Saw blade sharpening for wood

Design features of band saws

  • , which has a hardness of 40 to 46 HRC.
  • . When cutting cheap wood, this moment is not so noticeable, but when cutting valuable and exotic types of wood, it is critically important.
  • . At the same time, the band tool works quickly and creates a high quality cut.
  • .

note!
In order for the machine to work always stably and efficiently, you should approach its maintenance with the utmost responsibility.
Sharpening and setting of band saws on wood must be carried out in a timely manner and competently.

Saw band design

Band saw machine

The band saw belongs to the category of cutting tools and is an integral part of specialized equipment for wood processing. It is a closed belt, on the outer edge of which there are teeth.

For manufacturing, special grades of steel are used. 9HF, B2F or C75. During the production process, the teeth are treated with high-frequency currents. This increases their hardness. It is this fact that affects the spreading of the cutting edges and maintainability. Often, several types of steel are used in the manufacture. The main belt is made of spring and the cutting part is made of steel with a large m of tungsten or cobalt.

Features of the use of band saws for wood:

  • wood requirements. The harder it is, the faster the blade will dull;
  • installation conditions. The tension indicator must be observed. If it is less than required, sagging will occur. With strong tension, the probability of blade breakage will increase;
  • periodic sharpening. This will require a special machine.

The implementation of the last point will increase the service life of the belt structure. However, sharpening on your own is problematic. you need to choose the correct layout, observe the angle of processing of the blades.

When buying a used saw, you need to pay attention to the presence of repair welds on the blade. They indicate frequent tool breakage.

Saw material

Band saws are made from different materials. depending on what material they are intended for cutting.

Saws for wood are made of tool alloy steel with a hardness of 40-45 HRC. Domestic manufacturers use steel 9HF, B2F (for band saws for metal), etc., foreign ones use their own steels (C75, Uddeholm UHB 15, etc.). When the teeth of such saws are hardened by high-frequency currents, they can acquire hardness up to 64 HRC and higher.

Hardened Band Saw Teeth

Saws for cutting carbon steels and non-ferrous metals of small thickness are also made of tool steel with mandatory hardening of the teeth by high-frequency currents. However, more often for cutting metal, bimetallic saws are used, in which the blade is made of spring steel, and the strip on which the teeth are cut is made of high-speed steel with high tungsten and cobalt. After hardening, it acquires hardness up to 65-69 HRC. High speed steel is electronically welded to the base of the saw.

Making a bimetallic band saw

Bimetallic saws are capable of cutting thick metal from tool, stainless, heat-resistant and other steels, titanium alloys and other metals.

Bimetal Band Saw

Teeth with higher wear resistance are obtained by hardfacing them with stellite (an alloy based on chromium and cobalt with additions of tungsten and / or molybdenum) or by soldering hard alloy plates to them. Such saws are superior in their cutting abilities to bimetallic ones. They are used to cut fiberglass, car tires, cables, reinforced plastics, high temperature alloys, graphite, aerated concrete, bricks and other materials that are difficult to cut.

Carbide Tooth Band Saw

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How to sharpen a band saw correctly

Immediately, we note that if there is no experience and skills in performing such work, it is better to entrust saw sharpening to professionals. Violation of the geometry of the teeth of the cutting edge, the appearance of dross on the metal or incorrect setting will significantly reduce the life of the blade.

Having decided to sharpen the band saw with your own hands, it will be useful to first familiarize yourself with the key definitions, the knowledge of which may be required in the process. So, for the correct formation of the cutting edge you will need:

  • setting. deviation of the teeth from the plane of the main saw blade;
  • the height of the teeth is the distance between the top point and the base;
  • pitch. the distance between the teeth, usually varies between 19-25 mm.
  • sharpening angle. depends on the intended purpose of the tool; for example, the recommended sharpening angle of carpentry saws is 35 °, indexing. 18-22, intended for sawing a bar. no more than 15 °.

The sharpening angle is determined by the manufacturer, therefore, when self-dressing the saw, it is recommended to adhere to these parameters.

Here are detailed instructions that will help you sharpen a closed saw correctly without resorting to the services of specialists.

Wiring

Setting band saws into wood is the first step in restoring the profile of the cutting edge. During operation, the location of the teeth can change, so until the correct geometry is achieved, it makes no sense to sharpen the saw part.

