SpudFiles Wiki - User contributions [en]

CALM

2005-12-18T21:26:14Z

67.180.152.250:

Compressed Air Launcher Modelling Program

by AKBiocca comcast net

The CALM modelling software works by computing the amount of air that passes
through the valve every 100 microseconds, subtracting the from the
pressure chamber and adding it to the bore. The force on the (tennis ball)
Projectile is computed, the net acceleration, velocity, and new position.
New pressures are computed for the bore and chamber. This is repeated
until the ball leaves the bore. This allows us to see what is
happening in some detail.

The CALM program is written in the Python language, and is available in source code
format, so you can see how it works and even make changes.

CALM is available at http://www.qsl.net/wb6zqz/calm.html

CALM Example

example launcher webpage at: http://www.qsl.net/wb6zqz/csv19/index.html

<pre>
Computer Modelled Launcher Performance*

CSV-19 Compact Sprinkler Valve 19 inch Launcher

16" SDR21 2.5" Barrel, 8" by 4" Schedule 40 PVC Chamber,
Rainbird 1" Sprinkler Valve, Over/Under configuration

system Cv 5.0 Ballwt 4.0 ounces

chp oal chl bbl fps sec xbp xcp ht tofl

30 19 8 14 79 0.020 0.2 20.5 76 4.4
40 19 8 14 105 0.017 1.3 29.7 117 5.4
50 19 8 14 123 0.015 2.5 38.8 146 6.0
60 19 8 14 138 0.014 3.7 48.0 168 6.5
70 19 8 14 151 0.013 4.8 57.1 188 6.9
80 19 8 14 162 0.013 5.9 66.3 205 7.2

Cv = system flow coefficient, gpm per psi
chp = chamber pressure in psi
oal = overall length inches
chl = chamber length
bbl = barrel length
fps = velocity feet per second
sec = barrel time in seconds
xbp = exit bore pressure
xcp = exit chamber pressure
ht = peak trajectory height in feet
tofl = time of flight in seconds

* note that these performance numbers are uncalibrated and subject to change
based on measurements with your own launcher. The Cv value can be adjusted to
fit your specific results. They seem to be quite close to the Dacron line
measurement, however measurements with new synthetic line were somewhat higher.
</pre>

CALM

2005-12-18T21:23:57Z

67.180.152.250:

Compressed Air Launcher Modelling Program

by AKBiocca comcast net

The CALM modelling software works by computing the amount of air that passes
through the valve every 100 microseconds, subtracting the from the
pressure chamber and adding it to the bore. The force on the (tennis ball)
Projectile is computed, the net acceleration, velocity, and new position.
New pressures are computed for the bore and chamber. This is repeated
until the ball leaves the bore. This allows us to see what is
happening in some detail.

The CALM program is written in the Python language, and is available in source code
format, so you can see how it works and even make changes.

CALM is available at http://www.qsl.net/wb6zqz/calm.html

CALM Example

example launcher webpage at: http://www.qsl.net/wb6zqz/csv19/index.html

<pre>
Computer Modelled Launcher Performance*

CSV-19 Compact Sprinkler Valve 19 inch Launcher

system Cv 5.0 Ballwt 4.0 ounces

chp oal chl bbl fps sec xbp xcp ht tofl

30 19 8 14 79 0.020 0.2 20.5 76 4.4
40 19 8 14 105 0.017 1.3 29.7 117 5.4
50 19 8 14 123 0.015 2.5 38.8 146 6.0
60 19 8 14 138 0.014 3.7 48.0 168 6.5
70 19 8 14 151 0.013 4.8 57.1 188 6.9
80 19 8 14 162 0.013 5.9 66.3 205 7.2

Cv = system flow coefficient, gpm per psi
chp = chamber pressure in psi
oal = overall length inches
chl = chamber length
bbl = barrel length
fps = velocity feet per second
sec = barrel time in seconds
xbp = exit bore pressure
xcp = exit chamber pressure
ht = peak trajectory height in feet
tofl = time of flight in seconds

* note that these performance numbers are uncalibrated and subject to change
based on measurements with your own launcher. The Cv value can be adjusted to
fit your specific results. They seem to be quite close to the Dacron line
measurement, however measurements with new synthetic line were somewhat higher.
</pre>

CALM

2005-12-18T21:23:18Z

67.180.152.250:

Compressed Air Launcher Modelling Program

by AKBiocca comcast net

The CALM modelling software works by computing the amount of air that passes
through the valve every 100 microseconds, subtracting the from the
pressure chamber and adding it to the bore. The force on the (tennis ball)
Projectile is computed, the net acceleration, velocity, and new position.
New pressures are computed for the bore and chamber. This is repeated
until the ball leaves the bore. This allows us to see what is
happening in some detail.

