SpudFiles Wiki - User contributions [en]

Pilot volume

2008-05-04T20:21:52Z

Necrosis: New page: ==Pilot volume== '''Pilot volume is the amount of air you need to displace before you actuate the valve''' This means that the smaller the pilot volume, the faster your valve will open, k...

==Pilot volume==
'''Pilot volume is the amount of air you need to displace before you actuate the valve'''

This means that the smaller the pilot volume, the faster your valve will open, keep this in mind.

Pneumatic cannon

2008-05-04T20:19:31Z

Necrosis: /* Common types of launchers */

[[image:pneumatic ballvalve cannon.jpg|right|thumb|300px|Pneumatic ball valve cannon]]
A '''pneumatic cannon''' is a cannon powered by pressurized gas, usually air or CO2. They generally require a little more work to build than [[combustion cannon]]s, but using typical compressor pressures of 120 psig or so and a decent valve, they will outperform most combustion launchers of the same size.

==Basic Elements==

Pneumatic launchers consist of five basic elements:

*Compressed gas storage reservoir ([[chamber]] for short)
*Filling valve (bicycle [[Schrader valve]]s, [[quick disconnect]]s, etc.)
*Firing valve ([[ball valve]]s, [[sprinkler valve]]s, [[piston valve]]s, bolt-style valves(see piston valves) [[quick-exhaust valve]]s, and [[burst disk]]s are the most common)
*[[Barrel]]
*[[Pressure gauge]] (for safety & repeatable launches)

==Operation & Theory==

In order to fire, the operator loads a projectile into the barrel, fills the chamber with a compressed gas (see [[Pneumatic air sources]] for common filling methods), and activates the main valve thus dumping the air in the chamber to the barrel.

The expansion of the compressed gas propels the projectile down the barrel. The barrel length determines the amount of energy transferred to the projectile and ultimately the velocity of the projectile.

Higher performance launchers use techniques such as:
* Faster valve opening times - see [[sprinkler valve modification]]
* Higher flow valves to maximize the airflow through the valve (Especially true for cannons with very long barrels)
* Using higher gas pressures.

Less common, but also effective in increasing power, some people will also use a gas with a higher speed of sound and particle speed (e.g. helium).

==Common types of launchers==
'''Piston valve launchers'''

[[Piston valve]] launchers use a [[piston]] in a valve that either seals the barrel or chamber. releasing air from the [[pilot valve]] will move the piston away from it's sealing position and air will go out the barrel.

This is generally an efficient type of launcher, as the opening time is moderately short and there is no choke of airflow in the actual valve.

'''QEV launcher'''

[[QEV]] launchers use a similar principle as the [[Piston valve]] only these can be bought from the store. These valves open even faster than piston valves because their [[pilot volume]] is much lower.

==Related Links==

Downloading the [[GGDT]] (Gas Gun Design Tool) is highly recommended to those interested in pneumatic launchers.

Pneumatic cannon

2008-05-04T20:13:57Z

Necrosis:

[[image:pneumatic ballvalve cannon.jpg|right|thumb|300px|Pneumatic ball valve cannon]]
A '''pneumatic cannon''' is a cannon powered by pressurized gas, usually air or CO2. They generally require a little more work to build than [[combustion cannon]]s, but using typical compressor pressures of 120 psig or so and a decent valve, they will outperform most combustion launchers of the same size.

==Basic Elements==

Pneumatic launchers consist of five basic elements:

*Compressed gas storage reservoir ([[chamber]] for short)
*Filling valve (bicycle [[Schrader valve]]s, [[quick disconnect]]s, etc.)
*Firing valve ([[ball valve]]s, [[sprinkler valve]]s, [[piston valve]]s, bolt-style valves(see piston valves) [[quick-exhaust valve]]s, and [[burst disk]]s are the most common)
*[[Barrel]]
*[[Pressure gauge]] (for safety & repeatable launches)

==Operation & Theory==

In order to fire, the operator loads a projectile into the barrel, fills the chamber with a compressed gas (see [[Pneumatic air sources]] for common filling methods), and activates the main valve thus dumping the air in the chamber to the barrel.

The expansion of the compressed gas propels the projectile down the barrel. The barrel length determines the amount of energy transferred to the projectile and ultimately the velocity of the projectile.

Higher performance launchers use techniques such as:
* Faster valve opening times - see [[sprinkler valve modification]]
* Higher flow valves to maximize the airflow through the valve (Especially true for cannons with very long barrels)
* Using higher gas pressures.

Less common, but also effective in increasing power, some people will also use a gas with a higher speed of sound and particle speed (e.g. helium).

==Common types of launchers==
'''Piston valve launchers'''

[[Piston valve]] launchers use a [[piston]]in a valve that either seals the barrel or chamber. releasing air from the back of the valve will set the piston away from it's sealing position and air will go out the barrel.

'''More to come'''

==Related Links==

Downloading the [[GGDT]] (Gas Gun Design Tool) is highly recommended to those interested in pneumatic launchers.