SpudFiles Wiki - User contributions [en]

Category:Projectiles

2007-09-14T04:37:23Z

SpudBlaster15:

For projectiles, ammo, ammunition, or whatever you call those things you send down range.

Category:Projectiles

2007-09-14T04:37:09Z

SpudBlaster15:

For projectiles, ammo, ammunition, or whatever you call those things you send down range.

Darts

Remotely Activated Gun

2007-09-08T19:34:58Z

SpudBlaster15:

'''Parts:'''

1) Cheap 1 channel R/C car ($15 at KB Toys)

2) 5v relay [http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=306-1019-ND Something like this should work]

3) Sprinkler valve (with solenoid)

4) A standard diode [http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=MUR180EGOS-ND This will work]

5) Two 9v battery clip (go to radio shack or take them from broken stuff)

6) Assorted batteries

7) Antenna wire (I used 20ft of enamel coated 26 gauge because it was green and blended well)

8) Assorted bits of wire

'''Tools:'''

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

'''....Part 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]]

'''...Part 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 becuase 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.

'''...Part 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 modded sprinkler valve unless you bough a separate solenoid valve to pilot 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 detonate 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 was the method used to make my [http://www.spudfiles.com/forums/anti-personnel-mine-t9631.html anti-personnel mine].

Remotely Activated Gun

2007-09-08T19:33:35Z

SpudBlaster15: Fixed horrible grammar and sentence structure.

'''Parts:'''

1) Cheap 1 channel R/C car ($15 at KB Toys)

2) 5v relay [http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=306-1019-ND Something like this should work]

3) Sprinkler valve (with solenoid)

4)A standard diode [http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=MUR180EGOS-ND this will work]

5)Two 9v battery clip (go to radio shack or take them from broken stuff)

6)Assorted batteries

7)Antenna wire (I used 20ft of enamel coated 26 gauge because it was green and blended well)

8)Assorted bits of wire

'''Tools:'''

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

'''....Part 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]]

'''...Part 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 becuase 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.

'''...Part 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 modded sprinkler valve unless you bough a separate solenoid valve to pilot 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 detonate 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 was the method used to make my [http://www.spudfiles.com/forums/anti-personnel-mine-t9631.html anti-personnel mine].

Chamber to barrel ratio

2007-08-03T06:10:06Z

SpudBlaster15:

The '''chamber to barrel ratio''', or '''C:B ratio''', is the volume ratio between the chamber and barrel. The ratio determines how much of the available energy is transferred to the projectile, and a good C:B ratio is a major factor in [[combustion cannon]] performance. The goal of an optimal ratio is to have the barrel end at the exact point where the projectile stops accelerating.

Higher ratio cannons are louder, since more energy is wasted as noise when the projectile exits the barrel. Too low a ratio will hurt performance, since a vacuum is formed behind the projectile when the combustion product cool. In extreme cases, it may even be sucked back into the chamber. [http://www.burntlatke.com/15cb-testday.html]

[http://www.burntlatke.com/launch.html Experiments] have shown that a C:B ratio of about 0.6-0.8:1 is the most efficient for a given chamber using potatoes as projectiles. The ratio will vary somewhat depending on the weight, friction and blowby of a certain projectile, but it's in that area for most common projectiles.

Two main theories exist when determining the optimal chamber for a particular barrel. A brief summary of both is found below.

1. A chamber volume that exceeds the optimal value for efficiency will increase performance due to more energy being available within the chamber. This theory is based on the fast combustion model, in which the fuel burns quickly, and the pressure rises to it's peak long before the projectile has moved a significant distance down the barrel, even if the chamber is largely oversized. When designing a launcher, a larger chamber will produce higher levels of performance.

2. The most efficient ratio will usually also produce the highest level of performance. This theory is based on the slow combustion model. A chamber that is too large takes longer to burn the fuel, meaning the pressure rises more slowly and to lesser levels, resulting in lower projectile acceleration. This phenomenon is similar to a slow opening pneumatic valve. If the chamber is grossly oversized, combustion may not complete until after the projectile leaves the barrel, further reducing performance. When designing a launcher, the chamber and barrel should be matched to each other for optimal performance. A ratio anywhere between 0.5:1 and 1:1 will be ideal under most circumstances.

No raw data has been presented to support either theory.

In short, C:B ratios are good for determining which barrel will yield the highest performance given a fixed chamber volume, and also for maximizing fuel efficiency and controlling noise output. When a definite answer is found, they will also be effective at determining which chamber volume will deliver optimal performance given a fixed barrel. A single value should not be interpreted as the optimal ratio for all cannons, however.

