MicroSwiss Bowden Extruder Coupling

This is a coupler design I prefer over the brass fitting which is meant to bite into the PTFE tubing. Ive found it very hard to get the correct torque such that the tubing isnt squished but that its is solidly connected to the extruder and wont pop out.

I previously used a 3D printed extruder which used this coupling design and after much searching I could not find one modified to fit on the MicroSwiss extruder. 

To print I recommend (if using a 0.4mm nozzle) 0.16mm layer height with 100% infill and no supports. Also keep up the cooling even on first layer (if using PLA) else I find the first layers dont cool properly.
 

I use Version 10 which hopefully fits on the extruder snugly. To install I would recommend two spanners, turning them in opposite directions with the bowden tube 

Ive included older versions in case they may help you:
Version 8 is easier to print but you need to cut away some plastic to allow a ±10mm space.

Version 9 fits a lot better but might be harder to print. I have noticed it was a little loose.

I will admit all versions are not 100% perfect but appears to be holding on and working for me. I may improve the model in the future.