An snowmobile is a unique vehicle; this type of transport has no equal in cross-country ability on snow.
Therefore, they are considered an indispensable assistant for any fisherman. In terms of design, it is a vehicle with skids for driving on snow, and it moves with the help of an aircraft propeller that rotates a gasoline engine. The sled is capable of reaching speeds of up to 150 km/h, which is an undeniable advantage over snowmobiles. With a cabin and soft suspension, a snowmobile can be the most comfortable vehicle after a car. But the car will not drive through impassable spaces covered with snow.

At first glance, everything is very complicated, but if you get into it, there are no difficulties, and you can really make a snowmobile yourself using available materials, without spending a lot of effort.

Technical characteristics of snowmobiles

A snowmobile is essentially a chainsaw, but with relatively little power it can reach high speeds. For example:

• Engine speed – 4700.
• Power – 15 hp
• The maximum propeller force is 62 kg.
• Screw diameter – 1300 mm.
• The highest number of propeller revolutions is 2300.
• The gear ratio is 1.85.
• The area of ​​the runners is 0.68 square meters.
• The capacity of the fuel tank is 40-50 liters.
• The highest speed is 40-50 km/h.
• The highest speed on hard snow is 50-70 km/h.
• The highest speed on snow, in open spaces is 70-80 km/h.
• The highest speed on snow crust is 100-110 km/h.
• Maximum weight (without driver) – 90.7 kg.
• Maximum weight with cargo – 183 kg.

Load capacity

Load capacity is the total weight of the vehicle with passengers and equipment. The snowmobile can accommodate up to 5 people. Therefore, when fully equipped, the weight of the vehicle can reach 300 kg.

In other words, a snowmobile is a fairly capacious type of transport that allows you to transport people and cargo over considerable distances in conditions of total snow cover. They may also not be replaceable in fishing or hunting conditions.

Movement range

If the vehicle does not have a powerful engine, then one tank with a capacity of 40 liters is enough to travel up to 300 km.

Fuel reserve

As a rule, a standard tank of 40-50 liters is installed. In addition, on the road you need to take a container of fuel with a volume of 20 liters. This fuel is quite enough to cover a significant distance without refueling. In any case, you need to correctly calculate the fuel supply, since in the snowy wilderness, it is unlikely that you will be able to refuel.

Travel speed

On ordinary compacted snow, a snowmobile can be accelerated to 50 km/h, and on untouched, long-standing snow – up to 80 km/h. The presence of hard crust allows the structure to accelerate to 110 km/h. At such a speed, there is a danger of capsizing, since the stability of the snowmobile decreases.

Design of brakes and engine starting

Since snowmobiles are an exclusive type of transport, the brake system has a far from classical design. The design of the brakes resembles a kind of scrapers that are mounted on the ends of the rear skis. They are activated by cables coming from the brake pedal. When you press the pedals, the scrapers go down, which slows down the speed of the snowmobile.

CALCULATION OF THE MAIN CHARACTERISTICS OF SPEED SLEEDS

The design of a snowmobile should begin with the calculation of the main characteristics that allow one to judge the driving and performance characteristics. But for this it is necessary to have tactical and technical requirements (TTT) for this vehicle. They form the basis of the calculation. Let's assume that TTT boils down to the following:

1. Snowmobiles must have good cross-country ability under moderately difficult road conditions.

2. Desired load - 100 kg without driver.

3. We want to have a closed sled, with a heated body, comfortable seat placement, freedom of entry and exit, heat and sound insulation lining.

4. Their range without refueling is at least 100 km.

Based on these data, we calculate the characteristics.

The degree of passability of snowmobiles is characterized by an abstract quality coefficient - “K”. The larger it is, the higher the vehicle's cross-country ability. For serial snowmobiles K = 0.24. This coefficient is determined by the formula:

K=T/C1x

where T is the thrust developed by the propeller when operating in place, C1x is the total running weight.

From the same formula you can find:

T = C1x K or C1x = T/K

The magnitude of the thrust force of the propeller is obtained from the formula T = N • 3.5, where N is the engine power in hp. s., and 3.5 is the value of specific thrust (traction force in kg per hp).

