8.0
Prusa MK4
How
Fantastic print quality
Fast and accurate
Open source
I do not like it
Expensive even as a kit
Too little and almost too late
For almost a decade, the Prusa Mk3 has been the best 3D printer you could buy it for less than $1,000, and the Mk4 – the natural evolution of the MK3 – would have retained that top spot if the landscape hadn’t changed so much in the last year. Now the MK4 is still a good machine, but is it great compared to the competition?
If you’ve been into 3D printing at all in the last 10 years, you’ll probably recognize the shape and even the colors of the Prusa Mk4. Prusa Research has been making open source printers for as long as I’ve been in the 3D printing industry, and the iconic black and orange Bedslinger is synonymous with excellent print quality and a sense of community.
The Mk4 has broadly the same shape and design as the Mk3, but features a lot of refinement. The MK4’s frame is made from thicker aluminum than the Mk3, providing greater stability, which is necessary when accelerating at the speeds these machines now travel at. The Mk4 also features an all-new extruder system called Nextruder, which uses a dual gear system to control material flow. This is particularly helpful with TPU – the very flexible filament used in phone cases – as it forces the pliable material to behave as it passes through the nozzle. The nozzle is also replaceable using a very simple, hand-tight screw mechanism. This allows you to change the nozzle size between prints, allowing you to use smaller nozzles for details and a larger nozzle for structural parts.
In fact, almost no part of the Mk3 is present in the MK4 in any meaningful way. It looks the same, but every part that can be upgraded has been updated. Although there is an upgrade kit to turn your Mk3S+ into a Mk4, you shouldn’t bother; You’ll spend just as much and replace almost all the parts anyway. Simply buy the Mk4 and keep your Mk3 for other projects or, better yet, donate it to your local school.
Prusa MK4
| Construction volume (mm) | 210x250x220 |
|---|---|
| Hot ending | All metal |
| Extruder type | Next rudder with direct drive |
| Nozzle diameter mm | 0.4 (0.2, 0.6, 0.8 compatible) |
| Maximum nozzle temperature | 290c |
| Maximum temperature of the building board | 120c |
| Official speed limit | 600mm/s |
| Supported material | PLA, PETG, ABS, ASA, Flex, HIPS, PVA |
| Automatic bed leveling | Yes |
| Filament runout sensor | Yes |
| Connectivity | USB memory card, WLAN and Ethernet with limitations |
| Time lapse camera | NO |
| slicer | Prusa tailor |
With all the upgrades, you’d expect the Prusa Mk4 to be significantly better quality than the Mk3, and that’s difficult. The Mk3 always gave me the highest quality, and whenever I needed something to print as smoothly as possible, I used the Mk3. The Mk4 offers the same level of quality without significantly improving it. It maintains this extremely high standard while printing at least twice as fast.
I have printed with PLA, ABS, TPU and PETG for almost 100 hours so far and every print has turned out very well except for some severe stringing. Even in my CNET test print, the tips were severely warped, which isn’t that common these days. Despite using PrusaSlicer – the slicer designed specifically for the Mk4 – I was unable to print the standard profiles without stringing. For each profile, the temperature had to be reduced by 8 to 10 degrees Celsius.
The rest of the CNET test and every printout I printed went very well. The details on this red dragon from Fotis Mint are exquisite, although you can see some lacing here too. Both the overhang test and the lockup test were near perfect even at the hardest levels, and the tolerance test – one of the toughest tests on the CNET model – showed that all four parts were easily removed. This is rare and only happens on five of the dozens of 3D printers I have tested over the years.
I am impressed with the quality of the prints on the MK4 and am pleased that it maintains the quality we expect from Prusa Research, even at high print speeds. The work that PrusSlicer does to ensure that these models are outstanding also deserves special praise. The organic supports that PrusaSlicer uses are nothing short of miraculous and have nearly eliminated the scarring that used to occur when printing with supports.
PrusaSlicer supports are excellent but stringing is poor
Even though speed isn’t everything, it is incredibly important in this day and age. When most of the best 3D printers are now fast 3D printers, Prusa needs to keep up with changing times. They almost didn’t make it and released the MK4 with no speed limit whatsoever over the Mk3. Luckily, Prusa managed to release an update within a few weeks, which helped keep the printer in the top 10 printers available to buy. Just two years ago, one could have argued that speed only degrades quality, and that is why manufacturers focused not on that but on that X1 Carbon from Bambu Lab To prove that you can achieve both speed and quality, every manufacturer must focus on both areas to be successful.
I would also like to see a more user friendly setup for using a network on the MK4. Although it has both WiFi and an Ethernet port, both require software other than the slicer to operate, making them complicated. Modern 3D printers should have easy access to remote printing and perhaps even an app. Prusa is well-positioned to do this as it only has a stake in PrusaSlicer, one of the companies best slicers There isn’t, but printables.com is, one of the best repositories for 3D models on the Internet. These resources should be pooled together to make printing on the MK4 from anywhere a breeze. Unfortunately, it requires a lot of shenanigans to achieve this.
Prusa has maintained its open source roots with the Mk4, which we all appreciate. The greatest achievement of the Mk2/Mk3/Mk4 series has been the ability to expand, update and tinker with it without fear, as long as you stick to the open source rules. This has resulted in some amazing projects, coursework, and life-saving techniques, and I think open source printers will always have a place in our community. Prusa is one of the last bastions of truly open source hardware, and I think it can preserve those roots while advancing 3D printing.
I like the Prusa Mk4, that’s true, but I think this will have to be the last upgrade of its kind. Iterative design has worked great for a while – look at the iPhone as an example – and I have no problem with incremental upgrades, but the MK5, or whatever they call the next machine, will have to be something completely different and vastly improved when Prusa wants to remain at the forefront of the consumer 3D printing market. The Prusa XLa 3D printer with multi-head tool changing for manufacturing, has many excellent innovations that I would like to see passed on to its smaller brother.
Last is the price. 18 months ago, $1,100 for the new Prusa printer would have been a perfectly reasonable amount of money. However, we now have printers that are almost as good, if not on par with the Mk4, but significantly cheaper. Luckily you can fit the Mk4 Kit form for $800, which is much more sensible, and I still think if you’re interested in how 3D printers work, then a DIY kit is the best way to get into the hobby. However, if you are only interested in the end result, there are some better options out there.
