How To Sharpen A Lawn Mower Knife Yourself

Way to travel

All electric lawn mowers, regardless of the type of cutting mechanism, are divided into self-propelled and non-self-propelled. The first ones are equipped with a clutch and a belt drive, as well as a gearbox, which reduce the engine speed to an optimal level for the wheels.

Non-self-propelled models Equipped with wheels both on a common axle and rotating separately.

Method of ejection and processing of grass

How To Sharpen A Lawn Mower Knife Yourself

High-speed rotating knife Not only cuts the grass, but also accelerates it, so that the centrifugal force pushes the cut vegetation against the deck, so it flies out through the rear or side window, depending on the configuration and operating mode of the mower.

If both holes are closed, then the cut grass passes between the ends of the knife and the walls of the deck, after which it falls down.

When working in this mode, Falling fragments are quite large, comparable to the themes that fly out through the windows provided for this.

If, however, an additional (mulching) knife is installed together with a standard knife, then the size of the grass falling to the ground will be reduced several times, therefore this mode of operation is called mulching. All rotary mowers can not only throw the grass back, but also collect it in the grass catcher, this mode is in demand where, for any reason, it is impossible to leave the mown vegetation on the site.

Drum mowers work a little differently. Rotating, the drum accelerates the fragments of cut vegetation inside it, which are pressed against the tightly fitting body of the lawn mower. Therefore, at the moment of passing through the exit window, they fly out under the action of centrifugal force.

All drum mowers are equipped with rear discharge only, however, some of them include a grass catcher, so such models can be used Not only for mowing, but also for men mowing grass from the site.

How to store?

The main prerequisite for storing lawn mowers is low humidity, so they can be stored in any dry room. Before storing, clean the device from grass residues and wipe it with a dry cloth to reduce humidity and protect metal parts from corrosion.

Failure to do so may cause condensation to build up inside the mower, causing a short circuit and electric shock.

How to remove and install a knife?

The blade of any electric lawn mower is a consumable item, so it must be changed or sharpened periodically.

To remove and install the knife, you need the following tools:

Wrench to match the head of the fixing bolt (included in the delivery);
Screwdriver (not always supplied) or wooden block to secure the knife.

Using a plank or screwdriver, secure the knife (many mower owners hold the knife with their hand, then unscrew the bolt by turning it counterclockwise.

Having unscrewed the bolt, remove the old knife, then put a new one in its place in the same position so that it coincides with the latches and tighten the bolt. To tighten the bolt Fix the knife with a screwdriver or a plank (often lawn mower owners hold the knife with their hands, because it does not require much effort).

In more detail, the removal and installation of the electric lawn mower knife is shown on this:

Lawn mowing

Let’s move on to the question of how to properly mow the grass. Start mowing by unrolling the extension cord and laying it in large loops to prevent twisting when removing the mower from the outlet. It can be laid with a snake or in any other way, the main thing is that during removal of the mower it does not get entangled and does NOT get in the way of the mower.

Then set the optimum cutting height for this area, then connect first the cable to the socket, then the lawnmower to the cable.

On the vast majority of models, the engine is turned on using a button and a lever; this is described in more detail in the operating instructions. Turn on the motor, move the mower away from the outlet, gently push the non-self-propelled model in front of you due to your physical strength, activate the self-propelled drive using a special lever.

The speed of movement should be such that even a meeting with dense grass does not lead to a decrease in engine speed (they are controlled by ear). If the speed has dropped and the sound of the mower has changed, then stop moving forward and back a little, then continue moving forward, but at a lower speed.

When working in the rear discharge mode, including with an installed grass catcher, a snake is the optimal trajectory along the section.

To do this, first move along the edge of the site as far as possible, then turn the mower and move to the width of the Mowing sideways, then move the machine towards the outlet.

If the turn is to the right, then the extension should be to the left of the mower, if to the left, then to the right. To reduce the likelihood of hitting the wire under the knife, it can be slung over the elbow of the appropriate hand. That is, when turning to the right, it is thrown over the left elbow, and when turning to the left, through the right.

