Designed for the Printrbot Alu extruder v1 but should work with other versions assuming the mounting has not changed. OpenSCAD file here: https://github.com/quillford/3D-Modeling/blob/master/Printer%20Mods/MiniMax/scad/printrbot_extruder_adapter.scad Print in ABS - I printed it in PLA, and it warped from the heat of the hotend. You may be able to get away with printing in PLA and keeping a fan on it.