My 9 yr old son built this air rocket launcher using a 2 litter plastic bottle, sprinkler system parts, and a remote control assembly from an old hovercraft. It started out a couple of years ago as an acorn gun powered by a foot air pump and evolved to this remote control launcher. My only contribution was to take him to the store to buy parts and submit this for him. I dont know the exact names of all the parts or the exact sizes but will we will do our best to describe them.

Step 1: Parts

Parts include
Bicycle foot pump,
hose from washing machine,
tire valve,
5 1/2 hose clamps,
Male quick release for garden hose,
4 " of 3/4 in rubber hose - came from an old pool pump,
2 litter Soda bottle - wrapped in duct tape,
Standard Y valve for outside hose spicket,
Another hose quick release shoved into 5" rubber hose and screwed into the Y,
Wire wrapping to help keep the Y assembly in the bottle.
Simple remote control system from old hovercraft. It just supplies power to the electric sprinkler valve,
Two 9 volt batteries,
Electric Sprinkler valve,
Another male quick release for garden hose,
10" of 1/2" rubber hose,
3/4" to rubber hose elbow from spare sprinkler parts,
3/4" PVC adapter - threaded into sprinkler valve,
6" of 3/4" PVC pipe,
3/4" to 1/2" PVC elbow,
6" of 1/2" sprinkler pipe, threaded at both ends,
1/2" to rubber hose elbow,
10" of 1/2" rubber hose.

Step 2: Full Assembly

The bicycle pump connects to the soda bottle via tire valve connected to a standard Y hose adapter fitted to the soda bottle. The bottle is pumped up to about 50psi. There is a a gauge on the foot pump. Once the bottle is pressurized, the pump side of the Y adapter is closed. It remains pressurized by an electric sprinkler valve that is connected to a simple remote control device from a hovercraft. Once the remote control is activated it launches the rocket about 100ft in the air. The rocket came from a hydrogen rocket set and is lightweight with a rubber head. The launch assembly is place in a box for ease of carrying only.

Step 3: Bottle Assembly

This part consists of a tire valve purchased from an automotive shop, two 1/2in hose clamps, 3" of approx 3/4" rubber hose. It came off an old pool pump, but you could probably use a piece of regular garden hose, and finally the last piece is a male quick release for a garden hose. This assembly screws onto the standard garden spicket Y.

Step 4: Bottle Assembly

Tire valve assembly screws onto the Y. The end of the Y that goes into the bottle has a male quick release screwed into that. On the male side, a 5" piece of rubber hose is firmly pressed all the way on. The rubber hose is then shoved into the bottle. Its pretty tight, but to make it safer, wire is wrapped through the Y around the bottle several times. The bottle is wrapped in tape as a safety measure. On the other end of the Y, the washing machine hose is screwed on.

Step 5: Launch Assembly

The remote control air valve is powered by two nine volt batteries. Another male quick release is inserted into a rubber hose, held in place with a hose clamp. The other end is connected to an elbow from sprinkler parts - last pict as I don't know what's thats called. It does screw into the electric valve.

On the other end of the valve a pvc adapter screws into the valve, on the other end is glued a piece of 3/4" PVC pipe, approx 5" long. Then a 3/4 to 1/2 in elbow is glued on. The one end of the elbow is threaded.

Next a sprinkler pipe is screwed into the elbow. On the other end of that is another sprinkler elbow part 1/2in to hose end elbow. A 10" piece of rubber hose is hose clamped to the end.

Notice there is duct tape on the rubber hose. This helps ensure an air tight fit when the rocket is put on the hose.

Step 6: Remote Assembly

My son pulled the remote unit out of an old hovercraft. Its pretty simple in that it only allows power to go to fans. He figured out how to connect it the the electric sprinkler valve.

Step 7: Conclusion

When not shooting off rockets, he shoves an acorn into the end of the hose and shoots it across the cul-de-sac. He also connects a rubber hose to the end of the Y, disconnects everything and goes mobile, shooting of the rocket or acorns.