DIY hovercraft model. Hovercraft. Specifications and photos. What is "hovercraft"

Roads are one of the most serious and intractable problems for rural residents, especially during the spring flood. An ideal alternative to any vehicles in such conditions are all-terrain vehicles on an air cushion.

What is such a transport?

The vessel is a special vehicle, the dynamics of which is based on the air flow injected under the bottom, which allows it to move on any surface, both liquid and solid.

The main advantage of such transport is its high speed. In addition, its navigation period is not limited by environmental conditions - you can travel on such all-terrain vehicles both in winter and in summer. Another plus is the ability to overcome obstacles no more than a meter in height.

The disadvantages include a small number of passengers who are able to carry all-terrain vehicles on an air cushion, and a fairly high fuel consumption. This is explained by the increased power of the engine, aimed at creating an air flow under the bottom. Small particles in the pillow can cause static electricity.

Advantages and disadvantages of all-terrain vehicles

It is quite difficult to say exactly where to start choosing such a model of a vessel, since it all depends on the personal preferences of the future owner and his plans for the purchased transport. Among the huge number of characteristics and parameters, all-terrain vehicles on an air cushion have their own advantages and disadvantages, many of which are known to either professionals or manufacturers, but not ordinary users.

One of the disadvantages of such vessels is their frequent stubbornness: at a temperature of -18 degrees, they may refuse to start. The reason for this is condensation in the power plant. In order to increase wear resistance and strength, economy-class all-terrain hovercraft have steel inserts in the bottom, which their expensive counterparts do not have. A sufficiently powerful engine may not pull the rise of transport to a fairly small coast with a slope of a couple of degrees.

Such nuances are found only during the operation of the all-terrain vehicle. To avoid disappointment in transport, before buying it, it is advisable to consult with experts and view all available information.

Varieties of all-terrain vehicles on an air cushion

• Junior courts. Ideal for outdoor activities or fishing in small waters. In most cases, such all-terrain vehicles are purchased by those who live far enough from civilization and can only be reached by helicopter to their place of residence. The movement of small vessels is in many ways similar to, but the latter are not capable of side sliding at speeds of the order of 40-50 km / h.
• Large ships. Such transport can be taken already for serious hunting or fishing. The carrying capacity of the all-terrain vehicle is from 500 to 2000 kilograms, the capacity is 6-12 passenger seats. Large vessels almost completely ignore the onboard wave, which allows them to be used even at sea. You can buy such all-terrain vehicles on an air cushion in our country - vehicles of both domestic and foreign production are sold on the markets.

Principle of operation

The functioning of an air cushion is quite simple and is largely based on a physics course familiar from school days. The principle of operation is to raise the boat above the ground and level the friction force. This process is called "exit to the pillow" and is a time characteristic. For small vessels, it takes about 10-20 seconds, for large ones it takes about half a minute. Industrial all-terrain vehicles pump air for several minutes in order to increase the pressure to the desired level. After reaching the required mark, you can start moving.

On small ships capable of carrying from 2 to 4 passengers, air is forced into the pillow using banal air intakes from the traction engine. The ride starts almost immediately after the pressure is set, which is not always convenient, since there is no reverse gear for all-terrain vehicles of the junior and middle class. On larger all-terrain vehicles for 6-12 people, this disadvantage is compensated by a second engine that controls only the air pressure in the pillow.

hovercraft

Today you can meet many craftsmen who independently create such equipment. The all-terrain vehicle on an air cushion is assembled on the basis of another transport - for example, the Dnepr motorcycle. A screw is installed on the engine, which in the operating mode pumps air under the bottom, covered with a leatherette cuff that is resistant to negative temperatures. The same motor carries out the movement of the vessel forward.

Such a do-it-yourself all-terrain vehicle on an air cushion is created with good technical characteristics - for example, its speed is about 70 km / h. In fact, such transport is the most profitable for self-manufacturing, since it does not require the creation of complex drawings and chassis, while differing in the maximum level of cross-country ability.

All-terrain vehicles on an air cushion "Arktika"

One of the developments of Russian scientists from Omsk is an amphibious cargo platform called "Arktika", which was put into service with the Russian army.

Amphibious domestic vessel has the following advantages:

• Full cross-country ability - transport passes on the surface of any terrain.
• It can be used in any weather and any time of the year.
• Large load capacity and impressive power reserve.
• Safety and reliability provided by design features.
• Compared to other modes of transport, it is economical.
• Ecologically safe for the environment, which is confirmed by the relevant certificates.

"Arktika" is a hovercraft capable of moving on the surface of both water and land. Its main difference from similar vehicles, which can only temporarily stay on the ground, is the possibility of operation both in swampy, snowy and icy areas, and in various water bodies.