There are 3 ways to open the saw:

  • classic. the teeth alternately deviate to the right and left sides;
  • stripper. the 1st and 2nd teeth deviate in different directions, the third remains even. This profile is created for sawing hard materials;
  • wavy. the most difficult option, resembling a wave in shape. Here, each tooth is individually shaped, and this type of setting is usually performed only in specialized workshops.

It should be noted that when wiring, not the whole tooth is bent around, but about 2/3 of the upper part. The procedure is performed on a special band saw setter. The cost of such a tool is quite high, so they buy it if you need to adjust several tools. Its presence can become the basis of a sharpening business.

Of course, the first time you can do everything correctly, even on an adjustable machine, it may not work, so at least the geometry of the profile should remain the same as before the start of work.

What you need to know about sharpening angles

The geometry of the teeth of band saws can be modified depending on the characteristics of the material being processed. This is expressed in the shape of the tooth and the distance between the individual elements of the cutting edge.

The saw band profile is determined by the markings applied by the manufacturer. It looks like this:

  • WM. a universal version designed for sawing soft and hard wood;
  • AV. used for longitudinal cutting and sawing of hard materials, such as frozen wood;
  • NV. has a narrow blade width, so it is ideal for shape cutting;
  • NU. a cutting edge with a wide tooth pitch, which provides high performance when cutting soft wood;
  • PV. almost a complete analogue of the previous blade, but has a flattened tooth shape;
  • KV. the profile is used for wide band saws intended for softwood;
  • PU. wide saw blade for cutting hardwood.

The pitch of the teeth is selected individually, depending on the material. For example, when cutting hardwood and metal, only fine-toothed blades are used to avoid damaging the cutting edge. Soft raw materials and thick-walled materials are processed with saws with a large tooth spacing, which allows to speed up the production process.

Sharpening and setting the saw

The main cutting element of any hand saw. a series of teeth cut into the blade and representing wedge-shaped cutters. Wood, in the manufacture of all kinds of products from it, is sawn along, across and at an angle Θ to its fibers, in this regard, transverse, longitudinal sawing and sawing at an angle to its fibers are distinguished, and in each case, use the appropriate type of saw, which differs from others in shape teeth.

When transverse sawing, transverse saws are used, the cutting edges of the teeth of which, when moving in the wood, cut its fibers like a knife and form a cut. Longitudinal sawing differs from transverse sawing in that the direction of movement of the saw is parallel to the grain of the wood. The leading edges of the rip saws cut the wood like knives in a plane, and, going deeper, form a cut. When sawing wood at an angle Θ, universal (mixed) saws with teeth that are an intermediate form of teeth for cross and longitudinal saws are used to its fibers.

Saw sharpening

Saw teeth sharpening. a kind of art that requires loyalty of hands, a good eye, and attention. It is not difficult to learn this business, you must have the desire and clearly adhere to the following rules:

  • The saw blade must be firmly fixed in a special device made of wood, which is also firmly installed on a well-lit work table. Sharpening saw teeth on stools or knees does not give a satisfactory result.
  • You should use a personal file, followed by cleaning the sharpened edges of the teeth with a velvet (with a fine notch) or file. It is desirable that the file is new, sharp and with a fitted handle. If at the right moment there was not one, then you can also use a second-hand one, but always brushed with a steel brush and rubbed with charcoal so that the file does not get clogged and does not become dull. When sharpening a tooth, the file should grip its metal and remove its layer depending on the pressure. And if it slides over the tooth without removing the metal, then the saw teeth are overheated or the file is worn out. In this case, it is necessary to repeat the sharpening with a new file. If in this case he slips over the tooth, then it remains to take another saw.
  • The file handle is clamped with the right hand, and the end of it is held by the left hand and the file is directed to the saw teeth. Working with a file, depending on the type of saw, is described below.
  • The pressure of the file on the teeth should be smooth and even and only to one side from you. When returning the file to its original position, it must not touch the teeth.
  • It is necessary to try to grind the metal from the edges of the teeth of at least the same thickness, driving the file the same number of times with the same pressure, which allows you to keep the angles, pitch and height of the teeth after sharpening.
  • Burrs form on the edges of the tooth from the side of the file exit, which reduce the sharpness of the tooth, and if they are not removed, then during the operation of the saw, they crumble, and the teeth become significantly dull. To remove burrs, the edges of the teeth are sharpened with a file with a velvet notch and deburred from the side edges with a wet donkey.
  • After sharpening the teeth, check their sharpness. Look at the tip of the needle and the edge of the razor blade: they are sharp, and do not shine in the light. And if they are dulled, then at the tip of the needle and on the edge of the blade, rounded surfaces appear, which reflect the light and shine well. The quality control of saw teeth sharpening is based on this principle. To do this, put the saw in front of your eyes and examine its teeth along the blade. If their cutting edges and tops are not shiny, then the saw teeth are sharpened satisfactorily, and if some of the teeth are shiny (this often happens), then they must be sharpened with a velvet file, deburred and re-check the light reflection from their edges and tops.

