What's next for the MK4 line?
I've been a Prusa MK3/4 user for about six years, and I have two MK4S printers that run in tandem.
When the CORE One was announced, I had to make a choice of whether to upgrade. I chose not to for a few reasons:
1) The advantages over the MK4S were modest - slightly larger print volume, slightly faster printing, and theoretically improved print quality - and not worth the considerable cost to upgrade both of my MK4S printers.
2) The added complexity of CoreXY printers creates the possibility of more complicated troubleshooting, maintenance, and repair issues - especially relevant for an essentially brand-new printer line where the possibility of unforeseen technical issues is higher.
3) Perhaps most importantly, I wanted to preserve upgradability. One of my printers started life as a MK3S kit and has fully been upgraded to a MK3S+, MK4, and now MK4S. The other started out as a MK4 and is now a MK4S. I absolutely love this aspect of Prusa printers and wanted to ensure that I was ready to take the next steps, and I felt that the prospect of continued upgrades was stronger for the MK4S than the CORE One (again, complexity).
So instead of the CORR One upgrade kits, I bought the Prusa enclosure for both printers, which I really like but which also makes me feel like I've doubled down on the MK4S line.
But that was 18 months ago. Since then, the CORE One has gotten all of the attention, including the rapid introduction of the CORE One L, with literally no hardware announcements about the MK4 line. Yes, I am aware of the steady stream of firmware updates and new features, but honestly the practical improvements are very modest. I was hoping to see at least some buzz about a MK4S+ upgrade in 2025, but that now seems unlikely.
I'm growing concerned that I picked the wrong horse and will end up trading them for CORE One printers in 2026.
Any other MK4S owners struggling with assessing the future of the model line and making choices?
RE: What's next for the MK4 line?
If you want my sincere opinion, the best upgrade would be to move away from Prusa and choose a brand that delivers reliable and well built machines with stable firmwares, instead of the never ending iterations of buggy firmware "updates" that Prusa offers to their long suffering customers. I'm not mentioning specific brands ( I don't like the Bambulabs business model, for instance ) but sure there're much better options nowadays that those overpriced and poorly built/assembled Prusa printers (specially the appalling Core One series).
RE:
If you want my sincere opinion, the best upgrade would be to move away from Prusa and choose a brand that delivers reliable and well built machines with stable firmwares, instead of the never ending iterations of buggy firmware "updates" that Prusa offers to their long suffering customers. I'm not mentioning specific brands ( I don't like the Bambulabs business model, for instance ) but sure there're much better options nowadays that those overpriced and poorly built/assembled Prusa printers (specially the appalling Core One series).
I'm not aware of any other 3D printer vendors that offer a hardware upgrade path like Prusa. I think that with most other vendors, you get what you buy, and any upgrades are totally on you and not supported by the vendor.
My first printer was like that - a FlashForge Creator Pro. Out of the box it sucked, and it sucked worse as it aged and features started to become unreliable. I spent increasing amounts of time trying to diagnose and fix its technical flaws with all kinds of homebrew upgrades. It was frankly a nightmare and it almost entirely killed my interest in 3D printing.
So my question is: What other vendors support upgradable printers? Particularly upgradability of one printer over the course of several years, through a sequence of upgrades?
RE: What's next for the MK4 line?
Things I would like to see, but probably wont happen.
400C hotend I think the draw back is the number of MK systems with PETG parts. I am willing to replace the parts needed to support a 400C hotend.
Aluminum heat bed
INDX for MK4s, That may be a user mod.
Some sort of linear motor closed loop system, that is affordable.
There is a lot updates to firmware and PrusaSlicer can do.
RE: What's next for the MK4 line?
400C hotend I think the draw back is the number of MK systems with PETG parts. I am willing to replace the parts needed to support a 400C hotend.
Why 400C for PETG? It's my understanding that 230C is fine for PETG, and that Prusa uses current Prusa printers to print parts for new products.
It's possible that Prusa might move to nylon or CF-based filaments for future printers, and those might benefit from extruders that support even higher temperatures.
Aluminum heat bed
That seems like an easy choice. My ongoing struggle with the MK4S - including today, literally - is printing larger models where the first layer reaches the edges or (especially) corners of the bed, where the bed temperature might be 10 degrees cooler. My failures of large-scale prints are almost always at the periphery where the filament didn't stick and either immediately curled/clumped up or curled later in the print.
It's clear that Prusa is aware of these issues, given its emphasis on consistent bed temperatures in its sales pitches for the CORE One. I agree with you that improvements to the MK4 line in this aspect are overdue.
INDX for MK4s, That may be a user mod.
I'm very eager to take the plunge on multi-material printing with the MK4 line, but of course I need any such solutions to be compatible with the Prusa enclosures. I think that the MMU3 is, but it's my sense that the MMU3 is still kind of crude and buggy, and that INDX is a step forward.
There is a lot updates to firmware and PrusaSlicer can do.
There's still a ton of room for improvement in PrusaSlicer and Prusa Connect, that's for sure.
But for actual print quality, I think that the value-add of firmware updates is limited to refinements of the operation of the hardware. For instance, the biggest functional improvement for the MK4S in the 2.6.0 firmware is auto-retraction, which can best be described as a mild convenience. I think that the ability to improve the MK4S is largely constrained by the limitations of its hardware.
RE: What's next for the MK4 line?
I don't see the INDX coming to bedslingers anytime soon, I mean how would it work anyway? I guess you could make a very limited system with only 2 nozzles parked next to the Z-rods, but that's about it, would be cool and useful in a PETG/PLA + support/ Flex and not that expensive to implement, so yeah sure, why not! But It's not like they're gonna "discontinue" the whole bedslinger style any time soon but development is most likely gonna slow down.. The whole point of these printers are simplicity = low cost, and ease of maintenance. As for 400C nozzles? that's also like, why?
I also think that bedslingers are kind of maxed out when it comes to speed, you can only swing a plastic part back and fourth so fast before it starts resonating beyond control, and at least with my mk4s the surface quality is on par with (if not better) my friends x1c, I haven't tested this but I suspect layer adhesion(pla/petG) with default profiles is slightly better on the mk4s.. would be interesting to test.
I can feel for you getting the big bulky and rather expensive enclosures, that's something I wouldn't do. They're not gonna get usefully warm inside anyway, I'd just put a bag over my mk4s if I need to eliminate drafts or raise the temp a hair...