Water Rocket with easy launching pad (simple!)

Step 4 Finishing and launch system

Now that you finished your rocket, do what you want with it. Spray paint it, add a recovery system, whatever you desire.

Now for the launch system
Materials:
Drill with TINY drill bit
Cork
Electrical tape
Big 28oz can
Air pump with inflation needle

Take your cork, and drill a LITTLE hole through the center. (where the inflation needle will be)
Next, tape around the circumfrence of the cork. Do this until it will fit very tight in the nozzle of the bottle.


To launch:
1) Fill the rocket 1/3-1/2 way with water
2)Stuff the cork in the neck of the bottle util pratically impossible to push any farther into the bottle.
3)Put the inflating needle through the cork (make sure the needle is already attached to the pump before doing this
4) Hold the hose alongside the rocket and place into can. Arrange the rocket so it is facing straight up or in the direction you want to launch. It should look like the pic below.
5) Start pumping and you should notice bubbles in the rocket. Make sure everyone is not near the launsh zone of the rocket. If you are pumping, stay as far as possibe from the rocket as you can (be ready to get splashed!) Once around 10 psi, you may hear a leaking noise. This is normal. The rocket should launch around 35psi (THE ROCKET WILL LAUNCH BY ITSELF). If it launches before 30psi, you need to put more tape around your cork. Replace cork every 20 launches, and every inflation needle every 50 uses or until it breaks. If your rocket is at 70psi, let the air leak out and try again.

Have fun and remember that I am not responsibe for your actions in this project. Be safe and ALWAYS do this outside.

Comments

[ROCKETMAN]

Tec. Note: a 2Liter soda bottle is usualy safe to 100psi but precuations should be taken to protect yourself and others from a bottle rupture. The person launching the rocket should be at least 15ft from rocket and spectators and others should be keept back at least 25ft. from rocket. Two more safety considerations: include a check valuve to prevent water from back feeding into the pump if there is a pause in the presurizing process and don't forget some kind of presure relief valuve in the event of a need for a launch abort.

[Boppo3]

Im thinking of making a backpack-type of air pressure tank for powering pneumatic cannons

i was thinking of using soda bottles... do you have any suggestions on the safety??

[ROCKETMAN]

Soda bottles would work but rember they are generaly only good to 100psi. There are kits avaible to convert empty freon tanks to refillable air tanks. They will safely hold more air under greater pressure. Down side they will be bulker and heavier. How much pressure do you want for your pneumatic cannons? How many firing do you want to make before you change or refill your air tanks? The answers you come up with and the compromises you can live with will help determin what you use for a backpack air suply for your pneumatic cannons. Good luck and be safe.

[Boppo3]

wow you normally work with air pressure do you? you're so experienced...

[ROCKETMAN]

I don't have as much experience as you imagine. I do take the time to observe other people's experiments when they post them on line. If you have the time to do a You Tube search you can find videos of other people's experiments some that went bad and some where they were looking to see just how much pressure a given type of container would hold without bursting. Look for a group that goes by the name of Air Comand they have a video of a 2 liter bottle they burst under controled conditions. It will make you think twice before you over pressurize a container. Do you research and be safe.