How To Put A Knife On An Al-Ko Gas Trimmer

With the advent of summer, many owners of household plots are concerned about the issue of how to put a knife on a trimmer. No less relevant are the questions of why and when it is advisable to replace the fishing line on the lawn mow with a more durable cutting element. In our article we will try to make out all this and give useful recommendations to summer residents.

  • Why you need to put a knife on a trimmer
  • What knives to put on the electric and lawn mowers
  • How to put the knife on the trimmer

Why you need to put a knife on a trimmer

The trimmer with a knife mounted on it is most convenient to use for more comfortable mowing of tall and coarsened grass in the country. The line on the lawn mowing in such cases can not cope. Thin breaks very quickly. Using a thick 2.3 mm cord or homemade rods with cables causes the vegetation to wind up on the spool. This increases the load on the engine. As a result, the piston group and other moving parts of the unit wear out very quickly.

How To Put A Knife On An Al-Ko Gas Trimmer

If the mowing of the weeds is carried out with an electric trimmer without a knife, only fishing line, even if it is thick with a curly section, the problem cannot be solved. There is always a risk of overheating the motor and damage the flexible shaft. And it’s all about the big torque of the electric motor. The grass wound on the spindle creates strong resistance to the shaft, resembling a speedometer cable, which does not withstand and twists.

In order to protect the equipment from premature wear, manufacturers have provided the ability to install special knives on trimmers. The design and shape of existing cutting elements makes it easy to cope not only with coarsened and overgrown grass, but also successfully deal with young shrubbery.

What knives to put on the electric and lawn mowers

Before buying and putting a knife on a lawn mow, we will find out what they are and in which cases they are used. Today, manufacturers offer consumers a large number of types of these consumables. In general, all cutting tools designed for mowing grass can be classified:

  • By the type of material from which it is made;
  • In the shape of its cutting blades.

The main material for making trimmer knives can be plastic or metal. The use of such consumables is largely dependent on two parameters:

  • Type of lawn mowers;
  • Square mowing.

For safety reasons, manufacturers do not recommend placing steel knives on electric trimmers. Almost all lawn mowers powered by mains and battery are equipped with plastic blades. Depending on the manufacturer, they can be of a single disc-shaped design with several blades or in the form of a special mowing head for the installation of removable plastic blades.

Straight bar at gas trimmer and curved at electric

To put a metal knife on an electric trimmer does not allow its design features.

  1. The curved rod of the unit reduces the distance from its working part to the legs of the mower. If the blades collide with a stone or other solid object, the braid is thrown to the feet.
  2. The high torque that we mentioned above, in the event of a collision of a metal knife with a solid object, transfers a large load to the flexible shaft of the trimmer and its motor. What causes their premature failure.
  3. The handle of an electric braid most often does not have a restrictive bar acting as a stop. Which does not exclude injury to the legs.

It is these features that allow the use of exclusively plastic knives on trimmers with electric motors. In a collision with an obstacle, the blades are destroyed, thereby protecting the legs of the mower from possible injuries.

The use of metal knives only on gas trimmers is also due to design features.

  1. The direct design of the bar increases the distance to the legs, which ensures complete safety.
  2. Convenient U-shaped and J-shaped handles allow to hold the tool firmly. D-shaped lawn mowing arms are equipped with a limiter resting on the leg of the pigtail, which does not allow the head to be allowed to close when the cutting disc meets a solid obstacle.
  3. The clutch of the gasoline engine allows you to smoothly gain speed to the optimum level. And when the blade collides with a hard surface, it can absorb part of the impact.

Thus, gas trimmers with an installed metal knife are best used in large areas. They will successfully cope not only with tall coarse grass, weeds, burdocks and nettles, but also shrubs, as well as young trees.

The shape of the blade blades placed on the trimmer does not affect the quality of the work performed. Speed ​​does not depend on them either. Triangular, trapezoidal, rectangular shapes are all the marketing ploy of manufacturers.