The CALM program is written in the Python language, and is in source code
format, so you can see how it works and even make changes.

CALM is available at http://www.qsl.net/wb6zqz/calm.html

CALM Example

example launcher webpage at: http://www.qsl.net/wb6zqz/csv19/index.html

<pre>
Computer Modelled Launcher Performance*

CSV-19 Compact Sprinkler Valve 19 inch Launcher

system Cv 5.0 Ballwt 4.0 ounces

chp oal chl bbl fps sec xbp xcp ht tofl

30 19 8 14 79 0.020 0.2 20.5 76 4.4
40 19 8 14 105 0.017 1.3 29.7 117 5.4
50 19 8 14 123 0.015 2.5 38.8 146 6.0
60 19 8 14 138 0.014 3.7 48.0 168 6.5
70 19 8 14 151 0.013 4.8 57.1 188 6.9
80 19 8 14 162 0.013 5.9 66.3 205 7.2

Cv = system flow coefficient, gpm per psi
chp = chamber pressure in psi
oal = overall length inches
chl = chamber length
bbl = barrel length
fps = velocity feet per second
sec = barrel time in seconds
xbp = exit bore pressure
xcp = exit chamber pressure
ht = peak trajectory height in feet
tofl = time of flight in seconds

* note that these performance numbers are uncalibrated and subject to change
based on measurements with your own launcher. The Cv value can be adjusted to
fit your specific results. They seem to be quite close to the Dacron line
measurement, however measurements with new synthetic line were somewhat higher.
</pre>

CALM

2005-12-18T21:22:48Z

67.180.152.250:

Compressed Air Launcher Modelling Program

by AKBiocca
comcast.net

The CALM modelling software works by computing the amount of air that passes
through the valve every 100 microseconds, subtracting the from the
pressure chamber and adding it to the bore. The force on the (tennis ball)
Projectile is computed, the net acceleration, velocity, and new position.
New pressures are computed for the bore and chamber. This is repeated
until the ball leaves the bore. This allows us to see what is
happening in some detail.

The CALM program is written in the Python language, and is in source code
format, so you can see how it works and even make changes.

CALM is available at http://www.qsl.net/wb6zqz/calm.html

CALM Example

example launcher webpage at: http://www.qsl.net/wb6zqz/csv19/index.html

<pre>
Computer Modelled Launcher Performance*

CSV-19 Compact Sprinkler Valve 19 inch Launcher

system Cv 5.0 Ballwt 4.0 ounces

chp oal chl bbl fps sec xbp xcp ht tofl

30 19 8 14 79 0.020 0.2 20.5 76 4.4
40 19 8 14 105 0.017 1.3 29.7 117 5.4
50 19 8 14 123 0.015 2.5 38.8 146 6.0
60 19 8 14 138 0.014 3.7 48.0 168 6.5
70 19 8 14 151 0.013 4.8 57.1 188 6.9
80 19 8 14 162 0.013 5.9 66.3 205 7.2

Cv = system flow coefficient, gpm per psi
chp = chamber pressure in psi
oal = overall length inches
chl = chamber length
bbl = barrel length
fps = velocity feet per second
sec = barrel time in seconds
xbp = exit bore pressure
xcp = exit chamber pressure
ht = peak trajectory height in feet
tofl = time of flight in seconds

* note that these performance numbers are uncalibrated and subject to change
based on measurements with your own launcher. The Cv value can be adjusted to
fit your specific results. They seem to be quite close to the Dacron line
measurement, however measurements with new synthetic line were somewhat higher.
</pre>

CALM

2005-12-18T21:22:26Z

67.180.152.250:

CALM

2005-12-18T21:15:57Z

67.180.152.250:

Compressed Air Launcher Modelling Program

by AKBiocca

The CALM modelling software works by computing the amount of air that passes
through the valve every 100 microseconds, subtracting the from the
pressure chamber and adding it to the bore. The force on the (tennis ball)
Projectile is computed, the net acceleration, velocity, and new position.
New pressures are computed for the bore and chamber. This is repeated
until the ball leaves the bore. This allows us to see what is
happening in some detail.

The CALM program is written in the Python language, and is in source code
format, so you can see how it works and even make changes.