Engine power. Usually, snowmobiles are made to fit an existing engine, the power of which is known.
For a single-seat snowmobile (Fig. 1), it should be at least 10-12 liters. s., for double rooms - at least 20 liters. With. RICE.
1. SINGLE SEAT AIR SLEDGE OF THE SIMPLE TYPE FOR AN 11-13 HP ENGINE (IZH-49; IZH-56 ETC.). The most suitable engines are M-61, M-62, K-750 - 28 hp each. With. To increase the service life, the calculation is carried out for a power equal to 85% of the engine power. Then we have: 0.85 N dv = 0.85 · 28 = 23.78 (rounded - 24 hp). Using the above formula, we determine the amount of thrust: T = 24 • 3.5 = 84 kg. Knowing these values, we find the total running weight of the snowmobile: C1x = T/K = 84/0.24 = 350 kg.

The influence of ski sole material on quality. The quality formula does not take into account movement resistance, which decreases when using new materials - plastics. They have a reduced coefficient of friction against snow in relation to carbon steel, the coefficient of which is taken as the initial value (see Table 1).

Table 1

Thus, if you cover the soles of your skis with polyethylene, the weight of the machine - while maintaining the same amount of quality - can be increased.

C1x = 350/0.735 = 476 kg.

The weight of the structure is usually 45-50% of the running weight. For convenience, we take it equal to 50%. Then

C1x = (476x50)/100= 238 kg.

The commercial load according to TTT will be 180 kg (driver - 80 kg, passenger - 80 kg and personal cargo - 20 kg).

Fuel and oil supply

C1gar. = C1x – (238 + 180) = 476 – 418 = 58 kg.

10% of the fuel is used as an emergency reserve and is not taken into account, 5% of the weight is oil for engine lubrication.

Then the estimated fuel weight will be:

P = 58x0.85 = 49.3 ≈ 50 kg.

The snowmobile's operating range is calculated based on the engine operating modes, which are distributed over time:

1) at maximum power—15%,

2) at the design operational level - 80%,

3) at idle, in parking lots—5%.

Average hourly fuel consumption according to engine performance curves:

1) 28x0.320 = 8.95 = (8.9x15)/100 = 1.34 kg/hour,

2) 24x0.275 = 6.9 = (6.9x15)/100 = 5.5 kg/hour,

3) 10x0.250 = 2.5 = (2.5x15)/100 = 1.25 kg/hour.

Numbers 0.320; 0.275 and 0.250 - fuel consumption in grams per liter. With. per hour at the specified power.

Then Gtotal ≈8.0 kg/hour.

The fuel reserve is enough to run the engine for 6 hours. According to the TTT, the range was set = 100 km. In this case, the speed was V = 100: 6 = 16.5 km/h.

Operating practice shows that the average speed is 35-40 km/h. If we take it equal to 35 km/h, then the possible range will be: 35x6 = 210 km.

Next, you need to decide on the motor installation diagram. When geared without a gearbox, the propeller will operate at 4000-6000 rpm. According to the condition of limiting the peripheral speed at the ends of the blades, its diameter is 1.1 - 1.2 m. When transmitted through a gearbox, the diameter can be increased, this is beneficial, since the traction force will increase. For the calculation, we take the installation of a transmission with a gearbox. At the same time, the clutch mechanism is retained, which allows you to disengage the propeller without stopping the engine. We take the propeller diameter to be 2 m. The speed is 2500 rpm for propellers with wooden blades and 2800 for propellers with metal ones.

Determining the width of the snowmobile. Knowing the diameter of the screw, we determine the overall width of the machine. It should be 50-100 mm larger than the diameter. The width of the snowmobile will be 2.050 mm.

Calculation of ski sizes. Recommended specific pressure on snow p = 600 kg per square meter of area. With a snowmobile weighing 476 kg, the area of ​​the skis is S = 476: 600 = 0.8 m. Taking the three-ski scheme, we determine the area of ​​each ski: 0.8: 3 = 0.267 m2. With a length of the working surface (in contact with the snow) equal to 1.65 m, we have the width of the ski:

0.267:1.65=163 mm.

