SpudFiles Wiki - User contributions [en]

Computer Applications

2010-01-07T03:53:45Z

Ramses: /* Launcher Range Calculator */ fixed link for download (I hosted it on mediafire)

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

==the [[GGDT|Gas Gun Design Tool]]==
Written by David Hall (D_hall of the [[SGTC]]), it is the most commonly used program to predict [[pneumatic cannon]] performance, and is free for the download at Hall's [http://www.thehalls-in-bfe.com/GGDT/].

Accuracy of the predictions is typically 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-modeled liquefaction of the propeller 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 .

==[[BAGS]]==
A newer simulation of a pneumatic gun written by btrettel. Like CALM, it is written in Python, is open source, and is not graphical. However, the model is significantly more advanced than CALM. And while it is not as advanced as GGDT, BAGS generally is within 5% of GGDT for similar inputs and subsonic speeds.

Changing options is done through editing the Python program at the moment.

BAGS is available at http://trettel.org/bags/ .

==[[EVBEC]]==
EVBEC stands for Energy & Volume Based Estimator for Combinations. Written by boilingleadbath, it is based on [http://www.burntlatke.com Latke's] chamber:barrel test data.

Hosted on spudfiles, it is free to [http://www.spudfiles.com/forums/viewtopic.php?t=1212& download] and use.

==[[SpudTool]]==
A great spudding tool made by Boogieman. [http://www.advancedspuds.com/SpudToolonline.htm Click here to try it out]

==[[ProMeterSuite]]==
Spud Calculators galore. Requires Microsoft Excel. [http://www.spudfiles.com/uploader/uploadFiles/ProMeterSuite.zip Download]

==[[Unit Converters]]==
[http://www.digitaldutch.com/unitconverter/ UnitConverter] is a handy online converter. You can convert metric pipe sizes to U.S. sizes, pressure, volume, energy and many other kinds of units. Put a shortcut in your web browser and you're never more than a second or two away from converting, for example, cubic inches to liters.

[http://joshmadison.com/software/convert/ Convert] is a downloadable windows application with capabilities similar to UnitConverter. Put a shortcut on your start bar and you're never more than a second or two away from converting, for example, cubic inches to liters.

==[[Launcher Range Calculator]]==
Predicts ballistic trajectory accurately taking into account both atmospheric and ballistic variables. [http://download864.mediafire.com/yteszeitnzeg/yhnz3rdzijt/LauncherRangeCalculatorV2-2.xls Download]

Update in pipeline, with plans to release beta version shortly. Update 1/9/2010: Most likely abandoned, but still functional. JoannaArdway, the creator,last posted on the forum Sep 14 2007.

==[[Ballistics Calculator]]==
Predicts and simulates ballistic trajectory accurately taking into account atmospheric and ballistic variables. The program is designed for TI graphing calculators.
[http://www.spudfiles.com/forums/new-ballistics-program-for-graphing-calculators-t14161,start,15,lighter,0.html]

==[[HCMP]]==
Metering tool for propane, butane, and mapp gas.
[http://www.spudfiles.com/forums/hcmp-t13837.html Download]

==[[Other Calculators]]==
[http://www.burntlatke.com/calc.html http://www.burntlatke.com/calc.html]

[http://www.1728.com/diam.htm http://www.1728.com/diam.htm]

[[category:Concepts]]

Lantern sparker

2009-04-19T20:11:26Z

Ramses: added hybrid comment in disadvantages

[[Image:sparker.jpg|frame|Replacement lantern sparker]]'''Lantern sparkers''' are a method of ignition and are usually cheaper and more arguably reliable than [[BBQ ignitor]]s or [[stun gun]]s. They work by spinning a knurled wheel connected to a rod of steel. A piece of flint pressed against a rifled section of the steel by a spring. When the wheel is spun rapidly, pieces of the flint material are shaved off and ignite spontaneously, causing a shower of sparks that are ideal for igniting a combustion mixture.

