Criteria for selecting discs for trimmers and instructions for replacing them

Cutting grass with trimmers occurs through the use of a mowing head with a fishing line and metal discs. Each type of cutting device has its own fundamental features. The use of fishing line is limited by the type of vegetation, therefore, where the head with cord cannot cope with the task, a metal disk is used. How to choose a cutting disc for a trimmer, what types they are, and how they are sharpened, we find out the details before purchasing the appropriate equipment.

What types of trimmer knives are there?

Initially, we note that metal discs can be used not only on gasoline, but also on electric trimmers. The main condition for the use of metal cutting knives on equipment is that the transmission mechanism (shaft or gearbox) in the design of the tool must be of a rigid type. A rigid gearbox is a metal shaft that transmits torque from an electric or gasoline engine to a working element.

There are models of trimmers with flexible shafts, the design of the gearboxes in which is represented by a steel cable. These are, as a rule, low-power electric lawn mowers that are not designed for heavy loads, as well as household lawn mowers. Metal discs cannot be used on trimmers with a flexible shaft (only plastic ones are allowed), as this will lead to rapid failure of the gearbox. Before you buy metal cutting cutters, you will need to find out the type of transmission mechanism of your tool - rigid or flexible.

What type of transmission mechanism is used on the trimmer is indicated in the technical description for the tool. If the trimmer has a curved rod, then its design uses a flexible shaft. Tools with a straight shaft can be equipped with rigid and flexible gearboxes, depending on the power of the trimmer.

Trimmer knives are classified according to the following criteria:

Material of manufacture - they come in plastic and metal.
Plastic knives are less efficient than metal ones, but they do not put more stress on the shaft and drive mechanism of the tool. Plastic discs are used on electric trimmers and lawn mowers for household use.
Design of cutting devices.
There are two types of steel discs - bladed and toothed (milling). Plastic knives are produced in the form of blades. Gear devices have a similar design to circular discs, while blade devices have large flat knives
Number of cutting edges.
The number of teeth and knives on the discs differs, which affects the performance of the cutting equipment. On gear disks the number reaches 80 links, and on bladed disks - from one to four pieces
Availability of additional spraying - steel toothed discs are additionally equipped with pobedit tips, which allows the tool to be used for mowing grass on lumpy surfaces.
When the disk comes into contact with obstacles in the form of earth and stones, the teeth do not become deformed or dull, which is achieved due to the presence of pobedite tips. Experts say that devices with carbide tips do not last long. The soldering tips wear out quickly, and then the cutter is used without any damage.

Plastic blades for trimmers not only cost less than metal ones, but also do not place high loads on the engine and transmission mechanism. This is especially true when the knife encounters obstacles. The higher the elasticity of the cutting knife, the less likely it is that the plastic discs will deform.

This is interesting!
Toothed discs with a large number of links are used for mowing various types of grass - dead wood, green lawn and thick-stemmed grass. The cut with such a disk is straight, clean and even. In addition, a large number of teeth prevents their rapid dulling, and the presence of additional holes on the surface of the circle (perforations) is intended not only for cooling, but also to reduce weight and increase inertia.

Trimmer disc

A trimmer is a fairly common garden tool purchased for cutting grass. Models with fishing line are suitable for soft grass, but if you need to fight with coarse growth and bushes, you cannot do without a disc trimmer.

Types of trimmer discs

The trimmer disc And to decide which trimmer disc is better

– iron or plastic, you need to decide what you will mow. Thus, a plastic disk is designed for short and sparse grass, while an iron disk can easily cope with very thick and tall grass, bushes, and dry grass.

Disc- shaped cutter for trimmer

can be with 2, 3 or 4 cutting edges. Typically, such components are included in the basic set of low- and medium-power tools. You can use it to fight thick grass and small bushes.

On powerful and professional equipment, saw blades are installed that have up to 80 teeth, and from time to time also carbide (pobedite) soldering on the teeth. Such a victorious disk

for a trimmer, it is occasionally used in private households; mainly, it is used on professional lawn mowers. It has a very long service life and versatility of use for both the freshest grass and dry impassable weeds.

The discs also differ in the width of the blade, which can range from 1.3 to 4 mm. Thin discs cut the grass cleanly, quickly and accurately, but they become dull more quickly. The thickest knives do not wear out for a long time, but are more suitable for rough growth and weeds.

As practice shows, the most common shape of a trimmer is round with teeth around the circumference. A frequent choice is also its variety with 4 large teeth and a row of small teeth between them. They are a great help in cleaning the area; they are simply installed on any model of trimmers.