How to put the knife on the trimmer

Putting a knife on the trimmer is not so difficult. The manufacturer supplies his tools with a special pin that allows you to lock the gearbox and a key with which you can unscrew the spool with fishing line. The most important thing to observe when changing the cutting elements is the safety precautions and the assembly sequence of disassembly.

The algorithm for installing the knife on the trimmer is as follows:

  1. Remove the protective cover;
  2. We block the drive. To do this, combine two holes. In the shaft hub and in the gear cup. After combining them, insert the pin into the holes;
  3. We turn off the spool with fishing line or the fastening nut holding the boot (clockwise, if the trimmer has not been used) clockwise from the hub;
  4. Next, install the cutting knife, so that the slots on the hub washer coincide with the recesses in the hole of the cutting disc;
  5. Install the boot;
  6. We twist the fastening nut (counterclockwise) while holding the locking pin;
  7. Tighten it using a pipe wrench;
  8. Return the protective cover to its place.

As you can see, there is nothing complicated. Now you can safely proceed to mow the weeds on the site.

After the blade of the knife has been processed, polished and polished, the knife is sent for assembly. The knife consists of a blade with a shank, an abutment of the handle or guard, as well as the handle itself with a structurally different pommel or without it. So, how to make a knife with its components on hand?

The guard is installed either on the underside of the handle or on both sides and is an integral part of the blade. The guard and shank are made of a single piece of steel, and its presence in the structure must be provided from the very beginning. The double-sided guard is fitted under the handle so that after polishing there are no gaps between it and the shank. Private craftsmen sometimes solder the blade and guard, so when buying a knife with your hands, always inspect the junction between the guard, blade and handle for its reliability.

By the way, the shank tapering up is an elegant way to shift the center of gravity without compromising the strength of the knife structure. However, with this method, it is not easy to grind the shank manually, you need to remove a lot of material. This form is more suitable for industrial production. The shank can be short (to the middle of the handle), sharp (in the form of a pin) or flat (for the entire length of the handle). The balancing of the knife, its weight and reliability depend on this. All types of construction have a right to exist and each is suitable for its own purposes.

After installing the guard, the handle is attached, which should fit snugly and without gaps to the shank and the guard itself. Sometimes a layer of material is applied between the handle and the shank. In the manual manufacture of the plate handle, the holes in each of the halves are drilled alternately. In industrial production. At the same time. Previously, both halves of the handle were attached to the shank with rivets on both sides, and the rivet head firmly fixed the structure. The disadvantage of such a fastening scheme is that there is a gap between the handle and the shank, where blood or moisture can accumulate, and this leads to metal rusting. In the modern world, craftsmen who make knives with their own hands add special adhesives to the structure that add a joint to tightness. However, the glue also has a drawback. With a serious lateral load (for example, a side impact), the halves of the knife handle may fall off. Therefore, knife assembly often combines the old and modern methods of fastening.

Rivets for knife handle

Rivets for the handle used in the assembly of the knife. There are quite a few. The simplest of the forms is a rounded pin inserted into the hole drilled under it. Such rivets for the knife handle, even when the wood is dry, will not fall out. These primitive rivets are enough when the handle is seated on glue. The second option is rivets with a large hat and a special hole in the middle, where the second half of the rivet is inserted. The third type of rivets used is screw rivets, which are the most durable type of fastening. Their halves are not driven in, but screwed into each other, making up a dense, single structure. Screw rivets must be recessed deeper, which weakens the handle design, and the process of installing rivets with a large hat is not easy. So, in fact, for reliable manual assembly of the knife, simple pin rivets with gluing are enough.

When the handle is turned, rivets for fastening are selected, holes are drilled in the shank. In order to make a knife, everything needs to be joined and glued together. The process of drying the glue is accompanied by a clamp on the halves of the handle. Rivets here play more of an auxiliary role. After the glue hardens, the protruding parts of the rivets are gently flattened and carefully ground, together with grinding the handle with medium sandpaper and then polishing it completely.

The harder the material of the rivets is, the slower they will grind compared to the handle, so the rivets often stick out a little in handmade knives (in the factory, the handle adjusts more precisely). The antler, for example, is not polished at all, so the rivet heads in such knives protrude slightly outward.