Build an Overhead Water Rocket Launcher Part 7 launch

Part 7 of 7 parts, instructions for building an overhead water rocket launcher, as seen on the Ask This Old House annual kids program.
Links to all 7 steps, as well as other science toy projects are at http://www.sciencetoymaker.org/

Category:

Science & Technology

Tags:

• build
• make
• water rocket
• ask this old house

[robert0joe]

I don't get it. You said it needs 30-40 PSI minimum to get out from the bottle. Why does 15PSI do the job. 15 PSI (Airpressure) + 300ml/1.5L (water volume/bottle capacity) flew at over two story- building?

[sciencetoymaker]

@robert0joe The reason I say it needs 30-40 psi becasuse it can get stuck on the bump. There is a little bulge on the pipe that seals the air pressure in the bottle.When adjusted properly you push the bottle onto that buge a little. It sticks, so if you don't get enough pressure to get it unstuck, the bottle just stays on even it you've released it.

Slater

[de0509]

HAHAHA. this is cool. man i never thought of a trigger mechanism for a launcher tht simple. n cheap. that gardenia thing isnt found in my country. thanks dude. so i will share an idea. make the long pipe short(a few inches) and dont use the tee. the short pipe goes straight to a cap (and valve). so i call it a cartridge. and you can make a fast reload launcher if you have a lot of ammo. i only made one. so still need to pump before each launch. but hey, water rockets really can kill :( ?!

[sciencetoymaker]

@de0509 Yes, a water rocket could really kill someone. Use with care.

Slater

[hellandlife]

@sciencetoymaker how does the water in the bottle not go down the pipe.... or do u not fill it up that far. :) also can u jsut clarify for me what diamiter of pipe u use ty

[sciencetoymaker]

@hellandlife Only a tiny bit of water goes in the pipe. After a few launches I tip it over and empty it. If you live in North America, use what is called 1/2" pvc pipe. Even the inside diameter is more than 1/2" really, but that's what they call it.

Slater

[robert0joe]

@sciencetoymaker I just figured out that it flew so high with small amount of air pressure because I only filled with 1/10 water. The potential energy is condensed to such a tiny reaction mass. Thanks anyway! I love the my new launcher!

Joe

[giovanni154]

Thanks men it was so useful for me!!!!!

[raducu8881]

cool man 

[sciencetoymaker]

@MrFmiller Indeed, at the website sciencetoymakerDOTorg there is a whole page of cool variations of water rocket launchers that people have sent in.

Slater