[[Burst disk]]s can be used to increase the performance of high ratio cannons, since they let higher pressure build up before the projectile starts to move. They will not increase the performance in near optimal cannons. [http://www.advancedspuds.com/burstdisk.htm Source]

The C:B ratio of [[pneumatic cannon]]s is much less fixed, since factors like air pressure and valve performance play a greater part in determining overall performance. It is advisable to use [[GGDT]] to determine the best design for pneumatic cannons.

[[category:Concepts]]

MAPP

2007-07-28T06:30:54Z

SpudBlaster15:

[[Image:mapp.jpg|frame|Typical MAPP Tank]]
'''MAPP''', a stabilized mixture of Methylacetylene and Propadiene (and trademark of BOC Gases) yields about 25% more muzzle energy (about 11% more velocity) than [[Propane]].<br>
Available in the plumbing departments of home improvement stores like Home Depot or Lowes.

Your [[fuel meter]] would be set up using the same torch head you may have modified for propane, although you'll have to meter in 4.6% by volume instead of the 4.2% of propane.<br>
Keep tank upright to prevent liquid fuel from contacting the torch head. Room temperature tank pressure is 94 psi.

MAPP gas has a noxious rotten egg odor to inform you of the presence of leaks, but you should still use liquid leak detector on all joints.

In Australia it is known as RazorGas and is a trademark of ELGAS.

[[Category:Fuels]]

BBQ ignitor

2007-04-03T01:01:15Z

SpudBlaster15: Altered description of battery igniters, fixed spelling.

[[Image:BBQ_Ignitor.jpg|right|thumb|250px|A simple piezoelectric igniter for a grill]]A '''BBQ igniter''' or grill igniter is arguably the simplest spudgun [[ignition source]]. It consists of a pushbutton, that activates a hammer mechanism that strikes a piezoelectric crystal. The crystal generates a high voltage pulse that can be made to jump a small spark gap. One of the main advantages to a BBQ igniter is that it doesn't use batteries, and is cheap and relatively small. Quality differs quite a bit though, some igniters last for many years while other break after some time of use. The spark is also the weakest of the common ignition sources, and achieving ignition may take several attempts in some circumstances (cold weather, sub-optimal fuel mixes, etc).
Piezoelectric igniters can also be obtained from a few other devices, notably long-nosed lighters, and some gas igniters and cigarette lighters.

There are also electric BBQ igniters that run on a 1.5V or 9V battery. They are similar in operation to a [[Stun Gun]] and are capable of producing much larger sparks than piezoelectric igniters. They are a very good alternative to a Stun Gun if you live in a state/country where such devices are banned by law.
[[Category:Ignition sources]]

Barrel

2007-01-13T06:08:34Z

SpudBlaster15:

The '''barrel''' is the pipe used to launch the projectile, and is, along with the [[chamber]], the only component found in all launchers. The diameter determines what projectiles will fit in the launcher, and the length affects how much energy is transferred to the projectile.

Modifications and improvements to the basic barrel include [[sleeving]], [[rifled barrel|rifling]], [[hop-up]]s and flatline barrels.

There are many diameters of barrels popular in spudding, below are some that fit certain ammo:

* 4.5mm brakeline - fits bbs, good for [[BBMGs]]
* 6mm brakeline - fits [[airsoft bb]]s, a commonly used ammo in BBMGs.
* 3/4" CPVC, 3/4" sch 80 PVC (looser fit), or 3/4" sch 120 PVC - fits .68" [[paintball]]s
* 1/2" sch 40 PVC (.602" id) - fits "AA" batteries, marbles.
* 1/2" sdr 21 PVC (.685" id) - fits .68 caliber paintballs.
* 3/4" sch 40 PVC (.804" id) - fits 12g [[CO2 cartridge]]s, C batteries.
* 1" sch 40 PVC (1.029" id) - size [[C cell|"C" batteries]], smaller sized [[bouncy balls]].
* 1.25" sch 40 PVC (1.360" id) - Fits size [[D cell|"D" batteries]], [[film canister]]s
* 1.5" sch 40 PVC (1.590" id) - a common size, good trade-off between power and [[potato]] usage. [http://www.spudtech.com/components.asp Available rifled from the [[SGTC]]]
* 1.5" sdr 21 PVC (1.700" id) - fits [[golf ball]]s. Traditionally [[sleeving|sleeved]] within SCH-80 PVC.
* 1.5" sdr 26 PVC (1.734" id)- fits golfballs, but it is thinner than sdr 21, so the golfballs fit a little looser. Traditionally sleeved within 2" SCH-80 PVC.
* 2" sch 40 PVC (2.047" id) - fits caulk tubes and (large) potatoes.
* 2" sch 80 PVC (1.913" id) - fits 1.5" nominal pipe well, making it ideal for [[sleeving]] Also used as a golf ball barrel by itself, with the golf ball held in place by a rag patch, or other wadding. Also fits normal light bulbs! [http://advancedspuds.com/concreteballs.htm (Details)].
* 2.5" sch 40 PVC (2.445" id) - fits [[tennis ball]]s well.
* 3" sch 80 PVC (2.864" id) - fits many drink bottles well.
* 3" sch 40 PVC (3.042" id) - fits normal [[steel can|cans]], empty propane torch tanks, certian wine bottles, and gatorade bottles.
* 4" sch 40 PVC (3.998" id) - fits 29 oz. cans