The track of the snowmobile is determined by the distance between the axles of the skis. It will be 2.050 - 0.16 = 1.890 mm.

Snowmobile base. For good stability, it is necessary to ensure a track/base ratio of l/b = 1890:0.65 = 2900 mm, or, rounded, 3 m.

Snowmobile clearance. This distance from the lowest point of the body to the snow surface must be at least 300 mm.

Dimensions along the screw axis. Knowing the ground clearance - 300 mm and the diameter of the propeller, we determine the distance from the ground to the engine axis: 2000: 2 + 300 + 50 = 1350 mm, where 50 mm is the distance from the end of the blade to the lower surface of the housing.

Snowmobile layout. Having received the main dimensions, you can proceed to the layout drawing (Fig. 2), while you must strive to reduce the center of gravity as much as possible, placing all this possible in the lower part of the body.
The center of gravity height should not be allowed to be greater than b/2. This allows you to make the angle between the lines drawn from the center of gravity (CG) to the outer edges of the skis equal to 90°. The larger this angle, the better the stability of the snowmobile. The center of gravity along the length should be located so that the load on the skis is uniform and equal to 476:3 = 159 kg. The center of gravity will be 1/3 the size of the base or at a distance of 1000 mm from the rear ski suspension axis. RICE.
2. LAYOUT DIAGRAM FOR CENTERING DOUBLE AEROSLEGE WITH 28 HP MOTOR (M = 61; M = 62, etc.). THE NUMBERED POINTS INDICATE THE CENTERS OF GRAVITY OF INDIVIDUAL UNITS AND LOADS ACCORDING TO WEIGHT TABLE 2. For calibration alignment, in accordance with the layout drawing, and obtaining the weight limit necessary for further design, we compile a weight summary of the structural units and loading of the snowmobile.

table 2

Two design axes are applied to the drawing: X-X and Y-U, and the centers of gravity of all parts and assemblies included in the calculation are indicated. Then alignment is performed according to the form shown in Table 3.

Table 3

Table 4

Dimensions are entered into it: in the X and Y column, the distance from the X-X and Y-Y axis to the CG point of this unit numbered in the table, that is, to points 1, 2, 3, 4, etc.

When all dimensions are determined, columns C1X and C1U are filled in by multiplying the distance from the corresponding axis by the weight of this part (assembly) of the machine. The resulting products are added separately for X and Y, and their sums are divided by the total running weight C1x. This will be the distance to the CG from the conventional axis X-X and Y-U.

For our calculation option, these dimensions will be:

from the X-X axis— 1848 mm

from the Y-U axis - 751 mm.

Next, the change in CG is calculated depending on the loading option:

1) full design load of the machine;

2) with one driver and a minimum fuel supply.

Based on the values ​​obtained from the calculation, a table of the main characteristics of the snowmobile is compiled, from which one can imagine the future machine, its driving and performance characteristics.

I. YUVENALIEV,

Moscow

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Features of snowmobiles for fishermen

A snowmobile for fishermen in winter, as useful as a boat in summer, although you can’t go very far with a watercraft in summer. And, nevertheless, on a snowmobile you can safely get to the center of any body of water, if there is strong ice. Although, if you compare it with a car, you can travel on a snowmobile in deep snow, which you cannot do with a car. In addition, the thickness of the ice required is somewhat less, since the snowmobile is much lighter.

How to make a snowmobile with your own hands

As practice shows, making a snowmobile is not so difficult, although you will have to stock up on time, tools, materials for work and drawings. At the same time, it is necessary to maintain precision in manufacturing, since here the laws of physics and aerodynamics come to the fore. The quality operation of all units, and therefore the durability of the vehicle, will depend on such knowledge.

Aerosleigh for fishermen Zipper

Housing design

The production of snowmobiles begins with the manufacture of the body, which consists of a frame and skin. To ensure that the frame has significant strength, the design has two spars. They have the following dimensions: 35x35x2350 mm. In addition to them, the design includes 5 power stringers, measuring 20x12x2100 mm. Plus, the body has a front compartment and a rear compartment where the engine should be located. The body must be aerodynamically shaped, so it tapers at the front.

