Potato cannon

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A potato cannon (sometimes known as gun cannon , not to be confused with toys of the same name) is a pipe-based cannon that uses air pressure (pneumatic), or combustion of combustible gases (aerosols, propane, etc.), to launch high-speed projectiles. They are built to fire pieces of potatoes, as a hobby, or to fire other types of projectiles, for practical use. Failed projectiles or weapons can be dangerous and lead to life-threatening injuries, including skull fractures, enukleasi, and blindness if a person is affected.

Potato cannons can trace its origins to the Holman Projector of World War II era, which is an anti-aircraft gun.

Video Potato cannon

The launcher type

All spud guns push the projectiles down their barrels using pressurized gas in the same way as firearms (albeit at much lower pressures). There are four basic ways that spud guns can use:

• By burning a mixture of fuel gas; this is generally called combustion launcher , and its pressure is limited mainly by the energy density of the air fuel mixture (less than 100 psi (0.7 MPa) with all the safe fuel).
• By releasing compressed gas (usually air) through the valve; Such launchers are usually referred to as pneumatic launchers , and their strength is limited mainly by air supply pressure, derived from compressors, manual pumps or bottled gas.
• With the explosion of dry ice bombs placed in pipes before the projectiles, commonly referred to as dry ice bomb cannons , this is limited by the material and size of dry ice bombs but the firing pressure can be about 200-300 psi (1 , 4-2.1 MPa).
• With the combustion of pre-pressurized fuel mixtures; these are called hybrid launchers , and produce higher pressures than normal firearm spud guns, limited only by the construction of the launcher (typically several hundred pounds per square inch).

Combustion launcher

Gun firearms usually have the most uncomplicated designs, the four basic elements of which are:

• Fuel system
• Combustion chamber
• Ignition source
• One barrel

To shoot, the operator loads the projectile into the barrel, adding fuel to the combustion chamber (eg aerosols or propane), and triggers an ignition source (often using piezoelectric barbecue burners). The fuel then lights up, creates a gas that expands heat, and forces the projectile out of the barrel. The distance varies greatly depending on many factors, including the type of fuel used, the fuel/air ratio efficiency, the combustion/barrel ratio, and the projectile flight characteristics. The general range varies from 100 to 200 meters, and there are reported cases of cannons exceeding 500 meters in distance.

Advanced combustion launchers may include injection of methane propane or calcium carbide (acetylene) to ensure proper fuel refueling, a room fan to mix fuel with air and accelerate ventilation after shooting, some splashes to reduce combustion time, and a high voltage ignition source (flyback circuit, stun gun, flash camera, etc.).

Combustion launchers are usually less powerful than their pneumatic counterparts or hybrids, especially when hairspray/alcohol is used as propellant. Bottle oxygen can be added to the firing chamber, although this can cause a pipe explosion when firing, potentially hurting anyone nearby.

pneumatic launcher

The pneumatic launcher is considered a bit more difficult to build due to the need for a completely airtight construction. This cannon has four basic components:

• Filling valve
• An air space
• Pressure release valve
• One barrel

In a pneumatic nail gun, air is pumped into the pressure chamber. Once the desired space pressure is reached, the pressure release valve is opened, allowing the gas to expand the barrel, pushing the projectile forward.

Filling valves are usually a common type available such as a Schrader or Presta valve but other assemblies to suppress the cannon such as a quick release joint with a ball or check valve have been used.

Pressure release valves are often one of the commercially available types such as a plumbing ball valve, an irrigation sprinkler valve or a quick exhaust valve. Experienced builders often create their own valves for this purpose to gain greater flow and faster actuation. The most common custom design used is the piston valve. Some valves are set to be triggered together sometimes used as an alternative to larger valves.

The range of pneumatic guns is more variable than the spud combustion rifle range because of the possible variations in the component. The general range is slightly higher due to greater strength, but the maximum range of some high power pneumatic cannons has been said to be over 1,000 meters (1,100 yd).

