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Prusa MK4 & MK4s Adapter

Updated on Apr 09, 2025

This document contains information for the Prusa MK4 and MK4S adapter, designed to work with the Infinity Flow S1 filament loader. To connect the S1 to your MK4/MK4S, you'll need the adapter that links the Bowden tube from the S1 to your printer's extruder.

This adapter is available here for download or purchase on our website.

Zip File Download: Prusa MK4 Adapter 

Contents:

  • MK4_Adapter.stl: Printable file
  • MK4_Adapter.stp: CAD file

 

Printer Compatibility

  • Prusa MK4
  • Prusa MK4S

 

Printing the Adapter

Print Settings: Original Prusa MK4 0.4 nozzle

  • Material: PLA
  • Layer Height: .2mm
  • Print Orientation: Ensure the adapter is oriented as in picture

After printing, inspect the adapter for any imperfections or weak spots, especially around mounting holes.

 

Hardware Modifications

Step 1: Front Cover

  • Unscrew 3 screws on front cover, "PG-case"
  • Remove cover

Note: Remove carfully as other parts are loose during this step

 

Step 2: Remove Hardware

  • Remove 3 screws on front cover
  • Remove white nylon washer inside cover

 

Attaching the Adapter

Step 1: Gather Hardware

  • A1_Adapter
  • Bowden Push Fitting (ECAS04)

 

Step 2: Adapter Assembly

  • Place adapter on table
  • Take off black ring from the fitting and place in adapter
  • Place blue seat on top
  • Gently press the adapter together (pliers recommended)

Note: Make any rubber gromet on the bottom of the fitting one is removed.

 

Step 3: Attach Adapter

  • Place 3 screws and washer into adapter
  • Insert into prusa head
  • Screw in

 

Step 4: Plugging in the S1

  • Insert the Bowden tube into the adapter's feed port ensuring the Bowden tube sits all the way down
  • Ensure the S1 is positioned securely and all connections are properly seated
  • Turn on the S1 and verify that it loads as expected
  • Begin printing :)

Note: Check all connections for a secure fit, and ensure there are no loose cables