==Disadvantages==
The main disadvantage of lantern sparkers is that they have the tendency to not spark when wet. AXE, hairspray, and [[starting fluid]] will all stop a lantern sparker from working if they get on the flint/steel sparking assembly. If you can afford it, a GOOD (usually expensive) BBQ ignitor or stun gun is superior.

A lantern sparker requires that one hand is used to operate the sparker. This only leaves one hand to hold the gun and absorb the gun's recoil. In practice, this makes firing a handheld gun somewhat unstable. For this reason, a gun mount is a good idea when using a lantern sparker on a large gun.

Lantern sparkers cannot be used on hybrid cannons, as they will leak.

It is generally considered to be a bad idea to mount the sparker in a [[cleanout]] plug. If the cleanout plug fails during firing, then the plug is blown directly into the hand that was operating the sparker. In addition, a loaded gun can fire accidentally if the gun is set down on the breech end (where the sparker is located).

Lantern sparkers can be triggered if they are struck inadvertently. For this reason it is best to mount the sparker in a protected place on the gun or to protect the sparker with a trigger guard.

==Advantages==
They are very cheap, $2~$5, the flints are replaceable, and they are widely available in stores that carry camping supplies.

==Installation==
The lantern sparker is mounted through a single hole in the [[chamber]] (or though a fitting) and captured with the nut supplied with the sparker. The flint and striker wheel assembly protrudes into the chamber, and may therefore be impractical or impossible to use in [[coaxial]] launchers.

[[Category:Ignition sources]]

FAQ

2009-04-19T20:05:09Z

Ramses: added hybrid section

==Introduction==
This page aims to answer some of the common '''"Which is better?"''' questions seen on the forums in a simple manner.

Normally, there is no simple resolution to the question, because if there were, you wouldn't need to ask it. For example, if we '''knew''' pneumatics were best, then you wouldn't see any combustions.

It's not as simple and clear cut as people asking the question might think. However, this page will hopefully give you the information you need to make the decision for ''yourself'', depending on what is most important to you in your launcher.

==Combustion vs. Pneumatic==

''"Which is better, Combustion or Pneumatic?"''

This is probably the most common question that gets asked on the forums, and the big problem with it is that it is unanswerable. Without knowing what a person wants from a spudgun, nobody can put one type ahead of another.

However, most experienced spudgunners will agree on this short list ''if muzzle velocity or muzzle kinetic energy is the only criteria used for ranking the guns'':

* [[Combustion Cannon|Combustion]]
* [[Pneumatic cannon|Pneumatic]]
* [[Hybrid Cannon|Hybrid]]

Where down is increasing "power" but also increasing difficulty to use, build and cost.

Below are the main advantages and disadvantages in easy lists to help you decide on your own:

'''Combustion cannons'''

Advantages:
* Usually cheaper and easier to build.
* Less sensitive to minor leaks (such as around a threaded cleanout plug).
* Usually quicker to refuel and reload.
* More portable. Just needs a can of some flammable vapour.
* Can be made bigger, but still kept practical.
* Easier to later upgrade.

Disadvantages:
* Less power, with a upper limit to what is practically possible (with all safe fuels).
* Less controlled (Maintaining consistency and altering power)
* Often inconsistent and unreliable (Advanced Combustion launchers can overcome this, but often cost more to construct).
* Potentially noisier. This can be remedied to some extent by having a good [[Chamber to barrel ratio|Chamber to Barrel Ratio]].
* Very large chambers are more prone to [[DDT|DDT]], although this is only likely to occur in chambers that are very long, on the order of 10m or more, depending on a whole host of other variables. The diameter of a tube is directly related to its DDT runup distance, i.e. the wider the tube, the less likely detonations are

'''Pneumatic cannons'''

Advantages:
* Normally more powerful, with less of a "ceiling" to power (The particle speed of the gas does limit power to some extent).
* More controllable and consistent, as power can be varied with pressure.
* Easier to simulate, with reasonable accuracy, in a modeling program such as [[GGDT]].