CALM is available at http://www.qsl.net/wb6zqz/calm.html

CALM Example

example launcher webpage at: http://www.qsl.net/wb6zqz/csv19/index.html

<pre>
Computer Modelled Launcher Performance*

CSV-19 Compact Sprinkler Valve 19 inch Launcher

system Cv 5.0 Ballwt 4.0 ounces

chp oal chl bbl fps sec xbp xcp ht tofl

30 19 8 14 79 0.020 0.2 20.5 76 4.4
40 19 8 14 105 0.017 1.3 29.7 117 5.4
50 19 8 14 123 0.015 2.5 38.8 146 6.0
60 19 8 14 138 0.014 3.7 48.0 168 6.5
70 19 8 14 151 0.013 4.8 57.1 188 6.9
80 19 8 14 162 0.013 5.9 66.3 205 7.2

Cv = system flow coefficient, gpm per psi
chp = chamber pressure in psi
oal = overall length inches
chl = chamber length
bbl = barrel length
fps = velocity feet per second
sec = barrel time in seconds
xbp = exit bore pressure
xcp = exit chamber pressure
ht = peak trajectory height in feet
tofl = time of flight in seconds

* note that these performance numbers are uncalibrated and subject to change
based on measurements with your own launcher. The Cv value can be adjusted to
fit your specific results. They seem to be quite close to the Dacron line
measurement, however measurements with new synthetic line were somewhat higher.
</pre>

CALM

2005-12-18T21:15:16Z

67.180.152.250:

Compressed Air Launcher Modelling Program

by AKBiocca

The CALM modelling software works by computing the amount of air that passes
through the valve every 100 microseconds, subtracting the from the
pressure chamber and adding it to the bore. The force on the (tennis ball)
Projectile is computed, the net acceleration, velocity, and new position.
New pressures are computed for the bore and chamber. This is repeated
until the ball leaves the bore. This allows us to see what is
happening in some detail.

The CALM program is written in the Python language, and is in source code
format, so you can see how it works and even make changes.

CALM Example

example launcher webpage at: http://www.qsl.net/wb6zqz/csv19/index.html

<pre>
Computer Modelled Launcher Performance*

CSV-19 Compact Sprinkler Valve 19 inch Launcher

system Cv 5.0 Ballwt 4.0 ounces

chp oal chl bbl fps sec xbp xcp ht tofl

30 19 8 14 79 0.020 0.2 20.5 76 4.4
40 19 8 14 105 0.017 1.3 29.7 117 5.4
50 19 8 14 123 0.015 2.5 38.8 146 6.0
60 19 8 14 138 0.014 3.7 48.0 168 6.5
70 19 8 14 151 0.013 4.8 57.1 188 6.9
80 19 8 14 162 0.013 5.9 66.3 205 7.2

Cv = system flow coefficient, gpm per psi
chp = chamber pressure in psi
oal = overall length inches
chl = chamber length
bbl = barrel length
fps = velocity feet per second
sec = barrel time in seconds
xbp = exit bore pressure
xcp = exit chamber pressure
ht = peak trajectory height in feet
tofl = time of flight in seconds

* note that these performance numbers are uncalibrated and subject to change
based on measurements with your own launcher. The Cv value can be adjusted to
fit your specific results. They seem to be quite close to the Dacron line
measurement, however measurements with new synthetic line were somewhat higher.
</pre>

CALM

2005-12-18T21:14:38Z

67.180.152.250:

Compressed Air Launcher Modelling Program

by AKBiocca

The CALM modelling software works by computing the amount of air that passes
through the valve every 100 microseconds, subtracting the from the
pressure chamber and adding it to the bore. The force on the (tennis ball)
Projectile is computed, the net acceleration, velocity, and new position.
New pressures are computed for the bore and chamber. This is repeated
until the ball leaves the bore. This allows us to see what is
happening in some detail.

The CALM program is written in the Python language, and is in source code
format, so you can see how it works and even make changes.

CALM Example

example launcher webpage at: http://www.qsl.net/wb6zqz/csv19/index.html

<pre>
Computer Modelled Performance*

CSV-19 Compact Sprinkler Valve 19 inch Launcher

system Cv 5.0 Ballwt 4.0 ounces

chp oal chl bbl fps sec xbp xcp ht tofl

30 19 8 14 79 0.020 0.2 20.5 76 4.4
40 19 8 14 105 0.017 1.3 29.7 117 5.4
50 19 8 14 123 0.015 2.5 38.8 146 6.0
60 19 8 14 138 0.014 3.7 48.0 168 6.5
70 19 8 14 151 0.013 4.8 57.1 188 6.9
80 19 8 14 162 0.013 5.9 66.3 205 7.2

