How to choose a chainsaw

Any owner of a country house must necessarily face the need for wood cutting operations. Especially it is in demand at carrying out of building or repair works which in a private home ownership usually always are. If the house has a furnace, then it is constantly required replenishment of fuel. Plus, everything - care for the local area: regular pruning of trees or a full cut of old, unnecessary, trimming of bushes and hedges, etc. Even the organization of leisure often requires the use of a saw - when it is necessary to prepare fuel for a grill or a summer grilling oven.

Use the "grandfather" approach with conventional and two-handed saws, ax, secateurs - it is possible, but it takes a lot of time, which usually is not enough, and requires considerable physical effort. It is good that in our time it is possible to purchase a modern mechanized tool that greatly simplifies the implementation of labor-intensive operations. So, the chainsaws are in great demand, due to the convenience of working with them and full autonomy - independence from the availability of a power source. But that the tool really lived up to the expectations of its owner, it is necessary to understand how to choose a chainsaw correctly, which should be paid special attention when buying.

Experienced users who have long used chainsaws in their daily work, probably know the basic selection criteria. But for those who are just going to buy this useful "helper" for the first time, at first it is necessary to understand at least a little about the device of the chainsaw - in order to make it clear what will be discussed when evaluating the characteristics of the instrument.

How the chain saw chainsaw

The range of chainsaw chainsaws is very wide, as they are used in a variety of areas.

• This is an indispensable tool both in companies engaged in industrial logging, and in forestry, carrying out regular work on cleaning the arrays of dead wood or unnecessary trees.

• In construction, chainsaws are used in the preparation of wooden parts of erected structures, cutting through window and door openings in log cabins from logs or beams, sampling the necessary grooves or spikes and for many other operations.

• The variety of domestic, economic use of chainsaw has already been mentioned above - it is an indispensable assistant to a good homeowner.
• Moreover, in the skilled hands of the master of the chain saw becomes a tool for creating artistic works - logs or decks are transformed into unique garden wooden sculptures.

But, despite such a wide range of use, all chainsaw chainsaws have approximately the same design and operate on a single principle.

We first consider the chainsaw from the outside:

The entire basic construction of the saw is closed with a plastic or metal casing( item 1).Inside there is a power unit( engine) and nodes and mechanisms that ensure its start-up and operation. At the top, the housing has a removable cover( key 2), which, when removed, opens access to the power and ignition systems.

Each saw has two working handles. Front - in the form of an arc girdled from above the body( item 3), and the rear( item 4), with the controls on it.

A tire( key 5) is installed in the front of the chain saw, with a saw chain stretched over it( key 6).

To start the power unit a manual starter is used, the handle of which is located on the left side of the body( key 7).To pre-fuel the carburetor on most models, there is a special button for the hand pump( key 8).Most often it is indicated by the pointer "Primer".

Directly near the rear handle, so that you can easily reach with your finger, is the switch for turning on and off the engine's ignition system( key 9).

There are always two filler necks on the left side of the housing - for fueling the saw( key 10) and for filling the chain and tire lubrication system( key 11).The necks are sealed with leakproof plugs. The location of the necks may differ from the example shown in the figure, but there are always inscriptions or pictograms that clearly indicate the purpose of the refueling capacity.

The engine speed is controlled by the throttle key( key 12) located on the rear handle of the saw. On the top of the handle, there is necessarily one more key - a stop button( key 13), without pressing which it is impossible to transfer the control action to the throttle. This - one of the boundaries of security in work.

A special safety guard( key 14) is always placed in front of the front handle, which is kinematically connected to the emergency chain brake.

sawing mechanism. On the opposite side of the chainsaw, there is a metal or plastic cover( key 15) that closes the rotation transfer unit from the engine to the drive sprocket of the saw chain. There is also a mechanism for adjusting the chain tension, its lubrication, and also two fixing nuts( key 16) that fix the installed position of the tire.

The internal combustion engine used in chainsaws is single-cylinder, two-stroke. Its dimensions, respectively - the diameter of the cylinder and its volume, directly depend on the power and predetermine the purpose of the instrument.

Two-stroke engines do not assume a dedicated lubrication system. For the normal operation of the mechanisms, it is sufficient to use the properly selected gasoline-oil mixture as a fuel. The gasoline component burns in the cylinder, and the oil component ensures lubrication of the friction units.