Installing the disc on the trimmer and observing safety precautions

Once you have decided which disc to use for the trimmer, you need to learn how to install it correctly. First, make sure that the mounting hole on the disk is the right size, otherwise the disk simply will not fit your trimmer. And even if you manage to secure it to the tool, the disc may come off during operation and seriously injure you.

Advantages of trimmer discs compared to fishing line

The trimmer disc has its advantages compared to the cord. You need to know these advantages in order to ultimately decide whether it is worth buying and using metal cutting knives. Let's consider all the advantages of trimmer discs:

Ability to cope with different vegetation, unlike fishing line.
This can be dead wood, long and thick-stemmed grass, and even small vegetation. The line is difficult to cope with medium-sized grass, and it is not able to cut thick-stemmed grass. The cord will either get tangled in the grass, or the line will quickly wear out, which is not at all rational
High speed of achieving results.
Unlike a fishing line, the disc cuts the grass efficiently in one pass (with good sharpening), without leaving “roosters”, so mowing with a trimmer with a metal circle is faster than when using a cord
Discs do not wear out, unlike cord.
Cutting knives or parts of the circle become dull, but the issue is resolved by sharpening. How to sharpen a metal trimmer wheel is described in the material below. With prolonged use, cutting devices wear out, but they last for at least 3-5 years
Long service life, unlike fishing line, which is due to the design of the equipment

There are also disadvantages to the cutting devices for trimmers under consideration. The first drawback is that you cannot use the tool with a disc when cutting grass near obstacles in the form of trees, buildings, stones, benches, etc. When a disk collides with an obstacle, the drive slows down, which is reflected in the following disadvantages:

Engine overheats
The cutting parts of the disc are damaged and become dull
Transmission mechanisms—flexible and rigid shafts (gearbox)—failure

If you plan to mow thick grass in a field, then it is impossible to do without a trimmer with a metal disc installed. The line is used for cutting small grass in garden areas near obstacles.

This is interesting!
Trimmers with a curved shaft design cannot use steel blades for safety reasons. If the disc hits an obstacle, a kickback effect occurs, whereby the cutting part can get under the operator’s feet. As a result, the operator risks serious injury.

Which is better depending on the tasks at hand?

Each type of disk performs better in the task for which it was created. The serrated circle is suitable for mowing dense, large and small, coarse thickets or shrubs. This is due to the fact that a huge number of teeth makes it possible to avoid winding the grass and subsequent problems. Its problem is that it is suitable only for high-power equipment.

READ How Much Line Should You Wrap On Your Trimmer Reel?

At the same time, blade discs are suitable for mowing thickets of the same type. In most cases, they are used for cutting grass in the field and preparing hay, because they can, without chopping the grass, not load the mechanism. Plastic knives are more suitable for small and dense thickets. They are used on small personal plots - country houses or garden plots. Now you have figured it out and can eventually choose exactly the disk that you need.

Choosing the best cutting knife for a lawn mower

Some manufacturers of trimmers with a rigid transmission shaft design additionally equip their tools with not only fishing lines, but also steel discs. This does not always happen, and if such a situation is appropriate, then, if necessary, a metal disk is installed instead of the mowing head with fishing line. However, this is not always the case. First, you need to make sure that you can use a steel disc on the trimmer. Let's consider all types and designs of cutting knives produced for trimmers.

This is interesting!
The mounting hole size on all metal discs is 25.4 mm or 1 inch. Models with a larger diameter are rare, and to use them you will need to use an adapter.

Basic rules for safe handling of metal trimmer blades

Such knives should only be installed on devices with a straight shaft. This circumstance is due to the design features of the cutting element.
If the disc hits a very hard obstacle during mowing (for example, a stone), it will usually bounce back towards the operator’s feet. For units with a straight rod, the distance to a person’s feet from the rotating head is quite safe.
Standard trimmers have U or J shaped handles for safe operation. If the design uses a D-shaped handle, then the unit is equipped with a special restrictive plug, which rests against the operator’s foot and ensures that the foot does not come into contact with the cutting parts.
Even if the cutting wheel has encountered a solid obstacle, causing it to bend, it is possible to correct this situation with the help of a simple hammer. To do this, you just need to straighten out all the irregularities with a few blows. However, this circumstance applies only to expensive brand models whose wheels are made of high-quality metal. Even the flexibility of the knives was specially incorporated into the design of the device by the manufacturer in order to reduce the load on the transmission and engine when colliding with hard objects.

In what cases is a serrated disc knife used?

