Description of sharpening knives for woodworking machines. How to sharpen jointing knives with your own hands? Sharpening angle of jointing knives

Sharpening knives for woodworking machines is a mandatory process that can be done with your own hands using special tools. Sharpening is the restoration of the previous cutting capabilities of hacksaws, scissor shafts, planers, jointers and other devices for wood processing.

To sharpen the blade shaft of a planer or jointer, you will need the appropriate device;
The sharpening work is done by hand;
Craftsmen learned to assemble sharpening devices;
When restoring hacksaws, jointing devices, sharpening knife shafts, be sure to adhere to several recommendations and strictly follow the technology;
If the teeth of hacksaws and knife shafts are sharpened incorrectly, the quality of wood processing with tools will significantly deteriorate;
Sharpening stones are a good alternative for a sharpening machine. But if you have the opportunity to assemble it yourself or purchase sharpening machine, be sure to use it.

Preparatory activities

If you need to sharpen knives for a woodworking machine, you should start with the required preparation steps. It is not so important what parameters the knife shaft or cutting sheets of hacksaws have 13 mm, 20 mm or all 200 mm, they will definitely need sharpening.

Some people prefer to send dull shafts to special workshops, where they can easily restore the previous sharpness of a 200 mm knife or small cutter lathe. But both ordering sharpening and buying new knife shafts is a financially expensive matter.

Preparation for sharpening begins with familiarization with available means surface restoration cutting tools and some recommendations.

To keep jointers, planers, and hacksaws in working order, assemble or purchase an appropriate sharpening device.
The simplest one budget option is a whetstone. But the quality of processing directly depends on your skills in working with stone. If there are none, achieve the required level sharpening is extremely difficult. Plus, stones are not able to cope with all types of cutting tools that are equipped with modern woodworking machines.
Choose a machine that can sharpen at low speeds, as this has a positive effect on the quality of the finish.
The recommended equipment for a sharpening machine is a water cooling system.
Carefully study the equipment of household woodworking machines. Often there is already a sharpening stone, which is optimally suited for processing the knives used.
If the stone is not included in the package, it will have to be purchased separately, leveled with a special device, and smoothed. This is the only way you can sharpen the knife shafts of jointing machines efficiently.
The machines have a function for setting the angle of inclination, which is adjusted with a special screw. By turning the screw and changing the position of the sharpening device, you can correctly fix the tool relative to the stone.
Next preparatory stage- This is a holder in which the knife shaft is installed.
If you are a beginner, it is not recommended to start your first job with 200 mm knives. Start literally with 13-15 mm, and gradually you will learn to process 200 mm and even 2 mm. To do this you need to accumulate certain experience.
The length of the knife is not a fundamental parameter, since the knife in the holder can move to the distance you require.
Make sure to hold the shaft firmly in place. Otherwise, you will get a significant distortion, due to which the quality of woodworking will suffer.
Study the operating manual of the purchased sharpening machine in detail. If this is a DIY tool, you will have to rely on drawings and available information on the Internet about a specific sharpening device project.

Sharpening

In order for the sharpening of knives for a woodworking machine to give a positive result, you can resume working with the equipment at the same level of quality, you need to adhere to a few fairly simple rules.

The sharpener holder can move left and right relative to the stone to sharpen knives.
Do not allow the blade to end up over the edge.
Immediately fix the holder at a distance of 12 mm from the edge of the grinding wheel.
When sharpening knives of 200 mm or smaller variations, make sure that the water cooling function is activated on the machine.
The cooling system requires constant monitoring. The tank usually has a small volume, so water needs to be added periodically. If it runs out and the sharpening process continues without cooling, you risk ruining a rather expensive knife.
As the knives are processed, water from the cooling system may accumulate on the floor. Since sharpening machines are electrical devices, ensure that water is drained away from your feet and wear rubber shoes. In any case, standing in a puddle of water while working with an electric machine is always dangerous. Follow safety regulations.
Keep the whetstone clean. It gets dirty quite quickly with active use.
The grinding wheels of machines are cleaned using a special device. The machines should be equipped with this cleaning bar, but if it is not included in the set, then you will have to purchase it separately.
Each subsequent sharpening, according to the operating rules, is performed only on the condition that the stone is cleaned. Therefore, after each sharpening, arm yourself with a cleaning bar and treat the machine with it.
On average, sharpening using a special machine takes about 10-20 minutes. It all depends on the type and size of the tool, which became dull as a result of woodworking operations.
After sharpening the tools of woodworking machines, do not rush to return them to their place and continue working. After processing on the machine, the tool needs to be fine-tuned.
Finishing consists of applying a special paste to the surface of the cutting element. Proceed according to the instructions provided by the manufacturer of the finishing paste on the packaging. Different pastes may differ slightly in application methods.

