CR-10 Extruder with NUT and PTFE insert

The Original extruder of the Creality CR-10 Printer has a terrible issue: The Bowden's pneumatic coupler threads DIRECTLY into the extruder's plastic. This union is prone to failure due to frequent uninstall-reinstall and by the high pressure generated by the filament pushing through the bowden tube.
To solve this issue i designed this piece, that uses a trapped M6 nut to thread the pneumatic coupler. Additionally, i resized the filament hole such that a piece of PTFE tube can be inserted and c