Do-it-yourself grass mower. For assembly, you will need such tools. The main advantages include

A neatly trimmed lawn is not only beautiful in itself, but also in a certain way indicates the status of the owner of the house. Nowadays, it is not difficult to find a suitable lawn mower in terms of performance and design. But there is another option. If a medium-power electric motor was lying around on the farm, then, after spending a few evenings, it can easily be turned into a simple and convenient home-made lawn mower, while saving not such a small amount of money that would have to be paid for a branded lawn mower - and even enjoying creativity.

DIY lawn mower

General arrangement of the lawn mower

In its simplest form, a lawn mower consists of the following components and parts:

Engine.

The frame on which they are fixed.

Protective cover.

Handles for management.

Details of the control system: switch, RCD, power cable with plug.

The frame of the simplest design is a metal sheet 2-3 mm thick with a hole in the middle for the passage of the motor shaft. The sheet is reinforced with a frame of metal corners. An engine is attached to the sheet from above, a protective casing from below, on the sides of the axle for wheels, handles for control.

If the motor is flanged, it can be mounted directly to the sheet by drilling holes in the latter that match the holes in the flange. If the engine is of a conventional design, two perpendicular racks from the corner must be welded or screwed to the sheet so that they coincide with the legs of the engine.

Homemade lawn mower

Homemade lawn mower. Fastening the electric motor to the corners.

Holes are drilled in the corners for mounting the engine. If the holes are made in the form of grooves, this will allow the engine to be displaced relative to the frame during mounting, thus changing the distance from the knives to the ground. This design feature will be helpful in choosing optimal height grass cutting. But it's easier to make holes for different positions of the engine in height.

The central place of the lawn mower is the cutting unit, which consists of a mandrel with two short (or one long) knives fixed on it.

Engine

A good option is asynchronous electric motor with a power of 500-600 W and above, with a speed of about 3000 rpm. A big plus of an asynchronous motor is its low noise. The higher the engine speed, the better and smoother the cut. In fact, the quality of mowing is determined not by the speed of rotation of the knives, but by the linear speed of the cutting edge relative to the grass. At the same number of engine revolutions, the linear speed of the cutters is the higher, the larger the grip (the diameter of the circle along which the cutting edge rotates). Therefore, with a large grip (more than 40 cm), the engine speed can be lower. However, in this case, the motor power must be greater - in order to overcome the increasing resistance. Practice shows that this option is quite workable: grip - 50 cm, engine power - 1 kW, speed - 1500 rpm. But in principle, the grass will be mowed, although worse, and a 500 W engine with a frequency of 1500 rpm. Only with a small motor power, it is necessary to sharpen the knives regularly.

To connect a three-phase motor to a single-phase network, it is necessary to use a circuit with working and starting capacitors. There is a lot of information on the Internet about connecting three-phase motors to a single-phase network. It is not difficult to find formulas for calculating the required capacitance of capacitors. In practice, they take about 200 microfarads for a motor with a power of about 2 kW. For a power of 500-600 W, 60-80 microfarads is enough.

When making a casing for the engine, it is necessary to provide holes for engine cooling.

You can also make a lawn mower with your own hands using a conventional electric drill with a speed of up to 3000 rpm. It is not so difficult to come up with a drill attachment to the frame. However, you need to understand that in terms of reliability and duration of continuous operation, a drill cannot be compared with asynchronous motor, so if you have to mow a relatively large area, preference should be given to the latter.

In the case of a drill, it is very easy to make a knife mount. A knife with a hole in the center is clamped with a nut on the bolt, and the bolt is clamped in the drill chuck.

Mandrel

Most simple design the mandrel is a disk or strip with a flange in which there is a hole equal to the diameter of the motor shaft. The flange is put on the shaft and stops on it, knives are attached to the disk or strip. The diameter of the disc or the length of the strip depends on the planned working width and the length of the knives. As a finished mandrel, you can use a pulley with a bore diameter suitable for the shaft of an existing engine. This will solve two problems at once - the centering of the mandrel and its fastening. But the pulley must be sufficiently reliable.

The mandrel must be securely fastened to the motor shaft. This is usually done with bolts screwed into the flange perpendicular to the axis of the shaft.

As a mandrel, you can use a stone holder for a sharpener.

