Introduction: Easy to Build, Easy to Use, Water Bottle Launcher!

About: I am a middle school computer teacher with an EE degree. I do programming to pay for my teaching habit. I am also one of the founders of LVL1 - Louisville's Hackerspace.

Here it is... a simple water bottle rocket launcher that you can build in an evening and play with the very next day. I first saw this design at the Tunnel Mill scout camp in southern Indiana. Kids will have a blast (no pun intended) launching water filled 20oz plastic bottles 50 ft or more into the air, all the while getting their weekly shower!

Step 1: Shopping (enough for 2 Launchers)

Shopping (enough for 2 launchers)
**** PRINT THIS LIST AND TAKE IT WITH YOU ****

Go to the hardware store and buy...

1 - 10 foot piece of 1/2 inch outer diameter PVC pipe.

8 - 1/2 inch PVC T???s

2 - 1/2 inch PVC elbows

6 - 1/2 inch PVC caps (you may want to buy a couple of extra T's, Elbows and Caps in case you mess up drilling or gluing)

1 PVC pipe cutting tool. Your really don't absolutely need this but it sure make cutting this pipe easier. You can use a hacksaw instead.

PVC Glue and cleaner (primer, often purple in color), comes in a two pack. Your neighbor probably has some you can borrow.

Go to the auto parts store and buy...

2 auto tire valves, also called Schrader valves. The end of them should be able to fit inside a 1/2 inch PVC pipe cap.

You will also need...

several 20 oz soda bottles. The ones that have previously held carbonated beverages. Wash them out or you may get ants!

An abundant supply of water. I like to take a 5 gallon bucket of water out to the launch site.

A standup bicycle tire pump.

A supply of neighborhood kids with dreams of becoming Astronauts! They will get wet!

A nice sunny day!

Step 2: Cut the Pipe!

Using the handy PVC pipe cutting tool, cut the pipe into eight (8) one foot sections and four (4) six inch sections. Use a permanent marker and a ruler to measure before you cut. Measure twice, cut once!

Step 3: Drill the Cap.

Put one of the pipe caps into a vice and drill a hole on the top of it that is big enough to fit the tire valve. You will only need two caps with holes in them (one per launcher). Go ahead and insert the valve into the cap from the inside, with the connector facing out.

Step 4: Glue the Contraption Together.

It is now time to take your project outside because PVC pipe glue fumes can knock you out. Lay the pipes out on a drop cloth or newspaper. Read the instruction on the PVC primer and glue! Use the purple primer to clean the ends of the pipes and the insides of the caps, elbows and T's. Carefully apply glue to the pieces and fit them together. You do not have to glue the valve to the cap, air pressure will do that job. This is not rocket surgery (or maybe it is), there really is not much you can mess up. If you do, cut the pipe off and try again. A few inches here and there are not going to hurt your launcher.

Let the glue set overnight. Have a break; drink a 20oz soda or two.

Step 5: Launch Day!

Gather your launcher, kids, 20oz soda bottles, bicycle air pump, a big bucket of water and excitement and take them to the launch area. Your launch area should be an open field, back yard, cul-de-sac but probably not your mother-in-law's living room.

Hook the pump to the tire valve. Fill your 20oz soda bottle 1/4 to 1/3 full of water. Carefully and quickly shove the soda bottle down on the launch pipe. Some bottles will fit on easily; some are going to be much tighter. Hold the soda bottle with your hands and have another person pump air into the launcher. When the air pressure is too great to hold, let go! KEEP YOUR FACE AWAY FROM THE PATH OF THE ROCKET! I told you that you would get wet.