Water rocket building kit (Infento compatible)

This German 1L reusable Coke Bottle is nice, handy, and is very tough due to its great wall thickness. The thread is differently to UK or U.S. 2l Bottles, so I designed something by myself since I wasn't lucky in finding suitable designs on Thingi.

The Gardena Hose Connector is a standard item. You remove the hose clamping ring and lay it aside. I can't say if the thread of any copy of this connector on the world market is the same - better buy the original.

The large seal with the rectangular x-section and the small round O-Ring are stripped from a Gardena water tub adapter.

For the 2 half rings that clamp around the Gardena Hose connector you will need 2 bolts M4x15 or similar, and 2 brass thread inserts M4, 6m long, 5mm outer diameter.

The valve can be cut from any bicycle or motorbike tube (leave a circle of 20-25mm of rubber). The air tight sealing happens automatically as you screw the Gardena Hose Connector into its seat. Its fulcrum will press firmly against the rub