If you did everything correctly, then the knife should be perfectly smooth, sharply sharpened, and free of any irregularities or burrs. Don't worry when the result doesn't meet your expectations the first time. This takes some time and a little experience. That’s why you should start with simple and inexpensive knives that you don’t mind ruining.

Owners of planing machines and electric planers periodically face the problem of sharpening cutting edges. A well-sharpened tool will ensure clean wood processing even at non-ideal angles and speeds. The easiest way is to sharpen knives and knife heads with your own hands using specialized equipment.

Knife sharpening is necessary

Planing knives require timely care because:

blunt surfaces process wood poorly;
when processing soft rocks with dull knives, the surface becomes covered with lint and unevenness;
worn edges crumble;
During planing with blunt edges, the engine and power units are overloaded.

Attempts to sharpen blades with your own hands using diamond stones, as a rule, give short-term results. Due to poor quality of editing, the blades have to be sharpened soon. Therefore, professional carpenters use only mechanical sharpening.

Types and designs of machines

The machines on the market are distinguished by the knife feeding mechanism:

manually;
automatically.

The machine for sharpening planing knives with manual feed consists of:

grounds;
abrasive stone;
carriages for fixing the knife.

During processing, the cutter moves forward with the help of a handle. Transverse movement of the cutter is ensured by a flywheel.

Automatic machines differ in size and range of options. Mechanisms for industrial use are installed on a powerful cast-iron frame. The carriage is equipped with a support. You can set the speed of movement of the blade and the thickness of the metal layer being removed. Industrial machines allow you to simultaneously sharpen several planer blades without changing settings.

	Corvette K-470	WTG-163	GA-630	GA-850	ZX-1000
Maximum length of knives, mm	630	630	640	850	1000
Abrasive disc diameter, mm	100	150	125	125
Sharpening angle, degrees	35…55	up to 30	35…45	35…45	Up to 30
Engine power, W	550	550	850	850	1500
Dimensions, cm	90 x 48 x 42	100 x 60 x 65	100 x 54 x 120	120 x 54 x 120	190 x 56 x 150
Weight, kg	75	60	112	125	250
Add. intelligence	Equipped with an asynchronous motor, wet sharpening possible	Processes cutters, circular saws	Wet sharpening possible	Can sharpen up to 4 blades, wet method	Wet method available grinding disc cup type, controlled via remote control

Table 1. Characteristics of some models of machines for sharpening planing knives

Compact automatic machines for home and small workshops are designed to process one cutter in one go. They also provide adjustable speed and automatic feeding tool.

Before starting work on any sharpening equipment, you should make sure that the frame is securely fastened. Machine vibration impairs the quality of sharpening and can lead to injury to the operator.

Basic rules for using manual feed equipment

Such machines are used for one-time work and for sharpening small batches of blades with your own hands, since the processing process is quite lengthy.

Before starting work, you need to make sure that the grinding surface is clean, without stains or streaks.
The movement of the carriage should be smooth, without jerks or jolts. It is forbidden to stop it when the cutter approaches the sharpener.
The faster the carriage moves, the lower the quality of sharpening. The optimal speed of movement is 5 - 6 m/minute.
For correct sharpening The amplitude of movement of the carriage is important. During a pass in each direction, it should move 10 - 13 cm further than the end of the knife. This ensures optimal contact between the cutter and the sharpener, which must be broken before moving in the opposite direction.

