Hedge Trimmers: specifications, types

— Bush cutter. In this case, classic hedge trimmers are devices that are equipped only with bush attachments (see "Attachments") and do not have long rods like those used in pole saws (see below). In full accordance with the name, they are designed to work with shrubs — both individual plants and hedges. They are available in various power and power options.

— For bushes/grass. This type includes compact battery-powered devices that have relatively low power and are not designed for difficult working conditions. Usually they are able to work with two types of nozzles — for bushes and for grass (see below) — however, not all models are regularly equipped with both nozzles. Anyway, tools of this type are intended more for decorative processing of vegetation than for serious garden work; this is due to both low power and limited battery life (for more details on both points, see below).

— Altitude cutter. As the name implies, this type of machine is designed to work at high heights from the ground, for example, to trim the branches of fruit trees. Their main distinguishing feature is their long length, which is usually ensured by the presence of a characteristic rod in the design. Thanks to this, you can easily reach most branches, even on a fairly tall tree (or to the edge of a tall hedge), without once again resorting to ladders or other similar devices. Most often, pole saws are equipped wit...h saw blades (see "Nozzles"), however, there are options with nozzles for bushes.

— Power grid. Powered by a conventional 230 V household mains. This option allows you to create quite powerful models, which are also much cheaper and easier to operate than gasoline ones, are quieter, weigh less and do not create exhaust gases. Of course, you will need an external power source for operation, and the battery life of the tool will be limited by the length of the power cord. At the same time, many modern "network" brush cutters are equipped with very long cords — about 20-30 m — which, moreover, can be supplemented with extension cords; and the 230 V network is distributed almost everywhere, from elite private houses to small summer cottages. However, the power cord has another significant drawback: it can create inconvenience when moving around the site (especially if there is thick grass hiding it). In addition, a tool with such a power supply has increased safety requirements: it cannot be used in wet weather, and special care must be taken during operation so as not to snag the power cable. Also, the power of electric models is generally slightly lower than that of gasoline ones.

— Battery. Powered by its own built-in battery. In terms of their main advantages, such models are similar to network brush cutters (see above): they do not create excessive noise and exhaust gases, are easy to maintain and cheap to operate. At the same time, the battery gives one important advantage — ba...ttery life: the tool does not require a constant connection to the network and works without a power cord, which ensures freedom of movement. On the other hand, such hedge trimmers are quite expensive, have a lot of weight (due to the battery), and their power is low and suitable only for relatively simple work. In addition, it is necessary to mention the limited period of work — in most models it is about 40-50 minutes, and even less if the working nozzle is heavily loaded or dirty. When the battery runs out of charge, it will have to be charged again, which will require a power source and can take quite a long time. Therefore, it is worth specifically looking for a battery model only if complex work is not planned, and freedom of movement plays a decisive role for you.

— Gas engine. The main advantage of a petrol engine can be called high power. Due to this, such brush cutters easily cope even with complex tasks that are beyond the power of electric models. In addition, such engines do not depend on external power sources and require only the presence of fuel in the tank to operate. However, gasoline tools have a number of disadvantages: heavy weight, high noise level, harmful exhaust gases, as well as difficulty in maintenance and high fuel costs. Therefore, this type of engine is found mainly in professional models that need to combine maximum battery life with high performance.

— For bushes. Nozzle designed for cutting branches of small thickness, characteristic of most shrubs. The general principle of operation of such a device is similar to clippers: there are two sets of teeth located close to each other, one of them is stationary, and the second moves back and forth at high speed during operation. As a result, each pair of movable and fixed teeth works in the manner of scissors, cutting leaves and branches that have fallen under the blades. The nozzle itself looks like a web stretched forward, on both sides of which the teeth are located; this allows you to move it in any direction during operation — to the right or left, depending on the situation. It should be noted that bush nozzles are able to cope with branches up to 2-3 cm (depending on engine power), but they are still not designed for use as full-fledged saws.

