We build a gas gun from plumbing fixtures. DIY potato cannon Shoot potatoes from plastic pipes

and, being completely delighted with it, they promised to build a more perfect model in the future. And now, three years later, we were again drawn to the vegetable artillery. Last time we were satisfied with the accuracy and range of fire, and now we decided to improve the rate of fire. Let us remind you: in order to load our first classic gun, it was necessary to unscrew the barrel, blow out the breech with a pump, install a potato in the barrel, supply gas from a can and quickly assemble the weapon.

Shells for loading into the magazine must be prepared in advance. They are cut from large potatoes using a piece of pipe with a diameter of 63 mm with sharpened edges. In the design of the gun we used four types of pipes. A 63mm pipe is used as the barrel. The combustion chamber has a diameter of 90 mm. The arc connecting the breech and tail is made of 50 mm pipe. A rammer is made from it, which must enter the trunk and push the potatoes into it. Finally, the magazine jumpers are cut from the 25mm diameter pipe.

We have not yet decided to go for a fully automatic gun. Although such designs exist. They are controlled by a computer controller, and all recharging operations are performed by numerous servos. The potato cannon does not produce serious recoil, the energy of which could be directed to mechanical reloading, so we limited ourselves to manual reloading, but with a lightweight magazine for six shells, an automatic system for purging and supplying gas to the combustion chamber.

Turbocharged gun

To reload our gun, the shooter moves the combustion chamber back, grasping a special handle. In this case, a purge window is released from under the housing, which is located exactly under the fan. The fan automatically turns on and blows through the combustion chamber, filling it with air and freeing it from combustion products. At this time, the shooter turns the magazine, placing another potato opposite the entrance to the barrel.

On the diagram gray pipes, corners and tees are shown, and adapter rings are shown in brown. When selecting components, be careful: the catalogs indicate the outer diameters of pipes and adapter rings. This means that an adapter ring with parameters 90x63 mm fits onto a 63 mm pipe, but does not fit into a 90 mm pipe - only into a suitable tee or coupling with the corresponding internal diameter.

A cylinder with a propane-butane mixture is attached to the body. A tube is connected to it, the other end of which is fixed exactly above the purge window. At the final stage of charging, the shooter briefly presses the canister button to supply gas to the combustion chamber. Thanks to the operation of the fan, all the gas enters the chamber and mixes well with the air. Now you need to quickly, before the gas flies out of the rammer hole, push the combustion chamber forward and secure the handle in the locking mechanism. In this case, the rammer, attached to the combustion chamber at the front, will pass through the magazine cylinder and push the potato into the barrel. That's it, the gun is ready to fire.

The automatic operation of the fan is very simple. When the combustion chamber is moved back to full speed, the button installed on it rests against the housing. In fact, it is the button that serves as a limiter for the backward movement of the breech. When moving forward, the handle performs the same role. The most important part of the design is the locking mechanism. It is a corner screwed to the body through which the handle is wound. Without such a lock, during a shot, the combustion chamber, instead of sending potatoes along the barrel, will roll back on its own.

The store is the most complex part of the structure. It is made from an adapter ring, lengths of 25mm pipe, six cylinders cut from 90mm pipe and twelve saddles. The structure is assembled absolutely reliably using glue. Note that the central adapter ring is attached to the axis between two similar couplings. They are also fixed with glue. The diameter of the cylinders is significantly larger than the diameter of the rammer, making it easier to push it to the barrel. The potatoes are held in the center of the cylinder by foam pads.

Plumbing designer

What a blessing that there are pipes and fittings made of polyvinyl chloride in the world! As a solution for installing a water supply system, they are completely unpopular, but lovers of technical creativity can build from them whatever their heart desires. Working with PVC pipes is reminiscent of playing with a construction set: assembly requires a minimum of plumbing work, since from the variety of fittings available for sale you can select ready-made “bricks” for almost any design.