Basic rules for working on automatic machines

Planing knives can be sharpened dry or wet. In the second case, the blade is constantly washed with a stream of water. The wet method is gentler on the blade and more effective;
Before processing begins, it is necessary to set the following parameters: sharpening angle, amplitude of carriage movement. The amplitude should be 15 cm greater than the length of the knife;
The blades are carefully fixed in the mobile carriage with your own hands.

Homemade machine for sharpening planing knives

The design, made at home with your own hands, allows you to quickly and efficiently sharpen knives to one set angle. This will change the factory angle, so all blades will need to be re-sharpened. The quality of planing will not deteriorate, but may even improve.

To make a device for sharpening straight blades of planing, jointing and thicknessing machines with your own hands, you need:

metal corner No. 50;
pipe round section with a diameter of no more than 50 mm;
electric motor from a washing machine;
powerful spring;
bolt with nut;
plastic handle (knob);
Bulgarian;
welding machine.

Making a machine with your own hands.

Cut a corner about 50 cm long.
We bend two pieces of pipe so that we get a stable stand for the corner, and weld the legs. The corner should be positioned vertically towards the master.
At the left end, behind the corner, we attach an electric motor. It is placed on two points: a rigid axis and a powerful spring; The spring is tightened and released using the adjusting screw, moving the motor closer or further from the angle guide.
We put an abrasive wheel on the electric motor shaft.
The engine is started by a switch located on the frame in a convenient location.
We feed the tool using homemade vise from a piece of pipe 25 cm long, a pressure plate, a bolt with a nut and a knob. We clamp the knife in a vice and move it along the guide, holding it by the knob.

Special machines are used to sharpen knives of planer and jointer types. The work can be done with your own hands; the machine can be assembled independently if necessary. Sharpening is carried out according to certain rules, several options are used. You need to be careful and not violate the technology.

Otherwise, knives for planers, jointers and planers will be poorly processed and will not be able to fully perform their functions. Except special equipment, you can use sharpening stones for sharpening, but a small sharpening machine that has a cooler is best suited for the job.

Preparatory work

Anyone who has a plane or jointer faces the problem of sharpening knives. It is expensive to constantly buy new ones, especially since knives can be easily sharpened with your own hands using special machines or sharpening stones. If the jointer is used frequently, like other woodworking equipment, then it will be inconvenient to constantly send knives to the workshop for sharpening. It is better to assemble the machine yourself. To ensure that the jointer is always in working order, it is recommended to sharpen it at home. The easiest way to do this is with a regular sharpener. You only need to take a sharpener with low speed, its quality should be high. Water cooling must be available.

You can also use a sharpening stone, but it must first be leveled with a special device. Usually it comes complete with a small sharpening machine, so there is no need to additionally look for such devices. After the editing is completed, it is necessary to smooth the stone; a block is used for this. Sharpening a jointer knife without this step will be problematic.

What to do next? You need to set the angle of inclination. A special screw will allow you to correctly secure the blade relative to the position of the sharpening stone. Using this screw, you can subsequently set any angle of inclination of the knife. Next, take the holder that comes with the machine. A jointing knife is installed in it. Experts advise starting sharpening knives with a width of at least 13 mm. The length is not critical; if necessary, the knife holder can be moved to any position.

The knife must be securely fastened in the holder, otherwise sharpening will be carried out skewed, and this will worsen the quality of the jointer. How to properly secure a knife in a holder? While holding the blade in the desired position, tighten the clamping screws until they stop. To control the sharpening angle, you must use a marker; it marks the sharpened chamfer of the knife. It is with this simple method that you can easily monitor the quality and progress of work. The sharpening will be correct if the corner of the knife touches the stone. The stone must be rotated manually to determine if further adjustment is necessary.

