Water rocket

Material

• 1 empty Coke bottle 1.5l
• 1 empty Rivella bottle 1.5l
• 1 tennis ball
• 1 thin plastic plate (disposable plate)
• A lot of duct tape (insulating tape is best)
• Connection adapter rocket to Gardena coupler (can be purchased at www.opitec.ch)

Working tools:

• sharp knife
• Scissors
• ruler
• waterproof pen

Operation

From the two bottles the drawn parts are cut out (see picture).

1. The upper ring from the Rivella bottle is glued to the bottom of the Coke bottle with electrical tape.
2. Now cut the tennis ball in half and tape it to the top of the Rivella bottle ring.
3. Next, on the plastic plate, draw in the four control fins with the tabs, cut them out, and bend the tabs to shape. Tape each of these four tabs nicely vertically at a 90 degree angle to the tall Rivella bottle ring with electrical tape 
4. Now tape the rivellaring with the control fins to the top of the coke bottle with electrical tape.

Note

The clean and straight assembly of the control fins on the Rivellaring and the Rivella ring on the Coke bottle has a great influence on the straight trajectory of the rocket!

And the rocket is ready! If you like, you can paint it with waterproof pens or embellish it with colored tape. And then, of course, the rocket needs some cool name...

Source reference

• Cover photo:Andi Flückiger
• Photos: Andi Flückiger