Product type
The device describes first of all the general principle of operation of the saw. The variety of modern saw is quite large: chain saw, (
band saw ( for wood and
metal), reciprocating saw (including
alligators),
circular saw (including
gas cutters),
miter saw,
cutting saw,
combined saw,
radial-cantilever saw. Here are the main features of these varieties :
- Chain. Saws, the working element of which is a chain with teeth of a special shape. The chain is closed in a ring and during operation moves along an oval-shaped guide bar. In common parlance, the name
“chainsaw” most often means this particular type of saw, but chain units can also be
electric. In general, chain saw are widely used both for wood (felling trees, trimming branches, etc.) and for other materials - in particular, for concrete and ice. Almost all instruments of this design are portable (see “Type”)
— Tape on wood. All band saw use a looped metal band with teeth as a working element. At the same time, unlike chain models, there is no tire in the design, and the necessary rigidity of the belt
...is achieved solely through the tension between two rollers. As for tape models specifically for wood, they are all made exclusively stationary (see “Type”) - this is one of the key differences from similar tools for metal (another difference is the design features of the blade itself).
— Tape for metal. Band saw designed for working on metal. In addition to the design features of the tape itself, they differ from wood models (see above) in that this type of saw can be made both stationary and portable. At the same time, hand-held band saw can be a good alternative to traditional hacksaws - although they are noticeably more expensive and heavier, and also require a power source, they have higher productivity and require virtually no effort.
- Saber. A type of saw, also called “electric hacksaw”. According to the key principle of operation, they are similar to conventional hacksaws: the blade of such a saw moves back and forth during operation. One of the key advantages of reciprocating saw is their compactness, which allows them to be used in cramped spaces where there is not enough space for a circular saw or chain saw. At the same time, replacement blades are quite universal; they are produced for different materials: wood, metal, concrete, stone. And some blades allow you to make neat cuts even in a combined material - for example, a roof that combines wood, roofing felt and metal.
— Circular (disc). The working element in such saw is a rotating rim with teeth (for wood) or a diamond abrasive coating (for stone, glass and other special materials). It allows you to make straight cuts quickly and easily, but the depth of cut is limited by the radius of the blade. Note that some types of saw described below also use a disc, but due to their specialization they are divided into separate categories. Specifically, circular saw can be either portable or stationary; the second type is usually made in the form of a table with the edge of the rim protruding above the surface - this makes it easier to work with long parts.
- Trimming. A variant of a circular saw designed for cross-sections of processed materials - boards, slabs, beams, etc. They have only a stationary structure (see “Type”), and the cutting rim can rise and fall relative to the base. On the base there is a platform with a mount for the workpiece; Many models are equipped with additional stops for long parts and/or devices for placing workpieces at an angle. When such a saw operates, the rotating rim is lowered onto the workpiece at the point of the cut, ensuring cutting; Most models allow the disc to be tilted relative to the base, for bevel cuts.
- Combined. Saws that allow two options for use - both as a miter saw and as a stationary circular saw. See above for more information about these varieties. Here we note that the combination saw resembles a miter tool, the upper moving part of which (with the motor and rim) is equipped with an additional table. Thanks to this, you can also use the saw as a stationary “circular saw” - by lowering the rim all the way and securing it in this position. The main disadvantage of such universal models is their rather high cost, which is why they are used mainly in the professional field.
- Cut-off. A specific type of miter saw, designed exclusively for working on metal - for cutting metal tubes, rods, profile elements and other parts where a large cutting length is not required. The design of such units is almost completely similar to cross-cut units, with the exception of the type of disks used and more powerful motors.
— Radial-cantilever. A specific type of miter saw. They use a cutting mechanism in the form of a rim, but it is installed not under the desktop, but above it, on a console - a special design that resembles a miniature crane. The “boom” of this crane can be rotated from side to side, and the cutting disc can be moved back and forth on it and rotated relative to the vertical. This makes the saw very maneuverable and expands its capabilities, but has a noticeable impact on its dimensions and cost.
- Petrol cutter. In fact, a gas cutter is a modification of a circular saw (see above), equipped, as the name suggests, with a gasoline engine. Such engines combine high power and autonomy; Their features are described in more detail in paragraph “Power source”. Here we note that gas cutters work well not only with wood, but also with concrete, stone and other similar materials, due to which they are widely used in construction and rescue work.
— Alligator. A peculiar modification of reciprocating saw (see the corresponding paragraph). Alligator instruments have two blades moving back and forth in antiphase: while one blade moves forward, the other moves backward. Due to this, the accuracy and safety of work significantly increases - the mutual movement of the blades reduces the risk that the saw may be pulled to the side. On the other hand, the cut is wider, and the tools themselves are more bulky, heavy and expensive than reciprocating saw.Bar/blade size
The largest tyre size (in chain saws) or disc (in circular saws and some others, see "Device") that is allowed for this tool. Tyres are sized by working length, rims by diameter.
A larger bar/wheel allows for deeper cuts but requires more powerful motors. Therefore, this parameter cannot be exceeded — this can lead to an overload of the engine with all the corresponding troubles. However, in many models with a disc it is physically impossible to install a nozzle with a diameter larger than the maximum allowable.
Also note that saws with similar bar/blade sizes may differ in maximum depth of cut (mostly due to differences in design or power). As for the specific dimensions, they depend on the type of saw (see "Device"). For example, large discs of
450 – 500 mm are found exclusively in stationary chain saws, the maximum figure for cutting models is
400 – 450 mm, for trimming —
300 – 350 mm, and sizes of
500 – 550 mm or
more clearly indicate that speech It's about a chainsaw chainsaw bar. Detailed recommendations regarding the choice of a tool for a given size can be found in special sources.
Cutting depth
The greatest depth of cut provided by the saw.
In most types of saws (see “Device”), the depth of cut directly depends on both the engine power and the size of the tyre / disk. The specifications give a value for the maximum allowable size of the working nozzle; when using nozzles of a smaller size, the depth of cut, respectively, will be less. But in band saws, this depth is rather weakly related to the actual length of the tape — it is determined primarily by the length of the open section of the tape, which is directly involved in the work.
Anyway, the greater depth of cut makes the tool more versatile, but comes at the cost of weight, price, and electricity/fuel consumption. So when choosing, it is worth considering the real features of the planned work and the dimensions of the workpieces that are planned to be cut. As for specific values, the most modest tools provide a depth
of up to 50 mm ;
50 – 75 mm is considered a low indicator,
75 – 100 mm is average,
100 – 125 mm is above average,
125 – 150 mm is already quite an impressive thickness, and the most powerful modern saws can have a cutting depth
of more than 150 mm.
Steel cutting depth
The greatest thickness of steel workpiece that a reciprocating saw can handle. Note that in practice, the maximum cutting depth will depend on the grade of steel and the characteristics of the material. It is not recommended to exceed the declared indicators - this is fraught with undesigned loads on the tool with all the ensuing consequences.
Stroke
The distance that, during operation, the reciprocating saw blade (see "Device") passes from one extreme point to another; in other words, the amplitude of the web vibration in normal operation. The larger the stroke (at the same stroke frequency, see below) — the greater the part of the blade in contact with the material being processed in one movement and the more performant the saw (although the power is needed for this).
Max. stroke rate
The highest frequency of blade strokes provided by a reciprocating saw (see "Device") in normal operation. A higher frequency, on the one hand, increases productivity and provides a more accurate cut, on the other hand, it increases the load on the blade and requires a rather high power.
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.
—
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.
—
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
—
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.
—
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.
—
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.
—
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.