Engine cooling system - air. For greater efficiency of heat transfer, the outer cylinder housing( item 1) is finned, and the flywheel of the engine has a peculiar configuration of the turbine with blades( item 5), which provide a forced powerful air flow.

Ignition of the working fuel mixture in the cylinder is carried out with a candle( item 2).The fuel supply from the carburetor to the cylinder is via a special connecting pipe( item 3).A silencer( item 4) is mandatory, which reduces the noise level of the unit and directs the exhaust to the side.

Any gearbox with a change in the number of revolutions from the engine to the drive sprocket is not provided - the speed is regulated only by the throttle valve. But the clutch system is( position 5) - the transmission of the torque is realized only when a certain speed is reached.

This mechanism operates on a centrifugal basis. Clutch shoes( their number can differ in different models) are tightened to the center by a spring( pos.2).The tension of the screed is designed so that, when idling, the pads do not contact the inner surface of the drum( key 3), which is rigidly connected to the chain sprocket( key 4), and the engine shaft( item 1) is not transmitted further.

When the number of revolutions is increased, the massive pads, overcoming the resistance of the springs under the action of the centrifugal force, are pressed against the inner surface of the drum, and the torque is transmitted to the saw chain.

The tire with the chain has a slot for inserting the saw pins( key 6) and centering holes for the stopper( pin), the position of which can be changed by a special screw( item 5) - this adjusts the chain tension.

Many chain saws in the same area have a toothed chain catcher( key 7).In the event of a chain break or chain, he should not allow injuries to the hands of the worker.

Here, through the screw pump, the oil supply channel from the tank for lubricating the chain and gears of the bus is also output. Many models are equipped with an adjusting screw, with which you can change the intensity of the feed.

The outer surface of the drum( key 3) also plays another function - it is part of the emergency braking circuit of the chain.

When assembling the unit, the drum is surrounded by a spring-loaded steel band ring( key 1).When the saw is inoperative, this belt is pressed against the drum by a spring. Before using the tool, the master presses the back panel( key 2) back. In this position, the belt is loosened and the drum can rotate freely.

Why is this done? Chainsaw is a tool of increased danger, and a chain moving along the tire can cause serious injuries. Especially dangerous is the phenomenon of a return stroke - when the tire is thrown up or to the side. In the working condition of the saw, the protective flap in the rear position is very close to the hand of the worker holding the tool by the front handle. In the event of a sudden throw of the saw blade upwards or to the side, the back of the brush will involuntarily move the guard to the front position, the spring-loaded belt will press the drum, and its rotation for 0.5 to 1 second will be stopped, and the chain will also stop. The engine remains on the move.

Scheme number 3 shows a screw that changes the position of the pin when adjusting the chain tension.

However, the work of such a brake requires special care of the master. If you add engine speed, without shifting the shield into the rear working position, then it is easy to overheat the mechanism and even cause fusion of the polymer parts of the structure with the output of the entire mechanism out of order. And it is strictly forbidden to work without an active chain brake.

To start the engine - to give him a starting torque that will provide the supply of a fuel mixture from the carburetor to the cylinder and create an impulse for sparking on the spark plug, a manual starter is used.

The starter design is simple. It is a drum with a cable wound around it, which ends with an external handle. The drum itself is located on a frame, which has a return spring - it provides reeling of the cable and returning the starter to its original position. The starter is located at most of the models on the left, coaxial with the crankshaft of the engine.

With a sharp pulling of the cord, the drum is given a slight forward movement, so that its slots fall into the reciprocal protrusions of the flywheel of the engine, and the rotational motion transmitted to the flywheel and then to the crankshaft.

Access to maintenance of the carburettor and a spark plug is carried out by opening of the top cover of a chainsaw.

is available. Here, of course, there are filter elements that ensure the cleaning of the air entering the carburetor. They require regular monitoring and cleaning - clogged filters often cause unstable operation of the engine or even its inability to start.

Many models have one more external control element - adjustment of the air damper of the carburetor( among the motorists the name "suction" usually appears).Such adjustment is necessary to facilitate cold start of the engine, before its heating, especially in conditions of low winter temperatures.

