Air Cannon

Problem/Finish Description

Too many people build cardboard boats that don't sink. Yet they don't want to take them home, so they get thrown away without sinking at cardboard boat competitions. Fewer boats sinking means that the cardboard boat event draws less of a crowd.

Some event organizers have tried to add demolition derbies at the end. But boats crashing into each other and poking at each other doesn't sink boats. Most audiences are not patient enough to wait hours for cardboard boats to sink on their own. How else could boats be sunk and people forced into the water?

Conceive

Develop technologies that allow cardboard boats to sink each other safely. Some of the ideas include:

Commando's swim underwater with box cutters
Spray people with tomato juice so they want to get in the water
Fire projectiles through the cardboard boats

Eventually the box cutter is going to accidentally cut someone in the boat.

Firing projectiles that can get through water soaked cardboard boats sounds plausible. Would need safety testing.

The best idea is spraying people with something that forces them off their boats. Then swimmers with box cutters may be effective.

Spraying people and firing projectiles using a T-shirt cannon seemed like a starting point.

Don't want hair spray cannons .. fire and explosions on cardboard boats in the water doesn't sound like a good mixture.

Design

Two attempts failed:

Electronic Valve Cannon -- too powerful

Conception:Air Cannon Materials
Design:Air Cannon Layout .. that put a lemon through 3/4 inch fiberboard
Implementation .. use sand bags to weight down, turn air compressor on, push lemon down barrel with broom stick, touch electronic valve wires to battery + -, video
Operation: .. would need to mount on cardboard boat or destroyer boat
Next Steps .. add button to fire, add pressure gauge, increase barrel size or start over with something simpler

No Valve Cannon -- requires projectile seal with barrel

Conceive:Compressed Air Tank .. fill with air compressor, put in cardboard boat, have enough to shoot several objects/liquids
Design:Parts for manual firing cannon
Implement:Have to connect air pressure hose, wait for it to fire .. distance is not predictable, video
Operation: .. would need to mount on cardboard boat or destroyer boat
Next Steps: figure out how to make snug fits more easily, try to increase snugness to shoot further

Ended up with a manual valve design that was built with off the shelf parts and a Schrader valve like those used on car or bicycle tires.

Implement

Shows operation of cannon with no cables, no electronics .. could shoot T-shirts, anything ... video

Operate

Charge up compressed air storage tank with air compressor
Charge up the cannon
Insert anything to shoot .. snugness doesn't matter
Turn the valve as fast as one can

Demo

Presentation

Next Steps

Should try to shoot a variety of liquids ... chart the spray pattern ... figure out what irritates people in cardboard boats so they jump in the water.

Compressed air cannon mounted on turret for the round cardboard boat

The next step was to design a turret for it. This turned out to relatively easy also. Everything was purchased at a hardware store.

The round boat was built, but this assembly was never integrated fully into it. There was no place to store the round boat. The boat was cut in half and then rebuilt into two boats that were destroyed in a cardboard boat competition.