If there is no suitable pulley or other suitable parts, you will have to order the manufacture of a mandrel to a turner or make it yourself from a pipe of a suitable diameter and a strip or circle welded to it. There are three problems here: finding a suitable pipe diameter, ensuring that the welded strip or circle is perpendicular to the pipe, and centering the mandrel after it has been manufactured. With some effort, all these problems can be solved.

As knives, flat tool steel with a thickness of 2-3 mm and a width of 20 to 50 mm is used. The thinner the knife, the better it cuts. However, a thick knife is stronger, which, given the obstacles encountered in its path in the form of bumps, various foreign objects and even stones, is very important.

The execution of knives has two main options. The first is a knife in the form of a long strip, which is attached to the mandrel symmetrically about its axis. The length of the knife in this case is equal to the width of the grip - usually 30-50 cm. The sharpened ends of the strip act as incisors. The knife and the mandrel in this case can be one integral part in the form of a plate, to which a flange with a mounting hole is welded or riveted.

The second option is two short knives 50-80 mm long, which are mounted along the edges of the mandrel at an angle of 180 ° to each other. They can be located straight or with a slight slope. You can fasten the knives with two or one bolt. The first method is more reliable, however, fastening with one bolt allows the knife to fold (without breaking or deforming) when it hits an obstacle - a stone or a bump. The fastening of the folding knives should be regularly inspected, because. over time, the screws can fray.

Steel for knives must be hard enough, but not brittle, otherwise the knives may break, which will not only require their replacement, but also create a risk of injury from a flying piece. The experience of amateur craftsmen shows that a hacksaw blade for wood with a thickness of 2 mm is very well suited as a material for lawn mower knives. The technology for making a knife from them is simple. Two blanks in the form of strips are marked on the canvas (or one long knife is made from the canvas with sharpening at the ends and holes for fastening in the middle), which are then cut out with a grinder. Holes for fastening are drilled in the blanks. After that, it remains to sharpen the knives, attach them to the frame and center.

If drilling holes is problematic, then you can put the canvas on a metal surface with a hole of a slightly larger diameter than the hole in the canvas should be, and hit with a punch. The protrusion formed after the impact is removed with a file (if the metal is soft enough) or on a sharpener. If the hole does not meet the desired diameter, the process is repeated.

In fact, there are many options for making workable knives, as well as materials for their manufacture. The main thing is to sharpen them well, center them (so that there is no vibration) and securely fasten them. When fastening the knives to the mandrel, use washers and locknuts. Without this, the mounting bolts will loosen from vibration.

If possible, it is better to make the cutting edges slightly bent down, like branded lawn mowers. This will reduce winding of the grass on the motor shaft. Or you can make a disc that covers the shaft. Also, if the engine power is close to the power of branded lawn mowers, you can buy a branded lawn mower blade (see here).

The diameter and position of the wheels must be selected so that the knives are located at a distance of 5-6 cm from the earth. This cutting height is considered optimal - both in terms of the aesthetics of the lawn and the quality of the haircut. If the grass is cut at too high a height, it will bend, allowing the blades to pass over it and remain uncut. Lower cutting is difficult because of the unevenness of the ground.

There is no unambiguous opinion about what number of wheels is optimal - 2, 3 or 4, among the craftsmen who operate homemade lawn mowers. 3 or 4 wheels are good because they set the exact distance from the knives to the ground. Two wheels make the mower more maneuverable and allow you to cut grass in any hidden places. In addition, it is easier to find two identical wheels than three or four. However, you can make wheels yourself, for example, from plywood and bearings, so the last argument is not so convincing. Ultimately, the choice is up to the artist himself.

If a two-wheeled lawnmower is selected, then there must be protection against touching the ground with a rotating blade.

If a three-wheeled lawnmower is selected, two wheels must be on the side of the handle so that the front of the mower can be lifted to turn by pressing on the handle.

The larger the diameter of the wheels, the better. A lawnmower with small wheels is more difficult to roll over the grass.

Some Helpful Tips

If the edge opposite the cutting edge is bent up at the knives (or the blades are riveted to them), they will work like a fan, lifting and rotating the cut grass with an air stream. At the same time, if a cutout is made in the casing (in the quadrant where the knives run) and a mesh bag or box is pulled over it, then cut grass will be collected in it.

At the end of the article there is a video demonstrating the operation of the second lawn mower.

Without a bag, the grass will stack in the direction specified by the cutout. Without a hole in the casing, the grass will be crushed, it will be mulching. But all this needs enough powerful engine, and to avoid stuffing the cut grass into the engine, the space between the engine and the knives must be covered with a disc.