— For grass. Attachments for cutting grass and leaves. Like bush (see above), two rows of teeth are used; and in general, a brush cutter with such a nozzle looks like an enlarged clipper, only not for hair, but for grass. At the same time, it is worth noting that it is not able to replace a full-fledged lawn mower: the cutting width most often does not exceed 20 cm, and the devices themselves are usually small battery models (see "Power") and are not structurally designed to work with large areas. Their main purpose is the decorative processing of small flo...wer beds, as well as edges that a conventional lawn mower cannot reach.

— Saw blade. Such nozzles are very similar to the working element of a chain saw: an elongated rounded base (tyre), along the edge of which cutting teeth move during operation. They are designed to cut thick branches that ordinary bush attachments (see above) cannot handle, and are used primarily in pole cutters (see "Type").

The length of the bar usually refers to the total length of the brush attachment or saw blade (see Attachments) supplied with the hedge trimmer. The longer the tire, the longer the cut that the tool can make at a time. In general, it is believed that a short length is typical for entry-level tools, while professional ones are equipped with larger attachments. However, here you need to take into account that the choice depends not only on the scale, but also on the specifics of the intended work: long attachments are less maneuverable and less suitable for topiary trimming of bushes. In addition, the cost of a brush cutter also largely depends on this parameter.

Overall length of pole saw (see "Type").

The height that can be reached with a pole saw from the ground depends on this indicator, without the use of additional devices (stools, benches, stairs, etc.). In modern models, the length of the rod can reach 4 m — this is enough to handle even fairly tall trees, and a longer length would make the unit too heavy and bulky.

When choosing according to this parameter, note that a too long rod affects not only the weight and cost of the pole saw, but also can be inconvenient when working at low heights. Therefore, it is worth looking for a "long-range" tool only if most of the work is planned to be carried out at high altitudes. However, some models of pole saws allow you to adjust the length of the rod in a certain range, which makes it possible to adjust the tool to specific working conditions. For such models, this paragraph indicates the largest value of the length.

The model is equipped with a telescopic rod, the length of which can be adjusted by the user. Increasing the length of the rod opens up the possibility of easy and simple pruning of trees / shrubs in hard-to-reach places. If the length of the average brush cutter holder, in the folded position, is 2 m, then the telescopic mechanism makes it possible to increase the length of the holder by an average of 1 m.

The distance between the individual teeth of the shrub attachment (see "Tips") supplied with the tool. The larger the pitch of the teeth, the easier the tool will cope with thick branches, however, the quality of the work will be quite rough. Conversely, more densely spaced teeth work "cleaner" but are less suited to tough conditions and large branches.

Hedge trimmer motor power expressed in watts.

The performance of the tool primarily depends on the engine power, and this concept includes both the overall speed of work and the ability to cope with difficult tasks like cutting thick branches. Therefore, when choosing, it is necessary to take into account both the general volumes of the planned work and the material with which you will have to deal. For example, a powerful hedge trimmer may be needed even if it is only a few metres of hedge — if the branches in this hedge are quite thick. On the other hand, "more powerful" does not always mean "better" — after all, this parameter affects the weight, energy consumption (or fuel consumption) and the price of the tool.

If we talk about specific numbers, then the optimal power for most household tasks will be about 400-600 watts. Battery models (see "Power"), designed for small amounts of work in simple conditions, may have less power, and in gasoline models (see ibid.), on the contrary, it can reach 900 – 1000 watts.

In addition to watts, power can also be expressed in horsepower; this designation is traditionally used in gasoline engines. 1 HP approximately equal to 735 watts.

Hedge trimmer engine power expressed in horsepower. For more information about the value of power in general, as well as the ratio of horsepower and another unit of power — watts — see the “Power” paragraph above. Here we note that such a designation is typical mainly for models with gasoline engines (see "Power").

