Original Prusa i3 MK3 Review

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Released in late 2017, the Original Prusa i3 MK3 is the newest version in the Prusa i3 family, designed by Josef Prusa and distributed by his own company, Prusa Research. It is the direct successor to the MK2 and the MK2S, rolling out with a dizzying number of upgrades and innovations other 3D printers under $1,000 can’t hope to match right now.

The MK3 is unlike any other product currently out on the market. It’s an almost flawless 3D printer, boasting a package of smart features that serve to make 3D printing as easy and as accessible as possible to everyone, from complete beginners to hobbyists and professionals.

Shipped from the Czech Republic, the MK3 is available in two packages, similar to the MK2: a DIY kit package and a pre-assembled package. For the DIY kit, the listed price on the Prusa Research official site is $749, while the pre-assembled package goes for $999. Keep in mind the tax and the shipping fee are not included in both listed prices.

It’s recommended that you go for the cheaper DIY kit. Because assembling a 3D printer from scratch will not only teach you about the inner mechanics of 3D printers but also make you more prepared for troubleshooting the inevitable issues down the road. And quite frankly, the $200+ price difference is a significant amount for most folks.

Unlike most other 3D printers, the MK3 is not readily available at popular online stores. Prusa Research ships the MK3 in batches, so the waiting game is longer than usual. Lots of customers have had to wait for weeks for their unit to arrive, especially the early birds in 2017. But don’t worry, the MK3 is definitely worth the wait.

It’s easy to get technical help for the MK3. Prusa Research employs a customer service team ready to answer inquiries anytime and in different languages. In addition, there are unofficial groups online that you can turn to in case you need help, most especially during the assembly of the MK3 DIY kit.

The Design

The open-framed MK3 looks identical to the MK2 and MK2S, at least on the surface level. It’s got the familiar orange-and-black color scheme and the LCD interface mounted at the base. But the similarities end there. The MK3 boasts upgrades in every other area.

A Cartesian style 3D printer, the MK3 is more robust than the MK2S, featuring a reworked Y-axis and a more stable aluminum frame overall. The print head is equipped with dual fans and a Bondtech extruder, which comes with a pair of gears for more force during the filament feed. This setup makes the MK3 more reliable, especially with flexible filaments. The print head also comes with an E3D V6 nozzle that can easily handle different types of materials with little to no issues.

The MK3 has a magnetic heated bed equipped with a replaceable spring steel sheet with a PEI surface, giving the print bed excellent adhesion out of the box and making the print removal extremely easy. The magnetic bed is not as flimsy as other magnetic print beds seen on other 3D printers – the magnets are really strong and have no trouble keeping the print bed in place. By default, Prusa Research includes the smooth PEI sheet in the package, but you can also opt for the textured, powder-coated PEI.

Most importantly, the motherboard the MK3 comes with is brand-new. The EINSY RAMBo motherboard with Trinamic drivers is the chief reason the MK3 runs a smooth and impossibly quiet operation. In addition, it can accurately detect and fix shifted layers, which translates to more consistency and better prints every time.

Like with the MK2 and MK2S, the spool holder of the MK3 is attached at the top. For other 3D printers with a similar setup, a top-mounted spool holder can affect the stability. This isn’t the case with the MK3, however. On the flip side, the spool holder can be tricky to attach. But the good news is that you can easily print a new one in case you break it during the assembly.

The Setup

The MK3 arrives in an impeccably organized and tightly secured package. Prusa Research has good quality control, which is even more impressive once you consider the sheer number of units the company ships per batch. In case you haven’t heard, the Prusa i3 printers are the most popular 3D printers in the world.

DIY kits are known for being a pain in the butt, especially for beginners. For most DIY kits, the daunting assembly process can take over 10 hours, and that doesn’t even include the initial calibration. But the MK3 DIY kit isn’t like that. It’s the easiest DIY kit to assemble, not counting semi-assembled DIY 3D printers like the Creality CR-10S.

The MK3 can be fully assembled in just six hours – Prusa Research says the current record is four hours, which is almost comical considering all the parts involved. And the biggest reason for that unbelievably fast assembly time is the comprehensive instruction manual for the MK3. It’s obvious that Prusa Research spent a lot of time on the manual to make sure everyone gets everything right the first time around. It’s detailed, easy to follow, and includes high-quality images.

Everything you need to get started right away is included in the package, and that includes a spool of PLA filament, pre-loaded tests models on the included SD card, and even a handbook that covers the basics of 3D printing. The latter is especially notable since lots of manufacturers don’t even bother with documentation, let alone a well-written handbook.

Once fully assembled, the MK3 lets you start your fun in less than one hour. Loading the filament is extremely easy and leveling the print bed is a trivial matter, courtesy of the automatic bed leveling technology. The automatic bed leveling technology ensures that the print head is always at an optimal distance from the print bed. In addition to all of that, the MK3 is already loaded with good print settings, so the first few prints won’t look like absolute crap, which is often the case for most DIY 3D printers.