The prototype of the presented amphibious vehicle was an air-cushion vehicle (AVP) called "Aerojeep", the publication of which was in the magazine. Like the previous machine, the new machine is single-engine, single-rotor with distributed air flow. This model is also a triple, with the location of the pilot and passengers in a T-shaped pattern: the pilot is in front in the middle, and the passengers are on the sides, behind. Although nothing prevents the fourth passenger from sitting behind the driver, the length of the seat and the power of the propeller installation are quite enough.

The new machine, in addition to improved technical characteristics, has a number of design features and even innovations that increase its reliability in operation and survivability - after all, an amphibian is a waterfowl. And I call it a “bird” because it moves through the air both above the water and above the ground.

Structurally, the new machine consists of four main parts: a fiberglass body, an air spring, a flexible fence (skirt) and a propeller unit.

Leading a story about a new car, you will inevitably have to repeat yourself - after all, the designs are in many ways similar.

Amphibious hull identical to the prototype both in size and design - fiberglass, double, three-dimensional, consists of inner and outer shells. It is also worth noting here that the holes in the inner shell in the new apparatus are now located not at the upper edge of the sides, but approximately in the middle between it and the bottom edge, which ensures faster and more stable creation of an air cushion. The holes themselves are no longer oblong, but round, with a diameter of 90 mm. There are about 40 of them and they are evenly spaced along the sides and in front.

Each shell was glued in its matrix (used from the previous design) from two or three layers of fiberglass (and the bottom - from four layers) on a polyester binder. Of course, these resins are inferior to vinyl-ester and epoxy resins in terms of adhesion, filtration level, shrinkage, and the release of harmful substances upon drying, but they have an undeniable price advantage - they are much cheaper, which is important. For those who intend to use such resins, let me remind you that the room where the work is carried out must have good ventilation and a temperature of at least + 22 ° C.

1 - segment (set of 60 pieces); 2 - balloon; 3 - mooring duck (3 pcs.); 4 - wind visor; 5 - handrail (2 pcs.); 6 – mesh protection of the propeller; 7 - outer part of the annular channel; 8 – rudder (2 pcs.); 9 – steering control lever; 10 - a hatch in the tunnel for access to the fuel tank and battery; 11 – pilot's seat; 12 – passenger sofa; 13 - engine casing; 14 - paddle (2 pcs.); 15 - silencer; 16 - filler (polystyrene); 17 - the inner part of the annular channel; 18 - lantern navigation light; 19 - propeller; 20 – propeller bushing; 21 - drive toothed belt; 22 - knot for fastening the cylinder to the body; 23 – attachment point of the segment to the body; 24 - engine on a motor mount; 25 - inner shell of the body; 26 - filler (polystyrene); 27 - outer shell of the body; 28 - dividing panel of the injected air flow

The matrices were made in advance according to the master model from the same glass mats on the same polyester resin, only the thickness of their walls was larger and amounted to 7-8 mm (for the casing shells - about 4 mm). Before baking the elements, all roughness and scratches were carefully removed from the working surface of the matrix, and it was covered three times with wax diluted in turpentine and polished. After that, a thin layer (up to 0.5 mm) of red gelcoat (colored varnish) was applied to the surface with a sprayer (or roller).

After it dried, the process of gluing the shell began using the following technology. First, using a roller, the wax surface of the matrix and one side of the stackomat (with smaller pores) are smeared with resin, and then the mat is placed on the matrix and rolled until the air is completely removed from under the layer (if necessary, a small slot can be made in the mat). The subsequent layers of glass mats are laid in the same way to the required thickness (3-4 mm), with the installation, where necessary, of embedded parts (metal and wood). Excessive flaps along the edges were cut off when gluing "wet".

a - outer shell;

b - inner shell;

1 - ski (tree);

2 - sub-slab (wood)

After separately manufacturing the outer and inner shells, they were joined, fastened with clamps and self-tapping screws, and then glued around the perimeter with strips of the same glass mat 40–50 mm wide, smeared with polyester resin, from which the shells were made. After attaching the shells to the edge with petal rivets, a vertical side strip of a 2-mm duralumin strip with a width of at least 35 mm was attached along the perimeter.

Additionally, with pieces of fiberglass impregnated with resin, carefully glue all corners and places where fasteners are screwed in. The outer shell is coated on top with a gel coat - a polyester resin with acrylic additives and wax that add shine and water resistance.