Pneumatic guns are usually stronger than firearms. A typical firearm produces an average space pressure of about 30 psi (210 kPa) with a peak of about 70-100 psi (500-700 kPa), while the average pneumatic gun can operate at a pressure of about 100 psi (700 kPa). More recently, it has become increasingly common for pneumatic metal launchers to use higher pressures, sometimes up to 500 psi (3.4 MPa) or higher.

Dry ice launcher

The dry ice cannon uses solid carbon dioxide sublimation to generate gas pressure to drive the projectile and is a variation of the burst disk cannon.

The oldest example involves dropping a piece of dry ice into a sealed tube at one end and sealing the other end by pressing the incoming projectile. When the carbon dioxide pressure from the fertile dry ice builds up high enough, the projectile will be blown up the tube. The pressure of the device is not too high because it only needs to build enough to overcome the static friction of a projectile that is jammed inside the barrel. Dozens of psi most likely. The range of possibilities is limited to 100 meters.

A more modern example is the dry ice bomb launcher. A plastic bottle containing water has some dry ice added and quickly sealed and falls into a closed tube at one end. A projectile is inserted thereafter. Water speeds up the sublimation of dry ice and the pressure from the resulting carbon dioxide gas eventually breaks the plastic bottle and launches the projectile. The cracking pressure of a 0.5 L plastic soda bottle is between 200 and 300 psi (14 and 21 bars) in the open air but when confined in a pipe, it can be higher.

Because of the operation of a dry ice bomb cannon extra security issues are present:

• The dry ice bomb used for propulsion can reach explosive pressure in seconds to hours depending on the quantity of water and dry ice. If there is too little dry ice, it also will not reach any explosive pressure at all. This time problem can lead to the belief that the cannons have failed to shoot but attempting to disassemble the cannon then can put extra pressure on the bottle needed for the seep.
• Any piping and reinforcement may not be strong enough for high pressure spikes when a dry ice bomb explodes and consequently breaks.
• Shelling cannons can be very large because of the high pressure combined with the large internal diameter pipe required for the bottle (5-9 cm, 2-3Ã,½ inches) so that it is not suitable for hand dismissal..

Compared to other spud gun operations, dry ice bomb guns are similar in principle to firing to light gas guns of the pneumatic type; Plastic bottles perform the task of the exploding disks though in a less controlled manner.

Another way to utilize dry ice in a spud gun is to use a sublimation of dry ice to create substantial pressure behind the valve, and place the barrel on the other side of the valve with the projectile loaded into it. The pressure behind the valve can reach more than 800 psi (5.5 MPa), and by releasing the valve quickly, the projectile can be launched. While this method is more controllable and in many ways safer than using soda bottles as burst disks (provided pressure and piping valves are used), it is limited in fast release valves, such as ball valves, generally no larger in diameter than 1 or 2 inches. In addition, they can not be opened as soon as the bottle of soda will break, and consequently there is less airflow immediately. However, this is offset by the fact that such a design can operate at more than twice the pressure of a typical dry ice bomb launcher, since the soda bottle will break only at 200-300 psi (1.4-2.1 MPa).

Hybrid launcher

The hybrid launcher consists of seven basic elements:

• Fuel system (usually propane meter)
• Air fill valve (see pneumatic launcher)
• One or more pressure gauges
• High-pressure combustion chamber
• The main valve is triggered by pressure (disk burst)
• One barrel
• Ignition source (see burning launcher)

A hybrid combines the principles of firearms and pneumatic spud guns. It uses a mixture of fuel and pre-pressurized air to gain more power from the given space volume.

To shoot, the operator first prepares a pressure-induced valve and then injects several times the normal amount of fuel and air more precisely. When the ignition source is triggered, the pressure from the combustion causes the main valve to open and push the projectile out of the barrel with the burning gas released. This hybrid is capable of producing higher speeds than a firing or pneumatic gun because the resulting pressure is higher than the firing rifle (for most fuels), and the shock wave is moving faster than pneumatically (for most gas), because higher temperatures. Projectiles fired by hybrids have damaged the sound barrier.

A hybrid using fuel and air mixture at atmospheric pressure twice is said to use a 2X mixture. Higher mixtures can be used and will result in higher pressures. Fuel and air need to be carefully measured and matched to ensure reliable operation; hence the use of accurate air pressure gauges and fuel meters.