Cross saws. The teeth of the cross-cut saws are sharpened using a triangular file with a fine notch with a 60 ° apex angle.

To sharpen the teeth, the saw is clamped into a special device that allows its blade to be installed at an angle of 45-50 ° to the plane of the desktop. The file is led parallel to the working table at an angle of 60-75 ° to the saw blade and thus the left edge A1A2B2B1 is sharpened in the first tooth.

Saw teeth are sharpened in several stages. First, with a file, they pass along the left edges of the odd teeth located in the far row, adjusting the hands to the same movement. Then they pass the file along the right edges of the same odd teeth, completing the sharpening of the main cutting edges with very sharp tops. After finishing the sharpening of the odd teeth, the saw blade in the sharpening device is turned over and thus the even teeth that are in the far row are sharpened. When sharpening the teeth of cross-cut saws, it is necessary to carefully ensure that sharp main cutting edges with a dihedral angle φ = 60-75 °, a short cutting edge and a sharp point are obtained in each tooth.

Longitudinal saws. Rip saw teeth in which the angle π

Tooth setting

It all starts with checking the distance between the teeth. It is designed to prevent the saw from wedging in the cut. It should be adjusted to the type of wood with which you most often have to work. If you have to work with hard wood, the teeth are set apart at a distance of 1.5-2 times greater than the thickness of the blade. For soft wood, the teeth of the hacksaw should be separated by a distance of 2-3 times more.

One of the key points in routing is maintaining uniformity. If the saw teeth are bent at different distances from the center, this will lead to permanent wedges and a deterioration in the quality of the cut and the speed of cutting wood. Therefore, it is recommended to use a device for setting the teeth, which is called “setting”. Thanks to the stop, it is impossible to bend the tooth to a greater distance than provided by the standard.

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The teeth are divided into two groups through one and are bent sequentially along the entire length of the cutting side of the blade. First, this procedure is carried out for one group, in which the set teeth must be bent in a certain direction, then it is repeated for the opposite direction.

How to determine when it is time to sharpen a hacksaw

In order not to shorten the service life of the hacksaw blade, it is necessary to sharpen it only when it can no longer perform a high-quality cut, or requires more effort while working with it. The main signs of a blunt saw are the following:

  • the tips of the teeth are rounded, their shape is distorted;
  • the sound of the saw has changed: there is a feeling that the wood is not cut, but is torn along the fibers;
  • the cutting speed has decreased compared to a new hacksaw;
  • nicks and scuffs began to appear on the cut;
  • hacksaw periodically wedges even with an even cut.

If at least one of these symptoms appears, then the hand saw needs service. This includes both direct sharpening of the teeth and their correct setting.

Do-it-yourself saw sharpening

The saw is prepared for sharpening by fixing it in a vise, the jaws of which should ideally be made of wood so as not to damage the saw surface. Step-by-step instructions for sharpening a hacksaw on wood with your own hands are as follows:

  • The hacksaw is fixed as close as possible with the teeth to the jaws of the vice, but so that their distribution is not disturbed when the wrench is clamped at an angle of 90 ° to the surface of the workbench.
  • The file is taken in the working hand with the handle, with the other hand it holds the tip from the back. This will distribute the effort evenly.
  • Sharpening a conventional hand saw is performed at an angle of 15-30 ° to the tooth. If the wear is not too strong, the “native” sharpening angle will be clearly visible.
  • The angle of the file to the blade should be about 30-45 °. To do this, you need to become so that the working hand is below the auxiliary.
  • The file should only move away from itself, with the same effort and number of movements for each tooth. For a sharp file, 3-5 strokes are usually sufficient to straighten a single tooth.
  • Thus, one side of the canvas is passed, after which it is turned over, fixed in the same way, and the actions are repeated for the second side.