When choosing a set of pipes and fittings, you need to remember the following. Firstly, you should choose pipes for pressure water supply, and not for sewerage. The latter are not designed to work under pressure, so a gun made from them may explode. Secondly, do not confuse PVC pipes with the more common polyethylene pipes, the connection of which requires a special welding machine. PVC pipes and fittings are designed for adhesive connections. It is important to remember that PVC glue causes irritation to the mucous membrane of the eyes and respiratory tract, so you need to work with it in a respirator, in a well-ventilated area.

Finally, when selecting adapter rings for connecting pipes of different diameters, you should be very careful not to confuse the internal and external diameters. Looking at the diagram, you might think that the design of our gun has too many unnecessary parts, those same adapter rings. This is due precisely to the desire to select elements of matching diameters so that they can be easily assembled without any mechanical modification.

Two long screws screwed into the pipe at an angle to each other form an excellent ignition system. Self-tapping screws are better than screws because they do not come loose and have a pointed end, which has a beneficial effect on spark formation. By turning them in one direction or another, you can adjust the gap between them. A special feature of this design is the “tightly” sealed combustion chamber. Therefore, before gluing the plug to the pipe, you should make sure that the ignition system is assembled and working, and that the handle is screwed securely and is not going to come loose. Repairing a sealed combustion chamber in the event of a breakdown will be problematic. For a similar reason, you should not use low-quality fuel: hairspray or deodorant. This will quickly lead to contamination of the electrodes, which can no longer be cleaned.

We couldn't do without plumbing work at all. The fact is that our gun requires a number of movable joints, and none of the standard fittings are designed for the pipe to pass through it. On the contrary, all adapter rings have coupling connections - special stops that secure the fitting to the end of the pipe for ease of installation. We had to grind off these stops using a drill.

In addition to PVC pipes and fittings, which the diagram will help you choose, to build a gun you will need an 8-centimeter computer fan, a 9-volt battery, a piezoelectric kitchen lighter, several metal corners and mounting profiles, as well as a can of propane-butane mixture for camping burners, which can be purchased at a sports store.

We were very lucky with the gas supply system. On one of the paint cans lying around in the editorial office, there was a button with a sprayer, the diameter of which exactly corresponded to the thickness of an aquarium hose, which had also been lying idle since time immemorial. All that remains is to put the hose on the button, and the button on the cylinder with the propane-butane mixture.

Laughing Gas

The air-fuel mixture is a capricious thing. Learning to feed just the right amount of gas into the combustion chamber is the main skill of a potato shooter. A mixture that is too lean will not ignite, and a mixture that is too rich will not ignite either. I would like to urge all experimenters to be careful, admitting, as an example, their own sloppiness. While practicing firing blanks, we significantly over-enriched the mixture. Desperate to set it on fire, we left the gun with the bolt closed. Returning a little later, we tried to flick the lighter again. During this time, the excess gas has evaporated, and the mixture in the combustion chamber is well mixed. As a result, the gun slammed so hard that half the employees on the floor had their ears ringing for half a day. So we learned, not without joy, that our gun was capable of firing with much greater force than we thought, and also that we should never fire indoors, even with blanks. And now we always use headphones or earplugs on the street.

Most computer coolers are designed for 12V voltage, but will work fine on a 9V battery. Don't be alarmed by the fact that there are four wires coming out of the fan. To make it work, the black wire must be connected to the negative terminal of the battery, and the yellow wire to the positive terminal. The fan is turned on by a button attached to the combustion chamber. When the breech is pulled back to reload, the button presses against the body, starting the purge process.

When assembling the gun, we expected that we would have to pay for the convenience of reloading in terms of range. A multi-shot gun is structurally more complex than a classic one, and its design has a “bottleneck” in the literal sense of the word: it is a rammer, the diameter of which is smaller than the diameter of the barrel. In addition, the purge window and the same rammer are places of potential leakage of working gases. That is why we strongly do not recommend using weapons for hand-held shooting.

Our forecasts turned out to be wrong. Through blowing with a fan ensured better filling of the combustion chamber with oxygen and better mixing of air and gas. Therefore, the pressure in the chamber during the combustion of the mixture increased, and with it the firing range increased. So we can safely recommend that you repeat our experience. Go for it, but be careful!

