Ender-2 3 Hotend Coupling mod

I found this Idea on Chep’s/Elproducts youtube channel and he got it from OneBadMarine.
https://www.youtube.com/watch?v=Fb4XMbZ0iA4&feature=youtu.be

It wasn’t possible for me to slice Cheps models in SLic3r so I recreated it in Fusion 360 and then changed it quite a bit to fit Ender 2 and 3 better and improve performance. I tested this for a few prints and it works well.

Changes:
5mm longer fitting.
Deeper cuts in the fitting (more flexible when compressed and less “angle”)
Inside dia decreased to 4.1mm (from 4.2) and added a cylindrical taper outward (so that the gripping surfaces are parallel when compressed).
Thread changed from M10x1 to M10x0.9 with 0.03mm negative offset (slightly smaller tread)
Different position for the collar.
Flat surface for the collar so it handle the force better
Nut inside diameter decreased 0.4mm
Cut out in the nut for the screw head on Ender printers.

Tube length:
Cut the tube so that it is level with the top side of the cooling fin bl