If, when performing sharpening work, apply an uneven force or make a different number of movements with a file, this can lead to displacement of the teeth in relation to each other, distortion of their size and shape. Ultimately, such a hacksaw will require professional resharpening, or even completely unsuitable for further use.

Height leveling

After the setting has been made, the hacksaw must be checked for the same height of the teeth. Since the force could be applied unevenly to it, there is a chance of the appearance of teeth with less wear, which will protrude above the rest.

To identify these teeth on a hacksaw, you can use a simple method. It will need thick paper or cardboard along the length of the cutting blade. The sheet must be laid on a flat surface, for example a table, well leveled, and then forcefully press the cutting part of the blade against it. Prongs that are knocked out of the general row will make deeper dents in the surface.

This makes them easy to spot and correct before sharpening. To remove excess height, various files are used. During this work, you should strive to preserve the shape of each hacksaw tooth as much as possible.

Required sharpening tool

To perform such a seemingly simple operation, you will need a rather impressive list of tools. However, if one of them is not at hand, you can try to find a replacement for it. What you cannot do without is a workbench with a vice, since only with their help the saw can be rigidly fixed for work. The rest of the list looks like this:

  • device “wiring”, which, if absent, can be replaced with high-quality pliers. In this case, you yourself will have to determine the approximate distance from the center for each tooth;
  • a sharpening bar with sandpaper or a set of files and files;
  • hammer;
  • additional light source;
  • in some cases, you may need a caliper and protractor to make accurate measurements.

A separate mention is the method of sharpening hand saws using an angle grinder. In this case, you will need the presence of the angle grinder itself, a workbench and a pair of clamps, since the blade will need to be fixed horizontally.

General requirements for sharpening

Sharpening a hacksaw is a rather painstaking process in which accuracy is important. To make it easier, you should only use good files and needle files that are sharp enough. If the saw has to be sharpened frequently, the best solution is to have a separate set of tools for the job. Before sharpening, it will not hurt to look at the teeth of the hacksaw. If their shade is darker than the canvas, then they are hardened. Sharpening such a hacksaw on wood will not work.

When sharpening at home, the metal should be removed evenly. An equal number of file passes are made for each individual tooth, regardless of how worn it was before the correction. In this case, you must not change the sharpening angle set by the inclination of the file, or rotate it around its axis. Movements should be made strictly from oneself, since it is with this technology that the effectiveness of removing the metal of the hacksaw is achieved, and the employee can confidently control the tool in his hands.

In order to avoid additional difficulties during sharpening, the saw blade should be firmly fixed in a vice. It is desirable to have source of direct light, which will allow you not to peer at the results of the work.

blade, sharpening, wood

How to sharpen a hacksaw on wood and spread the teeth

Hacksaws of various types are used in everyday work in personal plots, summer cottages, as well as during repairs in which natural wood is used as the main material. The saw requires periodic maintenance. At a certain moment, you need to sharpen the hacksaw on wood, since it began to perform its function worse than before. In order not to spoil the canvas and return the tool to its former performance, you need to follow a few simple tips.

Saw set

Setter Pliers

The setter pliers are a good tool. It is very convenient to use, the sawtooth drift to the side will be as you need.

Hacksaw set. It is also a good thing and is inexpensive. average. The design is elementary: several slots and an adjustable protractor. The tooth is inserted into a suitable slot and set by pressure on the handle. The positioned goniometer ensures the uniformity of the spreading.

Hacksaw set

The technology is simple: the blade is inserted between two teeth and by turning the ax, the teeth are bent to the sides.

Setting the teeth with an ax

The saw can be set using a self-tapping screw. It is more secure. This requires a long screw to make it easier to hold. Before work, it needs to be slightly modified. You need to grind off his hat a little on one side. to make it flat. This is necessary so that when it is applied to the tooth, it does not slip and deform the latter.

Place the hacksaw flat on soft wood (pine, spruce). Holding the screw by the leg, apply a hat to the tooth and hit it with a hammer. The tooth is folded back. The operation is performed through the tooth. After the saw blade is turned over, and the operation is repeated in the same way.

