Prusa i3 MK3S+ 3D Printer Review

The Original Prusa i3 MK3S is one of the best 3D printers on the market. Read on to find out about its performance, specs, print quality and setup.

Original Prusa i3 MK3S+ Review

Prusa is one of the leading 3D printing manufacturing companies in the world. The company is constantly improving its open-source ecosystem, from software to hardware. The Prusa i3 MK3S is an upgrade that features recommendations collected from customers of previous Prusa printers.

Prusa i3 MK3S


Original Prusa i3 MK3S Specs

Printer Specs

Manufacturer Prusa Research
Build Volume 250 x 210 x 210 mm
Print Bed Heated, Removable, PEI Coating
Filament Diameter 1.75 mm
Layer Height 0.05 – 0.35 mm
Nozzle 0.4mm default, wide range of other diameters/nozzles supported
Third-Party Filament Yes
Max. Extruder Temperature 300°C / 572°F
Extruder Direct Drive, Bondtech gears, E3D V6 hotend
Max. Print Bed Temperature 120°C / 248°F
Print Surface Removable magnetic steel sheets(*) with different surface finishes, heatbed with cold corners compensation
Supported Materials Wide range of thermoplastics, including PLA, PETG, ASA, ABS, PC (Polycarbonate), CPE, PVA/BVOH, PVB, HIPS, PP (Polypropylene), Flex, nGen, Nylon, Carbon filled, Woodfill and other filled materials.
Connectivity SD Card, USB
Onboard Controls Yes

Power & Software

Host/Slicer Software TabPrusa Control/Prusa Slic3r
OS Mac, Windows, Linux
Firmware Marlin
Open Software/Hardware Yes (GNU GPLv3)
Power Consumption PLA settings: 80W / ABS settings: 120W

Physical Dimensions

Printer Dimensions (without spool) 50×55×40 cm; 19.6×21.6×15.7 in (X×Y×Z)
Weight 7 kg

The technical specs of the MK3 are largely the same as that of the MK printer. Here are the specs:

Prusa i3 MK3S Features

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The Prusa i3 MK3S+ looks like its predecessor. The printer has a sturdy frame with the iconic orange-colored 3D parts. Staple features found in modern 3D printers, such as power recovery and removeable magnetic print bed are also in this printer.

Redesigned Extruder

The new Prusa i3 MK3S features a redesigned extruder system. This extruder has been redesigned to make it easy for users to change the nozzle of the PTFE tubing without having to take apart the whole assembly.

Apart from this, the nozzle and the extruder nozzle are now closer to the X-axis. This helps to reduce resonance while improving print quality.  The new extruder also has better Y-axis belt tensioning and improved cooling.

Updated Filament Sensor

The Prusa i3 MK3S also has a new optical filament sensor that makes it compatible with specific filaments. This sensor is more reliable than the original sensor.

The new optical filament sensor is triggered by a simple mechanical lever. This way, it is not affected by the optical properties of the filament.

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Older Enhancements Included

The older enhancements found in the Original MK3 printer have also been incorporated in the MK3S. Examples of these enhancements include anti-rust coating for the PEI sheets, a new Einsy case, textile sleeves to replace spiral wraps, new genuine Gates belts, more robust plastic parts, and dozens of firmware.

New Print Profiles on Slic3r Software

Apart from hardware upgrades, the MK3 also has some software upgrades. New print profiles have been included in the Slic3r Prusa Edition 1.41.3 or newer versions.

You can download the latest version of the software here.

The slicing software now has a new 70μm profile that offers an option of between 50μm and 100μm. This is a great alternative for 3D printing miniatures.

The 150μm Optimal and 200μm profiles have also been packaged into Quality and Speed modes, respectively. The Quality mode ensures your prints come up with high details while the Speed mode improves the printing speed without compromising quality.

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Upgrades & Pricing

The fully assembled Prusa i3 MK3S model comes at a higher price (check current price) than the DIY kit (check current price).

If you have the old Prusa MK3, you can purchase the upgrade kit (check current price) if you will be printing the plastic parts on your own. If you don’t want to print the parts, there is an additional charge of about $40.

Old Features of the Prusa i3 MK3S

MK52 Magnetic Heatbed

The Prusa i3 MK3S has a removable magnetic PEI-coated spring steel bed. This heatbed makes it easy to use the printer. As the sheet cools down, you can pop off the parts by simply flexing the sheet inwards.

Automatic Bed Leveling

The Prusa i3 MK3S has automatic bed leveling, which ensures you get accurate prints the first time.