Principle of operation

The operation of potato guns is based on the same principles as in firearms (a projectile sets in motion a mixture of gases under high pressure), but with lower operating pressure. According to the method of setting the projectile in motion, all products can be divided into four types:

• With ignition of the fuel-air mixture (pyroelectric). Productivity is limited by the combustion energy of the mixture.
• Using the energy of compressed gas (usually air) released through a valve. Such installations are usually called pneumatic catapults, and their power is limited by air pressure obtained by a compressor, hand pump or compressed gas in a cylinder (the principle of operation of such a gun is described in detail in our ).
• By exploding a dry ice bomb Their power is limited by the materials used and the size of the dry ice.
• Hybrid or combined type - using the energy of a compressed fuel-air mixture. In this case, the power is limited only by the mechanical strength of the materials used.

​This time we will start assembling a pyroelectric cannon. The principle of operation of such a gun is quite simple: the fuel mixture is ignited in the combustion chamber of the gun. The resulting gas pushes the projectile out.

Our gun will consist of three components:

• The combustion chamber
• Ignition system
• Trunk

To fire a shot, you need to push a projectile (for example, a potato) into the barrel with a ramrod, inject fuel into the combustion chamber (most often, aerosols or propane), and activate the ignition system, which is most often used as a piezoelectric element of a gas lighter. The ignited mixture creates hot gases, which, expanding, push the projectile out of the barrel.

Assembling a prototype potato cannon

In order to minimize the risks of working with a cannon, we will start small: we will assemble a miniature sample of a potato cannon that will shoot grapes (:

Let's start by assembling the combustion chamber and the muzzle of our gun (we'll deal with the fuel mixture ignition system later). For this we need:

• Fitting, coupling, 2 plugs for PVC pipes with a diameter of 50 millimeters;
• Polypropylene pipe, 50-70 cm long and 16-20 millimeters in diameter;
• Sealant or “liquid nails”;
• Construction knife;

​

Let's start by assembling the combustion chamber. ForTo do this, we need to install a plug in the fitting for PVC pipes:

Do not forget to reliably seal the structure. To do this, apply a layer of sealant to all fastened parts.

The combustion chamber is ready! It's time to assemble the barrel of our gun. To ensure a reliable connection between the muzzle and the combustion chamber, the adapter shown below was found to fit the diameter of the polypropylene pipe.

Using a construction knife or a large-diameter drill, we cut out a hole in the second plug to install the muzzle of our gun. We glue the polypropylene pipe with our adapter. Using sealant or liquid nails, we connect the resulting structure with the plug:

After the resulting structure has dried, you can connect the barrel to the combustion chamber of our gun: apply sealant and install it in the free end of the coupling.

It's time to tackle the fuel mixture ignition system. For these purposes, you can use a regular piezoelectric element with contacts located inside the gun body. But during testing of the prototype gun, such a system often malfunctioned, so it was decided to use an already proven system: a car spark plug paired with an old one (instead of a magneto, you can use the same piezoelectric element from the lighter).

To install the candle, we must drill a hole in our gun with the same diameter as the thread of the candle.

Next, you should install the candle in the hole. We traditionally coat the joints with sealant. To increase the reliability of the connection, you can install a nut of a slightly larger diameter with inside spark plugs, having previously lubricated the spark plug threads with sealant.

To connect to the magneto, you can use an old spark plug wire or ordinary high-voltage wires (to avoid dielectric breakdown in unnecessary places).

All that remains is to further strengthen the structure with self-tapping screws (they need to be screwed in at the junctions of the elements of our gun). And... our gun is ready!

To avoid risk when working with this gun, it should be launched from a safe distance (10-15 meters). For this reason, it is recommended to use long connecting wires.Attention! Do not shoot handheld under any circumstances!

Tests

Make sure children, relatives, pets and neighbors are kept a safe distance from the gun!