It should be noted that using the same technology (the outer and inner shells were made using it), smaller elements were also pasted out: the inner and outer shells of the diffuser, the rudders, the engine cover, the wind deflector, the tunnel and the driver's seat. A 12.5-liter gas tank (industrial from Italy) is inserted inside the case, into the console, before fastening the lower and upper parts of the cases.

inner shell shell with air outlets to create an air cushion; above the holes - a row of cable clips for hooking the ends of the scarf of the skirt segment; two wooden skis glued to the bottom

For those who are just starting to work with fiberglass, I recommend starting the manufacture of a boat with these small elements. The total mass of the fiberglass hull, together with skis and an aluminum alloy strip, diffuser and rudders, is from 80 to 95 kg.

The space between the shells serves as an air duct along the perimeter of the apparatus from the stern on both sides to the bow. The upper and lower parts of this space are filled with building foam, which provides an optimal cross-section of the air channels and additional buoyancy (and, accordingly, survivability) of the apparatus. Pieces of foam plastic were glued together with the same polyester binder, and strips of fiberglass, also impregnated with resin, were glued to the shells. Further, the air comes out of the air channels through evenly spaced holes with a diameter of 90 mm in the outer shell, "rests" against the skirt segments and creates an air cushion under the apparatus.

A pair of longitudinal skis made of wooden bars are glued to the bottom of the outer shell of the hull to protect against damage from the outside, and in the aft part of the cockpit (that is, from the inside) there is an under-engine wooden plate.

Balloon. The new hovercraft model has almost twice the displacement (350 - 370 kg) than the previous one. This was achieved by installing an inflatable balloon between the body and segments of the flexible fence (skirt). The balloon is glued out of PVC material Uіpurіap, manufactured in Finland with a density of 750 g/m 2 , according to the shape of the body in plan. The material has been tested on large industrial hovercraft such as Khius, Pegasus, Mars. To increase survivability, the cylinder can consist of several compartments (in this case, three, each with its own filling valve). The compartments, in turn, can be divided in half lengthwise by longitudinal partitions (but this version of their execution is still only in the project). With this design, a broken compartment (or even two) will allow you to continue moving along the route, and even more so to get to the coast for repairs. For economical cutting of the material, the cylinder is divided into four sections: bow, two stern. Each section, in turn, is glued together from two parts (halves) of the shell: the lower and upper ones - their patterns are mirrored. In this version of the cylinder, the compartments and sections do not match.

a - outer shell; b - inner shell;
1 - nasal section; 2 - side section (2 pcs.); 3 - aft section; 4 - partition (3 pcs.); 5 - valves (3 pcs.); 6 - lyktros; 7 - apron

On the top of the cylinder, “lyktros” is glued - a strip of Vinyplan 6545 “Arktik” material folded in half, with a braided nylon cord embedded along the fold, impregnated with “900I” glue. "Liktros" is applied to the side rail, and with the help of plastic bolts the cylinder is attached to an aluminum strip fixed on the body. The same strip (only without the enclosed cord) is glued to the balloon and from the bottom-front (“at half past seven”), the so-called “apron” - to which the upper parts of the segments (tongues) of the flexible fence are tied. Later, a rubber bumper was glued to the front of the cylinder.

Soft elastic guard"Aerojeep" (skirt) consists of separate, but identical elements - segments, cut and sewn from dense lightweight fabric or film material. It is desirable that the fabric is water-repellent, does not harden in the cold and does not let air through.

Again, I used Vinyplan 4126 material, only with a lower density (240 g / m 2), but domestic percale-type fabric is quite suitable.

The segments are slightly smaller than on the "balloonless" model. The pattern of the segment is simple, and you can either sew it yourself, even manually, or weld it with high-frequency currents (FA).

The segments are tied with the tongue of the lid to the lippase of the balloon (two at one end, while the knots are inside under the skirt) around the entire perimeter of the Aeroamphibian. The two lower corners of the segment, with the help of nylon construction clamps, are freely suspended from a steel cable with a diameter of 2–2.5 mm, wrapping around the lower part of the inner shell of the housing. In total, up to 60 segments are placed in the skirt. A steel cable with a diameter of 2.5 mm is attached to the body by means of clips, which in turn are attracted to the inner shell with petal rivets.

1 - scarf (material "Viniplan 4126"); 2 - tongue (material "Viniplan 4126"); 3 - pad (fabric "Arctic")

Such fastening of the skirt segments does not much exceed the time of replacing a failed element of the flexible fence, compared to the previous design, when each was fastened separately. But as practice has shown, the skirt turns out to be efficient even if up to 10% of the segments fail and their frequent replacement is not required.

1 - outer shell of the body; 2 - inner shell of the body; 3 - overlay (fiberglass) 4 - bar (duralumin, strip 30x2); 5 - self-tapping screw; 6 - cylinder lyktros; 7 - plastic bolt; 8 - balloon; 9 - cylinder apron; 10 - segment; 11 - lacing; 12 - clip; 13-collar (plastic); 14-cable d2.5; 15-string rivet; 16-grommet

The propeller installation consists of an engine, a six-bladed propeller (fan) and a transmission.