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Sharpening process and operating rules

The holder moves to the right and left, movements are made relative to the sharpening stone. The blade should not be allowed to go beyond the edge. It is best to immediately install the holder 12 mm from the edge of the working circle. If sharpening is carried out, water cooling must be supplied. You will have to add water to the tank, you need to make sure that it does not run out. It is necessary to ensure that water does not accumulate on the floor near your feet. This is done for security reasons.

When performing work, you must ensure that the stone remains clean at all times, as it gets dirty quite quickly. A special whetstone is used for cleaning; it is recommended to carry out this procedure frequently, since only clean stones can be used for sharpening. The choice of stone itself depends on what kind of knives are used. Today, manufacturers produce jointing knives from soft or hard tool steel, so working conditions will vary.

Sharpening takes approximately 20 minutes, then fine-tuning is done. A special paste is used for this. After polishing, there should be no burrs left on the surface, otherwise the jointing knife will not be ready for use. The test is simple to carry out; a finished knife with excellent sharpening should easily and evenly cut a sheet of paper while hanging, leaving a neat cut.

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How to make a machine with your own hands?

To sharpen a jointer knife, you need to use special sharpening machines. This is especially important when jointers, planers and other woodworking equipment are used frequently. The sharpening machine is compact in size and can be installed even in a garage or small shed. summer cottage. Before starting assembly, you must prepare the appropriate tools that will be used during assembly of the sharpening machine:

the table on which the work will be carried out;
faceplate;
vacuum cleaner;
engine;
casing for the machine.

You need to start assembling the machine by finding a suitable faceplate. It is one of the most important parts for a sharpening machine. All jointer knives are quite narrow, so they can only be sharpened using a suitable type of faceplate. Then the sharpening work will be high-quality, safe, and fast. The faceplate takes up the bulk of the cost of all equipment. It’s more profitable to make a sharpening machine yourself; you won’t need expensive parts for it. Manufacturing will be quite justified if you have to frequently carry out woodworking.

You need to buy new faceplates; it is recommended to take American or German-made elements. They have the most high quality, and the cost fluctuates at 25,000 rubles. Next, you need to select a motor for the future sharpening machine, it is best to take a 1-1.5 kW motor, you can even use a used element. Motors from old ones are excellent for the machine. washing machines, but first you need to make sure the engine is working.

The motor is mounted under the tabletop, the faceplate is mounted to the moving part.

It is imperative to provide a button to turn the machine on/off. It should be located within reach of your hand. The faceplate is covered on top with a casing, which is made in the form of a square. One corner of the casing must be cut off, since sharpening will be done on this side jointing knives with your own hands. A hole is made in the lower part of the tabletop; it will be intended for a vacuum cleaner pipe, with the help of which all contaminants that arise during sharpening will be removed. In addition to sharpening jointing knives, a similar machine can be used for other work, for example, for processing ax blades, saws and other tools used in the garden.

Jointer knives can be sharpened various methods. Special sharpening stones are suitable for this. However, you can assemble a compact sharpening machine yourself. It will be used to sharpen a variety of tools including saws and axes.

Sharpening knives with your own hands is a painstaking procedure due to the hardness of the products being cut, the frequency of use of the tool, and the thickness of the cutting edge.

The need for surgery arises regardless of the quality of the blade. How to do this at home? Let's try to figure it out.

Why do you need to sharpen knives? Is it possible to do it yourself?

Any housewife knows that sharpening knives is very important: working with a blunt tool is not only difficult, but also dangerous. The process slows down significantly and requires serious effort, as a result of which the muscles of the hand quickly tire. In addition, the blade is capable of jumping off at the most crucial moment and causing injury.

You can take the product to a workshop, where they will quickly sharpen it for you. But where is the guarantee that the work will be done correctly and the blade will not be damaged? In addition, this service is far from free and requires significant time. And sometimes this is really lacking when preparing for a celebration, for example, in order to prepare dinner on time. If you have a knife sharpening machine at home, you won’t have to go anywhere. The quality will depend only on your skills, the tools and devices used.

Why do knives lose their sharpness?

No matter how high-quality the steel of the blade is, sooner or later any knife will become dull. Why is this happening?