The frequency of movement of the teeth in bush or grass attachments (see "Tips"). The design of most of these tools is such that for one revolution of the engine, the teeth make one complete cycle of movement back and forth; therefore, the stroke rate is usually determined by the speed of rotation of the engine and is indicated in revolutions per minute.

It is believed that the quality of the tool’s work largely depends on this parameter: the more often the stroke, the cleaner the cut will be. Ratings up to 2200 rpm are usually typical for entry-level devices, up to 2800 rpm are average, and advanced models can have speeds of 3400 rpm and even higher.

The cutting part of the device is fixed on a special swivel hinge with the ability to change position in one plane. By changing the angle of inclination of the blade, the operator can adjust the tool to perform a particular task. Adjustment of an inclination of a nozzle allows to increase considerably safety of work. As a rule, the saw blade (tire) has a fixed value of working positions, which are limited by the angle of inclination of the nozzle.

The rotary handle allows to carry out a cut from the most convenient position for the operator. It provides a comfortable grip on the tool to perform a specific cut. Usually, the position of the rotary handle is adjusted by rotating around its axis.

The brush cutter is equipped with a special telescopic rod and removable wheels from the box, which allows you to cut the lawn while standing. At the same time, the rod handle, usually, has a separate button for turning the device on and off, and the rod itself is made retractable so that each user can adjust it to their height.

The working volume of the petrol engine installed in the hedge trimmer (if equipped, see "Power"). Usually, the larger the volume, the higher the engine power (see above). On the other hand, power is usually directly indicated by the manufacturer, and besides, it depends not only on this parameter, but also on a number of other factors. Therefore, in fact, volume is usually a secondary indicator, allowing to some extent to assess the economy of a brush cutter: for equal power, a larger engine is likely to have a higher fuel consumption.

The volume of the fuel tank installed in the brush cutter with a petrol engine (see "Power").

The larger the tank, the more fuel can fit in it — the longer the unit can work without refueling. And knowing the approximate fuel consumption, by the volume of the tank, you can also estimate the approximate time of work on a single refill. At the same time, brush cutters rarely have to work without interruption for a long time, refueling, usually, does not cause any particular difficulties (if there is a supply of fuel, but this supply is not difficult to provide); in addition, a volumetric tank would have a noticeable effect on the dimensions of the unit, and in a filled state, also on its weight. The latter is especially critical, given that the instrument is supposed to be “carried around”. In light of all this, the tanks of modern brush cutters are made small — usually about 0.5 liters or even less.

Features of a complete set of a cordless hedge trimmer. Most of the devices out of the box have one battery. But there are models that are equipped with a replaceable battery ( 2 batteries included). This solution allows you to extend the time of work with the device by replacing a discharged battery with a charged one. And the absence of a battery in the kit will be appropriate if you buy a brush cutter, for which a universal battery from other brand devices is suitable. Or you yourself want to choose a model with the required capacity. And for low-power devices there is a built-in battery.

The type of battery installed in the battery-powered hedge trimmer (see above).

— Ni-Cd. One of the first types of batteries used for power tools. Nickel-cadmium batteries are well-suited for heavy loads, have quite a decent capacity per unit weight, while charging fairly quickly and are resistant to temperature extremes — the latter is important, given that brushcutters, by definition, are used outdoors. On the other hand, such batteries have a number of significant drawbacks, the most important of which is the “memory effect”: if the battery is started to be charged without completely discharging it before, it will accumulate less energy (as if “remembering” that part of the charge was not needed last time). (hence the name of the effect). In addition, some components of Ni-Cd cells are considered environmentally unsafe. As a result, this type of battery is considered obsolete and is gradually being replaced by more advanced options.

— Ni-Mh. Nickel-metal hydride batteries were created as a development of nickel-cadmium batteries, in an attempt to eliminate their main shortcomings. Such batteries are practically devoid of the "memory effect", they use safer materials in their construction, and at the same time they have all the main advantages of the original technology — in particular, reliability and resistance to temperature extremes. Of the shortcomings, one can only note the need to comply with specific rules for long-term storage.