Working with the mower will be safer if one of the handles is equipped with a lever, which, when released, cuts off the power supply to the engine.

Security measures

When taking on the manufacture of a lawn mower with your own hands, you need to understand the danger posed by the operation of such devices. If we talk about the main threats, then there are two of them: defeat electric shock and injury from rotating knives. Both are classified as very serious, so security measures must be taken very carefully.

It is necessary to carefully insulate all points of connection of electrical wires - both on the engine itself and on the control parts. The insulation on the supply cable must not be damaged. To power an electric motor, it is necessary to have a double-insulated cable with at least 3 cores. The body of the mower is reliably grounded, for which one of the cable cores is used. Or they connect the lawn mower to the network without fail using an RCD - a residual current device designed to de-energize electrical devices when a person touches their parts that are energized due to insulation failure.

The mower must not be operated without a protective cover. When working, make sure that there are no people nearby. Broken knives fly out at high speed. And if the operator himself is protected by a casing, then for lawn mowers, the front area of ​​\u200b\u200bthe mower remains open. Mow preferably in rubber boots. This will protect against the consequences of hitting various objects that are thrown by a rotating knife.

In wet weather and early in the morning when there is dew.

Below is an example of an incorrect homemade lawn mower.

Wrong homemade lawn mower

The engine is completely open, while there is no makeshift casing for it, there is not even a protective disk on the side of the knives, although there is a huge hole there. There is no casing protecting the lawnmower from a flying knife or a thrown stone. The handles are welded on and cannot be tilted and cannot be removed when storing or transporting the mower.

Homemade lawn mower - how to make a lawn mower

If desired, the grass mowing process can be mechanized by making a home-made lawn mower for this with your own hands, using low-power electric or gasoline engines (chainsaw, moped, motor scooter) to drive the knife of a mechanized mower. Homemade lawn mowers are especially convenient for those who have a garden. After all, often the soil in the garden is not dug up, and the grass mowed and chopped by a lawn mower overheats well and replenishes the reserves of nutrients taken by trees from the soil.

We will tell you how you can make a lawn mower with your own hands. Someone with locksmith skills at home, he can make a mechanized lawn mower from improvised means. Suitable for such a homemade lawn mower are single-phase electric motors from washing machines, support wheels from worn-out baby carriages, water pipes and steel corners. It is important to select a suitable electric motor as the drive for the lawnmower blade. Most garden plots have a single-phase alternating voltage of 220 V. Therefore, the easiest way to drive a lawn mower blade is to use an electric motor from a worn-out washing machine. The power of the washing machine motor is usually between 180 and 250 watts. A more powerful drive is preferable. But even with an engine power of 250 W, the cutting width of the lawn mower should not exceed 250 mm. A knife grip width of 400 mm or more requires a drive power of 500 ... 750 W.

As an electric drive for a lawn mower knife with a grip of 400 mm, three-phase electric motors connected to a single-phase network according to a triangle circuit with a phase-shifting capacitor can be successfully used. The capacitance of the capacitor can be approximately selected, assuming that 6.6 ... 7 microfarads of capacitor capacitance should fall on 100 W of electric motor power. So, for an engine with a power of 1.1 kW, paper capacitors with a total capacity of 70 ... 80 microfarads are enough (the reverse voltage of the capacitors is at least 250 V). Start capacitors are not used because the mower initially starts with no load on the shaft.

As an example, I give here the design of a homemade two-wheeled lawn mower made by myself (Fig. 1).

Homemade lawn mower - how to make a lawn mower with your own hands

Rice. 1. The design of a homemade lawn mower:

1 - mower knife; 2 - frame; 3 - protective visor; 4 - support wheels; 5 - rack mounting the electric motor; 6 - electric motor; 7 - switch; 8 - handle;

9 - flange for attaching a lawn mower blade; 10 - protective grille.

The peculiarity of this homemade lawn mower is that the electric motor for driving the knife is installed here above the axis of the support wheels. As a result of this arrangement, the mower blade can be easily tilted back and forth to change the cutting height of the grass. This quality is very important when the mower is used for mowing tall grass, which is always difficult for industrial mowers to cut. In the proposed design of a homemade lawn mower, mowing tall grass is facilitated by raising the front of the lawn mower relative to the ground (Fig. 2).