Tooth setting with a self-tapping screw

What should turn out

When sharpening, you need to ensure that the teeth of the hacksaw are sharp and resemble a shark’s tooth in shape. Only such a tooth saws well. the hacksaw will not slide on the tree, but will “bite” into it. And then it will become clear why the “correct” saw cuts itself.

How to sharpen a saw for wood: a simple step-by-step instruction | (Photo Video)

A sharpened hacksaw for wood cuts itself. any professional carpenter or joiner will confirm this. If you don’t agree with this, then it’s time to sharpen the tool.

Sharpening a hacksaw for wood also includes setting the saw teeth. For this, there are special adaptations, as well as improvised tools.

Tool used

Since the saws differ in shape and purpose, they also have different teeth. And in order to sharpen a hacksaw with high quality, you need a different tool.

Triangular file with one working side. The profile of this tool is not standard, if for an ordinary triangular file all sides are equal and are working, then this file has one working side, and in shape it is an isosceles triangle with a very large base.

With such a triangular file with one working side, it is convenient to process fine or oblique teeth. When working, it acts only on the surface to be treated, on others it only slides. There is no risk of grinding the adjacent tooth.

Plain triangular file. A compact tool that is convenient for sharpening most standard wood saws.

Plain triangular file

Triangular file. Ideal for sharpening large-toothed saws.

Sharpening process

For sharpening, the saw must be firmly fixed so that it does not vibrate when exposed to a file. Otherwise, the quality of work will be low.

They fix the hacksaw blade vertically, often in a vice, in homemade clamps, but if there is neither one nor the other, then you can do without them.

The fixing method without special devices is “at the edge of the workbench”. The hacksaw blade is laid so that only the saw teeth hang from the edge of the table. However, the handles of the saw are always thicker than the blade, and therefore the place next to it cannot be put tightly to the workbench. Therefore, you need to use the corner of the table, and then the saw handle will not interfere.

If there is a clamp, then you can fix it like this.

And this is a method without a clamp, fixation is done only by the hand of the sharpener. It is quite convenient and safe.

Fixing the saw without a clamp

A file or a file is taken in the right hand, and, pressing the hacksaw blade with his left hand, they begin sharpening.

Sharpen the saw teeth through one. The movement of the file with this method is made upside down. The file is applied to the sharpened tooth and is forced downward with a downward movement.

The file must be held tilted in two planes. In the horizontal direction, it is about 30 degrees. Vertical. about 60 degrees. The angles of inclination are individual for each saw, because they can differ both in the shape of the tooth and in its size.

Sharpening the left edge of the tooth.

Sharpening the left edge of the tooth

Sharpening the right edge of the tooth.

Sharpening the right edge of the tooth

This is what should be obtained: to the right of the file pointer. processed teeth, to the left. no.

To the right of the file pointer. processed teeth, to the left. not

Best way to sharpen saw blade

How to quickly and easily sharpen a hacksaw with a file

How to quickly and easily sharpen a hacksaw with a file

How to sharpen a saw for wood: a simple step-by-step instruction | (Photo Video)

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Shapes of the cutting part and the angle of sharpening of the blades

The geometry of the cutting elements of band saws can be varied, which directly depends on the material that is intended for cutting. Woodworking machines are most often equipped with special saws, with which you can carry out:

  • carpentry work;
  • sawing logs and beams;
  • use on dividing saws.

The sharpening angle is determined strictly by the tool manufacturer. The rake angle will be as small as possible when using hardwood. Band saws for metal are equipped with saws with different blade shapes, which directly depends on the metal used for sawing. If it is necessary to cut thin-walled metals and at the same time have thin chips, the rake angle when sawing will be zero, then standard cutting is used. The sharpening angle can be varied. It directly depends on the structure of the device.

A tooth that has a positive rake angle is found in saws commonly used for cutting thick-walled metal. The step of the blade, with the help of which the sawing of thin metal is carried out, is rather small. In order to cut thick-walled metal, it is necessary to use devices that have a large number of blades. In some cases, the equipment has a variable pitch to eliminate the resonance effect. The change in the distance between the teeth directly depends on a certain group.

Setting the cutting elements of the band saw

Divorce is the bending of band saw blades in different directions. This significantly reduces the friction of the blade and prevents it from pinching. To ensure free movement of the blade against the walls of the material being cut, its width must be greater than the thickness of this material.