Engine- RMZ-500 (similar to Rotax 503) from the Taiga snowmobile. Produced by Russian Mechanics OJSC under license from the Austrian company Rotax. The motor is two-stroke, with a petal inlet valve and forced air cooling. It has established itself as a reliable, powerful enough (about 50 hp) and not heavy (about 37 kg), and most importantly, a relatively inexpensive unit. Fuel - AI-92 gasoline mixed with oil for two-stroke engines (for example, domestic MGD-14M). Average fuel consumption - 9 - 10 l / h. The engine was mounted in the aft part of the apparatus, on a motor mount attached to the bottom of the hull (or rather, to a wooden engine plate). Motorama has become higher. This is done for the convenience of cleaning the aft part of the cockpit from snow and ice, which get there through the sides and accumulate there, and freeze when stopped.

1 - output shaft of the engine; 2 - leading toothed pulley (32 teeth); 3 - toothed belt; 4 - driven toothed pulley; 5 - nut M20 for mounting the axis; 6 - remote bushings (3 pcs.); 7 - bearing (2 pcs.); 8 - axis; 9 - screw bushing; 10 - rear strut support; 11 - front over-engine support; 12 - front strut support-bipedal (not shown in the drawing, see photo); 13 - outer cheek; 14 - inner cheek

Propeller - six-bladed, fixed pitch, 900 mm in diameter. (There was an attempt to install two five-bladed coaxial screws, but it was unsuccessful). The screw sleeve is duralumin, cast. The blades are fiberglass, coated with a gel coat. The axis of the screw hub was lengthened, although the old 6304 bearings remained on it. The axle was mounted on a rack above the engine and fixed here with two spacers: two-beam - in front and three-beam - at the back. In front of the propeller there is a mesh fence grille, and behind - air rudder feathers.

The transmission of torque (rotation) from the engine output shaft to the propeller hub is carried out through a toothed belt with a gear ratio of 1: 2.25 (the drive pulley has 32 teeth, and the driven pulley has 72).

The air flow from the screw is distributed by a partition in the annular channel into two unequal parts (approximately 1:3). A smaller part of it goes under the bottom of the hull to create an air cushion, and a large part goes to the formation of propulsion (traction) for movement. A few words about the features of driving an amphibian, specifically - about the beginning of the movement. When the engine is idling, the machine remains stationary. With an increase in the number of its revolutions, the amphibian first rises above the supporting surface, and then begins to move forward at revolutions from 3200 - 3500 per minute. At this moment, it is important, especially when starting from the ground, that the pilot first raise the rear of the apparatus: then the aft segments will not catch on anything, and the front ones will slide over bumps and obstacles.

1 - base (steel sheet s6, 2 pcs.); 2 - portal rack (steel sheet s4.2 pcs.); 3 - jumper (steel sheet s10, 2 pcs.)

The control of the "Aerojeep" (changing the direction of movement) is carried out by aerodynamic rudders, pivotally fixed behind the annular channel. The steering is deflected by means of a two-arm lever (motorcycle-type steering wheel) through an Italian Bowden cable going to one of the planes of the aerodynamic steering wheel. The other plane is connected to the first rigid link. On the left handle of the lever is fixed a carburetor throttle control lever or a “trigger” from the Taiga snowmobile.

1 - steering wheel; 2 - Bowden cable; 3 - knot for attaching the braid to the body (2 pcs.); 4 - Bowden braid of the cable; 5 - steering panel; 6 - lever; 7 - thrust (rocking chair is conditionally not shown); 8 - bearing (4 pcs.)

Braking is carried out by "throttle release". In this case, the air cushion disappears and the apparatus rests on the water with its body (or skis on snow or ground) and stops due to friction.

Electrical equipment and appliances. The device is equipped with a rechargeable battery, a tachometer with an hour meter, a voltmeter, an engine head temperature indicator, halogen headlights, a button and a check for turning off the ignition on the steering wheel, etc. The engine is started by an electric starter. Installation of any other devices is possible.

The amphibious boat was named "Rybak-360". It passed sea trials on the Volga: in 2010, at a rally of the Velkhod company in the village of Emmaus near Tver, in Nizhny Novgorod. At the request of the Moscow Sports Committee, he participated in demonstration performances at a celebration dedicated to the Navy Day in Moscow on the Rowing Canal.

