Power source
By type of power source, all modern saw can be divided into electric and
gasoline. The common difference between them is that electrical units are more compact and lighter, less noisy, easy to maintain and do not produce exhaust gases, so they can be used indoors without restrictions. Petrol tools, in turn, combine high power and independence from power grids, but they are heavy, bulky, more difficult to operate and repair, more expensive (both in terms of their own cost and fuel price) and are generally designed for use outside premises. Therefore, most modern saw are made electric, which in turn can use different types of power:
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Power supply (230 V). Connection to a standard 230 V household network, in other words, a regular socket. This option can be used both in portable saw and in stationary tools of relatively low power (up to 3.5 kW). There are sockets almost everywhere where there is electricity at all, and the operating time of such units is almost unlimited (as long as there is voltage in the network). The main disadvantage of such a power supply is the presence of a power cord that does not allow you to go far from the outlet (and with a portable tool, you also have to make sure that the cord does not get under the canvas).
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Power supply (110 V). Tools powered in the American and Japanese manners - from power networks with a voltage of 110
...V. Power tools with such an operating supply voltage are produced for the market of North and Central America, the Land of the Rising Sun, Saudi Arabia. Also, 110 V power grids are found in the UK. To avoid tool failure when connected to standard 230 V household networks, you will need an additional link in the face of a step-down transformer or a special 110 V converter.
- Power supply (400 V). Powered by a three-phase power supply with a voltage of 400 V. Such power is suitable even for high-power saw, but it is far from being available everywhere - basically a three-phase connection is available in workshops, workshops and other industrial premises. Therefore, this option is found exclusively in stationary tools (see "Type") of high power, for which a conventional socket is no longer enough.
- Accumulator. Powered by own battery. The main advantages of this option are mobility, the ability to work independently of sockets and the absence of a power cord that can interfere with work. On the other hand, such a power supply is not suitable for high-power saw, other things being equal, a cordless tool turns out to be noticeably heavier and more expensive than a mains one, and the operating time is limited by the battery charge. However, in most cases, the battery is made removable, which allows you to keep several batteries ready and change them as needed.
- Battery / power supply (230 V). Tools that allow two power options - from an outlet and from its own battery. See above for more details on each option, and their combination makes the saw as versatile as possible. So, if there are sockets nearby, you can work from the network, saving battery power (or even recharging it in the process), and if there is a problem with the sockets or the network cable interferes with work, you can switch to the battery. On the other hand, such versatility affects the price, and the tool itself still turns out to be more cumbersome and heavy than a purely network one.Engine size
The volume of the engine of a gasoline saw (see "Power source"). On the one hand, the power and performance of the tool depend on this indicator, on the other hand, its weight, price and fuel consumption. Accordingly, it is necessary to choose a model taking into account the specifics of the planned work, and it does not always make sense to chase large volumes. In particular, for simple household tasks, an engine capacity of about 40 – 50 cm3 is considered quite sufficient, and in professional models this figure can exceed 100 cm3. More detailed selection recommendations can be found in special sources.
Engine location
The location of the motor in the electric portable saw (see "Type").
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Longitudinally. The longitudinal arrangement allows you to achieve a good balance, allowing you to work comfortably in different positions; this is especially true for cutting branches from trees and other similar work, where the cutting plane can be located at different angles. In addition, such a tool has a smaller width and a longer length, which can make it easier to work in hard-to-reach places. On the other hand, such saws are more expensive than cross-cut saws.
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Transversely. The transverse arrangement of the engine slightly worsens the balance compared to the longitudinal one and makes it difficult to saw along an inclined plane, at an angle to the vertical. In addition, the length of such saws is noticeably shorter. However, for the simplest work with sawing from top to bottom, they are no worse than longitudinal ones, but they are much cheaper. Yes, and a small length in some cases can also be a virtue.
Power
Saw motor power in watts. For petrol tools (see "Power Source"), horsepower is additionally indicated, see below for details.
The higher the power, the better the tool is suitable for voluminous work and hard materials, the greater the depth of cut it can provide and the easier it can cope with significant loads. In addition, for different types of saws and different types of materials, the actual power values \u200b\u200bcan also be different. For example, a power of
2.5 – 3 kW is actually the limit for
chain saws, but in
chain saws this is an average figure, among such tools there are models of
3 – 4 kW and even
more. Detailed selection recommendations for various cases can be found in special sources.
