Extruder Upgrade Kit Prusa i3 MK2.5/MK3
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.
NOTE: With the new Add-Ons this kit supports the MK3S filament sensor also. Download the files for the printable Add-Ons here.
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 MK2.5 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 a 25mm pancake stepper that have 18Ncm in torque for a lightweight but powerful extrusion and a new stepper cable for connecting the motor.
NOT included:
- The original 50×15 radial part-cooling fan is used in this setup and is therefore not included.
- The original 40x40x10 heat-sink cooling fan is used in this setup and is therefore 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 therefore 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.
NOTE: E-steps needs to be updated
The E-steps needs to be updated to 415 step/mm for 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 step/mm 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)
This project is licenced under GPL V3 and the STEP-files are available for download here.
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.
You can download the STL file bundle: MMU2s Add-On for Bondtech MK2.5/MK3
Documentation / Download Summary:
- Installation Manual for Prusa i3
- Printable Add-Ons for MK3S
- Guide for available X-Carriage
- G-code file for MK2.5
- G-code file for MK3
- STEP-files
- STL file bundle: MMU2s Add-On for Bondtech MK2.5/MK3
- Bondtech Firmware Variation Updates For Prusa 3D Printers
- Bondtech Prusa i3 - Firmware Update GUIDE