Technical data "Aeroamphibian":

Overall dimensions, mm:
length……………………………………………………………………..3950
width…………………………………………………………………..2400
height…………………………………………………………………….1380
Engine power, hp……………………………………………….52
Weight, kg……………………………………………………………………….150
Load capacity, kg………………………………………………….370
Fuel reserve, l……………………………………………………………….12
Fuel consumption, l/h………………………………………………..9 - 10
Overcome obstacles:
rise, hail………………………………………………………………….20
wave, m………………………………………………………………………0.5
Cruise speed, km/h:
by water………………………………………………………………………….50
on the ground………………………………………………………………………54
on ice………………………………………………………………………….60

M. YAGUBOV Honorary Inventor of Moscow

The quality of the road network in our country leaves much to be desired. Construction in some directions is impractical for economic reasons. With the movement of people and goods in such areas, vehicles operating on other physical principles will do just fine. Do-it-yourself full-size ships cannot be built in artisanal conditions, but large-scale models are quite possible.

Vehicles of this type are capable of moving on any relatively flat surface. It can be an open field, a pond, and even a swamp. It is worth noting that on such surfaces unsuitable for other vehicles, the SVP is able to develop a fairly high speed. The main disadvantage of such transport is the need for large energy costs to create an air cushion and, as a result, high fuel consumption.

Physical principles of operation of the SVP

The high permeability of vehicles of this type is ensured by the low specific pressure that it exerts on the surface. This is explained quite simply: the contact area of ​​the vehicle is equal to or even exceeds the area of ​​the vehicle itself. In encyclopedic dictionaries, SVPs are defined as vessels with a dynamically generated reference thrust.

Large and hovercraft hover above the surface at a height of 100 to 150 mm. Air is created in a special device under the body. The machine breaks away from the support and loses mechanical contact with it, as a result of which the movement resistance becomes minimal. The main energy costs are spent on maintaining the air cushion and accelerating the apparatus in a horizontal plane.

Drafting a project: choosing a working scheme

For the manufacture of an operating model of the SVP, it is necessary to choose an effective hull design for the given conditions. Drawings of hovercraft can be found on specialized resources, where patents are posted with a detailed description of various schemes and methods for their implementation. Practice shows that one of the most successful options for media such as water and hard ground is the chamber method of forming an air cushion.

In our model, a classic two-engine scheme with one pumping power drive and one pusher will be implemented. Small-sized do-it-yourself hovercraft made, in fact, are toys-copies of large devices. However, they clearly demonstrate the advantages of using such vehicles over others.

Ship hull manufacturing

When choosing a material for the ship's hull, the main criteria are ease of processing and low hovercraft are classified as amphibious, which means that in the event of an unauthorized stop, flooding will not occur. The ship's hull is sawn out of plywood (4 mm thick) according to a pre-prepared template. To perform this operation, a jigsaw is used.

A homemade hovercraft has superstructures that are best made from Styrofoam to reduce weight. To give them a greater external resemblance to the original, the parts are glued on the outside with foam plastic and painted. Cabin windows are made of transparent plastic, and the rest of the parts are cut from polymers and bent from wire. Maximum detail is the key to similarity with the prototype.

Air chamber dressing

In the manufacture of the skirt, a dense fabric made of polymeric waterproof fiber is used. Cutting is carried out according to the drawing. If you do not have experience transferring sketches to paper manually, then they can be printed on a large-format printer on thick paper, and then cut out with ordinary scissors. The prepared parts are sewn together, the seams should be double and tight.

Do-it-yourself hovercraft, before turning on the injection engine, rest on the ground with their hull. The skirt is partially rumpled and is located under it. The parts are glued with waterproof glue, the joint is closed by the body of the superstructure. This connection provides high reliability and allows you to make mounting joints invisible. Other external parts are also made of polymeric materials: a propeller diffuser guard and the like.

Power point

As part of the power plant there are two engines: forcing and sustainer. The model uses brushless electric motors and two-bladed propellers. Remote control of them is carried out using a special regulator. The power source for the power plant are two batteries with a total capacity of 3000 mAh. Their charge is enough for half an hour of using the model.

Homemade hovercraft are controlled remotely via radio. All components of the system - radio transmitter, receiver, servos - are prefabricated. Installation, connection and testing of them is carried out in accordance with the instructions. After the power is turned on, a test run of the motors is performed with a gradual increase in power until a stable air cushion is formed.

SVP Model Management

Self-made hovercraft, as noted above, have remote control via the VHF channel. In practice, it looks like this: in the hands of the owner is a radio transmitter. The engines are started by pressing the appropriate button. Joystick controls the speed and direction of movement. The machine is easy to maneuver and quite accurately maintains the course.

Tests have shown that the SVP confidently moves on a relatively flat surface: on water and on land with equal ease. The toy will become a favorite entertainment for a child aged 7-8 years with a fairly developed fine motor skills of the fingers.