The entire hull is reinforced throughout its entire length with four frames located at equal distances from one another. They are made of solid plywood, 10 mm thick. For greater reliability, frames, especially wide ones, have transverse reinforcement with special beams.

First of all, the lower frame is mounted, on which the frames are installed. Spacers are also mounted here, which are attached to the frames with corners. After this, the stringers are secured. The frame is glued with casein glue. The joints are fixed with gauze, after which these places are generously saturated with glue. Another option is also possible: first the bandage is soaked in glue, and then it is wrapped around the connection points.

The body is sheathed with sheets of plywood, and duralumin sheathing is mounted on top. The driver's seat can also be made of plywood or a factory-made plastic one installed. In the rear, behind the seat, there is a luggage space where tools, spare parts, a container of gasoline, and the fisherman’s personal belongings can be stored.

Propeller system

The propeller engine installation requires a more serious approach than assembling the cabin and hull. To rotate the propeller, they mostly take the engine from the IZH-56 motorcycle. The propeller shaft is mounted on a bearing, which is located on the frame.

The engine is mounted on a wooden plate using two brackets and four struts. The plate has dimensions of 385x215x40 mm. It is advisable to sheathe the slab on both sides with plywood, 5 mm thick. Duralumin corners are attached to the legs of the struts.

To make it possible to adjust the V-belt transmission to the screw, a plate made of plywood or textolite is provided between the channels and the plate. The engine is cooled by a fan, which is mounted on the crankcase using a bracket.

Travel suspension

Installation of the chassis is a continuation of the 2 previous stages. Plywood, 10 mm thick, is used as skis. To strengthen them, a thicker beam is used, and the upper part of the ski is sheathed with stainless steel. The entire ski mechanism is attached to the body using M6 screws.

The design of the ski also consists of an undercut, which is made of a pipe with a diameter of 8 mm. The ends of the pipe are flattened. The pipe is attached in the middle part of the mount under the “hog”. Undercuts allow the snowmobile to remain stable when turning.

The front of the ski flexes. To do this, the ski is placed in boiling water (only the part that needs to be bent) and bent using a device (slipway). To ensure that the front part of the ski retains its shape, a metal plate is installed. The ski spring is made of wood and has three parts.

The lower part is made from birch, which has dimensions of 25x130x1400 mm. The axle shaft is attached to it. The upper and middle parts are pine. Together they are connected with M8 bolts and duralumin sheets. There is a special shock absorber in the front of the ski, which prevents the ski from digging into the snow when moving. It is made of a rubber band. The back of the snowmobile is already heavier, and together with the harness, the ski is always directed upward.

Acceleration of the snowmobile's movement is carried out by pressing the corresponding pedals, and changing the direction of movement is carried out by means of the steering column.

To avoid any problems with the operation of the snowmobile, it is better to take a ready-made propeller, since it is very difficult to make it yourself, especially the first time.

How to equip a snowmobile?

Any vehicle must have several mandatory instruments, such as a speedometer, tachometer, ammeter and ignition switch. A fuel level indicator wouldn't hurt either. All main instruments are installed on the front panel made of PCB.

You can install some additional devices, but only if there is at least some sense. Well, for example, a GPS navigator, which may be needed if the path is long and the places are unfamiliar.

There should also be a carburetor air and throttle lever in the cockpit. It is advisable to install a rear-view mirror on the left side of the cabin, and a visor on top of the cabin.

Snowmobile based on a chainsaw engine

This design is much simpler than the design described above. The engine used here is a chainsaw motor. Despite its simplicity, it is unlikely that anyone will decide to go fishing on such snowmobiles.

To travel long distances, you need a motor with a power of about 12 hp, and the motor power of a chainsaw is only 4 hp. The installation principle is the same as in the first case.

If the reservoir is not far away, just a few kilometers away, then you can go fishing on such snowmobiles, equipping them with a place to move fishing equipment.