Disadvantages:
* Takes longer to fill, unless you have a decent [[compressor]] or [[Gas bottle|bottled gas]] (Especially true with large chambers).
* More expensive, particularly if you include the cost of a compressor or regulated CO2.
* Less portable.
* More complicated to construct and much less forgiving of construction problems (such as weak or leaking joints and fittings).
* Leaks are a greater problem since the gun needs to maintain pressure for the entire time between filling and firing. (And, leaking can cause a valve to open prematurely.)

'''Hybrid Cannons'''

Advantages:
*Extremely powerful, sometimes capable of thousands of ft·lbs and supersonic velocities.

Disadvantages:
*Must be made of metal to be considered safe.
*Requires the replacement of a [[burst disk]] after every shot (with exceptions).
*Requires a source of compressed air (not CO<sub>2</sub>) as well as compressed gas.
*Fairly expensive to build.

----

As a final note, a large majority of the launchers that Spudfiles (and other similar spudgun forum) users build are pneumatic cannons, but amongst people who don't take it up as a hobby, combustion cannons are more common.

==Working on==

* [[PVC vs. ABS]]

==To come soon==
* Metal vs. Plastic
* Boys vs. Girls (I'm kidding about this one)

Wantedpages

2009-04-19T19:43:55Z

Ramses: /* Accessories and improvements */

I am making this as a page to list pages people want to see created. This page separate from the [[Special:Wantedpages|page from the special section]] which shows non-existent pages with links to them. These can either be a result of a wanted page or just bad linking.

==Building materials and construction==
*Threads
*Flange
*Cleanout
*Plug
*Cap
*Elbow
*Chamfering
*Teflon tape
*ABS
*Syringe
*Fire extinguishers
*Epoxy

==Accessories and improvements==
*Hop-up
*Suppressors
*Muzzle brake
*Propane bottle adapter
*Propane bottle adapter how-to make
*Painting
*Ramrod
*Ballistic pendulum

==Theories==
*Blowby
*Automatic firing
*Semi-automatic firing
*Drag coefficient (CD)
*Cleaning
*Hang-time

==Fuels and related==
*Alcohol
*Hydrogen
*Methane
*Helium
*Oxygen
*Nitrogen
*Air
*CO2

==Valves==
*Gate valve
*Globe valve
*Hammer valve

==Tools==
*HCMP
*Launcher Range Calculator
*ProMeterSuite
*SpudTool

==Ammo==
*Airsoft BB
*0.177 BB
*Water

==Other==
*Spudfiles

Remotely Activated Gun

2009-04-14T00:20:06Z

Ramses:

Sometimes it is handy to have a way to fire a spudgun from a distance (remote control). You might want to remotely fire the gun for [[safety]] reasons (i.e., you are not completely sure the gun will survive the firing) or for some other reason. The easiest way to do this would be to run a pair of long wires from the gun to the remote firing location. Alternatively, a radio control (R/C) system can be used.

Below is a description of how you might go about building an R/C system to remotely fire your spudgun. This write-up is for remote control of the solenoid valve of a [[pneumatic cannon]] but it can be easily modified to remotely control the ignition circuit of a [[combustion cannon]].

'''Parts:'''

# Cheap 1 channel R/C car ($15 at KB Toys)
# 5v relay [http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=306-1019-ND Something like this should work]
# [[Sprinkler valve]] (with solenoid)
# A standard diode [http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=MUR180EGOS-ND This will work]
# Two 9v battery clip (go to radio shack or take them from broken stuff)
# Assorted batteries
# Antenna wire (I used 20ft of enamel coated 26 gauge because it was green and blended well)
# Assorted bits of wire

'''Tools:'''

Dremel,
Wire cutters,
Multi meter (this is absolutely essential),
Soldering iron

'''Step One: Disassembly'''

Take off the R/C car body, then use the dremel to cut the forward section of the car off. Next, remove the motor from its housing and unsolder the two wires going to it. Now, cut off the rear section of the car using the dremel. All that should remain of the car is the battery compartment, a small switch, and the circuit attached to the battery box. A diagram of the before and after of this step is provided below.