There is a filter in the fuel tank, which ensures the cleaning of the mixture from suspensions. The fuel pump, as such, is not, except for the "primer" for preliminary manual pumping. Equalization of the pressure in the tank and outside( so that there is no discharge during fuel production) provides a special breather on the tank cap. His condition also requires a regular "look", since with a clogged breather the engine of the chainsaw will constantly stall. The arrangement of specific models of chain saws, especially for different manufacturers, may have some differences. However, the basic scheme for all remains approximately the same.

For more visibility of information about the chainsaw device - demonstration video:

Video: the device and the principle of the chainsaw

What is appreciated when choosing a chainsaw?

Which criteria for evaluating the tool should be given special attention when buying chainsaws?

The intended purpose of the

tool First, you should really know how much work will be done on the chainsaw, and with what regularity. This primarily determines the choice of the required model.

• If it is necessary to perform small jobs with low frequency, for example, one-off firewood for a fireplace or barbecue, pruning trees, performing simple operations when processing wood blanks, you can restrict yourself to purchasing an inexpensive model belonging to the class of household chainsaws.

These tools are usually designed for very short continuous work - within 20-30 minutes, and in total not more than 1.5-2 hours per day. But even in this mode it is not recommended to exceed the threshold of 20 hours of its use within a month. The engine resource of the unit is small, usually within 400 hours of operating time, and that the chainsaw remained an "assistant" as long as possible, it requires appropriate, very rational use.

The power of the power unit of a household chain saw does not usually exceed 1.5 kW, and the cylinder capacity is about 40 cm³.Household class saws, as a rule, have a very effective muffler, reducing to a minimum the noise effect of their work.

For all these disadvantages, these chainsaws have undeniable advantages. It is compact and has a small mass. Such qualities make it possible to use the tool of the household class practically to everyone, regardless of the level of physical fitness of a person.

• The second class of chainsaws is semi-professional, or, as they are often called, "farmer".

This is already a fairly serious tool that can withstand several hours of continuous operation( about 4 hours a day).The power of the power unit reaches 2 ÷ 2.5 kW, the volume of the cylinder - up to 60 cm³.

Such a chainsaw is perfectly suitable for any household needs, including - for regular harvesting of firewood, stalling of small trees and their sawing on logs, for performing a variety of construction operations. Most often, these saws are used by carpenters when building log or timber houses. Such saws are also used on logging, but only for cleaning trunks from knots and branches.

The motor resource in this chain saw is usually about 1000 hours. For the "arsenal" of the owner of a country house permanently residing in it, this is, apparently, the best option. Of course, both the overall dimensions and mass of the chainsaw are already much higher than those of the household class tools, and working with it will require a certain preparedness.

• Finally, the chainsaw is a professional class. Their very name speaks for themselves - they are designed for continuous work during the working shift - up to eight, or even more hours, under heavy loads.

These chainsaws always have a powerful power unit( 3 kW and above, with a cylinder volume of 60 to 90 cm³), a long tire is shown allowing to work with thick trunks, an "aggressive" shape and sharpening of chain teeth capable of sawing dense wood even on strongfrost. The laid-in service life is measured in thousands of hours.

A similar tool is used, usually in logging sites. Apply it to economic needs and unprofitable, and uncomfortable. Chainsaws of this class are always massive and dimensional, so in construction they too will not become good assistants. The operation of the saw is always accompanied by a sufficiently high level of noise: in the conditions of the forest it is not a matter of principle, but for household use it is hardly suitable. In addition, working with a professional tool requires very high physical readiness and the appropriate qualification of operators.

All other parameters of tool selection directly or indirectly depend on the accessory of the chainsaw to this or that class.

Types and parameters of tires and saw chains

Chainsaws are always equipped with standard tires. Their size( length) corresponds to the capabilities of the engine, and to exceed it is extremely dangerous - you can easily "kill" the drive, not designed for excessively large loads.

The range of tire lengths - usually 10 inches for a household tool up to 18 - for a "farmer"( for professionals it can be much longer).For each specific model, the manufacturer specifies the allowable dimensions. The use of shorter tires, in principle, is possible, although not very welcome. Installation of longer, beyond the upper limit of the range - is strictly prohibited.

Some models of exactly the same power and design can go on sale with tires of different lengths. Here you can focus on the nature of the proposed work - to trim trees and shrubs it is better to have a shorter tire, as it will be more convenient to work with, and for sawing firewood - longer, taking into account the diameter of the logs.

Tires may differ in design.