— Li-Io...n. The most advanced type of modern batteries. Lithium-ion batteries combine small size and weight with high capacity, charge quickly, are practically not subject to the "memory effect" and are generally unpretentious in operation (besides, many of these batteries have recently built their own controller that optimizes charge-discharge cycles) . At the same time, they are sensitive to low temperatures and are more expensive than other types.

Operating voltage of the battery in a battery-powered hedge trimmer (see above). This parameter is usually selected by the manufacturer according to the characteristics of the engine: the greater the power, the greater, the battery voltage is likely to be. In fact, voltage data may be needed only if the battery fails and it will be necessary to replace it with an equivalent one. In addition, there are formulas that allow you to roughly estimate the battery life depending on the battery voltage, its capacity and the power of the tool; they can be found in special sources.

The capacity of the battery that comes standard with the battery-powered hedge trimmer (see above). Expressed in amp-hours, one ampere-hour means that the battery is capable of delivering 1 amp for 1 hour.

Last but not least, the battery life of the tool depends on the capacity of the battery. However, it is impossible to directly evaluate the battery life of a brush cutter by this parameter: the fact is that it depends on a number of other factors, ranging from engine power and battery operating voltage to the degree of complexity of work and contamination of the nozzle. Therefore, it makes sense to compare different models with each other in terms of battery capacity only if they do not have significant differences in other characteristics. But at the same time, brush cutters with a capacious battery a priori allow the device to work more.

The name of the battery that is compatible with the device. It helps to buy a spare or find a suitable one in case of a breakdown of the main one.

The maximum time for which the cordless hedge trimmer can work without additional charging. Note that the maximum period is indicated, which is often overestimated by the manufacturer and is calculated at idle. Under load, this parameter will be less.

The time it takes to charge the brush cutter battery from 0 to 100%.

Approximate noise level produced by the hedge trimmer in normal operation. This parameter allows you to evaluate how comfortable it will be to work with the tool: the lower the noise level, the less discomfort it causes for the operator and others, and the lower the likelihood that special hearing protection will be needed during operation. At the same time, note that loud noise is an inevitable side effect of high power — it would be too expensive and difficult to make a powerful and low-noise tool. In addition, this figure is only approximate. Firstly, different manufacturers may indicate it differently: for idling, for full speed, for half power, etc. Secondly, the actual volume of work may also differ from the claimed one due to the peculiarities of a particular situation: for example, working with thick branches leads to an increase in the load on the engine, which can also affect the noise level.

Another specific point is that the decibel used to measure this indicator is a non-linear value: an increase of 1 dB corresponds to an increase of 1.26 times, 3 dB — 2 times, etc. Therefore, to assess the loudness of work, it is easiest to use comparative tables. Here is one of the simplified versions of such a table for the range in which most modern hedge trimmers work:

65 dB — loud conversation at a distance of a metre;
70 dB — loud conversation of several people at the same distance;
75 dB — shout from the same distance;
80 dB — the ringin...g of a mechanical alarm clock, a loud cry at a distance of 1 m;
85 dB — loud screams at a distance of 1 m;
90 dB — heavy truck or freight car at a distance of 7 m;
95 dB — subway car at a distance of 7 m;
100 dB — noisy industrial shop.

The total weight of the brush cutter. Usually indicated for a fully equipped tool, with an attachment installed and, in the case of a petrol engine, a full tank of fuel; however, there may be exceptions. Usually, the relevant data is indicated in the official documentation.

This parameter is important, first of all, taking into account the fact that the tool during work will have to be kept on weight most of the time. Accordingly, the lighter the brush cutter, the longer you can work with it without interruption, the less often you have to rest. On the other hand, a large weight also has its advantages: a heavy tool is more stable and does not “tear out of hand” as much under high loads on the nozzle.