Band saw set types

Divorce can take several forms. It may have different names from different manufacturers. Most often it can be:

  • Standard, which is characterized by the opposite bending of the cutting elements in various directions. It is most commonly used for band saws that cut hard material.
  • Wavy, which belongs to the category of complex structures. Divorce in this case has a variable meaning. In this case, a kind of wave is formed.

Divorce consists in folding not the entire canvas, but only a certain part of its top. The parameters are determined strictly by the tool manufacturers. Their range is 0.3 to 0.7 millimeters.

Protecting. The divorce consists in bending two teeth. In this case, the third remains in place. Designed for band saws for extremely hard material. In shape, every third tooth resembles a trapezoid. The location is the center of the canvas. With its help, the most correct direction of the saw band is carried out.

Woodworking machines are characterized by a versatile sawing tool design. The spread for soft rock processing must be larger than for hard rock equipment. But the divorce should not be such that the wedge is located in the center without a cutout. The divorce must be characterized by the same arrangement of all cutting elements. It is necessary to spread the teeth in such a way that the deviation is no more than 0.1 millimeter. If the saws are unevenly positioned, this will lead to the fact that the band saw equipment will move to the side during operation.

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Sharpening recommendations

During the work of the canvas, its rupture is very often observed. This is due to the fact that it is poorly sharpened. This is due to the concentration of stress in the blade profile, if the sharpening is carried out at a low-quality level. The need for the procedure is determined by the condition of the band saws. If the surface roughness of the cut increases, then this leads to dullness of the tool.

Tool sharpening is carried out using diamond, electrocorundum, CBN discs. Their choice directly depends on the characteristics of the material being processed. The sharpening of the blade, the production material of which is tool steel, is carried out with corundum wheels. The procedure for bimetallic tools is carried out correctly if a diamond or CBN wheel is used. The instructions will tell you how to carry out this procedure. The most important thing is that the angle does not change in the process.

Wheels of various diameters can be used for sharpening. The choice of one of them is determined by the parameters of the device. For this purpose, profile, flat, dish-shaped, cup circles are most often used. Sharpening is correct if the peripheral speed is 20 to 25 meters per second.

The principle of sharpening tape blades

If there are chipping on the tool, chipping will be observed on the edge of the workpiece. That is why it is imperative that sharpening is carried out correctly. During this process, it is necessary to work not only with the front, but also with the back of the canvas. Sharpening of devices can be carried out in different circles. In this case, it is necessary to take into account the angle of the canvas. If you want to carry out the procedure correctly, then you need to learn it from a specialist.

In order for the band saw equipment to work efficiently, it is necessary not only to select it correctly, but also to sharpen it in a timely manner. For this purpose, special circles are most often used. This procedure is as simple as possible, which allows it to be easily performed by a master without appropriate experience.

If you find an error, please select a piece of text and press CtrlEnter.

When you start sharpening band saws, you should know that the correctness of this process depends on how high-quality your lumber will be. boards, beams, slats, etc. Sharpening band saws is a responsible process, but not very difficult. By following the recommendations below, you will quickly learn this simple, but very useful process in sawmilling.

First of all, you need to inspect the tape for visible cracks, broken teeth. To do this, take the tape in your hands with the teeth away from you and move your hands, slightly wringing the tape, start watching. If defects are found, the tape must be sent for repair, or simply thrown away.

Secondly, the tape must be cleaned of dirt and wood resin adhered to it. After all these procedures, the tape is ready for sharpening.

Gently take the tape to avoid injury, as the teeth are sharp enough to hurt your hands and insert it onto the sharpening machine. The tape must be installed on all holders on the machine and fixed with a special clamp.

We lower the pusher rod into the groove between the teeth, with the help of this rod, the tape feed is regulated. A sharpening stone is lowered onto the belt from above, it is fixed with a rod that regulates the sharpening depth.

Before starting the sharpening machine, set the sharpening angle, for a summer forest this angle is 55-60 degrees, and for a winter one 70-80. The angle is set by turning the bed on which the stone is fixed, according to the divisions, on the machine body.

Please note that the sharpening stone has a 45 degree chamfer and during preparation for the sharpening process, you must correct the stone if the chamfer does not correspond to the above angle. Dressing is done with a diamond tool or a simple large stone.