The position of a homemade lawn mower when mowing tall grass

Rice. 2. The position of a homemade lawn mower when mowing tall grass (25 ... 30 cm).

As the mower moves forward with the front end up, the high-speed rotating blade creates multiple cutting planes. Grass shredding will be finer, the higher the blade speed and the slower the mower moves across the lawn. Tilt driving is only necessary for tall grass. With a well-groomed lawn and low grass, the knife is oriented parallel to the ground.

Now about the design of a homemade lawn mower in more detail. The frame of the mower (see fig. 1) is made of half-inch water pipe. The handle is made of the same pipe and can be easily detached from the body, which is important when transporting the mower in public transport. The “detachability” of the handle from the frame is ensured by a sleeve welded to the frame, in which the handle is fixed with a bolt. The electric motor is attached to the rack (Fig. 3) with four bolts.

Motor mount

Rice. 3. Rack of fastening of the electric motor.

In addition, to change the height of the grass cut, more holes were drilled on the rack, which allows you to move the engine in a vertical plane when adjusting. Support wheels are taken from a baby stroller, their diameter is 280 mm. On the lathe a bushing was made for attaching the knife (Fig. 4, a) and two axles for the wheels (Fig. 5, a). The axles are connected to the brackets by welding, and the brackets are also welded to the frame.

Knife mount

Rice. 4. Knife mount:

A - bushing; b - single knife; c - double knife design (installed when using a high-speed engine 2850 rpm).

The knife (Fig. 4, b) is made from an automobile spring taken from a GAZ-69. The protective grille is made of nails with a diameter of 5 mm, for which the necessary holes are drilled in the pipe. To prevent the knife from touching the ground while mowing tall grass, a support ski is provided, made of a steel bar with a diameter of 8 mm (Fig. 5, c).

The design of the wheels (a), grilles (b), and lawn mower skis

Rice. 5. The design of the wheels (a), grilles (b), and lawn mower skis.

When using a single-phase lawn mower, it is necessary to strictly observe the requirement of electrical safety rules. To power the electric motor, it is necessary to have a special double-insulated cable with at least 3 cores. The body of the mower is reliably grounded, for which one of the cable cores is used. Switch electric drive securely fastened to the handle (it should be comfortable to use). Do not use the mower in wet weather and early in the morning when there is dew. When working, rubber shoes must be worn on the feet, and rubber gloves on the hands. For those who make such a homemade lawn mower with their own hands, I wish you successful work in your summer cottage.

DIY lawn mower

Today, only the lazy do not mow their lawn. A sea of ​​​​all kinds of modifications of lawn mowers has appeared in stores, choose to taste. But perhaps the best lawn mower is the one that is made by hand.

At the end of the 90s, when lawn mowers had just appeared on sale and were prohibitively expensive and the grass was pearling like crazy, and all the hand scythes were broken, he built such a mower. I spied the design in the store, at the branded one. At first it was made with a 220v collector engine, which suddenly overheated and burned out, although the whole season mowed with grief in half with it. So that there were no more problems, a 380v engine was bought and it justified itself. In those ancient times, lathes and other hobby machines were a curiosity, so the rotor bushing had to be ordered from a turner, the rest was done by welding and a grinder. The mower is simple and reliable, like a Kalashnikov assault rifle, There is enough power, I don’t disdain to ride on the molehills, If the neighbors have already changed more than one Chinese one due to breakdowns, mine works like a clock. From maintenance, only washing from grass from a hose, well, maybe once a year the rotor can be sharpened with a grinder, although it does not affect performance.

A lawn mower is a wonderful alternative to a hand scythe, making it easier and faster to cut grass in a variety of places, including those where a regular scythe simply won't turn. But behind the comfort and convenience is a complex modern mechanism that requires tireless attention and regular maintenance.

Regardless of the manufacturer, all units have a similar design. Therefore, do-it-yourself repair of a Viking lawn mower is carried out similarly to the repair of other brands: Husqvarna, Shtil, Bosch, Gardena, Oleo Mac. A homemade lawn mower will not be an exception, but repairing a breakdown requires basic knowledge. Consider the most typical causes of engine failure, and do-it-yourself lawn mower repair in the field.

Repair of the mechanical part for all types of lawn mowers

Regardless of the type of engine, the mechanical part of the scythe includes knives, a device for ejecting or collecting cut grass, and a transmission mechanism. Most often, knives fail or the fishing line ends.