We owe the final design, as well as the informal name of our craft, to a colleague from the Vedomosti newspaper. Seeing one of the test "take-offs" in the parking lot of the publisher, she exclaimed: "Yes, this is Baba Yaga's stupa!" Such a comparison made us incredibly happy: after all, we were just looking for a way to equip our hovercraft with a steering wheel and a brake, and the way was found by itself - we gave the pilot a broom!

It looks like one of the dumbest crafts we've ever made. But, if you think about it, it is a very spectacular physical experiment: it turns out that a weak air flow from a manual blower designed to sweep weightless withered leaves from the paths can lift a person above the ground and easily move him in space. Despite the very impressive appearance, building such a boat is as easy as shelling pears: with strict observance of the instructions, it will require only a couple of hours of dust-free work.

With the help of a rope and a marker, draw a circle with a diameter of 120 cm on a plywood sheet and cut out the bottom with a jigsaw. Immediately make a second circle of the same kind.

Align the two circles and drill a 100mm hole through them with a hole saw. Keep the wooden disks removed from the crown, one of them will serve as the central "button" of the air cushion.

Lay the shower screen on the table, put the bottom on top and fix the polyethylene with a furniture stapler. Cut off the excess polyethylene, stepping back a couple of centimeters from the staples.

Tape the edge of the skirt with reinforced tape in two rows with a 50% overlap. This will make the skirt tight and prevent air loss.

Mark the central part of the skirt: there will be a “button” in the middle, and around it there are six holes with a diameter of 5 cm. Cut out the holes with a craft knife.

Carefully glue the central part of the skirt, including the holes, with reinforced tape. Apply tapes with 50% overlap, apply two layers of tape. Re-cut the holes with a craft knife and fasten the central “button” with self-tapping screws. The skirt is ready.

Turn the bottom over and screw the second plywood circle to it. 12mm plywood is easy to work with, but not stiff enough to withstand the required loads without warping. Two layers of such plywood will fit just right. Put on the edges of the circle thermal insulation for plumbing pipes and secure it with a stapler. It will serve as a decorative bumper.

Use cuffs and elbows for 100mm vent ducts to connect the blower to the skirt. Secure the engine with brackets and zip ties.

Helicopter and puck

Contrary to popular belief, the boat does not rely on a 10-centimeter layer of compressed air at all, otherwise it would already be a helicopter. An air cushion is something like an air mattress. The polyethylene film, which is covered with the bottom of the apparatus, is filled with air, stretched and turns into a kind of rubber ring.

The film adheres very tightly to the road surface, forming a wide contact patch (almost over the entire area of ​​the bottom) with a hole in the center. Pressurized air comes out of this hole. A very thin layer of air is formed over the entire contact area between the film and the road, over which the device easily slides in any direction. Thanks to the inflatable skirt, even a small amount of air is enough for a good glide, so our stupa is much more like an air hockey puck than a helicopter.

wind upskirt

We usually do not print exact drawings in the "master class" section and strongly encourage readers to involve creative imagination in the process, experimenting with the design as much as possible. But this is not the case. Several attempts to slightly deviate from the popular recipe cost the editors a couple of days of extra work. Do not repeat our mistakes - follow the instructions clearly.

The boat should be round, like a flying saucer. A ship relying on the thinnest layer of air needs an ideal balance: with the slightest weight loss, all the air will come out from the underloaded side, and the heavier side will fall to the ground with all its weight. The symmetrical round shape of the bottom will help the pilot to easily find balance by slightly changing the position of the body.

To make the bottom, take 12 mm plywood, use a rope and a marker to draw a circle with a diameter of 120 cm and cut out the part with an electric jigsaw. The skirt is made from a polyethylene shower curtain. The choice of a curtain is perhaps the most crucial stage at which the fate of a future craft is decided. Polyethylene should be as thick as possible, but strictly homogeneous and in no case reinforced with fabric or decorative tapes. Oilcloth, tarpaulin and other airtight fabrics are not suitable for building a hovercraft.

In pursuit of the durability of the skirt, we made our first mistake: the poorly stretched oilcloth tablecloth could not cling tightly to the road and form a wide contact patch. The area of ​​a small "speck" was not enough to make a heavy car slide.

Leaving an allowance to let in more air under a tight skirt is not an option. When inflated, such a pillow forms folds that will release air and prevent the formation of a uniform film. But polyethylene tightly pressed to the bottom, stretching when air is injected, forms an ideally smooth bubble that tightly fits any bumps in the road.

Scotch is the head of everything

Making a skirt is easy. It is necessary to spread the polyethylene on the workbench, cover the top with a round plywood blank with a pre-drilled hole for air supply and carefully fix the skirt with a furniture stapler. Even the simplest mechanical (not electric) stapler with 8mm staples will cope with the task.

