Prusa I3 MK2.5S-MK3S Bondtech Extruder Upgrade

Upgrade Your Extruder

Upgrade your extruder to a Bondtech Mini Geared with higher gear ratio – 3:1 – that allows for extra push force and higher resolution.

Print Faster Or With Higher Quality

Use a lightweight extruder that will allow your 3D printer to print faster or to achieve better surface quality.

Reduce 3D Printing Issues

Decrease the risk of heat creep to avoid clogs and improve filament feeding to avoid slipping and deformation that cause under and over extrusion issues.

Upgrade kit With Optimized Design

This is the latest generation Bondtech upgrade for the popular Prusa I3 MK3S, with an optimized design achieved with the help of the community.

Bondtech Extruder For Prusa i3 MK2.5S & MK3S

This kit contains only the necessary parts to convert your current extruder to our own popular design based upon our 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.

Lightweight BMG (Bondtech Mini Geared)

With this version we also lower the moving weight to reduce ghosting and vibrations or to allow increasing the printing speed. 15% of weight saving was achieved.

Product Main Features

This extruder upgrade kit is for the Prusa i3 MK2.5S / MK3S.
These are its main features:

• 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.

Addressing 3D printing Issues

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.

Updating the Firmware

To use this upgrade in the MK2.5S / MK3S, the E-steps and Z_Max needs to be updated. Check out the latest version of our firmware 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.
All credits to Leon Van Roosmalen for his amazing design. Download and print it from here: Bondtech Prusa MMU2S MK2.5S / MK3S Adaptation.

Community involvement

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.