Immediately, we note that straightening with a simple stone is more difficult and requires some skills, it also does not comply with safety regulations.

Start the sharpening machine

You have prepared the machine and saw to start sharpening, now we will proceed to the very process of sharpening the band saw.

First of all, turn on the feed at the lowest speed, for this there are toggle switches for turning on the engine and a feed rate regulator, it decreases or increases the engine speed.

Saw Blades & Router Bits Sharpening Jig

Using the screw on the feed bar, move the saw tooth forward or backward and make sure that the stone with the flat side (without chamfer) starts touching the straight side of the tooth.

Then we turn on the second toggle switch, which drives the engine with a stone. Little by little, without sudden movements, you begin to lower the stone with the help of a screw rod that fixes it, until the stone completely passes through the from one tooth to another.

In no case should the ribbon turn blue, so try not to lower the stone too much, just push the feed rod back or forward, otherwise the stone will simply “eat” your tooth. Sharpening of band saws, should be smooth according to the factory tooth profile.

By manipulating the feed screws and the stone lowering rod, it is necessary to achieve a complete absence of burrs at the tip of the teeth. The finished work of the machine can be considered after passing the band saw at least two circles.

Sharpening band saws in winter

Winter sharpening practically does not differ from summer sharpening with the only difference, the angle of inclination of the teeth more straight reaches 90 degrees, depending on the freezing of wood. The more the wood freezes, the greater the sharpening angle, but keep in mind that in the summer with such an angle the load on the saw increases and its quick failure is possible.

How to sharpen band saws on wood correctly

In order for the processing of various materials to be carried out correctly, it is necessary to look after and monitor the condition of the band saws. For this purpose, machines for sharpening and setting band saws are used. Timely care will ensure long-term use of instruments.

Saw band design

Band saws are a special continuous design characterized by the presence of cutting elements on one side. This is the cutting element with which woodwork is carried out. Most often, band saws are used in a variety of band saw blades. With their help, cutting of various parts is carried out. With the help of these blades, a sufficiently high cut quality is ensured. All this is provided only if the saw has a good set. Also, the tool must be serviced in a timely manner.

Band saws are made of heavy-duty metal, which ensures not only high quality of the cut, but also the durability of the saw. The teeth have a universal angle, which allows for the highest quality cutting of the material.

Sharpening band saws for wood video.

Yuri Romanovich, Head of Service Department at Wood-Mizer Industries LLC, gave a lecture on the theory of Wood-Mizer band saws at a seminar in the Chelyabinsk Region. He focused on the terminology, sharpening and setting of band saws, maintenance of the sharpening and setting devices, and also gave recommendations for sawing with narrow Wood-Mizer band saws.

Wood-Mizer Band Saw Theory
Each band saw manufacturer uses its own specially developed steel. The band saw is required to be as stable as possible in the cut, which directly affects the surface quality of the material being cut, and also allows a high cutting speed to be developed, which ensures high productivity.

In addition, a certain durability is required from the band saw. The main indicators of band saws for wood are as follows: thickness (1.06 mm or 1.14 mm); web width (32 mm or 38 mm); tooth pitch (22.23 mm); tooth spread (0.58 mm); tooth angle (10 °); tooth height (6.4 mm). In addition, the number of indicators includes an individual digital code. In order to get the most out of the band saw, it is necessary to perform a number of actions with both the saw and the machine. First, you need to prepare the saw depending on the type of wood being cut.

Next, you need to correctly install the saw blade on the pulleys: there must be a certain distance from the cavity of the tooth to the edge of the pulley. The condition of the belts on the wheels must be constantly monitored. If the saw is 0.8 mm from the pulley, the belt must be replaced. It is very important to use the correct belt thickness.

The saws “sit” on the belt with a lot of pressure, so any thickening in the belt adds pressure to the saw, which causes the saw to vibrate and shorten the saw’s lifespan. Sometimes sawdust can build up under the belt, with the same results as the thickening on the belt. The saw should be supported on both sides of the log as close to it as possible.