Cv = system flow coefficient, gpm per psi
chp = chamber pressure in psi
oal = overall length inches
chl = chamber length
bbl = barrel length
fps = velocity feet per second
sec = barrel time in seconds
xbp = exit bore pressure
xcp = exit chamber pressure
ht = peak trajectory height in feet
tofl = time of flight in seconds

* note that these performance numbers are uncalibrated and subject to change
based on measurements with your own launcher. The Cv value can be adjusted to
fit your specific results. They seem to be quite close to the Dacron line
measurement, however measurements with new synthetic line were somewhat higher.
</pre>

CALM

2005-12-18T21:13:35Z

67.180.152.250:

Compressed Air Launcher Modelling Program

by AKBiocca

The CALM modelling software works by computing the amount of air that passes
through the valve every 100 microseconds, subtracting the from the
pressure chamber and adding it to the bore. The force on the (tennis ball)
Projectile is computed, the net acceleration, velocity, and new position.
New pressures are computed for the bore and chamber. This is repeated
until the ball leaves the bore. This allows us to see what is
happening in some detail.

The CALM program is written in the Python language, and is in source code
format, so you can see how it works and even make changes.

CALM Example

example launcher webpage at: http://www.qsl.net/wb6zqz/csv19/index.html

<pre>
Computer Modelled Performance*

CSV-19 Compact Sprinkler Valve 19 inch Launcher

system Cv 5.0 Ballwt 4.0 ounces

chp oal chl bbl fps sec xbp xcp ht tofl

30 19 8 14 79 0.020 0.2 20.5 76 4.4
40 19 8 14 105 0.017 1.3 29.7 117 5.4
50 19 8 14 123 0.015 2.5 38.8 146 6.0
60 19 8 14 138 0.014 3.7 48.0 168 6.5
70 19 8 14 151 0.013 4.8 57.1 188 6.9
80 19 8 14 162 0.013 5.9 66.3 205 7.2

Cv = system flow coefficient, gpm per psi
chp = chamber pressure in psi
oal = overall length inches
chl = chamber length
bbl = barrel length
fps = velocity feet per second
sec = barrel time in seconds
xbp = exit bore pressure
xcp = exit chamber pressure
ht = peak trajectory height in feet
tofl = time of flight in seconds

* note that these performance numbers are uncalibrated and subject to change
based on measurements with your own launcher. The Cv value can be adjusted to
fit your specific results. They seem to be quite close to the Dacron line
measurement, however measurements with new synthetic line were 20% higher.
As the line ages the performance at higher heights drops slightly due to
increased drag from wear on the line.
</pre>

CALM

2005-12-18T21:11:55Z

67.180.152.250:

Compressed Air Launcher Modelling Program

by AKBiocca

The CALM modelling software works by computing the amount of air that passes
through the valve every 100 microseconds, subtracting the from the
pressure chamber and adding it to the bore. The force on the (tennis ball)
Projectile is computed, the net acceleration, velocity, and new position.
New pressures are computed for the bore and chamber. This is repeated
until the ball leaves the bore. This allows us to see what is
happening in some detail.

The CALM program is written in the Python language, and is in source code
format, so you can see how it works and even make changes.

CALM Example

<pre>
Computer Modelled Performance*

CSV-19 Compact Sprinkler Valve 19 inch Launcher

webpage at: http://www.qsl.net/wb6zqz/csv19/index.html

system Cv 5.0 Ballwt 4.0 ounces

chp oal chl bbl fps sec xbp xcp ht tofl

30 19 8 14 79 0.020 0.2 20.5 76 4.4
40 19 8 14 105 0.017 1.3 29.7 117 5.4
50 19 8 14 123 0.015 2.5 38.8 146 6.0
60 19 8 14 138 0.014 3.7 48.0 168 6.5
70 19 8 14 151 0.013 4.8 57.1 188 6.9
80 19 8 14 162 0.013 5.9 66.3 205 7.2

Cv = system flow coefficient, gpm per psi
chp = chamber pressure in psi
oal = overall length inches
chl = chamber length
bbl = barrel length
fps = velocity feet per second
sec = barrel time in seconds
xbp = exit bore pressure
xcp = exit chamber pressure
ht = peak trajectory height in feet
tofl = time of flight in seconds

* note that these performance numbers are uncalibrated and subject to change
based on measurements with your own launcher. The Cv value can be adjusted to
fit your specific results. They seem to be quite close to the Dacron line
measurement, however measurements with new synthetic line were 20% higher.
As the line ages the performance at higher heights drops slightly due to
increased drag from wear on the line.
</pre>

Computer Applications

2005-12-18T21:02:30Z

67.180.152.250: /* CALM */

The certain members of the spudding comunity have written computer programs pertaining to spudguns:

==the [[GGDT|Gas Gun Design Tool]]==
Written by David Hall (Dhalls of the [[SGTC]]), it is the most commonly used program to predict [[pneumatic cannon]] preformance, and is free for the download at Hall's [http://www1.iwvisp.com/thehalls/ggdt/index.html website].