In the process of interacting with the material being cut, the cutting edge loses microscopic fragments of steel. At the same time, its shape changes, and the blade loses its sharpness.

In addition, such a process causes deformation of the blade. When cutting food, we apply force, which almost always deviates in one direction or another. Of course, if this were the only reason, then there would be no need to sharpen knives so often. Another detail is important, the influence of which on the severity is much more significant.

It is almost impossible to maintain the direction in accordance with the plane of the blade. As a result of this, the thinned edge is slightly curved, and it becomes much more difficult for the knife to overcome the resistance of the material being cut. This process occurs especially quickly if the blade is made of low-quality steel.

There is a point of view that hot water can dull the blade. To some extent this is true. During contact with steel, salts dissolved in water react with the metal, causing a change in its properties far beyond better side. But such an impact is not decisive and does not have serious significance.

Knives prices

Basic principles of knife sharpening

There are several sharpening methods. The choice depends on the time you have, the purpose of the knife, and the tools and accessories available.

The general principles are:

initial processing is carried out with coarse abrasive;
subsequent grinding is performed with fine-grained material;
For final finishing, leather or various pastes of varying degrees of abrasiveness are used.

To make work easier, you can use purchased or homemade device for sharpening knives.

At what angle should knives be sharpened?

The sharpening angle mainly depends on their purpose and, accordingly, the quality of the material from which they are made. What sharpening angle should be used for knives designed for various needs is indicated in the table:

In some cases, the angle can be reduced to 15º if the tool is used for special purpose, for example, slicing fresh baked goods.

Materials used

Do-it-yourself manual knife sharpeners can be made using bars of varying degrees of abrasiveness. The latter are conventionally divided into the following groups:

the roughest, which is not used in this case (from 200 to 250);
rough - to form the profile of the cutting blade of the blade. If no visible defects are detected, such stones are not used (from 300 to 350);
medium - like those listed above, are used infrequently, mainly for rough adjustment of the blade profile (from 400 to 500);
small - the main type of stones used for sharpening knives (from 600 to 700);
very small - used to bring an already sharpened blade to a mirror-like appearance.

These stones are made from various materials. A do-it-yourself hand sharpener can be made from natural and artificial bars. Natural - from natural stone(corundum, slate, etc.). Artificial - made of synthetic materials or diamond. Moreover, natural ones wear out more and are not very grainy.

Prices for abrasive stones

abrasive stones

Before use, it is preferable to moisten the bars with water or soap solution.

Please note: You should use a block that has a length significantly greater than the blade being sharpened.

In addition to abrasive bars, the following can be used:

homemade devices that serve as their holder;
knife sharpening machines;
mechanical sharpeners;
musats are devices for fine-tuning a sharpened blade and are several metal disks nested one inside the other.

This list may be expanded. We have provided only the main tools used.

Manual sharpening rules

In order to sharpen the cutting edge correctly, you must follow the specified sequence of actions:

at the initial stage we carry out the work with a medium or coarse grain block, depending on the condition of the blade; it would be more correct to secure the block from displacement;
determine the required sharpening angle; on each side of the blade, its size is half of the total; the main thing is to keep this angle unchanged;
movements should not be jerky; no significant effort should be made;
The initial move is made from yourself, the edge should pass along the entire length of the block. Please note: when contacting the block, the blade must be directed at a right angle to the direction of movement;
at the point where the blade is rounded, it should be rotated to maintain the desired angle;
when completing the movement, the blade should not leave the block, because this may cause it to become dull or damage the side surface;
then we move in the opposite direction;
We continue the sequence of these operations until a thin bending strip appears on the blade; when checking its presence, you cannot run your finger along the blade, because you can easily get hurt on the sharp edges; if the knife is sharpened correctly, this edge should be the same width throughout the entire blade;
turn the tool over and repeat the operations until a similar result;
we take a smaller whetstone and sharpen it further, but we no longer move towards ourselves - only in the forward direction; since the grain size of the bar is smaller, the size of the burr along the edge is also reduced;
We process the reverse side in the same way;
we repeat these operations on both sides on an even smaller stone; if the burr still remains, remove it with the finest-grained stone; We remind you that movements are still carried out in one direction - away from you; We reduce the clamping force towards the end of the operation.