When operating in side discharge mode, the cable should always be on the opposite side, and to reduce the likelihood of being hit by a knife, it can also be thrown over the elbow.

When working with the grass catcher, watch out not only for the indicator of its fullness, but also for the sound that the lawn mower produces. If the sound changes, but there is no thicker grass area, the grass catcher is overfilled, so stop the engine and remove the grass cuttings.

Electric lawn mowers: device, operation, malfunctions

Electric lawn mower. It is a complex tool, so it is very important to use and maintain it correctly.

Improper maintenance or use can result in not only serious damage to the mower, but also injury.

The general rules for safe use are the same for all lawn mowers, however, there are nuances that apply only to certain types of THESE machines.

The information that you will find in this article cannot fully replace the user manual of a particular model, but it will give a general idea of the correct use of electric lawn mowers, including their maintenance and repair.

Let’s give answers to the following questions:

What is the device of an electric lawn mower;
How to use it correctly: how to turn it on, how to mow the lawn;
How to maintain: disassemble, sharpen a knife, can it be washed with water, mows wet grass, how to store;
The most frequent malfunctions: does not turn on, stopped working, smoke and what could be the reasons;
Other nuances of operating THESE devices.

Cleaning and straightening

After removing the knife, clean it of dried grass residues and dirt. I don’t need to clean it up to a metallic sheen. But on the very blade there should be nothing outsider.

Straightening is done with a hammer and an iron bar or a piece of rail that serves as an anvil. When new fractures and cracks appear when leveling the knife, it is useless to restore such a point. If cracks are small after leveling. Grind off the cracked strip of steel until the blade is completely flat.

Editing Edges

Experienced craftsmen also carry out grinding of the newly sharpened knife.

Instead of a grindstone or emery wheel, install a felt wheel on the motor shaft.
Turn on the engine and apply a little GOI grinding paste to the wheel, lightly pressing a piece of the compound against the rotating wheel. Make it evenly layer on the circle.
Press the torch to be machined against the turntable and move the sharpened point in any direction. Do not allow the point to turn towards the fibers of the circle (do not sharpen “against the grain”). This can spoil the circle itself, and provoke injury.
If the surface of the circle is the beginning of the Cernett from a removable metal powder, apply a little more paste on it, and continue processing.

How to sharpen a lawn mower knife?

Required inventory
The ways
Angle selection
Phased execution
Do I need to sharpen a knife after purchase?

It is also possible to mow the mechanical slanting grass on the site using a blunt knife. But rough cutting of the grass with a mower will spoil the appearance of the lawn: it will delaminate in the longitudinal direction. The resulting fringe will be “callous” for several weeks. To keep the lawn completely flat, it is recommended to check the mower blade at least once a month. And undermine it if necessary.

Angle selection

Sharpening angle. Just as important as keeping the knife balanced in the center. Ideally, it is 30 degrees. Too small an angle will turn the knife into a kind of razor blade, magnified dozens of times and dull at the first cut of grass or bushes.

Sharpening the blades

Mower blades are sharpened with:

Chisels, files and sandpaper;
Angle grinder (with sanding discs)
An electric drill or any motor with a special attachment on which a round whetstone is attached;
On an emery machine.

Make sure there are dents, notches and dents on the knife blade. For quality sharpening, you will most likely need pressure. They hold the knife firmly in position ideal for fast sharpening. Small notches and dents are removed with a chisel or file or a coarse sharpener.

Sharpening performance will increase when you use a drill with an adapter on the chuck of which a sharpening stone or emery wheel is attached. Now plug in and run your drill or sharpener. Start sharpening a serrated sharp knife.

When sharpening, you must adhere to certain rules.

DO NOT apply excessive force to the product, smoothly move the emery wheel.
Avoid friction overheating when sharpening.
Dampen the knife periodically with soapy water.
Keep the sharpening angle constant. This will help to avoid the saw effect on the cutter. The unevenness is sharp, its “pockmarked” line will lead to the formation of the smallest notches in the first minutes of work.