Accuracy of the predictions is typcialy within 5-10% of the actual value, although there has not been much testing of very long where the (unaccounted for) flow resistance due to barrel length is significant, or very high pressure launchers where the non-moddled liquification of the propellent gas(ses) may take place.

==[[CALM]]==
Standing for <b>Compressed Air Launcher Model</b> this is a Pneumatic Launcher simulator program by AKB of the [[SGTC]]. Since it is written in the Python programming language you can read the code and see how it works. It is not graphical, but produces tables of pressure, velocity, height, etc.

CALM can be downloaded at http://www.qsl.net/wb6zqz/calm.html .

==Works in progress==

Computer Applications

2005-12-18T21:01:16Z

67.180.152.250: /* Works in progress */

Computer Applications

2005-12-18T21:00:35Z

67.180.152.250: /* CALM */

The certain members of the spudding comunity have written computer programs pertaining to spudguns:

==the [[GGDT|Gas Gun Design Tool]]==
Written by David Hall (Dhalls of the [[SGTC]]), it is the most commonly used program to predict [[pneumatic cannon]] preformance, and is free for the download at Hall's [http://www1.iwvisp.com/thehalls/ggdt/index.html website].

Accuracy of the predictions is typcialy within 5-10% of the actual value, although there has not been much testing of very long where the (unaccounted for) flow resistance due to barrel length is significant, or very high pressure launchers where the non-moddled liquification of the propellent gas(ses) may take place.

==[[CALM]]==
Standing for <b>Compressed Air Launcher Model</b> this is a Pneumatic Launcher simulator program by AKB of the [[SGTC]]. Since it is written in the Python programming language you can read the code and see how it works. It is not graphical, but produces tables of pressure, velocity, height, etc.

==Works in progress==
AKB is working on a simulator for the flight of projectiles. It is planned to include cross and headwinds.

PVC pipe

2005-12-18T20:23:56Z

67.180.152.250:

'''PVC pipe''' and fittings are the most common material for spudgun construction. It is cheap, lightweight and availble in a wide range of dimensions and ratings. PVC is usually joined by [[solvent welding]], which is easy to do and requires no special tools. Threaded fittings are also used, but then solvent welded to the pipe. PVC is easy to machine, and parts are sometimes [[bushing modification|customized]] to fit a certain purpose.

PVC is usually colored white or shades of gray, but transparent PVC pipe is also available. It's more expensive than normal PVC, but is somewhat popular in combustion launchers, where clear parts will let you see that happens inside during the combustion process.

One of the main disadvantages of PVC is that it becomes brittle in cold weather, which may lead to chamber failure, especially in pneumatic launchers. When PVC fails under pressure it breaks into sharp shards, which are propelled at high velocity. Because of this danger PVC pipe is not rated for use with pressurized gasses, and the use in spudguns is to be regarded as outside of specifications. When proper precautions are taken, it is still very safe to use.

===Naming Conventions===

====Schedule====
Schedule is a method of denoting pipe dimentions with a standardized set of nominal sizes. Note that this is a ''size'' convention, and does not neccessarily denote a pressure rating. [http://harvel.com/pipepvc-sch40-80-dim.asp Harvel] has tables of dimentions for SCH40 and SCH80 pipe sizes.

====SDR====
SDR (Standard Dimension Ratio) pipe has the same O.D. as Schedule pipe, but with different pipe I.D. All SDR pipe in a series has the same ratio of O.D to wall thickness throughout the sizes, and thus has the same pressure rating. All SDR pipe is rated for pressure, but becuase it often has relatively thin walls (in smaller diameters), it should be [[sleeving|sleeved]] or otherwise reinforced before use (in some cases). [http://harvel.com/pipepvc-sdr-dim.asp Harvel]
has charts of dimentions and pressure ratings for SDR pipe.
(Larger diameters of some SDR pipe actually has thicker walls than Schedule pipe. For example, SDR21 pipe 5" and up in diameter is thicker than Schedule 40 and is used
in well casings. SDR21 2.5" (Tennis Ball Barrels) are thick enough to not require sleeving in barrel use). SDR21 1.5" Golf Ball barrels are not rugged and sleeving is advisable.

{{Stub}}
[[Category:Construction materials]]