Metal toothed disks have the shape of a circle, along the base of which the corresponding number of teeth are located. These teeth come in different types, shapes and sizes. The more teeth, the more effectively the tool copes with thick grass and even small trees. Milling wheels for trimmers gain speed faster, which is their advantage. They also have a high moment of inertia, which is their disadvantage. This negatively affects the driving device of the tool, as the starting power increases, and as a result, the motor overheats during frequent stops. In addition, the equipment differs in the presence and absence of perforation.

Perforated wheels with holes and a large number of teeth, up to 40 teeth, effectively cope with mowing thick, tall and small, coarse grass and shrubs.
The greater the number of teeth, the less the grass is crushed. Circles with a large number of teeth do not get grass wrapped around them. Discs with teeth in the amount of 60-80 pieces are intended for mowing grass with small trees existing on the territory, the thickness of the stems does not exceed 7 cm
Read also: How to lubricate a rotary hammer gearbox and how to do it correctly
Solid - discs that do not have holes in the structure.
They are heavy, so installing them on lawn mowers with an engine capacity of up to 30 cm3 is strictly not recommended. The tool simply will not be able to pull out the heavy cutting element. Compared to perforated ones, they weigh 1.5-2 times more. Effectively cope with thick and sparse grass. The smaller the number of knives, the more the grass is chopped, and at the same time the load on the motor increases. The load on the gearbox also depends on the angle of sharpening of the teeth.

If the operator is faced with the task of mowing thick grass and dead wood, it is recommended to choose discs with perforations and a large number of teeth. Solid discs are suitable for cutting green grass of different densities, but they are used exclusively on powerful lawn mowers with an engine capacity of more than 40 cm3.

This is interesting!
Pobedit-tipped milling discs allow you to mow grass close to existing obstacles. For cutting grass for hay, it is recommended to use steel ones with a large number of teeth. The smooth sharpening of the teeth on these knives allows you to effectively cut grass. For cutting thick-stemmed plants (raspberries, ragweed), solid discs with a number of knives of 16, 24 and 32, as well as perforated ones with any number of teeth, are used.

Criteria and conclusions about the correct selection of cord or which line to choose for the trimmer

If you are going to make hay or mow meadow grass for cattle, then you will need not only a gasoline trimmer, but also metal discs. Heads with fishing line are not suitable for such purposes, since they are intended for the following purposes:

Mowing grass on the lawn and garden paths
Cleaning the garden area
Cutting weeds, dry grass and thickets at the dacha

Depending on the type of work planned to be performed, it is necessary to select a tool and line for it that are appropriate in terms of power. To cut young, short and thin-stemmed grass, a round-shaped cord is used, and if you are going to deal with thickets in the country, then it is better to use an angular type of string - square or in the shape of a star.

If, when using an electric trimmer, the sound of a round fishing line rustling is heard, then when using a lawn mower, such noises are not terrible. To reduce noise, you need to buy a fishing line with coils. Nylon string with a square or hexagonal shape is able to cope with thick-stemmed vegetation such as raspberry, ragweed and other weeds. If a regular round string is inexpensive, then models of different shapes will cost a little more. The most expensive cords are two-component ones, which consist of several materials.

https://youtube.com/watch?v=vFM1sw_78rM%3F

What applications are paddle blades for trimmers suitable for?

Compared to toothed or milling discs, paddle discs are lightweight, so they are used on low-power trimmers. Bosch equips its electric lawn mowers with exactly these types of cutting blades. Their advantage is the minimum moment of inertia, which eliminates the negative impact on the drive mechanism.

The number of blades affects the chopping of grass. The fewer blades, the more the grass being cut is crushed. For mowing homogeneous and similar grass, two-bladed discs are used. Their advantage is that they throw the cut shoots aside. To cut grass in the field when making hay, it is recommended to use 4 or more blade attachments. They do not crush the grass being cut, and do not load the drive mechanism of the tool.

This is interesting!
When choosing disks, special attention should be paid to the thickness of the blades. Manufacturers produce forged and stamped nozzles. Stamped ones are cheaper, and as a rule, when they hit stones or come into contact with other obstacles, they break off. It is recommended to choose exclusively forged wheels, which differ from stamped ones in the absence of characteristic areas of chips and cuts.

How to choose the best trimmer blade?