Power Panic

The MK3S can recover and resume print jobs in case of a power loss thanks to its EINSY RAMBo motherboard. The printer can monitor power to detect blown fuses. Moreover, there are Trinamic drivers that are super-fast, quiet and can correct layer shift during the printing process.

Prusa i3 MK3S Test Prints

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The Prusa i3 MK3S is not a complete overhaul of the MK3. Therefore, it does not have a lot of new features. Nevertheless, it is still a worthy upgrade.

The print quality is mostly the same as you would get with an MK3. However, there are some improvements that we noted.


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We printed the 3DBenchy using the Prusa i3 MK3S and we were impressed. The printer easily handled the tricky overhangs and curves of the boat.

Autodesk Kickstarter Test

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We used the i3 MK3S to print the Autodesk Kickstarter, and we noted some differences:

  • Z-axis alignment: 2.5 of 2.5 (no layer registration effect was visible)
  • XY Resonance: 2.5 of 2.5 (no ringing was detectable)
  • Bridging: 5 of 5 points (no bridges contacted the surface beneath them)
  • 2 of 5 points (30°, 20° and 15° overhangs showed some minor irregularities)
  • Fine Negative Features: 5 of 5 points (all pins were removable by hand)
  • Fine Flow Control: 2.5 of 5 points (the spikes were printed to their full height. However, there was some stringing at the top)
  • Dimensional Accuracy: 5 of 5 points

Overall, the printer attained 24.5 out of 30 points

Fun Prints

We also printed other items with the MK3S. For example, the golden vase was flawless, apart from a small crease on the base.

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The vintage VW bus also turned out well. This was a three-part print as we had to switch to different filament colors.

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This print of a funny looking guy also came out nicely. The print was a bit stiff at first but then loosened.

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Generally, we loved how our fun prints turned out.

Long Distance Prints

With long distance prints, we experienced some problems. For example, we tried to print a plague mask. Initially, the print went well.

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However, after the job had been completed in 39 hours and 30 minutes, we ended up with a filament nest.

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A second trial print also failed but at a different spot. However, we were impressed that the printer noticed the failure and immediately stopped printing. This helped to save some of our filament.

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We tried another long-distance print, this time with a bowl skull and the job was successful. However, the print had about a centimeter of layer shifting and the default setting support structures were way too hard to take off.

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Apart from the problems we experienced with the plague mask, the Prusa i3 MK3S handled all prints hassle-free.

Software: Slic3r Review

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The Prusa i3 MK3S slicer has a simple design and is easy to use. This powerful slicer comes with multiple customization options and settings.

The software is fairly easy to get started with. When you open it, you will see preconfigured settings for most common Prusa filaments as well as the different Prusa 3D printers.

While Cura is a one-size-fits-all slicer, the Prusa Slic3r is particularly developed for Prusa 3D printers.

Our Verdict

The Prusa i3 MK3S is reliable, well-built, and produces high quality prints. This printer is easy to use and delivers consistently.  While the printer is certainly not a budget option, its performance justifies the price.

Moreover, there is a huge community base of Prusa fans online that will be happy to help you with any issues you may encounter.

Finally, since the printer is open source, it can be hacked and upgraded.

But if you are looking for a similar printer to the Prusa i3 MK3S, check the Anycubic Mega S.

 Why We Love the Prusa i3 MK3S

  • Excellent customer support from Prusa
  • Comes with Slic3r PE slicing software, which is easy to use
  • Beautiful bridging and overhangs
  • Print, pause, and restart capabilities
  • Crash detection
  • Autocalibration
  • Large and helpful community
  • Sturdy build
  • Exceptional print quality

What You Should Be Aware Of

  • This printer is not a major upgrade to the old i3 MK3
  • Has dense support structures in default settings
  • Long distance prints are less reliable

Verdict: Prusa i3 MK3S 3D Printer Review

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The Original Prusa i3 MK3S does not disappoint. The printer works great in default settings, producing exceptional prints. This easy-to-use machine is not particularly different from the previous version. However, the updates improve its overall performance.

The Prusa i3 MK3S straight-out works. The printer’s slicer is easy to use and the prints pop off easily. While you may struggle with long-distance prints, the models printed are impressive. This is definitely one of the best 3D printers for the money.

Where to Buy the Prusa i3 MK3S+ 3D Printer

You can buy the Prusa i3 MK3S 3D printer at Prusa or Top3DShop.

Here is a video review of the Prusa i3 MK3S 3D printer:


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