Prusa i3 MK2

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Prusa i3 MK2 Documentation
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Prusa i3 MK2

Release status: working

Prusa i3 MK2 is a design by Josef Prusa.
CAD Models
External Link

The Prusa i3 (iteration 3) MK2 is the most popular 3D Printer design by RepRap Core Developer Prusajr. The i3 MK2 incorporates lessons learned from the previous three Prusa designs. See also: Prusa Mendel (iteration 2), Prusa i3 MK3.

Infobox info icon.svg.png Derivates
The Prusa i3 is a very popular design, which led to many people creating derivates. We list these derivates in Category: Prusa i3 Derivate. Also check the Prusa i3 Variants page, as well as the Prusa i3 Development page


Main improvements

The following is a list of the main improvements made upon the Prusa Mendel Iteration 3

  • Enhanced frame rigidity by conection the Y axis to the PSU cover.
  • Easy assembly
  • Bigger build area (250x210x200mm)
  • Zoned PCB heatbed MK42
  • Better Z motors
  • Automatic bed leveling with an inductive proximity sensor


The development of the Prusa i3 MK2 is hosted on github:


Offical kit available (May 2016)

In May 2016, the official kit became available from Prusa.

Multi Material upgrade available (September 2016)

Multi Material kit has been released in September 2016.

This kit allows you to print not only just one filament, but also 2-4 colors simultaneously. Since multi material extruders take huge place on the X-axis, prusa decided to use Bowden type extruders instead of direct drive system.

MK2S has been available (March 2017)

In March 2017, the MK2S has been released. This update contains following components:

  • Better LM8UU mounting on Y axis
  • Better LM8UUs and smooth rods
  • Better P.I.N.D.A. probe mount
  • Improved cable stress relief on extruder
  • Better electronics cover

MK2 users are able to get upgrade kit for $49. When this upgrade has been announced, new shipments of the MK2 was automatically upgraded to MK2"S".

MK3 and MK2.5 upgrade (February 2018)

Following the release of the Prusa i3 MK3, Prusa3D released two upgrade kits - a full MK3 upgrade and a partial MK2.5 upgrade. The MK2.5 upgrade offers most of the functionality of the MK3 (except power panic, a more rigid frame, a taller Z axis and smoother stepper drivers) for about 1/3 of the price,because a full MK3 upgrade requires all electronics to be swapped out for 24V variants.

Further development of the MK2.5 is identical to MK3 in most aspects, using just slightly modified printed parts and firmware.

MK2/S discontinued (February 2019)

In the MK3S release announcement, Prusa stated that the MK2S is no longer being produced and that stocks are dwindling. The MK2S can no longer be ordered from Prusa.

Printed Parts

OpenSCAD files for the printed parts are available on the Github repository or Prusa Research.



The original printer runs on 12V.

Inductive proximity sensor (PINDA)

The original printer uses a custom - made "PINDA probe". It is a 5V NPN normally closed inductive proximity sensor. The probe is 35mm long and has an M8 thread on the outside. It has a 4mm sensing range with 3% repeat accuracy and a 1000/s sample rate.

Stepper Motors

The Prusa i3 MK2 uses, including the extruder, 5 NEMA17 stepper motors. Two of these motors, the Z axis motors, are connected to the same stepper driver of the electronics and have integrated trapezoid leadscrews.

Controller Electronics

In it's original configuration Prusa i3 MK2 is using RAMBo mini board from Ultimachine.


Prusa i3 MK2 extruder is designed around E3D V6 hotend. It uses a 38mm NEMA17 stepper motor with a hobbled gear mounted directly to the motor's shaft.

Heated Bed

The Prusa i3 MK2 was released together with PCB Heatbed MK42. There is a PEI sheet glued on top of the PCB for print adhesion. There 9 metal discs embedded in the heatbed that serve as measuring points for the inductive sensor. The measuring points are placed in a grid pattern and the printer can compensate for a warped bed after measuring the height of every measuring point compared to the others.