Hand trimmers mow vegetation using either a line or knives.
In the first case, the functionality of the trimmer is limited to mowing soft grass with medium and low height, since plant debris is wound on the flexible shaft or sticks to the spool. By installing a trimmer blade, it is possible to cut off tougher stems and trim young bushes. Classification can be made according to the following criteria:

According to the material of the knife: metal and plastic knives are known. The choice is often limited not so much by the user’s desire as by the drive power - metal knives are heavier, and the trimmer shaft equipped with them picks up speed more slowly, which adversely affects the durability of the engine. At the same time, the cutting ability and durability of steel knives is much higher than that of plastic ones.
According to the design of cutting edges. They are distinguished by significant variety, and can be with four or more teeth, single- or uneven-high, as well as solid or with technological holes.
According to the shape of the knife itself, which can have a solid disk blade, or can be made in the form of several blades with the same distance between them.

The choice of the size and design of the trimmer knife is made depending on the tasks assigned, the type of rod and engine power.

If the trimmer shaft is bent in the shape of the letter J, then it is not advisable to use a steel blade, since if it comes into contact with a massive obstacle, such as a stone, the trimmer will be sharply thrown back towards the mower.

Then even a high restrictive cover will not save the worker from a leg injury. On trimmers with a straight shaft, the rebound distance will increase.

Plastic trimmer blades, although less durable, are quite capable of cutting most types of grass. In addition, their increased elasticity does not create additional loads on the flexible shafts of electric trimmers.

The inertia of perforated knives is significantly less than solid ones, and this does not particularly affect the durability of the tool, given that the tool is made of high-quality tool steel.

The exception is cheap Chinese-made products: there knives can be made of any steel.

When the capabilities of the fishing line are not enough, you should think about replacing it with a steel or plastic knife. If a replacement blade is included with the trimmer, there are no problems: the cutting equipment is replaced in accordance with the trimmer's operating instructions. But this is not always the case.

You can determine the suitability of installing a knife on an existing electric trimmer (there will be no such problems with a gasoline trimmer) by the actual number of revolutions of the flexible shaft. If, when replacing a spool with fishing line with a knife, the engine reaches the set number of revolutions in a second or less, then replacement is possible, otherwise the engine will overheat greatly and the trimmer gearbox will quickly fail.

It is interesting to compare the three most common types of knives with each other - multi-toothed disk, as well as with two and three blades.

Usually, several such knives are included with the trimmer, but you can also purchase them separately by measuring the outer diameter of the knife and the configuration of the mounting hole. For example, circular knives from Stihl and Husquarna are interchangeable.

Disc knives differ in the number of teeth, height (they can be of different heights), as well as the continuity of the blade. Such knives are most often installed on trimmers from Stihl, Huter, AL-KO, equipped with a straight bar, and are characterized by the greatest rigidity.

They cope well with old growth and long stems, but when working with young grass, sticking of the mowed mass to the inner surface of the protective casing is often observed.

A trimmer with a perforated blade, compared to a solid one, picks up speed faster. The disadvantage of circular knives is the increased moment of inertia, so the starting power of the drive increases. On cheap designs and with frequent stops in operation, this leads to overheating of the engine and negatively affects its durability.

The Bosch brand equips its electric trimmers with such knives. Their moment of inertia is minimal and has virtually no effect on the performance of the drive.

The ease of use of this design lies in the fact that separate replacement of each blade is possible. For trimmers of such designs, the bar is curved in the shape of the letter J. Two-bladed knives work stably on a homogeneous mowed mass.

They throw the cut shoots well to the side and do not allow residues to stick or wrap around the rod shaft.

Three-blade and two-blade knives are quite competitive with disk knives in their capabilities, but the thickness of the blade should not be less than 2 mm.

It is easy to distinguish them - on stamped blades, traces from the cutting punch are clearly visible with the presence of characteristic chipping and shear zones, which is not present on forged ones.

Shark knives

“Shark” is an attachment of three bladed knives, with each blade fixed relative to the other at an angle of 120°. The advantage of this design is that each blade can be adjusted individually. As a result, when mowing an area with different types of vegetation (grasses, weeds, dead wood), the quality of mowing will be approximately the same.

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In addition, since the interval between each blade cutting the grass is shorter, the grass will be thrown more rapidly. The “Shark” head is compatible with many standard sizes of electric trimmers, has a low dead weight, but requires periodic adjustment of the blades, which are attached to the base with conventional screws.

The moment of inertia of a circular knife can be reduced by independently perforating its surface, for example, on a punching press. The perforation holes must be located strictly symmetrically relative to the center of gravity of the knife. The tool becomes lighter, but its cutting ability does not change.

You should not use a trimmer knife tipped with carbide - the quality of the cut will remain at almost the same level, but the weight of the tool will increase.