Power
The power of the saw engine expressed in horsepower (hp). This designation is traditionally used in gasoline models (see "Power Source") along with watts; 1 HP ≈ 735 W.
For more information about power, see the paragraph of the same name above.
Idle speed
The speed of rotation of the engine in a saw with an internal combustion engine (see "Power") with no load on the blade and with the speed controller fully released (set to minimum). Theoretically, the lower the idle speed, the lower the fuel consumption without load (ceteris paribus); however, the difference between modern chainsaws is usually so insignificant that this parameter is more of a reference than a real practical value.
Chain pitch
Regular chain pitch for which the chain saw is designed (see "Device"). A step is the distance between two adjacent chain teeth; the greater this distance, the higher the productivity of the saw, however, for a large step, higher power is required, and the cut is rougher. Therefore, this parameter largely determines the class of the saw and the specifics of the work for which it is designed. The current standard options are:
— 1/4". The smallest size, found in a low power tool — 1-1.5 hp. It has not received wide popularity due to poor performance.
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0.325 ". One of the most popular options among amateur-class tools. Saws for such a chain have a power of up to 3 – 3.5 hp, they are suitable for both cutting branches and felling trees of small thickness.
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3/8 ". He is 0.375". Slightly larger pitch than 0.325" is better suited for rough scale work. Also considered a household and semi-professional option, very popular.
— 0.404 ". The largest tooth pitch in modern chain saws. Rare, used in the most powerful professional tools designed for heavy work — for example, logging.
Note that it is allowed to install chains on saws with a finer pitch than the regular one, but not with a larger one. The latter is fraught not only with a decrease in the quality of work, but also with a critical increase in loads, with the possibility of tool breakage.
Chain speed
The maximum speed of the chain relative to the material that a saw of the appropriate design can provide (see "Device"). Higher speed allows to achieve faster and cleaner cuts, but requires more engine power; low speed, in turn, reduces productivity, but allows you to achieve good traction with a relatively low engine power. More detailed recommendations regarding this parameter can be found in special sources.
Features
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Chain brake. A device that ensures the saw stops during the so-called. reverse kick. In accordance with the name, it is used in chain saw (see “Device”). Kickback can occur, in particular, when the very tip (toe) of the tire comes into contact with the material being processed. The bar and chain are thrown towards the operator, which can lead to injury. To avoid this, a chain brake is provided: during a reverse strike, it stops the saw almost instantly.
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Anti-vibration system. Various design solutions that reduce tool vibration during operation. Strong vibrations, especially long-term ones, negatively affect the quality of work and condition of the tool, and also lead to rapid fatigue of the operator; The anti-vibration system allows to eliminate these phenomena to a certain extent.
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Keyless chain tension. Possibility of adjusting chain tension in chain saw (see “Device”) without the use of special tools - wrenches, screwdrivers, etc. This function is especially convenient in light of the fact that during more or less long-term operation, the saw needs to be periodically checked and, if necessary, the chain must be tightened right on the spot - and this is more convenient to do without unnecessary devices.
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Oil-free saw set. Saws that do not require additional lubrication of sawing equipment. Such models
...are unsuitable for long, productive cuts and are suitable for minor work. But the absence of the need for lubrication greatly simplifies the maintenance of the device and “keeping it in shape.”
- Smooth start. A special control system used in electric saw (see “Power source”). Without a soft start, the electric motor “starts” very abruptly, which leads to jerking of the saw and creates the risk of letting go of it. In addition, when started in this way, the tool consumes high currents, creating a significant load on the electrical network. The soft start system allows you to avoid these phenomena: the electronics limit the starting currents of the electric motor, avoiding tool jerks and voltage surges in the network.
— Electronic engine protection. A protection system that turns off power to the saw motor in the event of a critical increase in load - for example, when the disk/chain jams. Such systems are used in electric saw (see “Power source”). They help avoid damage to the unit due to overload. At the same time, we note that the electronic protection is reusable; after it is triggered and the problem is eliminated, it is enough to turn on the power again - and the saw can be used again.
