Bottle rocket launcher interface

After having printed some of the available designs from Thingiverse, I had to try my own solution to the problem : Please welcome the Bottle Launcher System based on the "gardena" interface.

The system can be combined with all gardena derivatives that screw onto a normalised soda bottle interface. In my situation I used this beautiful solution:
https://www.thingiverse.com/thing:781367

The conversion nozzle I screwed onto the plastic nozzle at the bottom, has a built in non-return valve.

After you've built the system please take care building up the pressure in the bottle.
All parts are plastic and are not as strong as brass parts. On the other hand I have not had any failures when pumping 15-20 times with a hand actuated dutch bicycle pump.