Trimmer – Make Optimal Choice: Trimmer Line, Trimmer Head, Trimmer Knife.

For a comfortable haircut of vegetation on the plot, optimal selection of trimmer characteristics will not be enough. Both for the electric trimmer and gasoline mowers, it is necessary to choose the right cutting tool. As such, a trim line (cord) or a special knife is used.
Fundamental when choosing what to mow is the type of vegetation. For convenience, the user can choose the type of cord, the type of trim head, the method of filling the cord into it, choose a knife of a certain shape. Therefore, it is necessary to become more familiar with these characteristics.

Trimmer line.

The standard cutting tool for all types of tools is a special trim line or cord, also sometimes called a string. Its thickness (diameter) ranges from 1.2 to 4 mm. For each trimmer, the maximum cord thickness is indicated, which can be operated without overheating the engine and accelerated wear of the sleeves.
In addition to differences in thickness, trimmer cord also has a different cross-sectional shape: a circle, a polygon (from three to a hexagon), an asterisk, rounded protrusions, etc. Besides, it can twist along the longitudinal axis in the form of a twisted square or a spiral-shaped round string, have various notches and notches. All these tricks are designed to increase efficiency when mowing vegetation.
The most versatile is a trim line with a circular cross-section, which can be cut as fresh grass and dead wood. In addition to such a universal cord, manufacturers also produce a more specialized fishing line.
Taking into account the fact that the smaller the contact area of ​​the cord with the stem, the higher the force of its impact, a figured cord appeared with a cross-section in the form of a polygon or asterisk with acute angles. Later, for strength, aluminum particles began to be added to it.

Square fishing line with a thickness of 2.4 mm will easily cope with thickets of dry weeds and even the stems of raspberry bushes. But the asterisk, on the contrary, is intended for sparing mowing of fresh grass. Due to the profile, it cuts vegetation cleaner, grass disappears faster after shearing and does not dry out as often as it does after applying a round line.

Round spiral-shaped fishing line is considered low-noise, but this parameter is relevant only for electric trimmers since the sound of a running gasoline engine blocks the whistle from any fishing line.
When using a trimmer line of figured cross-section, its thickness must be taken less than the maximum for a given trimmer. this will avoid problems with feeding the line from the cutting head. Refill in the coil such a cord should be in gloves.
Trimmer line has a variety of colors, and in most cases, it does not have a functional value. But for some manufacturers, the color determines the diameter of the cord (for example, Stihl) or the properties of the material used (for example, Oregon).
For the manufacture of trim lines use nylon (polyamide) or polypropylene. Leading manufacturers for the production of cords used polypropylene PP6. Various low-quality polyethylene is often added to Chinese fishing line to reduce the cost. But in any case, after long-term storage, polypropylene cord becomes brittle. To increase the elasticity of such a line before use should be soaked in water for half an hour.
In no case should not use thin wire or stranded wire as a trim cord. Thinking in this case about the strength and durability of fishing line, they forget that the trimmer string is specially made in such a way that breaking off softens the dynamic impact on the transmission and the engine of the instrument. Also, and the cable and wire still break off. At the same time, broken off pieces, broken up to high speed, easily break through leather shoes.

Trimmer head.

A trimmer head, often also called a mowing head, is a specially designed reel with a cord of a certain length inside it. A cord of 8–15 m is wound on the inner spool, the ends of which are pulled out of the coil to the required length as they wear out or break when they encounter a too hard obstacle.

As a rule, for different models of trimmers, certain mowing heads are used, which differ in both the internal structure and the method of fastening. For some trim heads, special adapters are available that allow you to use such heads on trimmers of various models and different manufacturers.

Trimming heads can be subdivided according to the feeding the fishing line into manual, semi-automatic and automatic. In the first, as is already clear from the very name, the line is fed from the head manually. To do this, you will have to stop working, turn off the trimmer, and manually lengthen the ends of the cord.
For the second, it is enough to attach a mowing coil to the ground. In this case, by pressing on hitting a special button, the anchor mechanism is released, and the cord is fed by centrifugal force. Elongation of the fishing line is carried out with the trimmer running.
In the third variant, to lengthen the cutting cord, one should reduce the engine speed, then with a subsequent increase in the speed, the automatic feeding of the trimmer line is carried out.
As follows from the above description, the most inconvenient is the mowing reel with manual feed of the cord, and the most optimal is the mowing head with automatic feeding. However, it did not win much love from users because of the increased consumption of fishing line, compared with other types. Therefore, the most popular and popular today semi-automatic trimmer heads.

Also, different models of trim heads differ in the way of filling the fishing line. They can be fast-loading (for example, Shindaiwa Speed-Feed) when there is no need to disassemble the reel for winding a new portion of the cord, and collapsible.

