The nozzle of my Numatic Hetty had a tear in it and was on its way to become unusable. I couldn't find a replacement part on Thingiverse, and Numatic only sells the whole hose.
I designed this replacement part and it is a drop in replacement.
Fusion 360 archive included to allow for further tinkering.
Update 2021-04-04: Uploaded a new version. The old version had a 0.5mm ring inside, but a tear/crack forms over time. The new has a 0.25mm ring, which suffices.
Printer:
Creality CR-6 SE
Rafts:
No
Yes
Resolution:
0.2
20%
Notes:
Print with 3 or 4 walls for optimum strength. Consider turning cooling down to increase layer adhesion. I used zigzag infill pattern.
Replacement
Using the end of a tea spoon you can push the locking tabs down and remove the existing nozzle. After this you can press the newly printed nozzle onto the hose.