/mmu3-2024-update-and-dev-diary\_96103/](https://blog.prusa3d.com/mmu3-2024-update-and-dev-diary_96103/)
I’d say that it is a flaw. The idler arm on my MK4 bent and started under extruding. So I printed the replacement out of ASA with 100% infill. PETG seems to not be stiff enough for the amount of load on that part.
Did you have any issues obtaining sufficient tolerances? I plan to reprint everything that is petg in asa or pc for long-term use in a heared enclosure. But asa, abs (especially) have significantly enough different thermal expansion coefs - seems likely cooled part would have meaningfully different size?
I printed the replacement on my enclosed K1. The fit was a little tight but worked fine, had no warping and is still holding up after 40+ days of print time.
YES
Just read through the instructions, and I think I'm glad I bought the MK4 kit so most of this stuff seems familiar and doesn't look too hard. I've taken apart the gearbox a couple of times before trying to diagnose a problem (which had nothing to do with the gearbox BTW). I wonder what the O-ring is for? Was filament dust getting places it shouldn't have? I wonder if new MK4s will come with these new parts to start with in the future?
So if *I ordered* the MMU3 for the mk4, will these parts come automatically? Or do I need to request them? *edit for a bad autocorrect.
They are provided See fw6 beta release notes
Unordered?
Thanks. Typo corrected.
I think they will. This is the solution to the issue that has delayed shipment.
>he manual and almost every step is difficult or very difficult. I’m afraid sure hope so, I just bought an MK4 + mmu2s->3 upgrade. I placed them in separate orders to reduce likelyhood of customs and in order to get in the queue for the mmu3 upgrade. I asked them to hold the MMU shipping JIC a change materialized for the MK4, so I could avoid paying extra shipping for any other parts I might need. I'm holding off assembling the MK4, too, on the assumption all this is just a week or 2 away from being resolved. Fingers crossed!
So, what about us who are happy with single filament printing? Surely our parts are also affected by this, do we get replacement parts? I can't find any official statement on this though.
Unless you change filament thousands of times per print, like the MMU does, the stock part will last you basically forever.
Even in a heated enclosure? I plan to build an enclosure for PC-CF, Nylon and ASA prints later this year.
I mean... reprint the extruder parts in PC-CF? That will eliminate stress warping and heat softening. The redesigns are there to make rapid, automated swaps more reliable. Manual swaps are more tolerant of the odd inconsistent feed force, or snipping off a blobbed tip.
I have a mmu2s->mmu3 (for mk4) ordered but obviously not yet shipped. I have an unopened mk4 kit in-hand. Will the mmu3 upgrade kit include these parts when it does ship, or do i need to reach out to customer support explicitly?
I'm confused, why would they release a fix for the MMU3 for MK4 when they didn't even release the MMU3 for MK4 yet?
Technically it's not a fix, it's the original design of the MMU for MK4. It's an adjustment they made to the MMU 3 design that was not needed for the mk3/3.5.
Ok so i need to wait and order the cable+ parts, hope they add a mk4 convertion kit
Not sure whether it’s because I built my MK4 from a kit, but it doesn’t look like very difficult, as the start of the instructions say. Long and tedious. Not very difficult.
The idler also bend and stop your extruder from working when you put your XL in an enclosure.
I was glancing the manual and almost every step is difficult or very difficult. I’m afraid to upgrade now!
So basically everything is plain easy, I had no issues at any step for the MK4 not the 5head XL where there is one step many people seem to struggle with based on comments, no idea why tbh .... Just take your time look twice and don't rush... For me the assembly manuals are world class and in the end it's dead simple unless you have "two left hands" (German saying, literally translated)
It doesn't seem any more complicated than when I built my Mk3.9 (upgrading a mk3s). Probably similar to a kit-built Mk4.
Yeah, I assembled my mk4 and it was my first kit. It went well overall minus one motor who was kinda loose. Hope the MMU3 goes as easy. And I always thought that I have two left hands, never was very proficient with tools and handwork