Prusa I3 MK2.5S/MK3S Extruder Upgrade Kit | Bondtech

  • Prusa I3 MK2.5S/MK3S Extruder Upgrade Kit | Bondtech
  • Prusa I3 MK2.5S/MK3S Extruder Upgrade Kit | Bondtech
  • Prusa I3 MK2.5S/MK3S Extruder Upgrade Kit | Bondtech
  • Prusa I3 MK2.5S/MK3S Extruder Upgrade Kit | Bondtech
Frequently bought together:


Bondtech Extruder for Prusa i3 MK3S & MK2.5S

Please Note: 

  • This Upgrade Kit does not include the gears (already supplied by Prusa)
  • This Upgrade Kit does require extra parts to install (X-Carriage Kit)

You can purchase the X-Carriage Kit here (SLS) or here (FFF)
Or you can download the STLs and 3D print them: Download the Front, Download the Back.

Firmware Update: To use this upgrade in the MK3S, the E-steps needs to be updated to 830, as it uses 32-bit microstepping. Use this file.

This kit contains the necessary parts to convert your current extruder to Bondtech's popular design based upon their BMG (Bondtech Mini Geared) extruder with 3:1 gearing ratio for better precision and resolution together with optimized geometry for the heatsink cooling and professional SLS 3D printed housing.
It is also compatible with the MK2.5S model.


With this version Bondtech has lowered the moving weight to reduce ghosting and vibrations or to allow increasing the printing speed. 15% of weight saving was achieved.


This extruder upgrade kit is for the Prusa i3 MK3S, or other Prusa i3 models upgraded to MK3S.

  • Adapted to fit Prusa’s new filament sensor;
  • Includes one Bondtech’s BMG extruder with 3:1 gearing ratio;
  • Optimized geometry for heat-sink cooling;
  • Less moving weight to reduce vibration and ghosting;
  • Professional SLS 3D printed housing.


The enhanced housing design improves cooling and decreases heat creeping issues that all metal hotends have when printing with PLA. This small enhancement will avoid many clogs.
The increased push force will drastically reduce slipping, shredding and deformation of the filament avoiding most of the common filament 3D printing issues that start with under and over extrusion.

Note from Bondtech: This is a co-development work with awesome guys in the Prusa Community like Chris Warkocki, Grégorie Saunier (Bear Upgrades), Olof Ogland, Erik Bjorgan, Josh Jones, Kyle Wiehe, Marc Evertz, Matt Harrison, Ocie Ward, Sando Bendig, Vecko Kojchevski (Vecko Extruder), Steven Mölby, and Yuri Delia that have provided excellent feedback and suggestions of how to develop the “perfect” extruder setup for the Prusa series printer. A lot of work has been put in this project and we tried to listen to all the inputs in order to find a solution that can be the best fit to the Prusa I3 MK3S.



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