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Introduction

Product Page

This Guide relates to this Prusa i3 MK2.5S / MK3S Upgrade Kit:

https://www.bondtech.se/en/product/prusa...


Acknowledgements

This is a co-development work with some 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), and last but not least 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, MK3, and MK3S.


Compatibility

The upgrade is compatible with the following machines:

Prusa i3 MK2.5S
Prusa i3 MK3S


Additional Information

The pictures in this guide is captured using a MK3s printer but can be applied to MK2.5S, with the exception of connecting the cables to your board. Please check Prusa's electronics guide on how to connect the cables on your specific board.


You will need :

  1. Before stripping down your printer, you can buy here or download and 3D print these models using Black PLA: Download X-Carriage R2 Rear
    • Before stripping down your printer, you can buy here or download and 3D print these models using Black PLA:

    • Download X-Carriage R2 Rear

    • MK3s users Download this X-Carriage R2 by Bondtech

    • MK2.5s users Download this X-Carriage R2 by Bondtech

    • If you are using Bear X-Ends or Revised X-Axis...

    • ... Download this X-Carriage by Bear Upgrades instead.

    • ... or Download this X-Carriage by Vecko Kojchevski instead.

  2. Before stripping down your printer, we recommend you to download and 3D print our PTFE Cutting Fixture.
    • Before stripping down your printer, we recommend you to download and 3D print our PTFE Cutting Fixture.

    • Download the PTFE Cutting Fixture

    • This step is optional. You can cut the PTFE tube without this fixture, but it's not so easy, and the risks of getting a bad cut are higher.

  3. In the User Interface rotate the Control knob no navigate and press it to select options. First search and select the option Unload Material Then select the material you have loaded to initiate unloading.
    • In the User Interface rotate the Control knob no navigate and press it to select options.

    • First search and select the option Unload Material

    • Then select the material you have loaded to initiate unloading.

    • After reaching processing temperature pull the filament up and out of the extruder.

    • If you will reuse the heater and thermistor for your Mosquito HotEnd it's recommended to loosen them now as they may get stuck when the heatblock is cooled down. Turn the printer off or set HotEnd temperature to 0 before preforming this step. The heater will get really hot otherwise.

    • Make sure the HotEnd have cooled down before you start stripping down the extruder.

  4. On the right hand side of the printer Turn the switch off. Disconnect the power cable.
    • On the right hand side of the printer

    • Turn the switch off.

    • Disconnect the power cable.

  5. On the left hand side of the printer This screw holds the Control Box back door. Use the 2.5mm Hex Key to unscrew it.
    • On the left hand side of the printer

    • This screw holds the Control Box back door.

    • Use the 2.5mm Hex Key to unscrew it.

    • While you unscrew it, the back cover will open.

    • Remove the screw and open the back door wide.

  6. Unscrew these 2 screws Remove the plastic holder Put the main cable aside.
    • Unscrew these 2 screws

    • Remove the plastic holder

    • Put the main cable aside.

  7. In the back of the extruder locate the 3 zip ties holding the main cable Use cutting pliers to cut the 3 zip ties. The main cable and sleeve is now released.
    • In the back of the extruder locate the 3 zip ties holding the main cable

    • Use cutting pliers to cut the 3 zip ties.

    • The main cable and sleeve is now released.

  8. Gently peel the sleeve from the main cable starting near the print head until the other extremity. Gently peel the sleeve from the main cable starting near the print head until the other extremity. Gently peel the sleeve from the main cable starting near the print head until the other extremity.
    • Gently peel the sleeve from the main cable starting near the print head until the other extremity.

  9. Locate and unplug from the Control Box the following cables: Filament sensor cable Radial Fan Cable
    • Locate and unplug from the Control Box the following cables:

    • Filament sensor cable

    • Radial Fan Cable

    • Axial fan cable

    • PINDA Z-off set sensor cable

    • Extruder motor cable

    • Isolate them from the others to proceed.

  10. Unscrew this central screw. To detach the heat block cables holder Remove these 4 screws.
    • Unscrew this central screw.

