Prusa MK4

The Prusa MK4 is an FDM 3D printer from Prusa with a 250 x 210 x 220 mm build volume.

Specifications

The Original Prusa MK4 (launched in 2023) represents the latest generation of FDM 3D printers based on the classic i3 Cartesian bedslinger layout developed by Prusa Research. Succeeding the widely acclaimed MK3S+, the MK4 introduces a complete 32-bit electronics platform, upgraded kinematics optimized for Input Shaping (resonance compensation), and the innovative Nextruder extrusion system featuring an integrated load cell.

Hotend and Extruder (Nextruder)

The mechanical core of the MK4 is the Nextruder: a direct-drive extruder incorporating a custom planetary gear reduction system (5.06:1 ratio) and a compact pancake stepper motor.

Calibration

To maintain optimal print quality and mechanical precision on the Prusa MK4, implement the following operational checks and calibration routines:

• Perform Load Cell Calibration:

During initial setup or after changing hotend components, execute the Load Cell test via the LCD menu. The nozzle tip must be completely clean and free of plastic residue; cold plastic behaves like a cushion and skews the load sensor readings.

Common defects

• Hardware defects and mechanical weaknesses
• PEI Sheet Dents from Calibration Overforce: Users have reported instances where the nozzle presses too hard into the PEI sheet during bed probing, leaving circular indentations. This occurs if there is cold, hardened filament on the nozzle tip, which acts as a solid spacer and delays the load cell trigger, or if the LoveBoard fails to transmit the contact signal instantly. Solution: Keep the nozzle clean.

What it is used for

Recommended Applications

• Rapid Functional Prototyping: Thanks to 0.9° stepper motors, Input Shaping, and Nextruder precision, the MK4 is ideal for producing high-accuracy functional prototypes with tight tolerances.