Making snowmobiles

Many may object and offer to buy a branded snowmobile. However, this transport has serious drawbacks. The main one is the too high price, which not everyone can afford. Also, a snowmobile for ice fishing is dangerous, especially in early autumn or late spring. Its considerable weight does not allow it to travel on thin ice, where light sleds can easily pass on skis. Often a propeller-driven unit is installed on a boat. This version of the snowmobile is considered the most reliable, which can be safely used all year round and on any ice.

To build a snowmobile you will need the following tools:

1. Welding machine.
2. Electrodes.
3. Mask.
4. Bulgarian.
5. Drill.
6. Drill.
7. Spanners.
8. Hammer.

Engine selection

The most complex and most expensive unit is the motor . For a light sled for one person, you can install a small motor from a saw. But its low power will not allow you to drive fast enough. In addition, such engines have a short service life. It is best to choose a more powerful motor from a motorcycle. With such an engine, the sled in the snow will develop very good speed even with additional load.

Air propeller

The snowmobile moves with the help of a propeller. It must match the engine parameters. Otherwise, the motor will start to overheat or will not work at full power. This is a rather complex unit that is very difficult to make at home. If you build it with your own hands, it will take too much time. On top of that, serious knowledge of aerodynamics is required. Therefore, it is better to purchase a propeller in a store.

Frame assembly

To build the frame you will need the following materials:

1. pipes,
2. clamps,
3. bolts,
4. nuts,
5. washers.

The easiest way to make a snowmobile is with three skis. This is the most common method, where the cost of material and construction time will be the lowest according to calculations. For these purposes, a triangular frame is made, which must be very strong. Because all the units will be attached to it. The structure will be light and durable if it is made of metal pipes. Craftsmen often make a frame out of wood. And although this is not the strongest material, it has one advantage. If for any reason the snowmobiles fall through the ice, they will still remain afloat.

Although this is the easiest option, for reliability and durability when building a sled, it is better to use iron pipes. First, you need to draw a drawing by hand and indicate the dimensions of the parts. In this case, it will be much easier to calculate the material consumption and correctly cut the pipes for the frame. First, they are laid out in a triangle on a flat floor. And the ends are connected by welding, and all seams are cleaned with a grinder. Then small bushings are cut from this pipe and welded to the ends of the frame. Three skis will be attached here. The two rear bushings are installed strictly vertically, and the front one for the steering mechanism is slightly inclined.

Engine Installation

Since snowmobiles use a propeller, the motor will have to be raised a considerable distance from the frame. To do this, you will first need to prepare two arched racks . They are easy to make from the same pipes that were used in the previous construction. One rack is attached by welding to the rear frame tube. And for the second, they make an additional crossbar inside the frame. When this work is completed, you need to install a mounting saddle for the motor at the top. It is easy to cut it out with a grinder from the old frame of the motorcycle from which the engine was removed. Or construct such a device with your own hands.

Propeller guards

To prevent the propeller from touching coastal bushes or tree branches, a fence is installed on the snowmobile. It is easy to make from the same material that was used to build the frame. To do this, you first need to bend the pipe into a large ring. Then, using a welding machine, attach it to the bottom of the frame, and the sides to the arc-shaped motor mounts. Often an additional grille is installed on the protective ring. Although this solution reduces the propeller thrust, it significantly increases the safety of the propeller.

Ski construction

When building skis, almost all anglers prefer to use the simplest material - wood . This is the cheapest and most accessible option that is easy to process. When making snowmobile skis, wooden boards made of oak or birch are usually used.

First, they are dried well, and then the ends are sharpened and bent. To increase strength, the lower plane of the skis is covered with duralumin or iron. And a support hinge is installed on the upper part, which is easy to make yourself. To do this, first cut out a square plate of sheet steel along the width of the skis. Holes for screws are drilled along the edges, and a large nut or thick metal washer is welded in the center.

Skis are attached to racks, which are made from pipes of smaller diameter. It should fit easily into the bushings on the frame. A hole is drilled at one end for the cotter pin, and two nuts are welded parallel to the other, as if on a hinge. You will get a kind of fork, which is inserted into the frame bushing and pinned on top. Then the hinge on the ski is combined with the nuts at the end of the stand and secured with a finger or pin. It can be made from a thin metal rod or reinforcement.