Breakage or bending of knives is visible to the naked eye. Depending on the material and the degree of damage, the knives are replaced or restored by simply bending them back to their original state. In case of severe wear, the cutting part can be sharpened. A do-it-yourself lawn mower made from a trimmer can fail for many reasons. Most often, this is an excess of the maximum permissible load on the torque and the engine, since a knife is used instead of fishing line.

During the inspection, check the condition of the air duct for feeding the grass into the container and, if necessary, clean it. More complex mechanical breakdowns require complex tools, special equipment, professional skills, and it is better to entrust the elimination of such malfunctions to professionals.

Do-it-yourself electric lawn mower repair

Not only factory-made, but also home-made electric lawn mowers fail. main reason stopping the electric motor is the loss of contact and the lack of power at the motor terminals.

Therefore, first of all, we check the presence of voltage in the power outlet, the condition of the electrical cord and the absence of its breakage. Then, if a commutator motor is used, you need to check the condition of the brushes and replace them if they are very worn. The brushed motor hand mower is durable but requires regular brush replacement.

Manual lawn mowers with an asynchronous motor also have problems. The phase-shifting capacitor often fails, but it is problematic to check it in the field. An indirect sign of a capacitor failure is:

• jerking of the motor at the time of power supply;
• strong heating of the engine even at low load;
• reduced turnover;
• characteristic buzz.

Do-it-yourself electric lawn mower is made from improvised materials that can fail. If a malfunction is detected, in any case, you need to make sure that voltage is applied to the motor terminals, and in its absence, check the operation of the switch.

If there is voltage, the capacitor or brushes are in order, then the burnt winding is the most likely cause of the breakdown. In this case, the unit will have to be handed over to a repair shop. Home-made electric lawn mowers most often have to be repaired on their own, since when assembling the device, all the nuances of its operation are not taken into account.

Do-it-yourself electric lawn mower repair video

Petrol lawn mower repair

Lawn mowers use gasoline two-stroke internal combustion engines. When deciding how to make a lawn mower with their own hands, they often use engines from other household appliances - chainsaws, compressors, motor plows and trimmers. The process of finding and fixing the problems of these engines is carried out according to one algorithm. Repair petrol lawn mower do-it-yourself begins with determining the cause of the failure.

The engine starts and runs normally, but the blades do not rotate.

In this case, failure of the mechanical part is guaranteed or, alternatively, its attachment to the motor shaft is destroyed.

Hard to start but works fine

A do-it-yourself mechanical lawn mower with a gasoline engine does not start well, but it works normally in operating modes (when gas is supplied). Such a malfunction can be caused by two reasons - a failure to adjust the idle system in the carburetor or the wrong fuel composition.

To eliminate it, you should start with fuel, combine gasoline and oil of the required grades in the required proportion and pour this fuel into the tank instead of the old one. If this does not help, remove and disassemble the carburetor and adjust the idle system in accordance with the manufacturer's instructions.

The engine does not start well and is unstable in all modes

The most likely causes are clogged fuel jets, clogged fuel filter, clogged air filter. To eliminate: jets are blown with compressed air, filters are changed or washed, depending on their design.

Engine starts but won't hold load

If the engine starts and runs at idle, but does not hold the load well during operation. Most likely, "oxygen starvation" takes place. Do-it-yourself repair of lawn mowers is carried out by replacing or cleaning the air filter by the “purge method”.

Repairing lawn mowers if the engine does not start

It happens that despite the presence and normal supply of fuel, the engine does not start. Most often, the absence of signs of life indicates a failure of the ignition coil. If, upon visual inspection, all electrical circuits are in order, then this coil will need to be replaced.

A less common case is heavy carbon deposits or a failed spark plug. It is determined by visual inspection of the unscrewed candle. Most effective method the definition of this malfunction is to replace the candle with another one that is known to be good. When thinking about how to make a lawn mower if the engine does not start, pay attention to replacing the candles with new ones, and preferably more reliable ones.

How to make a lawn mower with your own hands video

Outcome

Given the peculiarity of the "field conditions" in which lawn mowers are operated, the manufacturers of these devices have tried to protect their consumers as much as possible from possible problems. But, as you know, even mechanical lawn mower handmade, made with your own hands, may one day let you down. We really hope that our advice will help you in this case and direct the troubleshooting in the right direction.