Procedure for working with the gun:

1. Spray a small amount of hairspray or other alcohol or acetone mixture into the combustion chamber of the gun;
2. Close the combustion chamber lid tightly;
3. Place a projectile in the cannon barrel (unripe grapes are ideal for the mini-model);
4. Install the gun securely; Never point the gun at people or animals!
5. Move to a safe distance;
6. Apply a spark to the combustion chamber (turn the magneto rotor, or apply a spark from a piezoelectric element);

The amount of fuel mixture must be selected experimentally. If there is a lack or excess of the mixture, the gun simply will not work. In this case, it is necessary to open the combustion chamber cover, blow it thoroughly (until the fuel mixture is completely ventilated) and repeat steps 1-6, while it is necessary to reduce or increase the amount of the injected mixture.

And asbonus test video" older sister"of our miniature potato cannon, the assembly of which we have just examined. This cannon no longer shoots grapes, but real potatoes, which fully justifies its name.

Potato shells rush up to a distance of ~100 meters (like three nine-story buildings!) and land back only after 10 seconds.

​ P.S.:Currently, tests on the firing range and destructive power of our designs are in full swing. So wait for new video reports of testing potato cannons from the Science for Children team...

Today many people hear about potato cannons. What are they and what are they for? The potato cannon is a weapon with a fairly long firing range. You can do it yourself. This article will tell you what devices are needed for this and how the gun works.

Principle of operation

The potato cannon is very similar to firearms, only has a lower operating pressure. In it, the projectile is also set in motion using a mixture of gases under pressure. Guns can differ in the way they eject the projectile. We will talk about weapons in which the fuel-air mixture ignites.

The gun consists of a combustion chamber, an ignition system and a barrel. To fire a shot, you need to use a ramrod to push the projectile, in our case a potato, into the barrel. Fuel is injected into the combustion chamber. It could be propane or some kind of aerosol. Now it is necessary to activate the ignition system. Typically, a piezoelectric element from a gas lighter is used for this. The mixture ignites and creates hot gases. They expand under the influence of high temperature and push the potatoes out of the trunk.

We'll tell you how to make a potato cannon below, but first you need to find out whether such a weapon is legal. Research the laws that apply where you live. In some places, such weapons are prohibited, and their manufacture and possession can be punished.

Once you've verified that potato cannons are legal in your area, you're ready to start making them.

Required accessories

The spare parts that we need to make the gun can be bought at a hardware store. The cost of all parts will be approximately 800-1500 rubles. Thus, a DIY potato cannon will not cost too much.

So, what should you buy? When going to the store, write the following list on a piece of paper:

• Plastic pipe with a diameter of 10 cm, bent at a right angle - 1 pc.
• Plastic pipe with a diameter of 5 cm (1.2 meters) - 1 pc.
• Adapter from 10 to 5 cm - 1 pc.
• Pipe cap with thread - 1 pc.
• Piezoelectric element - 1 pc.
• Sealant - 1-2 packs.
• Aerosol can with butane - 2-3 bottles.
• Potatoes - 1 bag.

Assembling the combustion chamber

When you have purchased everything you need, you are concerned about the question of how to make a potato cannon. Well, let's start in order and make the combustion chamber.

First of all, screw the cap onto the end of the curved pipe, having previously coated the thread with sealant.

We insert a narrow pipe into the adapter. It will play the role of the barrel of our gun. The structure must be straight and have a strong connection.

A small hole should be drilled in the side of the resulting “shoulder”. So we assembled the combustion chamber. The main thing in this work is to choose the optimal size. If it is very short, then the potato will fly out quickly, and if it is long, then the speed of the projectile will slow down.

Insert a piezoelectric element

The piezoelectric element is a necessary thing; without it, the potato cannon will not work. Instructions on how to insert it are given below.

We wrap the piezoelectric element with wire. There should be a small gap between its end and the spark generator.

Now we insert our “spark” into the hole that we drilled in the pipe. We seal the hole with sealant so that there are no gaps left and air cannot penetrate inside.