Reinforced tape is a very important element of the skirt. It strengthens it where necessary, while maintaining the elasticity of other areas. Pay special attention to the reinforcement of the polyethylene under the central "button" and in the area of ​​the air holes. Apply adhesive tape with a 50% overlap and in two layers. The polyethylene must be clean, otherwise the tape may peel off.

Insufficient amplification in the central part caused a funny accident. The skirt was torn in the "button" area, and our pillow turned from a "donut" into a semicircular bubble. The pilot, eyes wide with surprise, rose a good half a meter above the ground and after a couple of moments collapsed down - the skirt finally burst and let out all the air. It was this incident that led us to the erroneous idea to use oilcloth instead of a shower curtain.

Another misconception that befell us in the process of building a boat was the belief that there is never too much power. We got hold of a large Hitachi RB65EF backpack blower with an engine capacity of 65 cc. This beast machine has one great advantage: it comes with a corrugated hose, which makes it very easy to connect the fan to the skirt. But the power of 2.9 kW is a clear overkill. The plastic skirt must be given exactly the amount of air that will be enough to lift the car 5-10 cm above the ground. If you overdo it with gas, the polyethylene will not withstand the pressure and will tear. This is exactly what happened with our first car. So rest assured that if you have any kind of blower at your disposal, it will be suitable for the project.

Full speed ahead!

Typically, hovercraft have at least two propellers: one main propeller, which tells the machine forward movement, and one fan, which blows air under the skirt. How will our "flying saucer" move forward, and can we get by with one blower?

This question tormented us exactly until the first successful tests. It turned out that the skirt glides over the surface so well that even the slightest change in balance is enough for the device to go in one direction or another by itself. For this reason, you need to install a chair on the car only on the move in order to properly balance the car, and only then screw the legs to the bottom.

We tried a second blower as a propulsion engine, but the result was not impressive: the narrow nozzle gives a fast flow, but the volume of air passing through it is not enough to create the least noticeable jet thrust. What you really need when driving is a brake. This role is ideal for Baba Yaga's broom.

Called a ship - climb into the water

Unfortunately, our editorial office, and with it the workshop, are located in the stone jungle, far from even the most modest reservoirs. Therefore, we could not launch our apparatus into the water. But theoretically everything should work! If building a boat becomes your holiday entertainment on a hot summer day, test it for seaworthiness and share with us a story about your successes. Of course, you need to take the boat to the water from a gentle coast on a cruising throttle, with a fully inflated skirt. There is no way to allow sinking - immersion in water means the inevitable death of the blower from water hammer.

Good day to all. I want to present to you my SVP model made in a month. I apologize right away, the introduction is not quite the same photo, but also related to this article. Intrigue...

Retreat

Good day to all. I want to start with how I got into radio modeling. A little over a year ago, for the fifth anniversary of the child gave a hovercraft

Everything was fine, charged, rode until a certain point. While the son, secluded in his room with a toy, decided to put the antenna from the remote control into the propeller and turn it on. The propeller shattered into small pieces, did not punish, since the child himself was upset, the whole toy was damaged.

Knowing that we have a Hobby World store in our city, I went there, and where else! They didn’t have the propeller they needed (the old one was 100mm), and the smallest one, which was 6’x4’ in the amount of two pieces, forward and reverse rotation. Nothing to do took what is. Having cut them to the desired size, I installed them on a toy, but the thrust was no longer the same. And a week later we had ship modeling competitions, where my son and I were also present as spectators. And that's all, that spark and craving for modeling and flying caught fire. After that, I got acquainted with this site and ordered parts for the first aircraft. True, before that I made a small mistake by buying a remote control in a store for 3500, and not a PF in the region of 900 + delivery. While waiting for a package from China, I flew a simulator through an audio cord.

Four aircraft were built during the year:

1. Sandwich Mustang P-51D, span-900mm. (crashed on first flight, equipment removed)
2. Cessna 182 ceiling and styrofoam, span-1020mm. (beaten, killed, but alive, equipment removed)
3. Plane "Don Quixote" from the ceiling and polystyrene foam, span-1500mm. (broken three times, two wings re-glued, now I fly on it)
4. Extra 300 from the ceiling, span-800mm (broken, awaiting repair)
5. built

Since I have always been attracted to water, ships, boats and everything connected with them, I decided to build a SVP. After digging around on the Internet, I found the site model-hovercraft.com and the construction of the hovercraft Griffon 2000TD.

Building process:

Initially, the body was made of 4mm plywood, sawed everything out, glued it, and after weighing, abandoned the idea with plywood (weight was 2.600 kg.), And it was also planned to glue it with fiberglass, plus electronics.

It was decided to make the body of expanded polystyrene (insulation, further penoplex) glued with fiberglass. A foam sheet 20 mm thick was cut into two 10 mm thick foam.