• In household and "farm" chainsaws, flat tires with low-profile chains are usually installed - they are more convenient to use with unloaded cuts and are least likely to be affected by a kickback effect. True, all this is due to reduced performance.
• For working at height, it will be more convenient to use a light-weight tire. These are two metal plates with a polyamide gasket in the middle.
• Professional chainsaw tires usually provide the option of replacing the head with an end sprocket, since this knot, when used constantly, will wear out the tool fastest. For economic use, such a bus is not needed.

The main parameters of the tire are shown in the picture:

tires 1 - the dimensions and position of the fastening holes and the guide adjusting pin must correspond to the chainsaw model.

2 - the width of the guide groove providing the wedding movement, but at the same time - and a reliable chain-holding on the tire. The size should correspond to the thickness of the shank of the tooth chain.

3 - the pitch of the teeth of the end sprocket must correspond to those of the leading sprocket and the parameters of the chain.

4 - the length of the tire( L), which has already been mentioned above.

As a rule, the main tire parameters are not only indicated by the manufacturer in the passport, but also on the product itself:

. The saw chain consists of the following elements:

1 and2 - cutting links of the chain, alternately - left and right, having a certain angle of grinding the faces. On each of their cutting links there is a ledge - the depth gauge cut-off( item 3)

4 - the leading links through which the rotation from the sprocket is transmitted, and the shanks of which keep the chain on the tire from lateral displacement.

5 - connecting links.

6 - rivets that collect all the links in a single design.

The main circuit parameters are shown in the diagram:

a is the value that determines the pitch of the chain, the distance between the first and third rivets, divided in half.

This value is standardized. In chains of small and medium power, that is, belonging to the household and "farm" class, chains with a pitch of 0.325 and 3/8 of an inch are used( this corresponds to a metric of 8.255 and 9.525 millimeters).Such a strange gradation at first sight, using decimals and simple fractions, was chosen only to prevent confusion: 3/8 of an inch is equal to 0.375, which is easy to confuse with 0.325, and so random discrepancies are excluded.

Chains with a pitch of 0.325 are distinguished by the lowest vibration indices during operation, but their performance is not high."The golden mean" is 3/8 inches, it's these chains that stand on most middle-class models. Professional chainsaws are equipped with chains in increments of 0.404, and sometimes even ¾ inches with a high profile of teeth, often with special carbide tips.

The second parameter of the chain is the thickness of the shank of the leading link( in the diagram it is designated "b") - this value has already been mentioned above.

And, finally, the length of the chain, if this element of the saw head is purchased separately, should match the size of the existing tire.

The shape of the cutting sections and their sharpening can vary from manufacturer to manufacturer. So, there are two main types of teeth - chisel and chipper. However, there are many intermediate options.

However, such subtle knowledge is interesting only to experienced masters - at the household level, the user will not feel much difference.

Another important note about the saw headset. The usual phenomenon is that chains and tires of the same manufacturer are designed exclusively for chainsaws of the same brand. There are exceptions - but they are single and do not "make the weather."Thus, when choosing a saw, you should immediately evaluate the availability of the service or the availability in the region of the opportunity to purchase spare parts for this model.

Evaluation of the convenience of working with a chainsaw

It is completely pointless to study the technical and operational characteristics of a chainsaw, if not "feel" it with your hands. This tool belongs to the group of increased danger, therefore it is extremely important that the chainsaw ideally "fit into the hand" of the master. And the owner himself should easily, without using excessive force, direct the movement of the working saw bar.

For this, the choice of ergonomics of a particular model is necessarily evaluated.

• Chainsaw must be balanced - in its fully assembled form, its center of gravity should be positioned so that when the tool is lifted by the front handle it maintains its balance. This is very important - do not have to spend extra effort to keep the tool in a horizontal position, which means that fatigue will not come so quickly.
• The mass of chainsaws is also estimated - the physical possibilities are different for people, and what seems easy for one person can become an unbearable weight.

