10 Bot. the 2-Liter Tennis Ball Rocket

Welcome to our 7 step lesson of how to build "10 Bot", our 2 liter tennis ball rocket.

• 2 Litter Soda Bottle (2)
• Duck tape
• Tennis ball
• Cardboard/Foam Board
• Large Garage Bag
• String (8 pieces)
• Hole Puncher
• Drill
• Air Conditioner/Cold Water

Label bottles 1 and 2. This will help you distinguish the different bottles so they won’t be confused. Next take a fairly large piece of cardboard paper or foam poster board, which ever you prefer, and draw three or four right triangles, again which ever you prefer. The triangles should have a base of 7cm and a height of 10cm. Once again label the “fins” 1, 2, 3, and/or 4. This allows you to keep track of all your fins.

First start with the bottles. Bottle 1 will not be cut under any circumstances. Just move it to the side. After cutting you have to shape the second bottle start by pressurizing it then heat the bottle up (drill a hole into the top of bottle number 2, once you’ve done that leave it on the drill. Place the drill over a hot place and rotate the bottle above it using the drill. Once the bottles reached a dome shape, turn the bottle once again in a cold state, such as and air conditioner or cold water). After shaping it take the second bottle and cut the top part of the bottle the rest of your bottle should be about 17cm tall. Next take your piece of cardboard with your fins and cut them out. Congratulations you have finished step 2. Ready to move on?

Take your large garbage bag, don’t open it leave it creased. Take a hole puncher and make four holes. When you completely open the bag you should have eight holes, if you don’t just make 8 evenly spaced holes. Next take eight pieces of string that are cut about 15in long. One by one tie the strings in the wholes. Next take your tennis ball and again one by one place the strings on the ball, securing it with tape. Make sure that when you are placing the strings the strings don’t get tangled within each other.

After making the parachute you have to take your fins and place them on your bottle. Place the fins that you labeled 1 and 3 and place them opposite from each other on both sides of bottle one. Then do the same with the fins labels 2 and 4. Secure your fins with tape. Make sure they’re secure because this give the rocket air resistance, so you want to make sure the fins are the right sizes and place in the right places.

Now that you have all your pieces scattered all over the place it’s time to put it all together. Start by putting the parachute and ball in the second bottle. Making sure that the ball is on top (closest to the opening). Then take bottle number one with your fins and attach it to bottle 2 with the parachute, simply by lightly placing the second bottle on the bottom of the first bottle. Yay! You finished your rocket. 

When you getting ready to launch the rocket fill your rocket with water about 2/3s full. Hot or cold water it doesn’t matter, just fill it with water about two-thirds of the way. After you filled you rocket with water, you’re ready to go ! Have fun !