[[image:rc detonator.jpg]]

'''Step Two: Re-wiring'''

*Note: I have written this part assuming you have acquired the same or very similar model R/C car as I used*

If you are using the same model car as I am then you will notice as soon as you turn on the car it should start moving backwards in circles, if we do not fix this as soon as we turn on the "detonator" the device will fire because any voltage forward or reverse can activate the relay. This is why we need the diode (Diodes only allow current to flow in one direction). Before we solder the diode, we are going to need to know which of the motor leads to solder it to. This is very simple to determine. Turn on the R/C car, but do not touch the remote. Use the multi meter to measure the voltage coming out of the wires which are used to supply power to the motor. If there is a minus sign on the screen, switch the multi meter leads until it disappears. Then, solder the diode (backwards) to the positive lead. Turn the car off (When the multi meter is reading a positive voltage, it would be the wire the red lead is touching). While you were reading the voltage of the motor, you should have noticed that the voltage output is only 3v. This will not activate our 5v relay (for obvious reasons). This is also very easy to fix. If you look at the battery box, you should see that there are three sets of wires connected to it (instead of the usual two). Find the positive 3v wire and connect it to the positive 5v lead on the box (Again, you need to use the multimeter, but you do not need the car to be on). After this is done, there should only be two sets of wires connected to the battery box.

'''Step Three: Wiring'''

Most of the tedious work is done now; all we need to do is connect the relay and 9v batteries. First, locate the wires that you removed from the motor's terminals. Solder them to the coil side of the relay. Next, solder the 9v battery leads in series, then connect one of the wires to the switch side of the relay, and the other to the solenoid. Lastly, connect the other solenoid wire to the remaining switch lead on the relay. All that is left to do is to mount the antenna, and you are done. Here is a basic diagram of how your final result should appear.

[[image:rc detonator circuit.jpg]]

'''The Remote:'''

The remote in its stock form will work just fine. The only reason I put mine in a cell phone was to give it that "terrorist effect". It was designed to be used in airsoft games, and I am known for using AKs (considered a "terrorist weapon" by most), so I thought it fit nicely. To get the remote to fit in the phone, I shaved off part of the circuit using a dremel, then wired the forward button to the end button on the cell phone key pad. Lastly, I modified the circuit to accept power from a car key fob battery; which is significantly smaller than a standard 9 volt.

'''Other Info:'''

This is a very basic R/C circuit, and is thus prone to picking up interference. This system was designed to be used in the woods; acting as a remote detonated mine. You must remember that this cannot be used in a [[sprinkler valve modification|modded sprinkler valve]] unless you bought a separate solenoid [[valve]] use as a [[pilot valve]] for the sprinkler valve (such as a small 1/4 NPT solenoid valve or similar). If the device goes off as soon as you turn on the power switch, the diode was inserted in the wrong direction. This is simple to correct. Simply unsolder the diode, then turn it 180 degrees and solder it back in place. The R/C receiver is relatively poor in quality, and in my mine it is paired with about 20ft of antenna wire, which would normally be wrapped around a nearby tree to give it an effective range of over 100ft. If you plan on using this underground (in the case of my mine), encase all of the electronic components in hot glue to prevent them from being damaged by water. Lastly, if the device seems to fire randomly, and external radio interference is determined to not be the culprit, the issue is likely the antenna. Ensure that the antenna wire is not making contact with any metal components of the circuit board.

This method was used to make a remote controlled [http://www.spudfiles.com/forums/anti-personnel-mine-t9631.html Airsoft "anti-personnel mine"].

'''Alternative Parts:'''

The 1-channel R/C Car transmitter / receiver pair can be replaced by several other systems.

One possibility is a remote car unlock R/C setup often available for cheap from electronics surplus places. For example, [http://www.allelectronics.com/ All Electronics] sometimes has a "keyless entry" system with two fobs (like a car uses) and the receiver. It'll easily handle the current required for a solenoid or a relay; [http://www.allelectronics.com/cgi-bin/item/RC-10/search/KEYCHAIN_REMOTE_CONTROL,_12VDC_6_AMP_.html CAT# RC-10] for $18.75. A little pricier than a cheapo R/C but you wont need a relay since this will handle 12V at 6A directly, and there is less chance of accidental triggering by interference.[[Image:RC-10.jpg|Car remote (R/C) entry FOB system]]

Another possibility is to use the pager function found on many cordless phones. With a little creative scrounging you can often get an unused cordless phone for free. [http://www.angelfire.com/ SixMhz] has an [http://www.angelfire.com/80s/sixmhz/rcphone.html excellent write-up] on how to convert the phone into a remote firing system.