The case is cut and glued, after which it is pasted over with fiberglass (1 sq.m., epoxy 750gr.)

The superstructures were also made of 5mm expanded foam, before painting, I went through all the surfaces and details of the foam with epoxy resin, after which I painted everything with acrylic spray paint. True, in several places the penoplex was a little eaten up, but not critical.

The material for the flexible fencing (hereinafter referred to as the SKIRT) was first chosen rubberized fabric (oilcloth from a pharmacy). But again, due to the large weight, it was replaced with a dense water-repellent fabric. According to the patterns, a skirt for the future SVP was cut and sewn.

The skirt and body were glued together with UHU Por glue. I put the motor with a regulator from the "Patrolman" and tested the skirt, the result pleased. The rise of the SVP body from the floor is 70-80mm,

I checked the ability to move on carpet and linoleum, I was satisfied with the result.

The fencing-diffuser of the main propeller was made of foam glued with fiberglass. The rudder was made from a ruler, bamboo skewers glued with Poxipol.

All available means were also used: rulers 50 cm, balsa 2-4mm, bamboo skewers, toothpicks, copper wire 16kv, scotch threads, etc. Small details were made (hatch hatches, handles, handrails, searchlight, anchor, anchor line box, life raft container on a stand, mast, radar, wiper leashes with wipers) for more detailed model.

The stand for the main motor is also made from ruler and balsa wood.

Navigation lights were made on the ship. A white LED and a red flashing LED were installed in the mast, since the yellow one was not found. On the sides of the cabin, red and green running lights are installed in specially made housings for them.

Lighting power is controlled via a toggle switch by a HXT900 servo machine.

Separately, the traction motor reverse block was assembled and installed using two limit switches and one HXT900 servo machine

Lots of pictures in the first part of the video.

Sea trials were carried out in three stages.

The first stage, running around the apartment, but due to the considerable size of the vessel (0.5 sq.m.) it’s not very good, so it’s convenient to ride around the rooms. There were no issues, everything went smoothly.

The second stage, sea trials on land. The weather is clear, the temperature is +2...+4, the side wind across the road is 8-10m/s with gusts up to 12-14m/s, the asphalt surface is dry. When turning downwind, the model skids very strongly (there was not enough strip). But when turning against the wind, everything is quite predictable. It has good straightness of travel with a slight rudder trim to the left. After 8 minutes of operation on asphalt, there were no signs of wear on the skirt. But still, it was not built for asphalt. It's very dusty from underneath.

The third stage is the most interesting in my opinion. Water tests. Weather: clear, temperature 0...+2, wind 4-6m/s, pond with small thickets of grass. For the convenience of video shooting, I switched the channel from ch1 to ch4. At the start, breaking away from the water, the ship easily went over the water surface, slightly disturbing the pond. Steering is quite confident, although, in my opinion, the rudders should be made wider (the width of the ruler was 50 cm). Water splashes do not even reach the middle of the skirt. Several times he ran into grass growing from under the water, overcame the obstacle without difficulty, although he got stuck in the grass on land.

Fourth stage, snow and ice. It remains only to wait for the snow and ice to complete this stage in full. I think it will be possible to achieve maximum speed on this model in the snow.

Components used in the model:

1. (Mode2 - throttle LEFT, 9 channels, version 2). V / h module and receiver (8 channels) - 1 set
2. Turnigy L2205-1350 (suction motor) -1pc.
3. for brushless motors Turnigy AE-25A (for blower motor) -1pc.
4. TURNIGY XP D2826-10 1400kv (marching engine)-1pc
5. TURNIGY Plush 30A (for main engine) -1pc.
6. Poly composite 7x4 / 178 x 102 mm - 2 pcs.
7. Flightmax 1500mAh 3S1P 20C -2 pcs.
8. airborne

   Mast height min: 320mm.

   Mast height max: 400mm.

   Height from surface to bottom: 70-80mm

   Full displacement: 2450gr. (with battery 1500 mAh 3 S 1 P 20 C -2pcs).

   Power reserve: 7-8min. (with a 1500 mAh 3S1 P 20 C battery, it sank earlier on the main engine than on the pressure one).

   Video report on construction and testing:

   Part one - the stages of construction.

   Part two - tests

   Part three - sea trials

   A few more photos:
   

   

   
   

   
   

   
   

   Conclusion

   The SVP model turned out to be easy to manage, with a good power reserve, it is afraid of a strong side wind, but it can be handled (requires active taxiing), I consider a reservoir and snowy expanses to be an ideal environment for the model. Not enough battery capacity (3S 1500mA/h).

   I will answer all your questions about this model.

   Thank you for your attention!