    • To detach the heat block cables holder

    • Remove these 4 screws.

    • And detach the rear plate.

  11. The rear plate holds the 5 cables detached from the control unit. Start by removing the Radial Fan cable Remove the Axial Fan and Extruder Motor cables in any order.
    • The rear plate holds the 5 cables detached from the control unit.

    • Start by removing the Radial Fan cable

    • Remove the Axial Fan and Extruder Motor cables in any order.

    • Remove the PINDA cable in second place.

    • Leave the Filament Sensor cable to remove last

    • While removing the cables through the back plate hole, use caution instead of force.

  12. After removing the cables from the back plate remove and save the following:
    • After removing the cables from the back plate remove and save the following:

    • The 4 screws that hold the back plate.

    • The nut embedded in the plate.

    • These screws and nut will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  13. Loosen these 3 screws first. Then loosen the top screw to take tension from the belt. On the carriage, remove both belt ends, one at a time.
    • Loosen these 3 screws first.

    • Then loosen the top screw to take tension from the belt.

    • On the carriage, remove both belt ends, one at a time.

    • Take both ends away from the carriage and place them over the build plate.

    • During assembling these belt ends will be reconnected.

  14. Remove the 3.0mm filament cord from this carriage hole Hold the carriage and linear guides with one hand. Pull the cord away from the carriage with the other hand.
    • Remove the 3.0mm filament cord from this carriage hole

    • Hold the carriage and linear guides with one hand.

    • Pull the cord away from the carriage with the other hand.

  15. We will now remove the extruder from the linear guides. Hold the extruder with one hand while cutting the zip ties. Cut and remove one zip tie. Cut and remove the other zip tie.
    • We will now remove the extruder from the linear guides. Hold the extruder with one hand while cutting the zip ties.

    • Cut and remove one zip tie.

    • Cut and remove the other zip tie.

    • Move the extruder away from the linear guides.

  16. Remove the Filament Sensor cover by unscrewing this screw. Unplug the Filament Sensor cable and pull it away from the PCB. Unplug the Filament Sensor cable and pull it away from the PCB.
    • Remove the Filament Sensor cover by unscrewing this screw.

    • Unplug the Filament Sensor cable and pull it away from the PCB.

  17. This is the filament sensor PCB. Remove this screw first. Then remove the PCB and store it.
    • This is the filament sensor PCB.

    • Remove this screw first.

    • Then remove the PCB and store it.

    • The Filament Sensor PCB and its Set Screw will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  18. Remove this screw to release the PINDA probe. Pull the PINDA probe upwards. Store the PINDA probe.
    • Remove this screw to release the PINDA probe.

    • Pull the PINDA probe upwards.

    • Store the PINDA probe.

    • The PINDA probe will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  19. Remove these 2 screws to detach the Radial Fan. Store the Radial Fan
    • Remove these 2 screws to detach the Radial Fan.

    • Store the Radial Fan

    • The Radial Fan and cable will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  20. Remove these 4 screws to detach the Axial Fan. Store the axial fan.
    • Remove these 4 screws to detach the Axial Fan.

    • Store the axial fan.

    • The Axial Fan will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  21. Remove this screw to detach the Extruder-idler. The Extruder-idler includes the secondary gear that will be used to assemble the Bondtech MK2.5S / MK3S upgrade.
    • Remove this screw to detach the Extruder-idler.

    • The Extruder-idler includes the secondary gear that will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  22. The secondary drive gear is attached to the Idle Door. Use the Hex Key to push the gear out of the Idle Door. Store the Secondary Drive Gear components.
    • The secondary drive gear is attached to the Idle Door.

    • Use the Hex Key to push the gear out of the Idle Door.

    • Store the Secondary Drive Gear components.

  23. Insert the axis... inside the ball bearings... through the gear axis.
    • Insert the axis...

    • inside the ball bearings...

    • through the gear axis.

    • Store the Secondary Drive Gear.