In the first embodiment, you can not remove the mowing coil from the trimmer. The end of the cable is passed through both ears in the reel, then the necessary amount of fishing line is wound and cut. Or both ends of a pre-cut piece of the required length of cord are tucked into the corresponding holes and screwed on.
In the second variant, to charge the new portion of the cord, the trim coil will need to be removed, disassembled and reeled on the line inside the spool. Different coil models have different ways of disassembling and winding the fishing line. But in all cases, the line should be wound in the direction indicated on the body by the arrow (both ends in one direction).
On cheap Chinese mowing heads, the so-called “Noname”, such an arrow is often absent. Also, on branded models, there can be two arrows in different directions (when the possibility of their use on trimmers with varying directions of rotation of the head is provided). In this case, the cord must be wound in the direction of rotation of the shaft (that is, the engine must wind it). If the cable is hurt in the wrong direction, then when you hit the button on the ground, it will fly too much.
The different variant is also possible. when the line is not fed when the semi-automatic mowing head is struck on the ground. It can be caused both by the incorrect winding of the fishing line and by the fact that after installation on the trimmer, they forgot to pull the ends of the cord out of the retaining slots on the spool.
Another nuisance when mowing vegetation with a trimmer cord is sintering the turns inside the coil. It happens because when meeting a too hard obstacle, the cord is sharply inhibited. With such jerks, it retracts inward and sticks together with the part wound around the spool. As a result, you have to interrupt work, disassemble the coil and tear off tight coils of the cord. To avoid this, in some cases, spraying with a silicone spray of fishing line wound onto a spool helps to be installed before installation in the reel.

Most often for trimmers used semi-automatic head of two spring-loaded parts (body and spool). Structurally, the spool can be in two versions. Two-section, when each end of the cord is wound into its section, which reduces its entanglement and sintering. Or one-section, when both ends of the fishing line are wound together.

Our craftsmen have invented a simple, cheap and elegant way to turn a single-section spool into a two-section one, the essence of which can be understood from the above photos.
To do this, a ring is cut from a heavy and thin plastic plate, the inner diameter of which corresponds to the thickness of the spool in the area of ​​winding the fishing line, and the outer diameter to the protrusion diameter. That is, along with the spool, such a ring should move freely. Then a cut is made for the cord; the ring is cut, put on the spool and the cut is glued together with adhesive tape. Now each end of the fishing line can be wound into the section intended for it.

The mowing head with the supply of pre-wound cord has two or four holes opposite to each other, from which the mowing ends extend. In addition to coils with feeding portions of fishing line, there are also trimming heads with plug-in pieces of fishing line of fixed length (for example, Oregon Jet-FIT).

In this case, the number of working “whiskers” can reach up to twelve. Some users consider this design rather convenient, but others are dissatisfied because they believe that this increases the consumption of the cord, and it is necessary to stop working to replace it. In such heads is used, as a rule, the fishing line with transverse notches.

Trimmer knife.

When mowing with a trim grass of high grass, it will be wound on the spindle in the place of attachment of the mowing head. How often this will occur depends largely on the design of the head and the properties of the mowed grass, but this is practically impossible to avoid completely. The optimum output will be mowing not with a cord, but with a trimmer knife specially designed for such cases.
The trimmer knife used as a cutting tool can be made of plastic or metal and have a different number of blades (teeth) of various shapes.

On models of trimmers with a curved bar, only plastic knives should be used (for the sake of the mower’s safety and commensurate with the possibilities of the flexible shaft). Besides, they often come complete with electric trimmers.

It can be either a special mowing head with replaceable removable plastic knives or a one-piece design in the form of a circular knife with different numbers of blades. Such trim knives in the teeth hard vegetation (dry grass, burdock, nettle, etc.).
For the treatment of large areas and cutting not only grass but also cutting off a bush or even young trees, metal knives are used. The only thing that such trim knives “fear” is collisions with objects that are too hard for them (for example, stones).
Metal knives can be used only on trimmers with a straight barbell. On a tool with a curved bar, they can not be installed. It is due primarily to safety. If, when mowing vegetation, the disc stumbles upon a solid obstacle, then, in this case, it is thrown back. For straight bar trimmers, the distance to the user’s feet is significantly further.
Plus, a T (U) or a J-shaped handle helps to hold the tool, and a special protruding restrictive bar is added to the D (O).shaped handle, which, resting against the foot, does not allow the cutting tool to reach it. Curved bar trimmers are usually equipped with a D (O).shaped grip without a stop.
Secondly, having a high torque metal disc knife creates a more significant load on the flexible shaft and the motor, which leads to a rapid breakdown of the tool.

As the user experience shows, the shape of the blades (triangular, rectangular, etc.) practically does not affect the quality and speed of mowing. But their number becomes essential when using the trimmer for harvesting hay. Three or four-dangerous knives when mowing too chopped grass.

Almost round eight-teeth cutters or with four large and additional smaller teeth between them are considered the most optimal for haymaking. Also popular are perforated discs with a large number of teeth. such a lightweight trimmer for the trimmer can be installed on low-power tools.
Using a trimmer cutter, that is, a disk knife with a large number of teeth, it is possible not only to clean the area from luxurious perennial weeds, raspberries, etc., without problems but also to cut trees with a trunk diameter of several centimeters.