We screw a self-tapping screw into the chamber to a depth of 1.5 cm. We wind a wire from the piezoelectric element to it from the outside of the chamber. When working, you should use a blue tape to avoid electric shock.

Now let's press the button. If a small spark runs along the wire from the piezoelectric element to the screw, then everything is done correctly.

How to load a gun and fire a shot

Our finished potato cannon needs shells. To charge it, we take a potato, put it in the trunk and push it with a ramrod. If you don't have one, you can use a narrow stick. You need to choose a potato of such a size that there is a small gap between it and the trunk.

That's it, the gun is ready for battle. If you decide to shoot with a small gun, it is recommended to place a rag in the barrel. It will prevent the projectile from flying out prematurely, and its flight range will be long.

Now you need to choose a target. You can only aim the gun at a target that is not near people or animals.

Well, are you ready to shoot? Then unscrew the cap and spray the aerosol into the chamber for 5 seconds. Everything needs to be done very quickly. Screw on the cap and press the ignition button. The potatoes flew.

Before the next shot, the gun must be cleaned and the above steps repeated.

Safety regulations

Shooting from a potato cannon is quite fun, but do not forget about the safety rules:

• Never point the gun at people or animals. The most suitable place for shooting is considered to be an empty open field.
• The potato cannon is a weapon! It can cause serious injury. It must be used with extreme caution.
• Familiarize yourself with current laws. If such a weapon is illegal, you will face penalties for using it.
• Do not glue gun tubes together. Otherwise, it may explode with a powerful shot.
• There is no need to load the gun unless you intend to fire a shot.
• At very high or low temperatures You cannot shoot potatoes in air. The fact is that plastic pipes can become fragile, which poses a danger both to the shooter himself and to those around him.

How to make a mini potato cannon

To make a potato cannon small size, let's take plastic bottle with lid. You will also need a small syringe, a piezo lighter button, a wooden pistol grip, glue, wire and

We make a hole in the pistol grip and cut a hole for the piezoelectric element. We install the button and contacts and fix everything with glue.

Use a knife to make two holes in the bottle at a distance of 0.5 cm from each other. We insert the wire from the piezoelectric element into them. When you press the button, a spark should run between the contacts.

Glue the bottle to the wooden handle.

Now we will make a barrel from a syringe. Let's cut it off top part and remove the piston.

We make a hole in the bottle cap into which we insert a syringe and fix the structure with glue. The mini potato cannon is ready.

You can shoot small pieces of potatoes or berries from such a weapon.

So, we learned how to make a potato cannon with your own hands. This process requires great care and accuracy. Shooting from a finished cannon should be done very carefully and under no circumstances should the gun be directed towards people or animals. You can only shoot at inanimate objects.

Potato cannon, in English. - Potato cannon or Potato gun is the favorite pastime of those who love both tinkering and hooliganism, and at the same time want to remain within the law. Probably, the harsh Russian cops will react poorly to such a hobby, but, having successfully originated in America, the potato gun also successfully spread throughout the world, only in a few countries it was banned.

For such a gun you will need: PVC pipes, which are used in plumbing. Namely - a cover, a coupling, an adapter, a pipe with a diameter of 50 and a tee with a diameter of 110. You also need to have on hand: a hacksaw, a knife, liquid nails, and tape.

Begin slowly gather, this unit. On the 110 tee from the end side we attach the roof, first spreading it with glue. On the opposite side, also on the glue, we place the coupling. Having secured the coupling, let the glue dry a little and insert the adapter from 110 to 50 pipe into it. The lid will screw on the side; it does not need to be glued by inertia.

Next we will make the barrel for the potato cannon. Take 2 meters of plastic tube with a diameter of 50 and cut it in half. Cut the second half lengthwise with a knife. Then we put the cut pipe on the whole one. In this way we strengthened the thin pipe of our trunk. Next, we reinforce this trunk with tape. After you have wound 2-3 layers of tape, glue the barrel into the combustion chamber (the part we made first) and go through it with tape again.