You can attach a drill or sharpener, and move the knife along the edge of an emery or grinding wheel.

The ways

First of all, it is recommended to remove the knife from the mower.

Manual way of sharpening knife blades. Using a grindstone and sandpaper without any motors or machines. Aligning a serrated and beaten blade with a hammer or sledgehammer is performed on an anvil, rails or a black bar.
The mechanized method, although it is supplemented by “Forge” processing, requires sharpening on an angle grinder, intently on a machine or drill. The last two options require a special attachment on which the grinding disc is put on.

The mower knife sharpens evenly and is sharp along the entire length (each). To prevent the ball bearings of the motor or gearbox from breaking, centering the knife is best done by a turner on the machine. But even without a lathe, the result will be quite decent.

The knife blades of various lawn mowers are almost always made of high quality steel, however, despite this, they still need to be sharpened periodically. And the main thing. Do this so as not to degrade the quality of the metal. However, no Special tools and skills are required for this, and any summer resident will easily be able to cope with such a task!

Why you need to sharpen your lawn mower knives?

Of course, it is quite possible to cut off excess lush green grass from your favorite lawn with a knife with blunt edges. But the grass, as a result of such manipulations, will begin to delaminate (this stratification will go mainly in the longitudinal direction), gradually turning into a sloppy fringe. And after a few days, it will dry out altogether and may even get sick for several weeks. That is why the cuts must always be neat and even. In this case, they take just a few hours and allow you to maintain a spectacular juicy green color of the lawn. And in order for them to be such, you need to periodically sharpen the knives of the used lawn mowers.!

Remove the knife

Before embarking on such an important event, it is important to try to protect yourself and your garden gadget as much as possible. This is especially true for gasoline lawn mowers (models with an electric drive are easily neutralized by an elementary disconnection from the network): first you need to free the spark plug from the cap, and then you need to completely eliminate the possibility of fuel leakage. This can be done in two ways. Both by draining the tank and by putting a rubber sealed membrane under the caps and shutting off the fuel cock. If the instructions contain Others, turn the mower over only towards the handle. And before doing this, you should go through the hose intended for the exhaust of crankcase gases. This will help avoid oil leakage.

The knives in different models of lawn mowers can have a wide variety of configurations, however, the screw threads always loosen the same way. Counterclock-wise. And to prevent possible rotation of the shaft, you can place a block firmly rested in the ground under the knife. And, of course, in order not to instruct anything.When installing the knife back, it is important to try to remember or even sketch the position of the blades.

What to do next?

The removed knife must be cleaned of hardened herbal juices, as well as dirt adhering to it. The easiest way to do this is using a metal brush. The surface of the knife is then examined for any curvatures or bumps. If any, they are straightened with an ordinary hammer with slightly rounded edges of the striker. As a rule, the knife starts to reign from the edges of the curved section, gradually moving towards its center. It also does not hurt to check the throwing blades that are often unbendable from impacts, because if they bend at unequal angles, this will inevitably lead to a deterioration in the air flow, as a result of which the cut grass will simply not be mulched properly.

Next step. Launching the descent. First, they get rid of chipped chips, bringing out the edge of the blade at the same angle along the entire length of the cutting part. A small file or an electric sharpener equipped with a carborundum stone will help to bring the descent at the required angle. It is important to try to remove the metal from the knife as evenly as possible. But the angle grinder for THESE purposes is categorically not recommended, as it can significantly degrade the quality of the sharpened blade.

Sharpen the blade

For sharpening the blade, a flat emery bar is usually used, the grit of which ranges from 400 to 600 grit. Before you start sharpening the blade, it is recommended to soak the bar for ten to fifteen minutes in soapy water. This manipulation must be repeated periodically during the sharpening process. And the knife should be sharpened by pulling the bar in the direction from the center of the sharpened area to its edge. At the same time, it is desirable that the stone is in the same position. This will help maintain a constant angle. And, of course, the same amount of metal should ideally be grinded from the blades of the knife.!