Remotely Activated Gun

2009-04-14T00:19:29Z

Ramses: added note about less interference for remote car fob thing.

Sometimes it is handy to have a way to fire a spudgun from a distance (remote control). You might want to remotely fire the gun for [[safety]] reasons (i.e., you are not completely sure the gun will survive the firing) or for some other reason. The easiest way to do this would be to run a pair of long wires from the gun to the remote firing location. Alternatively, a radio control (R/C) system can be used.

Below is a description of how you might go about building an R/C system to remotely fire your spudgun. This write-up is for remote control of the solenoid valve of a [[pneumatic cannon]] but it can be easily modified to remotely control the ignition circuit of a [[combustion cannon]].

'''Parts:'''

# Cheap 1 channel R/C car ($15 at KB Toys)
# 5v relay [http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=306-1019-ND Something like this should work]
# [[Sprinkler valve]] (with solenoid)
# A standard diode [http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=MUR180EGOS-ND This will work]
# Two 9v battery clip (go to radio shack or take them from broken stuff)
# Assorted batteries
# Antenna wire (I used 20ft of enamel coated 26 gauge because it was green and blended well)
# Assorted bits of wire

'''Tools:'''

Dremel,
Wire cutters,
Multi meter (this is absolutely essential),
Soldering iron

'''Step One: Disassembly'''

Take off the R/C car body, then use the dremel to cut the forward section of the car off. Next, remove the motor from its housing and unsolder the two wires going to it. Now, cut off the rear section of the car using the dremel. All that should remain of the car is the battery compartment, a small switch, and the circuit attached to the battery box. A diagram of the before and after of this step is provided below.

[[image:rc detonator.jpg]]

'''Step Two: Re-wiring'''

*Note: I have written this part assuming you have acquired the same or very similar model R/C car as I used*

If you are using the same model car as I am then you will notice as soon as you turn on the car it should start moving backwards in circles, if we do not fix this as soon as we turn on the "detonator" the device will fire because any voltage forward or reverse can activate the relay. This is why we need the diode (Diodes only allow current to flow in one direction). Before we solder the diode, we are going to need to know which of the motor leads to solder it to. This is very simple to determine. Turn on the R/C car, but do not touch the remote. Use the multi meter to measure the voltage coming out of the wires which are used to supply power to the motor. If there is a minus sign on the screen, switch the multi meter leads until it disappears. Then, solder the diode (backwards) to the positive lead. Turn the car off (When the multi meter is reading a positive voltage, it would be the wire the red lead is touching). While you were reading the voltage of the motor, you should have noticed that the voltage output is only 3v. This will not activate our 5v relay (for obvious reasons). This is also very easy to fix. If you look at the battery box, you should see that there are three sets of wires connected to it (instead of the usual two). Find the positive 3v wire and connect it to the positive 5v lead on the box (Again, you need to use the multimeter, but you do not need the car to be on). After this is done, there should only be two sets of wires connected to the battery box.

'''Step Three: Wiring'''

Most of the tedious work is done now; all we need to do is connect the relay and 9v batteries. First, locate the wires that you removed from the motor's terminals. Solder them to the coil side of the relay. Next, solder the 9v battery leads in series, then connect one of the wires to the switch side of the relay, and the other to the solenoid. Lastly, connect the other solenoid wire to the remaining switch lead on the relay. All that is left to do is to mount the antenna, and you are done. Here is a basic diagram of how your final result should appear.

[[image:rc detonator circuit.jpg]]

'''The Remote:'''

The remote in its stock form will work just fine. The only reason I put mine in a cell phone was to give it that "terrorist effect". It was designed to be used in airsoft games, and I am known for using AKs (considered a "terrorist weapon" by most), so I thought it fit nicely. To get the remote to fit in the phone, I shaved off part of the circuit using a dremel, then wired the forward button to the end button on the cell phone key pad. Lastly, I modified the circuit to accept power from a car key fob battery; which is significantly smaller than a standard 9 volt.