The easiest way to make a homemade knife is in the blade version. For this you will need:

A piece of pipe (copper is better than steel) of a suitable diameter for making an adapter sleeve for the output part of the flexible shaft.
A sheet of steel no more than 1 mm thick for the washer.
A regular cotter pin in accordance with GOST 397-66, for attaching the base to the trimmer shaft.
Stainless steel strips 1…1.2 mm thick, for making knife blades.
Fasteners (it is better to use rivets rather than screws or a nut for a knife, even if it is included in the original kit).

The general view of a homemade trimmer knife is shown in the figure.

The production of equipment is carried out in the following sequence. First, mark out the general dimensions of the device so as not to go beyond the protective casing. Then a sleeve is made from a piece of pipe.

To improve the fit, the bushing is split and seated along the outer surface of the output part of the trimmer shaft. Since the diameter of the washer is determined solely by the dimensions of the available space, it can also be selected from the nearest standard sizes.

The washer is welded to the bushing in such a way that the formed seam leg is minimal.

Fastening with rivets with a slight vertical play will allow for better cutting, especially of woody stems.

During installation, it is worth carefully checking the presence of minimum (at least 1.5 mm) gaps between the pipe and the blades in order to prevent rubbing of the blades during their possible thermal expansion.

The final fixation of the device on the shaft is done with a cotter pin.

Plastic circles for trimmer - when to use

While gasoline trimmers use metal milling and blade discs, it is recommended to use plastic discs for power tools. Their main advantage is their low weight, so the load on the electric motor is completely eliminated. Structurally, the nozzle is a plastic base on which knives are attached around the perimeter. Knives are made of soft plastic, which, when in contact with an obstacle, bends without deforming. The knives are mounted on a round base at an angle of 120 degrees.

They are designed for cutting thick grass with electric trimmers when the fishing line cannot cope. If the nozzle has a high moment of inertia, then it can be reduced by making symmetrical holes. When teeth become dull, they should be sharpened at a 30-degree angle using a low to medium grinding wheel.

Disk design	Application	Characteristic
Perforated milling machine with 40 teeth	Accurate cutting of lawn and tall grass. An excellent option for cutting grass in fields and forest belts	Eliminates winding of grass on the disc and low load on the gearbox. High efficiency when mowing large volumes of grass
Perforated milling with more than 40 teeth (60-80)	For small trees with a stem thickness of 7-8 cm	Suitable for cutting grass with growing small trees
Solid with number of teeth from 8 to 32	Cutting thin and tough raspberry and currant bushes. Effectively cope with mowing grass, but only with powerful equipment	Effectively cuts stems of small shrubs. Put a load on the gearbox
Blade with one, two and three knives	Coarse grass, overgrowth	They crush the grass several times, shredding it, which increases the load on the gearbox
Blade with 4 knives or more	Overgrowth and hard braid, can be used for making hay	Has a low moment of inertia
Plastic discs	For fine and thick grass in garden plots	Does not load trimmer electric motors

Which trimmer disc is better?

Abrasive tools that are used to process various surfaces include: a grinding disc, bars, heads and segments, sandpapers for grinding various materials and belts with abrasive coating. To get at least a small idea of the enormous variety of processing tools, just look at the photo of abrasive discs.

Abrasives that are used to make grinding wheels include diamond chips, quartz stone, corundum, and silicon carbide.

Abrasive discs for metal are used to make the surface of iron workpieces more pleasant to the touch, with smooth margins.

When to use a trimmer disc instead of a fishing line

The difference between a metal disc and a trimmer fishing line is already clear. When is it necessary to finish mowing with a fishing line and attach a metal circle to the trimmer? This question is popular among beginners, since if you continue to mow large, thick grass with a cord, it will quickly wear out. This is due to the fact that the fishing line begins to break at high speed on thick-stemmed grass, which leads to its damage and, accordingly, rapid wear.

You should use knives on the trimmer when mowing the following vegetation:

Tall and rough grass cover
Weeds and dead wood
Young shoots of trees up to 7 cm in diameter
Domestic thick-stemmed plants such as raspberries, rosehips, currants

The use of knives eliminates rapid wear of the fishing line, and also increases the efficiency and productivity of the lawn-mowing tool.

This is interesting!
Manufacturers produce metal disks with an outer diameter from 220 to 255 mm.

How to sharpen a disc if it is dull

For owners of country houses, land plots, and lawn lovers, a trimmer is an assistant that speeds up routine work. When using a tool, a number of questions arise related to which attachments are best to use, and how to create their replacement without the help of others.

