Saturday Science Sessions – Water Cannon!
Water gun. Water cannon. Water blaster. Whatever you want to call it, one of my all-time favorite projects is the Water Cannon 1.0!
The most simple waterguns contain a reservoir to hold a volume of water, and use a pump connected to a trigger to shoot water out of a nozzle.
Over the years, water guns have become increasingly more complex in order to increase performance i.e. power and water output for maximum soakage! Technology ranges from using pistons, syringes, motors, and extensive variations on pressurized systems.
This water cannon uses the same science as the famous Super Soaker line of water guns – an air pressurized reservoir. A partially filled water reservoir is pressurized; where the reservoir has a one-way valve to pressurize the system and a two-way operato-controlled valve to release the water once pressurized.
As air is pumped in to the system, the air becomes compressed, which increases the pressure. This in turn pressurizes the water in the reservoir. When the operator opens the two-way valve, the pressurized water is pushed out through the nozzle as the air attempts to re-equilibrate with atmospheric pressure.
In this case, three 2-L pop bottles act as the water reservoir, a ball valve acts as the two-way valve and nozzle, and a bike valve acts as the one-way valve to pressurize the system. The result: an epic high-pressure stream of water. Oh, and did I mention a kick-back if you’re not holding on tight enough!