'''Other Info:'''

This is a very basic R/C circuit, and is thus prone to picking up interference. This system was designed to be used in the woods; acting as a remote detonated mine. You must remember that this cannot be used in a [[sprinkler valve modification|modded sprinkler valve]] unless you bought a separate solenoid [[valve]] use as a [[pilot valve]] for the sprinkler valve (such as a small 1/4 NPT solenoid valve or similar). If the device goes off as soon as you turn on the power switch, the diode was inserted in the wrong direction. This is simple to correct. Simply unsolder the diode, then turn it 180 degrees and solder it back in place. The R/C receiver is relatively poor in quality, and in my mine it is paired with about 20ft of antenna wire, which would normally be wrapped around a nearby tree to give it an effective range of over 100ft. If you plan on using this underground (in the case of my mine), encase all of the electronic components in hot glue to prevent them from being damaged by water. Lastly, if the device seems to fire randomly, and external radio interference is determined to not be the culprit, the issue is likely the antenna. Ensure that the antenna wire is not making contact with any metal components of the circuit board.

This method was used to make a remote controlled [http://www.spudfiles.com/forums/anti-personnel-mine-t9631.html Airsoft "anti-personnel mine"].

'''Alternative Parts:'''

The 1-channel R/C Car transmitter / receiver pair can be replaced by several other systems.

One possibility is a remote car unlock R/C setup often available for cheap from electronics surplus places. For example, [http://www.allelectronics.com/ All Electronics] sometimes has a "keyless entry" system with two fobs (like a car uses) and the receiver. It'll easily handle the current required for a solenoid or a relay; [http://www.allelectronics.com/cgi-bin/item/RC-10/search/KEYCHAIN_REMOTE_CONTROL,_12VDC_6_AMP_.html CAT# RC-10] for $18.75. A little pricier than a cheapo R/C but you wont need a relay since this will handle 12V at 6A directly, and there is little chance of accidental triggering by interference.[[Image:RC-10.jpg|Car remote (R/C) entry FOB system]]

Another possibility is to use the pager function found on many cordless phones. With a little creative scrounging you can often get an unused cordless phone for free. [http://www.angelfire.com/ SixMhz] has an [http://www.angelfire.com/80s/sixmhz/rcphone.html excellent write-up] on how to convert the phone into a remote firing system.

Union

2009-02-10T20:57:01Z

Ramses: changed male threaded parts of union to female threads

[[Image:Union.jpg|right|thumb|250px|A diagram of a union]]A '''union''' is a fitting that allows a threaded joint without requiring the joined pipes to be rotated. They are usually made of either steel, brass or PVC. Most unions are [[pressure rated]]. A union consists of two female threaded pieces, connected by a threaded oversized nut. The pipe couplings are either socket-weld, [[sweating|capillary]] (for brass) or threaded. PVC unions have been known to blow up when used in [[hybrid]]s, Boogieman and LuckyThirteen13's PVC unions have exploded before. Variations on the union exist, like 90 degree unions. Alternatives to unions include [[flange]]s and [[camlock coupling]]s.

[[category:fittings]]
[[Category:Construction materials]]

==External Links==
*Unions on [http://www.mcmaster.com/ McMaster]
**[http://www.mcmaster.com/nav/enter.asp?psearch=FAM=plasticppf&FT_138=899 Plastic Unions]
**[http://www.mcmaster.com/nav/enter.asp?psearch=FAM=ssppf&FT_138=899 Stainless Unions]
**[http://www.mcmaster.com/nav/enter.asp?psearch=FAM=ssppf&FT_138=899 Iron/Steel Unions]
**[http://www.mcmaster.com/nav/enter.asp?psearch=FAM=ssppf&FT_138=899 Aluminum Unions]
**[http://www.mcmaster.com/nav/enter.asp?psearch=FAM=ssppf&FT_138=899 Brass Unions]