Sharpening is finished. It is also possible to finalize the blade on a leather strip. An old belt will do just fine.

How to make a homemade device

It is quite possible to make a machine for sharpening knives at home yourself. Let's look at some of them.

Option No. 1: the blade is fixed on a stationary platform

This device helps sharpen the blade by ensuring the required edge angle. Below is a tool for sharpening knives with your own hands. Drawings and drawings.

A homemade knife sharpener can be made in the same way as shown in the figure.

The principle of operation and design are clear. The manufacturing sequence is as follows:

the base can be chipboard or steel plate; it is marked and drilled out for the stand and blade holder;
on the side of the base opposite to the mounting of the rack, a hole is drilled for an M8 bolt to attach the knife clamp;
two M10 studs are made: one for the stand, the second for the holder for the abrasive stone;
a bracket is made for attaching the holder stud to the stand (by drilling and bending a steel or aluminum plate;
the brackets for the sharpening stone holder itself are made from two corners;
a clamp for the blade is made;
The structure is assembled in the form shown in the figure.

This device has one drawback: it is not able to provide a right angle between the movement being performed and the blade of the blade at the point where it is rounded.

Option No. 2: with a movable platform and a magnetic holder

This problem is solved using the following construction. It is performed in a similar way, but a magnetic holder is used to attach the knife. Thus, it is possible to move magnetic holder with a blade installed in it and rotated to the required angle. This knife sharpening device is equipped with a plate at the base or can be attached to the table, as shown in the photo.

It will greatly facilitate the process of sharpening knives.

How to sharpen jointer knives with your own hands

Any man who has such equipment in his home has had to deal with sharpening his knives. To accomplish this, special devices and abrasives are used. Certainly, if the machine is frequently used, it is advisable to have the necessary device at home. Let's look at how to make it yourself.

How to make a machine for sharpening a jointer knife yourself (step-by-step instructions)

To make a sharpening machine with your own hands to sharpen this knife, you will need to select the necessary parts:

plan-washer;
bed;
electric motor;
vacuum cleaner;
fencing.

Manufacturing is carried out as follows:

The electric motor is mounted directly under the frame; You should definitely take care of equipping it with “stop” and “start” control buttons;
A plan washer is installed on the output shaft, which is closed by a square guard with a cut-out groove;
A hole is made on the bottom plane of the table the size of a vacuum cleaner sleeve, the latter is designed to remove dust generated during sharpening.

What you need to know

The electric motor may not necessarily be secured under the base of the washer. It is possible to use a belt drive, but this will complicate the design.

Using this machine you can also sharpen axes and saws.

Ice screw sharpening

The sharpness of the ice drill allows the fisherman not to make efforts to drill holes in the ice during winter fishing. But for this it is necessary to sharpen the knives of this device.

Sharpening methods are quite varied. One of them is to use a self-made tool.

How to make a machine for an ice drill with your own hands

Two steel strips with a thickness of 4 mm and dimensions of 60x200 mm are required. You can use automotive spring steel, but it is difficult to bend. Therefore, it is advisable to choose a different material.

Work progress

First, the frame of the device is completed. The strips are bent so that the knife chamfers, which are pressed against the edges of the rounding, are at the same level and parallel to each other.

Then a clamp for the items being sharpened is made from another strip.

Holes are made in the plate and body. The pressure plate is attached to the body with a bolt connection, clamping the knives. It is checked how tightly they adhere to the surface of the end part of the abrasive wheel.

If the angle of the knives is incorrect, the device should be modified by bending the arc of the body. After making sure of the correct placement, we disassemble the device and weld the stiffeners to the body arch.

It is better to place the emery wheel horizontally, this ensures water retention on its surface. Cooling the knives with water will prevent the steel from overheating when sharpening.