After all the plastic parts are assembled, let's start filling. After drilling the holes, screw a screw into the combustion chamber. A spark will jump between it and the wire. A cheap piezo lighter for gas stoves was chosen as a spark source. There are two wires coming from the piezoelectric element, we screw one to the screw, the second at a distance of 5mm from it. We screw the lighter itself to the gun body with tape, leaving the spark button free.

Operating principle and first tests of a potato cannon

We take potatoes slightly larger than the diameter of the trunk and press them into it with force. Next you need to push it further with something. For this purpose, you can make a cleaning rod from a ski pole. We push the potatoes to the end of the barrel, but not into the combustion chamber itself. To do this, you can make a notch on the ramrod so that you can see where to push the projectile.

Then we take an aerosol can with acetone, unscrew the cap, spray a little into the combustion chamber and close it back. We press the button of the piezo lighter, the explosion of the projectile is pushed out by burning acetone vapors.

Fragment of an article from the site popmech.ru:
In one of the previous issues, we built a potato cannon - a powerful firearm capable of sending a potato traveling 250m. Now it’s minus fifteen outside, and I don’t really want to start shooting in the street. We decided to build a miniature version of a potato cannon for shooting indoors using office supplies. The beauty of the mini-gun is that most of the parts for it can be found in any office. The combustion chamber can be an ordinary plastic bottle - from glue, putty or ink. Be careful not to use containers larger than 150 ml: the fuel mixture will ignite and expand in the combustion chamber, and the plastic may not be able to withstand too much fuel. We liked the bubble liquid bottle. It is important that the container has a securely screwed lid: it will have to be unscrewed to ensure ventilation of the combustion chamber. One barrel hole for purging will not be enough.

The barrel from a permanent marker is suitable as a barrel. As a rule, they are made collapsible and the inner surface has a smooth cylindrical shape - what is needed for a smooth-bore gun. A hole should be made in the bottom of the combustion chamber corresponding to the diameter of the marker, and the barrel should be glued into it with superglue. In our case, a rubber cylinder placed on the marker body to improve grip allowed us to further compact the structure and make it airtight.

The ignition system is based on a piezoelectric lighter for gas stoves, for which you can run to the nearest supermarket. We were lucky: there were gun-shaped lighters on the counter. Better case Can't find one for a mini-gun. We disassembled the lighter body and connected two long wires to the piezoelectric element. The wires can be soldered or simply secured with electrical tape.

Office pins are ideal electrodes for igniting a gun. They should be inserted into the wall of the combustion chamber not far from each other. Due to the curvature of the walls of the jar, the needles will converge and form a gap of 1–2 mm. Wires from the piezoelectric element are connected to the pins. Pointed electrodes when pressed trigger form a reliable spark. All that remains is to attach the camera to the body of the lighter (this can be done using car clamps) - and the mini-fire gun is ready.

The recipe for the perfect shell is like a chapter from a cookbook. Take a raw potato, cut it into slices 1 cm thick. Using a mold, squeeze a shell out of a slice. The role of the mold can be played by a cap from the same marker, another body, or even the barrel itself. Place the projectile in the barrel and push it with a cleaning rod (pencil) as close to the combustion chamber as possible. The potato projectile is good for its density and good fit to the barrel. If the projectile does not allow air to pass through, it will happily fly out, like a cork from a bottle. In case you want to stay within the office arsenal, replace the potato with an eraser.

Propane is ideal as a fuel for gas burners. Western gunsmiths often recommend using hairspray. It is also made on the basis of petroleum products, but when the base burns, the varnish settles on the electrodes and makes it difficult to ignite in the future.
Spray some propane into the chamber. A large outdoor gun only takes 2-3 seconds of spray, so for the mini version the spray needs to be very short indeed. A typical mistake of novice shooters is to over-generously fill the gun. An over-enriched mixture does not ignite well.

Always screw the combustion chamber cap on tightly, otherwise it will fly into your eye when firing. Do not point guns at people and wear safety glasses.

Thanks to my sister for scanning the article for me.