Vacuum canon

The vacuum canon differs from ordinary pneumatic cannons because they apply negative pressure to the front of the projectile to "pull" out of the barrel. They usually fire light projectiles and have no practical application beyond showing air pressure theory.

Maps Potato cannon

Primary material

Plastic

• PVC-U (Polyvinyl chloride, unplasticized): Very popular because of its availability and relatively low cost. PVC pipes are available in various sizes and pressure ratings. In industry, however, they are illegal for compressed air applications - if they are damaged under plastic pressure it can fail explosively.
• ABS (Acrylonitrile butadiene styrene): Other popular plastic plating materials, more expensive and less common than PVC but available in the same size and pressure ratings. Unlike PVC is used in compressed air systems because it divides rather than crushes on failure. It also has a greater temperature tolerance (-40 ° C to 80 ° C, or -40 ° to 175 ° F) compared to 0 ° C to 60 ° C or 30 ° to 140 ° F for PVC).

Rarely firearms become powerful enough to break the sound barrier, although there are some cases that occur with special designs. The spud guns used are usually hybrids; but some pneumatic cannons have achieved achievement, either by using a special low density gas, such as helium, or high pressure combined with a fast valve. There is also one case of combustion design reported to reach super sonic speed.

The difficulty in breaking the barrier arises from the speed of the particles in the gas. Projectiles can not travel faster than gas particles, which are limited to travel at the speed of sound. The problem is solved by increasing the particle speed, either by:

• Uses a lighter molecule, as happens when helium is used in pneumatics.
• Heating the gas to a much higher temperature, and thus giving them more energy. It allows hybrid and combustion to achieve supersonic speed.
• Using steel and pressure is much higher than 800 psi (55 bar) or more, but reaching this pressure is difficult. Gas CO ₂ , although it can achieve this pressure, is not suitable because of its high density.

The supersonic speed can theoretically be achieved by pneumatics with a considerable "dead space" between the main valve and the projectile. Incoming air can increase the pressure quickly in this dead space, creating high temperatures sometimes enough to reach supersonic speeds. This particular effect has not been successfully used, but has been discussed, since both adiabatic heating and shock are documented in the gas.

The highest recorded projectile speed of a spud gun is 933.3 m/s (3.062Ã, ft/s) (about 2.7 times the speed of sound) with 16.6 grams (256 gr) 20 mm plastic slug from a hybrid using 20 MPa (2,900 psi) mixture of pre-ignition air and propane.

Supersonic velocity has been obtained using a vacuum bazooka associated with nozzle de Laval. This also depends on a significant decrease in the density of the gas.

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Practical use

Although spudguns are made and used for recreational purposes, there are other devices that work on the same principle in many other areas with more serious use.

Entertainment

• Promotional sports cannons: Portable pneumatic guns that run on bottles CO ₂ are common in major sports games in the US where they are used to project items such as T-shirts or food wrapped into the audience. Such "air guns", often called, tend to be made of higher quality materials than the average pneumatic spindle, but they use the same method of operation.
• Special effects cannons: In film and theater production, pneumatic guns (such as air mortars) are often used as pyrotechnic-free projection methods. These can vary from simple ball valves, manually operated models to electronically triggered designs operated from the remote control panel depending on the exact requirements.

Industry

• Hail cannon: This is a very large device consisting of combustion chamber and a large funnel shape mounted on it. The gas mixture is ignited in the combustion chamber and the funnel directs the explosive wave upward. They are meant to protect plants from hail damage by disrupting the formation of hail with shock waves. But there is no scientific evidence of its effectiveness.
• Air cannon: This can mean:
  • Pneumatic spudgun
  • Water cannon (mechanical), pressurized air tool for creating high pressure shock waves under water
• Rare bird: this device is basically an automatic burning cannon. They require propane gas bottles and lead-acid batteries. At certain intervals they light a propane/air mixture to produce a loud explosion (up to 150 decibels close to the device) to frighten birds from crop fields or near airport runways.
• Chicken guns: Many parts of the plane should be able to withstand the impact of flying birds, known as birdstrike. Pneumatic weapons are used to project birds, usually dead chickens, into products designed to mimic bird attacks. Aircraft canopy, engine, and critical flight control surfaces will typically undergo a type of stress testing to determine if they are strong enough to withstand bird attacks in flight.
• The shock tube: used to test hypersonic and supersonic burning ramjets.
• Pneumatic line throwers to launch lanes for rescue missions or between ships for filling at sea as well as a host of other apps.