When working with a lawn mower, fishing line is often used, which costs less than discs. Apart from the price, it also has the following practical advantages:

can be used with a large number of trimmer heads;
fishing line is safer to use than discs.

The disadvantage of the fishing line is that it is only suitable for mowing short grass, because otherwise it often gets clogged. This is acceptable for both electric and gasoline scythes. When the grass wraps around the spindle, there is tremendous resistance on the shaft and it becomes damaged. With all this, the piston system can also fail (in gas mowers) or the electric motor can overheat and burn out (in electric mowers).

In a number of different situations, knives are more effective. They are used for mowing:

tall and coarse grass cover;
weeds;
tree shoots;
domestic (for example, raspberries, currants) and wild (rose hips) shrubs.

Cutting attachments of this type are also called discs or cutters, but the essence does not change.

Walk-behind mowers are designed for mowing grass, bushes and young trees. The quality and productivity of work depends on the sharpness of the blades. Over time, knives even with pobedit tips become dull. In this case, you can use 2 methods:

purchase the latest cutter;
sharpen old blades without soldering without the help of others.

To properly sharpen knives, proceed as follows:

carefully disassemble the trimmer, removing the cutter at the same time;
inspect it for cracks that make further use impossible;
if the blades are bent, they are smoothed using a hammer;
clamp the blades securely, not very tightly, but so that they do not move;
Based on the size of the disk, choose a metal file so that it is comfortable to work with;
all cutting (upper) edges of knives are sharpened to an identical degree (at an angle of 30 degrees);
assemble the lawn mower in reverse order.

Discs with soldering made of hard materials are only replaced with new ones, but not sharpened.

Sharpening can be done on an emery machine at low speeds - this will speed up the work process. In this case, a grinding wheel with a medium grain size is used for work. Knives should be sharpened after wearing gloves and goggles.

For brush cutters, plastic and steel cutting attachments with different numbers of blades and sharpening are used. These prerequisites determine the scope of introduction of knives. Therefore, they should be selected taking into account the nature of future work. Replacement and sharpening of trimmer blades should be done carefully to avoid injury.

Instructions for replacing a disk on a lawn mower with a step-by-step description

Having understood the design of cutting knives, it remains to find out the process of replacing them and installing them on the tool. If the lawn mower has a head with a fishing line, and you plan to install a metal disk, then no modifications to the design will be necessary.

To install a metal disc on the trimmer, you must follow the following instructions:

To begin, remove the plastic protective casing - not necessary. Depending on the tool model, the dismantling process may vary. If the trimmer has a metal casing, then there is no need to remove it. The plastic casing is removed in order to install the metal
Using a special hex key or screwdriver, you need to lock the gearbox. The hole for blocking the shaft can be located on the side or on the end side
The mowing head or spool, if installed, is unscrewed from the tool
A disk is installed in place of the head or spool. The inner diameter of the disk should be located in a special groove. The nozzle is installed so that the front side (with the letters) faces up
After installing the disk, a locking washer of the appropriate size is installed. After this, the fastening nut is screwed in, having previously blocked the gearbox shaft. The direction of rotation for screwing the fastening nut is counterclockwise
After completing the work, it is necessary to install a protective metal casing. If it is not there, you should leave the plastic casing

As you can see, the procedure for replacing the disc on the trimmer is not at all difficult and takes no more than 5 minutes. The video below shows how to properly change mowing heads and wheels on lawn mowers.

Algorithm for installing a knife on a trimmer

Changing the blade on the trimmer is quite simple. In the kit with it, manufacturers include a key for removing the cutting attachment (spool with fishing line) and a pin designed to block the gearbox. To change the disk, you need to do the following:

remove the casing that performs protective functions;
insert the pin into the aligned holes located on the shaft and gearbox, and in this way block the drive;
if a spool with fishing line is installed, then unscrew it clockwise and find a nut to tighten the knife;

put the boot on;
locking the gearbox with a pin, tighten the fastening nut, tightening it with a wrench;

READ How to Wear a Trimmer

The method of installing the knife on the trimmer is demonstrated in detail below.

When working, pay attention to safety precautions to avoid cutting yourself.

Sharpening trimmer discs correctly - what you need to know about it

During the operation of lawn mowers with cutting metal knives, their dullness is observed. This is normal, but you should not continue to use this attachment. Dull knives have low performance, so in addition to unsatisfactory mowing results, you will also get overheating of the tool motor and gearbox wear. If the trimmer's knives or cutting disc teeth become dull, they need to be sharpened. Some people prefer to buy new cutting wheels, which is not at all rational.