    • The Secondary Drive Gear will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  24. Detach Extruder cable from the housing guide. Detach Extruder cable from the housing guide.
    • Detach Extruder cable from the housing guide.

  25. Unscrew and remove this screw. Unscrew and remove this screw.
    • Unscrew and remove this screw.

  26. To remove the carriage mount we need to loosen up 2 more screws. One sitting below the hotend on the left hand side. The other sitting below the hotend on the right hand side.
    • To remove the carriage mount we need to loosen up 2 more screws.

    • One sitting below the hotend on the left hand side.

    • The other sitting below the hotend on the right hand side.

  27. With the carriage mount facing down, pull the top group up to detach it. Remove the Filament Sensor cable from the carriage mount Remove the Filament Sensor cable from the carriage mount
    • With the carriage mount facing down, pull the top group up to detach it.

    • Remove the Filament Sensor cable from the carriage mount

  28. Embedded in the Carriage Mount there are 4 square nuts that must be removed. Use an Hex Key to push each square nut out of the housing. Store the square nuts.
    • Embedded in the Carriage Mount there are 4 square nuts that must be removed.

    • Use an Hex Key to push each square nut out of the housing.

    • Store the square nuts.

    • The square nuts will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

    • If you buy our X-Carriage kit, you will not need to remove and store these square nuts.

  29. Unscrew these 2 screws. Pull the Hotend's front housing upwards. Put it aside.
    • Unscrew these 2 screws.

    • Pull the Hotend's front housing upwards.

    • Put it aside.

  30. At this stage all elements will come apart. We will later need the following: Hotend and cable; Main drive gear;
    • At this stage all elements will come apart. We will later need the following:

    • Hotend and cable;

    • Main drive gear;

    • 2 magnets;

    • Filament sensor steel ball.

  31. Unscrew the set screw on the primary drive gear... with a Hex Key... To isolate and store the Primary Drive Gear.
    • Unscrew the set screw on the primary drive gear...

    • with a Hex Key...

    • To isolate and store the Primary Drive Gear.

    • The Primary Drive Gear will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  32. Remove the PTFE tube from the Hotend and store the whole assembly: Hotend;
    • Remove the PTFE tube from the Hotend and store the whole assembly:

    • Hotend;

    • Cable;

    • Cable Mount;

    • Cable Mount Screw.

    • The Hotend, Hotend cable, and Hotend cable mount with screw will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

    • If you did not remove the heater and thermistor in step 3 and will use them in your mosquito hotend, you can remove them now.

  33. Remove the Steel Ball housing from the Print Head housing. Remove and store the Steel Ball.
    • Remove the Steel Ball housing from the Print Head housing.

    • Remove and store the Steel Ball.

    • The Steel Ball will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  34. Remove the long magnet... by pushing it from the housing using a Hex Key...
    • Remove the long magnet...

    • by pushing it from the housing using a Hex Key...

    • while holding in place the other magnet.

    • Hold the second magnet to avoid attraction and collision of the magnets. THIS MAY BREAK THEM.

    • Both magnets will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  35. First remove the lever that contains the short magnet. Then  remove the magnet from the lever. Store the short magnet.
    • First remove the lever that contains the short magnet.

    • Then remove the magnet from the lever.

    • Store the short magnet.

    • The short magnet will be used to assemble the Bondtech MK2.5S / MK3S upgrade.

  36. 1x 3.0mm Main Cable Guide; 1x Main Cable Sleeve;
    • 1x 3.0mm Main Cable Guide; 1x Main Cable Sleeve;

    • 1x Long Magnet; 1x Short Magnet; 4x square nuts; 1x square nut; 5x M3x10 screw; 1x M3x18 screw;

    • 1x Filament sensor PCB; 1x PCB set screw;

    • 1x Primary Drive Gear; 1x Secondary Drive Gear;

    • 1x Filament Sensor Cable PCB; 1x Steel Ball;

    • 1x PINDA probe with cable;

    • 1x Axial Fan with cable; 1x Radial Fan with cable;

    • 1x Hotend with cable; 1x Hotend cable mount with screw.

Finish Line