Inside diameter (id) data from www.harvel.com
[[Category:Components]]

Primer

2007-01-12T07:00:41Z

SpudBlaster15: /* Health and Safety */

A primer is a chemical substance used to prepare an object for painting or gluing. However, to potato-gun enthusiasts, primer is generally used in the process of combining PVC/CPVC fittings and pipes by preparing them for the gluing process.

== How to use Primer ==

Primer is to be applied liberally to all PVC/CPVC joints, pipes or fittings (by use of a brush) where they are going to be connected together. In many cases, a brush is supplied with the primer.

== Health and Safety ==

Primer is a mixture of methyl ethyl ketone, cyclohexanone, tetrahydrofuran, and acetone.<br> Tetrahydrofuran is a known carcinogen in animals, so primer should be used in a well ventilated area. Gloves can be worn, but care should be taken to avoid spilling primer on them, as acetone penetrates through latex and rubber gloves, where it is absorbed through the skin. In addition, long term exposure of skin to these low-polarity solvents will severely dry your skin out, possibly leading to dermatitis. Swallowing primer may result in death, and chronic inhalation of primer fumes can cause damage to several vital organs including the central nervous system, liver, and kidneys. Symptoms of acute (short term) overexposure include dizziness, headache, nausea, confusion, vomiting, and unconciousness.

Be sure to read warnings and instructions.

== Types of Primer==

There are two basic "types" of building primer commonly used with potato cannons: clear and purple primer(s). The difference is simply that purple primer has a dye added to aid in the enforcement of building codes. This dye is essentially impossible to remove, as it soaks into the pipe fairly deeply.

Both of these are manufactured by many various companies and can usually be found at your local hardware store. Purple primer is easier to see when applied, clear primer can often be hard to detect after in dries. However, purple primer often leads to messy and unsightly purple smears on and around the project you are working on, best prevented by a generous application of masking tape around the non-joint area prior to gluing. Both are equally effective at getting the job done; it is up to you to decide which to use.

== External links ==

Wikipedia article on primer: [http://en.wikipedia.org/wiki/Primer_%28paint%29]

Primer

2007-01-08T05:35:33Z

SpudBlaster15: /* Health and Safety */

A primer is a chemical substance used to prepare an object for painting or gluing. However, to potato-gun enthusiasts, primer is generally used in the process of combining PVC/CPVC fittings and pipes by preparing them for the gluing process.

== How to use Primer ==

Primer is to be applied liberally to all PVC/CPVC joints, pipes or fittings (by use of a brush) where they are going to be connected together. In many cases, a brush is supplied with the primer.

== Health and Safety ==

Primer is a mixture of methyl ethyl ketone, cyclohexanone, tetrahydrofuran, and acetone.<br> Tetrahydrofuran is a known carcinogen in animals, so primer should be used outside, while wearing rubber/latex safety gloves. In addition, long term exposure of skin to these low-polarity solvents will severely dry your skin out, possibly leading to dermatitis. Swallowing primer may result in death, and chronic inhalation of primer fumes can cause damage to several vital organs including the central nervous system, liver, and kidneys. Symptoms of acute (short term) overexposure include dizziness, headache, nausea, confusion, vomiting, and unconciousness.

Be sure to read warnings and instructions.

== Types of Primer==

There are two basic "types" of building primer commonly used with potato cannons: clear and purple primer(s). The difference is simply that purple primer has a dye added to aid in the enforcement of building codes. This dye is essentially impossible to remove, as it soaks into the pipe fairly deeply.

Both of these are manufactured by many various companies and can usually be found at your local hardware store. Purple primer is easier to see when applied, clear primer can often be hard to detect after in dries. However, purple primer often leads to messy and unsightly purple smears on and around the project you are working on, best prevented by a generous application of masking tape around the non-joint area prior to gluing. Both are equally effective at getting the job done; it is up to you to decide which to use.

== External links ==

Wikipedia article on primer: [http://en.wikipedia.org/wiki/Primer_%28paint%29]