Prusa I3 MK2.5S / MK3S Extruder upgrade
A lightweight high-resolution extruder upgrade for the popular Prusa I3 MK3S 3D printers, optimized design with the help of the community.
This Upgrade Kit does not include the gears (already supplied by Prusa).
This Upgrade Kit requires extra parts to install (X-Carriage Kit).
You can buy it from us or you can download the STLs and 3D print them. Check download links in the Resources section.
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:
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.
Article number : EXT-KIT-68
EAN code : 7350011410651
Net weight : 291,5g
Gross weight : 380,2g
Package Size : 137x94x65mm
Gearing ratio : 3:1
E-steps value : 830
Extruder Housing: SLS Printed parts in Polyamide 12;
Lightweight 25 mm pancake stepper with 18 N/m torque.
Max Input Current : 0.8A
Max chamber working temperature : 80℃
343,2g of parts coming out and 291,5g of parts coming in. A 51g (15%) weight save.
X-Carriage: Requires buying or 3D printing new X-Carriage R2 Front and Rear;
Firmware: Bondtech adapted version required.
Licensing: This Project is licenced under GPL V3.0 and the STEP-files are available for download.
Bondtech Github. Contains Stepfile, installation manual, exploded view, and others.
The STL Files For Additional Parts Required Available As Free Download
The 3D printed parts of this kit can be downloaded from our server.
MK2.5S / MK3S: Click here to download the Rear.
Note! This firmware is for Mk2.5s and MK3s users with the new filament sensor.
Bondtech specific changes:
- Estep set to 830. (415 for MK2.5s)
- Adjusted Z_MAX_POS 205 to allow Z and XYZ calibration.
- Changed printer name.
Download the firmware here:
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