This is interesting!
All types of cutting discs, including those with Pobedit tips, can be sharpened.
To sharpen a pobedite-tipped wheel, you will need a special diamond wheel. What the process of sharpening a disk with pobedite soldering on the teeth is is described in detail in this material. Step-by-step description of how to sharpen a trimmer disc:

First you need to remove the cutting element from the tool. It is unsafe to sharpen a tool
Inspect the element for professional suitability. The presence of cracks, chips and other deformations is unacceptable. If there are any, it is necessary to replace the device
To sharpen a disc, tools and materials such as a sharpener, a file, and a grinder are used. Which is better to choose depends on the skill of the operator. The easiest and safest way is to use a file. To do this, the cutting equipment is attached to the jaws of the vice, and the sharpening process is carried out manually at an angle of 30 degrees.
If you are using a sharpener (emery) or a grinder, then in this case you will need to sharpen it carefully. When sharpening, you must not allow the metal to turn red (the metal will be tempered), otherwise this will lead to rapid wear and abrasion of the cutting part
The best option, which is recommended for beginners (it is also used by experienced craftsmen), is to use a file. Using a file, you can sharpen the cutting edge with the highest quality and precision at an angle, which will positively affect the performance of the tool.
If you need to sharpen a milling disc with a large number of teeth, then for such cases it is recommended to use a grinder with a thin abrasive wheel

The video below explains how to properly sharpen milling discs with a large number of teeth.

After finishing the work on sharpening the trimmer's mowing disc, all that remains is to install it in place and check the effectiveness of the tool. After sharpening, keep in mind that it is better not to touch sharp parts, as you may get injured.

To summarize, it should be noted that the effectiveness of grass cutting depends on the correct choice of trimmer disc. A fishing line is used to mow grass on the sides of roads and paths, but to control weeds in the country, as well as to make hay in fields and forest plantations, gas cutters with metal discs are used. If your budget allows, it is recommended to buy 3 types of metal disks and try them on your own to feel the difference.

Pros and cons of SSD drives

Before purchasing an SSD drive, you need to evaluate the pros and cons that the user will receive from such a solution. The obvious advantages of SSDs over hard drives are:

High speed. Even the fastest hard drive

theoretically cannot beat SSD;

Protection from damage. Desktop computers rarely find themselves in stressful situations, and this feature is not important for them. However, it is quite possible for a laptop to fall, and if it has a solid state drive installed, it is unlikely to fail, whereas the mechanical elements of the hard drive may cause damage
Quiet operation. SSDs do not have rotating elements, unlike hard drives. As a result, even under intensive operating conditions, the drives are completely silent;
Low power consumption;
Instant transition to working condition. SSDs take no time to start from rest, whereas a HDD takes a few seconds to reach operating speed;
Light weight and dimensions.

The disadvantages of SSD drives include the high cost and difficulty of purchasing such large-capacity drives.

SSD controller

Its speed, durability, support for additional technologies and many other basic parameters largely depend on the stability and literacy of the controller in the solid-state drive. You need to choose an SSD with storage from one of the leading companies in the industry: Intel, Marvell, Sandforce or Indilinx.

Please note: If the drive has a high operating speed, but it contains a bad controller from an unknown company, there is a high probability that such a drive may take a long time to complete or will have problems with writing/reading information. That is why it is not recommended to buy an SSD without a name, about which there is no information except for the maximum sequential read/write parameters.

SSD capacity

The main parameter when choosing a solid-state drive is its capacity. On the market you can find models with different free space for storing information, and before purchasing it is important to decide for what purpose the drive will be used.

Most often, SSD drives are purchased to increase the loading speed and operation of the operating system. If only Windows, Linux, or another system will be installed on the disk, it makes sense to choose a drive with a capacity of 128 GB or 256 GB, depending on how much information the user saves in system folders, for example, My Documents. On average, the operating system takes up 40-60 GB (if we are talking about Windows).

If you are purchasing an SSD as a single storage device for your computer, you should choose

SSD size, depending on the purpose of the PC and the activity of working on it.