Disadvantage of the device

The disadvantage of this machine is that it cannot be used if the chamfers on the knives are located at different angles. Since different manufacturers of ice augers have different designs, a universal device can be of great help.

Making a universal device for sharpening an ice drill

It overcomes the above obstacle. The knives are adjusted with screws, and there is also the possibility of reliable fixation in different positions relative to the abrasive wheel.

This device will require door hinge with a minimum stroke and an M8 screw with a nut. Holes with a diameter of up to 7 mm are drilled on the shelves of the canopy to secure the knives.

A clamping strip with a groove for a clamping screw is made from a metal strip 3 mm thick. They are welded to the canopy slats.

Additionally, you can drill a few more holes for greater versatility of the device, so that non-standard knives can be sharpened.

How to sharpen planer knives

This equipment also widely used at home. It allows you to bring untreated lumber to the required condition. Naturally, knives for woodworking machines need to be sharpened periodically.

To make the necessary devices, you will need different materials: steel, wood, etc.

The clamp itself is made of wood. Grooves are made on it at 45º. Knives are edited using a belt grinder or an abrasive stone.

It is important to maintain the exact angle - this ensures correct processing.

Sharpening with an electric sharpener

Equipment equipped with an electric drive greatly facilitates the work and reduces the duration of the process. But similar devices require precision movements and work experience.

A do-it-yourself electric knife sharpener is made with an installed tool rest to support the work being sharpened, with the ability to adjust the gap between it and the abrasive wheel.

Please note: A protective shield must be equipped to protect the eyes from dust.

Processing is performed with the front surface of the circle. Can't use it side faces. The knife is placed on the tool rest with the cutting edge up and held along the axis of the product. The movement is carried out evenly, smoothly, without strong pressure.

After sharpening on both sides, the final finishing of the cutting edge should be done with fine-grained stones until the bend of the edge of the blade completely disappears.

Of course, you can make a knife yourself, but specialized sharpeners are offered for sale that are absolutely safe and allow you to freely sharpen knives for any purpose.

To do this, after turning on the device, the knife is inserted into the desired slot and evenly drawn along it until the edge is completely sharpened.

These devices provide excellent sharpening quality. Their disadvantage is the inability to adjust the angle of the cutting edge.

Useful video: ideas for sharpening knives

Whatever equipment and tools you use, the main thing is to maintain safety when performing this operation. Remember that it is much easier to cut yourself with a dull knife than with a sharp one. Therefore, let the knives in your home always be sharpened.

To sharpen such knives, Tormek has the SVH-320 attachment. It consists of an independent support and mandrel.

The support is installed on the machine on two screw stands, each of which has an adjusting nut. The nuts have digital scales for precise vertical adjustment of the caliper position. An aluminum guide is installed on screw racks on two axes. Its design is such that the mandrel with the knife clamped in it makes strictly horizontal working movements. The angle of inclination of the guide, and therefore the sharpening angle of the knives, is adjusted using a spring-loaded adjusting screw.

There is a steel rod on the guide, on which there are two stop bushings. They serve to limit the movement of the mandrel along the guide. The bushings are placed in the required position on the rod and locked on it using screws in the body of the bushings. Loosen and tighten these screws using the small hex wrench included with the SVH-320.

The knife to be sharpened is clamped into a mandrel with a U-shaped profile and five screws. You can clamp knives up to 300 mm in length and at least 13 mm in width. I saw somewhere in a Tormek advertisement how knives with a length of 450-500 millimeters are sharpened using the SVH-320. But it seems to me that this is more a way out than the norm. At the top of the mandrel, in the center, there is a pin, which during sharpening rests against the stop sleeves.

Well, it's time to get down to business. I fill the machine with water up to normal.

Sharpening this type of knife is quite a responsible undertaking. It is worth using the TT-50 device. The working surface of the abrasive wheel will become smooth and clean. The rotation of the circle will be smooth, without beating.

The grooves that form after using TT-50 can be used for good. In this state, the abrasive wheel removes metal fairly quickly. And this is true when you sharpen knives with small potholes from knots, and even worse, nails.