The MK3 is compatible with most printing software, including Cura and Simplify3D. But in case you prefer a printing software that specifically caters to the Prusa i3, you can use either PrusaControl or Slic3r Prusa Edition. The former is meant for casuals and beginners while the latter includes more advanced options for intermediate users.

The Features

There’s a lot to unpack here. Seriously, the MK3 is so packed with features that it’s ridiculous it doesn’t retail for over $2,000. First of all, the MK3 is a completely open source 3D printer – the Prusa i3 design was Josef Prusa’s contribution to the RepRap project. This means the MK3 source files are easily accessible on the internet for everyone, from individuals to companies, to use.

The MK3 is a smart 3D printer. It’s equipped with a number of sensors designed to keep the entire operation safe, convenient, and idiot-proof. Leading the way is the filament sensor, which keeps track of the presence and movement of the filament. The moment the MK3 detects it is about to run out of filament, it pauses the print to allow you to load a fresh spool of filament.

Furthermore, the MK3 can detect a clogged nozzle, in which case the procedure is the same: the MK3 pauses the print and offers you the chance to clean the nozzle before resuming the print. Though a lot more reliable than the filament sensors on other 3D printers, the MK3 filament sensor isn’t 100 percent on point. It’s easily fooled by clear filaments, so it’s best to turn it off before you print with transparent materials.

The MK3 comes with a power panic feature. In case of a power loss, the MK3 shuts down all the heating components and – get this – moves the print head to the side in order to keep the already printed object from getting messed up. And as soon as the power comes back, the MK3 can resume from where it left off as if nothing happened.

On a related note, the MK3 can also detect if the print head is being compromised. If you hold the print head during prints and prevent it from moving, the MK3 will immediately stop the operation to avoid potential damage. Finally, the MK3 comes with a pair of thermistors. The first thermistor measures the ambient temperature while the second is set in the PINDA 2 probe to account for temperature drift.

For connectivity, the MK3 can connect through USB and SD card by default, with an option for wireless connectivity. The default connectivity options should be enough for you unless you really want to send prints over the network.

The Performance

The MK3 is easy to prepare for prints. As noted above, loading the filament is extremely easy and will not require you to make significant adjustments. In addition, the print bed heats up really fast, embarrassing the slow-heating print bed of the Creality CR-10S, arguably the second-best 3D printer under $1,000.

The MK3 print quality is beyond impressive. If you’ve seen 3D models produced by the MK2 or MK2S, then you know what to expect. It’s smooth, accurate, and ridiculously detailed. It’s definitely right up there with the print quality of the Ultimaker 3, the LulzBot TAZ 6, and the Creality CR-10S – three of the most highly regarded 3D printers on the market.

For example, the MK3 can create the popular Eiffel Tower 3D model, which involves intricate details, with incredible ease. It’s the same thing for everyone’s favorite test model, the 3DBenchy. The best part is that the MK3 is already capable of producing good results out of the box and will only require a fair amount of tinkering for more complex 3D models.

The MK3 is significantly faster than the MK2S, allowing you to print more objects per week. In addition to that, the MK3 is extremely quiet. It’s so quiet that you can barely hear it even at close range, even in the normal mode. The low noise level is really impressive, especially considering the MK3 is an open-framed 3D printer.

The MK3 has an open filament system and has no trouble printing with filaments from third-party manufacturers. It can already print with several types of materials out of the box with minimal tinkering on your part – most 3D printers are limited to PLA at the onset. The Bondtech extruder, the E3D V6 nozzle, and the heated build plate allow the MK3 to print with even the most complex materials. Combine that with the large build size of the MK3 and you get a lot of room for experimentation.

Prusa Research offers a multi-material upgrade for the MK3, which allows you to print with multiple filaments using just a single extruder system. It’s a good add-on if you want to be fancy and want colorful prints, but not something we recommend right off the bat.

The Verdict

Tech Specs
Resolution: 50 microns
Volume: 9.8 x 8.3 x 8.3 in
Filament: 1.75 mm
Types: ABS, PLA, Flexible, HIPS, Nylon, and others
Weight: 14 lb
Connect: USB, SD card
The Pros
Open source
Easy to use
Fantastic print quality
Extremely quiet
Removable magnetic heated print bed
Good adhesion on the print surface
Filament run-out sensor
Power panic
Crash detection
Automatic bed leveling
The Cons
Filament sensor has issues with clear filaments
No enclosure

This is a highly recommended 3D printer. The MK3 is one of the best 3D printers you can get today. It is without a doubt the best 3D printer under $1,000, edging out the Creality CR-10S by a significant margin. It offers outstanding quality for a reasonable price and comes with a truckload of features. There are only two legit reasons you should go for another product in the same price range: a) you are on a strict budget and would rather get a significantly cheaper product, and b) you want a larger build volume.

Original Prusa i3 MK3: 4.9/5

4.2/580 ratings
Warning; 3D printers should never be left unattended. They can pose a firesafety hazard.