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Additional SSD options and parameters

When shopping for SSDs, you may notice various items and options listed in their specifications. Let's decipher the common ones:

IOPS indicates how many operations per second the drive can perform. This is worth paying attention to, since in most cases it can tell more about the actual speed of the disk than information about the maximum read / write parameters;
MTBF is the time it takes a solid-state drive to fail. This parameter is measured in hours, and not all drive manufacturers indicate it. MTBF is calculated based on tests performed, during which drives are loaded to failure, after which average values are calculated;
TRIM is an option that is present in the controller of almost all SSD drives. It follows from this that the brain drive will always be aware of which cells are cleared of the information previously contained in them, thereby the disk gets the opportunity to use them;
SMART A diagnostic option that is present in almost every solid-state storage device. This is necessary so that the disk
can independently assess its condition, thereby approximately calculating the time before failure;
Garbage collection is an option designed to automatically clean up memory from phantom files and other garbage.

The myth that SSDs work several times less than hard drives has long been dispelled. With a standard load, an SSD can be used for 10 years or more without problems.

Cutting system

Trimmers work using rotating cutting elements, which can be dense knives (metal, plastic) or soft mowing line (cable).

1. Thick knives are more suitable for equal open terrain and thick grass with hard stems. The tool will create an even cut. This type is practical for maintaining lawns along businesses and near private homes.

2. When working on hilly areas and near fences, a fishing line is needed. Knocking over solid obstacles will not cause harm, and contact with the ground will not stop the process. But these trimmers do not cope well with dense vegetation and get tangled.

Power

The trimmer power is indicated in kW and affects performance. The higher this value, the faster the cutting element rotates and the larger the area will be processed.

1. Garden tools can have a small figure from 0.25 kW and reach 1.8 kW.

2. For utilities to maintain the area in neighborhoods and along roadsides where you will have to work all day and mow a lot of grass, it is advisable to purchase models with a power of 0.9-1.8 kW.

3. For giving and caring for a small lawn, an engine with parameters of 0.25-0.7 kW is sufficient.

Electric trimmers

This type of tool works in a 220V household network. The electric motor rotates the shaft and starts the cutting mechanism. To use the device, you must have a power outlet and media nearby. This partially limits the maneuverability and scale of the tool, but allows it to work silently.

Also, such a device does not have harmful emissions into the atmosphere. Such models are well suited for country houses and private companies with a small area, where you can get by with one reel of media.

Advantages:

Lungs;
Make little noise and not disturb the neighbors;
Inexpensive;
There are powerful models;
No harmful emissions;
Adjustable handle height;
Possibility of installing various knives.

Flaws:

The inconvenience of wire, which can be cut accidentally;
Limited area along the transfer length.

Tank volume and battery capacity

In the case of self-contained fuel trimmers, tank capacity plays an important role. This can be from 0.3 to 1.5 liters. Manufacturers calculate its volume based on the engine's ability to operate continuously for a certain period of time.

1. With a minimum tank you can mow for 20 minutes, after which you will need to stop for a break to cool the engine and refuel.

2. You can work with the maximum indicator for more than an hour, which is convenient for commercial use over large areas.

For cordless models, the battery is measured in amps/hours. 1 unit of V/H is enough for 15 minutes of work. Charging takes three times longer.

1. For cosmetic care of a small clearing far from an outlet, 2 A/h is sufficient.

2. To care for the territory of a kindergarten or a small company you need 3-4 A/h.

Mounting type

To operate the device, it is hung on the operator’s body. One or two belts are provided for this.

1. The application of single belt trimer is used to provide or decorate a small company area.

2. In the case of a large area, you will need to mount the backpack, which evenly distributes the load and reduces vibration.

Gasoline trimmers

The principle of operation of this type is similar to electric, but the rotation here is provided by an internal combustion engine. To do this, an additional fuel tank is attached to the bar, thanks to which the device receives a larger mass.

With the help of such a tool, you can move freely around the territory and even work where there are no buildings or electricity. There is no need to constantly remember the cord and be afraid to cut it. It is actively used for mowing grass on the side of the road, maintaining the excellent condition of yards in multi-storey areas and on the territory of large enterprises.

Advantages:

Powerful models;
Replacing knives;
No space limitation;
High performance;
Robust design;
Wide range of commercial use.

Flaws:

Heavy;
Additional fuel costs;
More noise;
Air emissions.

Line diameter

This indicator ranges from 1.4 to 3.3 mm and indicates the ability of the cutting element to cut a certain thickness of the stem and branches of the bush.

1. For a summer cottage, 1.4-2 mm is enough, which will remove the grass and keep the lawns looking neat.

2. Employees who monitor the condition of the road, where thick grass often grows, need to purchase 2.44.7 mm.

3. To improve an abandoned area, you need a strong fishing line measuring 3.0-3.3 mm, capable of cutting through tough stems and bushes.