Sharpened blades must also be “corrected”. To do this, you need a small piece of moisture-resistant sandpaper, the grain size of which has a range from 600 to 800 grit. The paper is moistened with water and rolled into a cylinder, the diameter of which reaches the order of 100.150 millimeters, and only after that the “straightening” is started. And before putting the blade back on the mower, it is important to make sure that the weight of its shoulders remains the same, otherwise (in case of imbalance) extremely unwanted vibration may occur. To check the balancing, first a smooth rod is clamped horizontally in a vice, and then a blade is put on it through the hole in the middle, and they also try to set it horizontally, observing its behavior. One shoulder should not overtighten the other. If the balance is not observed, then a little more metal is grinded from one of the shoulders. And only then can the sharpened knife be reinstalled on the mower.!

Remove the knife

The blades in different models of lawn mowers can have a wide variety of configurations, but the screw threads always loosen the same way. Counterclock-wise. And to prevent possible rotation of the shaft, you can place a block firmly rested in the ground under the knife. And, of course, in order not to instruct anything.When installing the knife back, it is important to try to remember or even sketch the position of the blades.

What to do next?

Next step. Launching the descent. First, they get rid of chipped chips, bringing out the edge of the blade at the same angle along the entire length of the cutting part. A small file or an electric sharpener equipped with a carborundum stone will help to bring the descent at the required angle. It is important to try to remove the metal from the knife as evenly as possible. But the angle grinder for THESE purposes is categorically not recommended, as it can significantly degrade the quality of the sharpened blade.

Why you need to sharpen your lawn mower knives?

Of course, it is quite possible to cut off excess lush green grass from your favorite lawn with a knife with blunt edges. But the grass, as a result of such manipulations, will begin to delaminate (this stratification will go mainly in the longitudinal direction), gradually turning into a sloppy fringe. And after a few days, it will dry out altogether and may even get sick for several weeks. That is why the cuts must always be neat and even. In this case, they take just a few hours and allow you to maintain a spectacular juicy green color of the lawn. And in order for them to be such, you need to periodically sharpen the knives of the used lawn mowers.!

How to sharpen a lawn mower knife yourself?

The knife blades of various lawn mowers are almost always made of high quality steel, however, despite this, they still need to be sharpened periodically. And the main thing. Do this so as not to degrade the quality of the metal. However, no Special tools and skills are required for this, and any summer resident will easily be able to cope with such a task!

Sharpen the blade

Sharpening process

The sharpening angle is approximately 30-50 °. The fastest and most convenient way to grind on electric emery. For manual work, you will need a flat file or an emery bar. If you are used to bringing everything to perfection, then fine sandpaper is also useful for finishing sanding. But this is optional. The movement of the bar or file should be made from the thickening to the sharp edge and from the fastening hole of the knife to its edge. In some models of lawn mowers, the knife has a complicated shape, which makes it difficult to use a grinding machine. In this case, all the main work will have to be done manually.

The main thing to remember is balancing. This is especially true when working on an electric grinding machine, since it is easier to sort through it with the removal of excess metal. In addition to files and machine tools, you can also use a drill or an angle grinder equipped with a special attachment with replaceable sandpaper wheels as a sharpening tool.

How to remove a knife

First, the lawn mowers have to be turned on their side. The cutting element is a bar with sharpening on both sides of the rotating shaft.

The knife is attached to the shaft either with one bolt with a counter washer, or with one lock nut, which can be unscrewed without any problems with an ordinary open-end wrench. But if the corners on the edges of the nut or bolt have already been deformed, then you can use a gas wrench.

How to sharpen knives in a lawn mower yourself

As a rule, even dull knives in a lawn mower do their job. But under a sharp knife, the cuts turn out to be even and neat, while the blunt rig tears the grass, so the view in the lawn is imperfect. The sharpening process itself is NOT particularly difficult. This can be done on an electric grinder or by hand. The main problem here is balancing the cutting rig. With a lawn mower shaft speed of almost 3000 rpm, even a slight imbalance leads to vibrations and increased bearing wear.