Military

• Light combustion gas weapons are gun-burning cannons that burn low molecular weight gas such as hydrogen to provide a specific boost higher than conventional high-molecular weight-weighted conventional propellants.

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Security

Spud guns are naturally dangerous and can present security problems if not built or used properly.

Users should follow the same rules as when handling conventional firearms (see weapons security), but given the often improvised materials and construction used in the spudgun, it is very important for the user to use ears and basic eye protection when operating the spudgun.

src: cdn.instructables.com

Legal issues

In some jurisdictions, firearms are prohibited or have limits on their use and may require license and certification of weapons.

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In popular culture

• In the "Workaholics" episode "To Friend a Predator", a Potato Gun was used in an attempt to stop the protagonist, but instead hit Blake in the back.
• In The Trailer Park Boys , Julian, Ricky, Bubbles, Corey and Trevor use spud guns to investigate the major damage to their marijuana plants. This is because the original weapon will attract too much attention.
• In the movie Tremor 3: Back to Perfection , Jack Sawyer suggested to Burt Gummer that they made a potato rifle against Ass-Blasters. Using part of the junkyard, they formed a potato rifle variant that fired a deadly flame arrow into Ass Blasters and killed two.
• In Nickelodeon's episode Drake & amp; Josh, Drake buys a potato rifle, accidentally hits Josh, causing him to drop the weight he raises, causing him to break his leg.
• Dwight Schrute on US version The Office has mentioned having spud guns in more than one episode.
• In the 14th episode of Season 4 of Prison Break, a burning potato rifle was used by Michael Scofield to launch a 40 mm smoke grenade.
The character of Maude Flanders was killed by an air cannon launching a T-shirt on the eleventh episode, "Alone Again, Natura-Diddily".
• In Duct Tape Forever (a movie based on The Red Green Show ) Edgar KB Montrose says to sell it as a toy to the kids to raise money.
• In the movie Aliens in the Attic , children build spud guns they use to fight aliens that attack the Earth.
• A MythBusters episode tests a potato cannon united by tape compared to the one held together using a PVC bonding agent. Another episode, testing MacGyver myths, supplied Adam and Jamie with materials to build potato cannons as part of a challenge for "MacGyver" to signal rescue helicopters; however, they use piping and other supplies that are present to make big kites instead.
• In the TV series House, MD "The Dig" episode, House attends a spud gun show with Thirteen, where he uses a spud gun to threaten a competing teenager who mocks House.
• The spud gun is one of many different weapons used in Bully , a game made by Rockstar Games. There are two types. One can do around the map, but can only shoot eight potatoes before having to get more ammo. The other is a pistol mounted that Nerds used at the observatory during the story mission facing the second boss.
• In Iron Man 3, Tony meets a boy named Harley, who has a potato rifle he uses to threaten Tony. At the end of the film, as a thank you for his help, Tony builds a newer and better Better Potato Harley.

src: cdn.instructables.com

See also

• Plastic pressure pipe system
• Candied pumpkin
• Vacuum bazooka

Other types of pneumatic guns

• Pneumatic gun
• Air gun
• The FN 303 is a hand-held, short-range, less lethal weapon that uses compressed air from a high-pressure bottle attached to a blunt, staining, pepper spray or a joint projectile of a 15-foot drum.
• Some paintball guns are pneumatic.

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References

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External links

• How Potato Pneumatic Potato Works - Audio impressions from the National High Magnetic Field Laboratory
• Spud gun-making instructions, Spud Gun, animation, how-to's
construction

Source of the article : Wikipedia