Prusa I3 MK2.5-MK3 Extruder upgrade

With the new Add-On this kit supports MK3s filament sensor.

This extruder upgrade kit is for the Prusa MK2.5 or the Prusa MK3 where you already have our Bondtech gears. This kit contains the necessary parts to convert to our freshly designed extruder that uses 3:1 gearing ratio for improved precision and resolution, optimized geometry for the heat-sink cooling and many other improved features.
It also reduces the moving weight to reduce vibrations and ghosting.

This is a co-development work with awsome 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 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 spent in this project and we have tried to listen to all the inputs in order to find a solution that can be fitted to a Prusa I3 MK2, MK2S, MK2.5 and MK3.

The extruder parts are not optimized for FDM printing but for SLS printing that we use to produce the housing parts in polyamide 12 for maximum precision and strength.

This kit comes with this 25 mm pancake stepper that have 18 Ncm in torque for a lightweight but powerful extrusion and a new stepper cable for connecting the motor.

The original part-cooling fan 50×15 radial fan is used in this setup and is not included.

The original 40x40x10 heat-sink cooling fan is used in this setup and is not included.
For more effective HotEnd cooling we recommend a fan with high pressure like Sunon’s MF40100V1-1000U-G99 or similar.

The original filament sensor cover is used and is not included.

This extruder will fit the stock  MK2.5 / MK3 carriage’s and also other popular designs like Vecko, Zaribo and Bear. Check the guide for available X-Carriage here:

The E-steps needs to be updated to 415 for MK2, MK2s and MK2.5 and is easy to do by downloading this g-code file, put it on the SD card and select to print the file esteps.gcode which will set the esteps and save it. For MK3 it needs to be 830 as it uses 32 bit microstepping, use this file instead.

Weight reduction is 121 g, from 387 g as default setup compared to 266 g for this setup (Extruder, motor)

MMU2s

To use the MMU2s together with the Bondtech an extra Add-On is required. This will allow sensor to trigger once the filament is reaching the drive gears.