• drum. Be sure to evaluate the position of the safety guard in front of the front handle. It happens that for some household models, the distance between the working position of the flap and the handle is very small. A person with a highly developed brush, and even wearing a working glove, will not easily hold the tool when cutting - any movement can cause an emergency brake operation. Naturally, there will not be any effective work under such conditions - it will turn into a total torment, or it may end with overheating of the brake drum. So, we'll have to choose a larger model.
• The convenience of placing the hand on the rear control handle is assessed. Pressing the accelerator key, after triggering the safety key, should be comfortable for the fingers, without jamming. Ignition interrupt switch should be located in the availability to instantaneous shutdown of the engine in case of need.

is of great importance for comfortable operation

• Even the smallest saw gives a tremendous vibration load to the user's hands during work - this causes rapid fatigue, and with frequent use of the tool can lead to even chronic joint diseases. Therefore, manufacturers try to minimize vibration effects by applying special elastic or spring dampers between the body and the power unit and, in particular, between the body and the front handle of the chainsaw. At this point, too, is to focus attention.
• When choosing a chain saw, you should always ask the seller for its refueling and start-up. It is necessary to make sure that the engine is easily, without problems, wound up and smooth, without failures, running at idle. You should try to "pick up" the motor, that is, its adequate response to the throttle key press. At the same time, it is possible to verify the regular operation of the clutch assembly( rotation on the chain at idle speed should not be transmitted), and an emergency brake( the forward deflection should almost immediately stop the chain).

• units. With a working chain saw, you can evaluate the degree of its noise, as well as the direction of exhaust of exhaust combustion products - this will subsequently be important for selecting the workplace and tool position with regard to the direction of the windor the location of the doors( gates, windows, ventilation hoods) in the workshop.

Which brand to choose?

And, finally, an important criterion of choice are the manufacturer's warranty obligations, the possibility of servicing, the purchase of replaceable elements of the headset and spare parts.

Unconditional leaders in the production of chainsaws are the companies STIHL and HUSQVARNA.The STIHL tool is more preferable from the point of view that it is much easier for him to purchase a headset, consumables and spare parts in our territories. The undoubted authority is enjoyed by the products of MAKITA, JONSERED, OLEO MAC, HITACHI, ZENOAH, PARTNER, ECHO and others. Among Russian buyers, Chainsaws of the brands "Taiga", "Ural", "Interskol", "Zubr", "Energomash" are completely running.

Of course, you should buy a chainsaw only in a specialized store, where the originality of the product will be guaranteed and all the obligations of the manufacturer are confirmed. Alas, we have to admit that in this sphere there is a huge number of fakes, which are practically indistinguishable from real models and that issue themselves only with separate "strokes".But here in the work they have nothing to do with the original, either in terms of effectiveness, or in a built-in resource, or in ensuring proper security.

Video: carefully, Chinese counterfeits chainsaw STIHL

And finally - several popular models from the leading chainsaw manufacturers:

Model	Illustration	Short description	Power, weight	Average price
HUSQVARNA 236		Small, light but powerful saw of household class. Bus 14 "with a chain pitch of 3/8" and a slot width of 1.3 mm. The capacity of the tank is 0,3 l. Additional centrifugal air purification systems for carburetor	1400 W 4,6 kg	11500 руб.
Stihl MS 180 14		One of the most popular models for personal use. The length of the tire is 14 ", the chain pitch is 3/8, the width of the groove is 1.3 mm. Automatic chain lubrication system. The capacity of the tank is 0,25 l.	1500 W 3.9 kg	13000 rub.
MAKITA EA3502S40B		Chainsaw for household needs. The length of the tire is 16 ", the pitch and thickness of the chain is 3/8 - 1.3 mm. Fuel tank capacity - 0,4 l	1700 W 4.4 kg	16700 rub.
ECHO CS-510-15		Powerful saw of semi-professional, "farmer" class of Japanese assembly. The length of the tire is 15 ", the chain is pitch 0.325 and a width of 1.5 mm. Increased safety system, economical fuel and oil consumption for light design features. Improved anti-vibration protection.	2600 W 4.9 kg	28100 rub.
ZUBR PBC-450 40P		Reliable and relatively inexpensive chain saw of domestic production, semi-professional class. Bus 16 ", the parameters of the chain - 0,325 - 1,5 mm. The capacity of the tank is 0.55 liters. Electronic ignition system, air pre-cleaning system, self-developed saw set designed for durability of use without sharpening.	1800 W 6,4 kg	12700 rub.
Hyundai X 560		Semi-professional chainsaw chain saw, with an elongated tire that allows you to dump thick trees and apply them in construction work with log cabinets. The length of the tire is 20 ", the chain is 0.325 - 1.5 mm. Engine decompressor system that facilitates the start-up of the unit. Relatively low price against the backdrop of high performance	3000 W 5.2 kg	16500 rub.