How to remove a knife
How to easily check the balance of the knife
Sharpening process
Re-balancing and re-installing the blade

How to easily check the balance of the knife

Balancing should be checked at least 2 times. Once before and after sharpening. First you need to fix in a vise some kind of flat metal plate. The edge of the plate must be in a horizontal position. A knife is laid flat across this rib.

If the balance is not disturbed, the equilibrium of the rig will be achieved when the rib is in the center of the knife hole. If, for balance, the knife had to be slightly displaced, then when sharpening, a little more metal should be removed from the side of the short overhang.

Re-balancing and re-installing the blade

At the end of sharpening, the balancing is checked again. If necessary, additional metal removal is carried out only on the side of the shorter overhang. The procedure is repeated until the knife is in equilibrium with the edge of the auxiliary plate passing exactly through the center of the hole of the rig.

The knife is installed in the reverse order of its removal. That is, the knife is set in place, the counter of the club is inserted and the bolt is screwed in.

If you have an electric sharpening machine at hand, then all the work, including the removal, sharpening and installation, will take no more than half an hour.

What you need to sharpen a knife at home?

To sharpen the cutting head you will need:

Two stools.
19 wrench (or another for the size of your nut).
File, 600-grit sandpaper and 5 x 10 cm block of wood.
Drill Grinding Disc.
Sharpener.

. Stages of grinding work. Why you shouldn’t sharpen the lawn mower knife yourself, and not Having experience?

Sharpening knives in a lawn mower requires certain skills, otherwise you can get an imbalance in the cutting attachment. However, if you still decide to try, then our sharpening tips will help you.

Most lawn mowers have a metal blade, and the quality of the cut depends on its sharpness. Over time, the knife becomes dull and needs sharpening. But sharpening it correctly is much more difficult than a kitchen.

1. Removing the knife

First, we fold the handle of the lawn mower, and put rubber gaskets on the neck of the gas tank and oil sump (or you can cover it with cellophane) so that when you turn the device over, the fuels and lubricants DO NOT flow to the floor. Turning the lawn mower over and place it on two stools or on one side. We take a key 19 or the second size, and unscrew the nut on the knife. If the nut DOES NOT fit, then sprinkle some WD-40 or plain water on it and wait 5 minutes. The nut should loosen.

3. Rough sharpening

We clean the nozzle from grass and dirt and clamp it in a vice. Then, using a flat or triangular file at an angle of 30. 50º, we begin to sharpen the knife with translational movements from the base (from the fixing hole) to the edges, and then from top to bottom. Try to count the “friction” from top to bottom in order to make the same amount on the other side of the knife and remove the same amount of metal. So after sharpening, there will definitely not be an imbalance of the nozzle. The Vira 820003 file with three edges 20 cm long is suitable for this job.

Some people prefer to additionally repulse the knife on the anvil before such sharpening, as is done with a conventional hand scythe, but we noticed that because of this, the metal on strongly bent knives can crack and the nozzle has to be thrown away.

Coarse sharpening can also be done with a conventional sharpener on a motor or a grinding attachment on a drill. With the proper skills, sharpening can be done much faster than with a file, but there is a possibility of “regrinding” one of the edges by removing more metal. If you sharpen knives, then there will be no particular difficulty. The main thing is to observe the correct angle. Grinding attachments are suitable for both drill and screwdriver.

Sources:

http://stroy-podskazka.ru/gazonokosilki/zatochit-nozh/
http://pikabu.ru/story/kak_samomu_zatochit_nozh_gazonokosilki_7121347
http://www.Asienda.ru/sadovaya-tehnika/kak-samostoyatelno-zatochit-nozh-gazonokosilki/
http://b-online.ru/instrumenty-i-tehnika/kak-samostoyatelno-zatochit-nozhi-v-gazonokosilke.html
http://ichip.ru/sovety/remont/pochemu-ne-stoit-tochit-nozh-gazonokosilki-samostoyatelno-ne-imeya-opyta-674612