— Brushless motor. The presence of a brushless (brushless) motor in an electric saw (see “Power source”). Such electric motors have a number of advantages over traditional commutator motors: in particular, they are more economical in terms of energy consumption, less noisy, and do not spark, which can be important in conditions of increased fire danger. The disadvantages of brushless motors are complexity and high cost.
— Engine brake. A device that additionally brakes the engine when the tool is turned off. The engine itself (and, accordingly, the working attachment) after switching off can still rotate for quite a long time by inertia; the brake stops this rotation almost immediately, so you don’t have to hold the tool suspended for extra time.
— Safety clutch. A device that protects the operator from sudden jerks, as well as the engine from damage due to a sharp increase in load. In such cases, the overload clutch disconnects the motor shaft, avoiding overload. Note that such devices can be either reusable or disposable - the latter are destroyed when triggered, and to continue operation you will need to install a new coupling.
— Laser marker. A kind of “target designator” that allows you to clearly determine where the cut will go. To do this, a clearly visible line is projected onto the workpiece, the location of which corresponds to the location of the future cut.
— Backlight. Lighting system built into the saw. This feature is definitely desirable when working in low light conditions. However, it can also be useful in bright external light: the place of work is often in the shadow (for example, from the tool itself), and without special lighting it can be difficult to work in such conditions.
— Speed regulator. The ability to limit the rotation speed of the saw motor (and, accordingly, the speed of the blade). This function is essentially a smooth speed control; it is especially useful in cases where full speed is not required - for example, when working with soft materials that require delicate processing.
— Maintaining speed. A function that ensures maintaining a constant engine speed (and, accordingly, a constant blade speed) regardless of the load on the tool. To do this, the tool’s automation regulates the output power depending on the current load: when the load increases, the power increases, when it decreases, it decreases. Permanent operating speed has a positive effect on both the quality of the cut and the service life of the blade and the durability of the entire tool.
— Stationary installation. Possibility of installing a portable saw (see “Type”) in a stationary manner. Most often, this feature is provided in circular saw (see “Device”), and for a stationary installation such a saw is usually turned “upside down” and fixed on a workbench or other base - thus, the sole turns into an impromptu work table. In addition, there are reciprocating saw with a similar function. In them, a stationary installation means the ability to secure the saw directly to the workpiece using a clamp - this allows you to make an even cut without the need to hold the saw suspended and constantly control its position in your hands.
— Water cooling (coolant). The saw has a water cooling system. In this case, we are talking about cooling the workpiece and the blade: water is constantly supplied to the cutting site using a special pump. Thanks to this, the heating of the blade is reduced, its service life is increased, the quality of the cut is improved and the amount of dust generated during sawing is noticeably reduced. The method of collecting water supply may be different: some models need to be connected to a water supply, others are equipped with their own water tanks. Note that water cooling is not required for sawing wood; but when working on stone, concrete and other hard and dense materials, it can be very useful.
— Keyless blade replacement. Possibility of replacing the saw blade without using wrenches, screwdrivers or other special tools. In other words, to replace the blade, the user does not have to look for an additional tool - you can open the fasteners, change the blade and secure it manually.
— Pendulum stroke. The presence of a pendulum function in the reciprocating saw (see “Device”). With this stroke, the blade, making a reverse movement, deviates slightly from the cutting line in the direction opposite to the teeth. This increases the cutting speed, reduces the heating of the blade and makes it easier to remove sawdust from the working area. At the same time, the pendulum stroke somewhat reduces the quality of the cut and is not suitable for curved lines. Therefore, this function is usually made switchable, and in some models it is also adjustable: using the switch you can change the amplitude of the pendulum.
— Display. The display shows important information about the operating modes of the saw. This can be: current strength, cutting speed, number of passes, operating time, etc. The information displayed on the screen depends on the modification of the sawing tool.
— Synchronization with a smartphone. The ability to connect the instrument with a smartphone or other gadget (for example, a tablet) via Wi-Fi or Bluetooth. The mobile application can provide information about the condition of the saw: battery charge level, temperature, etc., and proprietary software often warns the user about the need to service the tool or replace parts. Some stationary saw support remote control from a smartphone (turn on/off, adjust speed, select operating mode, configure various parameters, etc.). Finally, the mobile application can be used to set a password for starting the tool or logging work performed.