But in addition to the speed of sharpening, it is also necessary to achieve the cleanliness of the sharpening of the wheel.

To do this, you still have to use a double-sided stone SP-650. I just lightly smooth them work surface circle. During the sharpening process, the grooves will smooth out quite quickly, but I will sharpen the first knife much faster than the others.

Here are our experimental knives. Two knives from a Makita planer, two knives from an electric planer. Knives from Makita are sharpened only on one side, knives from an electric planer are sharpened on both sides.

I put a long knife from a thickness planer into the SVH-320 mandrel without any gaps or distortions. I tighten the central screw, then the adjacent ones, and then the outer screws.

I install the SVH-320 caliper on the machine, as shown in the photo.

I put the mandrel on the caliper guide. To do this, you may have to raise the caliper using the adjusting nuts.

Adjusting the sharpening angle with the SVH-320 can be done using a permanent black marker. The Tormek manual contains only this method, and I have already described it in the topic about sharpening hatchets.

I sometimes set the sharpening angle using the WM-200 protractor, as shown in the photo. This method is good when the knives are constantly being serviced by me, and I know exactly at what angle I sharpened them last time. Using the nuts on the caliper screw posts and the spring-loaded screw, we set the required sharpening angle.

There are only two settings here, but they affect each other. At first, people have difficulties with fine tuning, but with the advent of skill and experience, the difficulties disappear.

After the sharpening angle is set, we fix the SVH-320 caliper by tightening the locking screws on the Tormek vertical guides. Then you need to make sure that the knife handle and the working surface of the circle fit tightly to each other and without distortions. The Swedes suggest doing this using two strips of tissue paper. I do this “for the light of day”, i.e. I install it on the opposite side of the machine table lamp and look at the light gap between the stone and the knife's RC.

If everything is in order, we proceed to the “rough” sharpening of the knife. The longitudinal movements of the mandrel with the knife must be uniform. I apply light but even pressure on the stone. Otherwise, the knife's surface will turn out to be wavy.

Having achieved a distinct burr along the entire length of the wheel, I move on to finishing sharpening. I take a double-sided stone SP-650 and smooth the working surface of the abrasive stone.

I do a “finish” sharpening. A few working passes are enough.

I get something like this:

Electric planer knives are sharpened in the same way. To secure them in the frame, three screws are enough.

Both sides of a plane knife are sharpened. Therefore, to sharpen two knives you will need 4 cycles of “rough-to-finish” sharpening.

The photo shows that I do not use stop bushings. I think they will be really useful when you have to sharpen a batch of similar knives. If you need to sharpen 2-6 knives, then, in my opinion, visual control is enough.

I get this RC:

I’m starting to fine-tune the RK knives on a “leather” circle. I pre-coat the circle with Tormek PA-70 finishing paste.

I do the fine-tuning of the RK on the opposite side of the knife.

I similarly adjust the RK of knives from a thickness planer.

Finishing with reverse side. It is important to achieve removal of the burr along the entire length of the RC.

I get this result. Well-sharpened knives confidently cut a sheet of newspaper. I am sure that the quality of the surface of wood planed with such knives will please the carpenter or cabinetmaker.

One of the disadvantages of the SVH-320 is water flowing down both sides of the sharpener. The fact is that when you sharpen long knives, water flows down the knife being sharpened, now to the left, now to the right. Water gets on the leather circle, and then on the drive wheel. The rubber surface of the drive wheel gets wet and the machine begins to slip.

I have learned to work around these problems. To prevent water from getting on my workbench, I first place a rubber car mat with beads on it. All spilled water will be collected in it. And to prevent water from getting on the drive wheel, I place a backing about 1 cm thick under the legs of the machine on the side of the leather wheel. In this case, the water no longer drips onto the leather wheel, but flows down the knife being sharpened back onto the abrasive wheel.

I'm mostly happy with this Tormek development. I have not yet come across anything that could be used to sharpen such knives better. Maybe over time someone will convince me.