The correct position of the guide rollers on the saw gives it additional stability when cutting and the ability to cut at the highest speed, prolongs the life of the saw and increases the lumber cut by the saw. To do this, it is necessary to turn the rollers towards the movement of the saw at an angle of 3 °, set a gap of 3 mm between the roller flange and the rear of the saw, lower the rollers (pressing the saw) by 7 mm, and also adjust in the vertical plane. The saw tension must comply with the manufacturer’s recommendations (150-170 atm).

The sawtooth shape has been developed and verified over the years. Therefore, it would be a mistake to believe that the saw will cut no matter what shape its tooth has. With proper use, the band saw can last until, as a result of regrinding, its width will not decrease to 65% of the original. The thickness of the saw is determined by the diameter of the pulleys on the sawing machine. The service life and cutting accuracy depend on the thickness of the saw.

Theoretically, the thinner the saw, the longer its service life, since the bending stress in it is lower, but, on the other hand, the greater the risk of its failure as a result of an oversight or non-observance of operating rules. Attachment angle (rake angle), tooth set, sharpness and correct tooth height are the four most important factors in a saw’s ability to cut. All four factors affect productivity and cut quality.

Basic terms
Tooth pitch is the distance between the top points of adjacent teeth. This parameter always remains the same. In the process of sharpening on serviceable equipment, it does not change. Tooth height is the distance from the lowest point of the sinus (cavity) to the highest point of the tooth. The bosom is the space between the teeth that “takes out” the sawdust when sawing.

When sharpening the saw, you must select enough material from the saw bore to obtain the appropriate height. The depth of the tooth cavity is about 30% of the step. To ensure a long saw blade life, the groove should not be hardened during sharpening and should not contain stress concentrators, scratches or burrs. There are many cracks in brittle burrs that can easily penetrate the saw, especially in valleys where stress is greatest. After sharpening, all burrs must be removed from the teeth.

If sharpened correctly, they can be easily removed with a wooden block. The angle of engagement (rake angle) is the angle of inclination of the leading edge of the tooth relative to the ordinate 90 °. It allows the tooth to cling to the wood when cutting. The tooth must remove enough wood for the saw to sink into the log itself. The value of the hook angle is selected in such a way as to reduce the feed force.

If the contact angle is too high compared to the feed rate, it will result in rattling, uneven (rough, rough) cuts and poor cut quality. The saw will pull sharply against the tree, and the leading edge may protrude too far beyond the sheaves. If this angle is too small, the saw will have to be forced into the log, which will reduce the cutting speed and, as a result, productivity. The size of the hook angle is determined by the type of wood and the rate of performance.

For most sawing operations, a hook angle of 10 °.15 ° is recommended. On saws with an incorrectly selected hook angle, cracks can form, especially in the sinuses (cavities) of the tooth. The radius at the base of the tooth is built into the saw grip and removes sawdust. During the sawing process, the force at the tip of the tooth acts against the tooth. This opposition creates a lot of stress at the base of the tooth. The radius spreads this stress over an area large enough to reduce the impact of stress on the saw’s lifespan.

Too low (small) radius will cause the saw to break. Too high (large) radius on the tooth will cause it to clog quickly, which will reduce the cutting speed and shorten the saw’s lifespan. The same is the effect of too much tooth height. In addition, too high a tooth does not hold the setting well.

Band saw preparation
Incorrect sharpening and setting of the saw is the main reason for its premature failure. Tool preparation is essential to get a quality cut. Therefore, work on the improvement of devices for sharpening and setting saws continues at Wood-Mizer continuously.

This type of motor is renowned for its long and trouble-free operation as it has no brushes or commutators. It is ideal for equipping a sharpening device, that is, an object where there is an abrasive material. oil and metal dust. Other types of engines fail quickly under similar conditions. At the time of installation of the saw, the head of the sharpening device rises up, and the saw itself is easily inserted into the clamp.

The control panel is mounted in such a position to provide easy access to the controls. A hole is provided in the cover of the sharpening device, to which a pipe can be connected to remove gases evolved during the sharpening process. The latter is especially important in workshops where several sharpening devices operate. The sharpener must be kept in good condition. Backlash in bearings and guides is not allowed. Vibration of the grinding wheel and backlash in the feed mechanism can damage the teeth.

Grinding wheels
Wood-Mizer supplies specially designed borosonic grinding wheels. They are available in three profile options to closely match the Wood-Mizer tooth design. The 10/30 profile is the most popular and versatile tooth profile, the 9/29 profile is ideal for sawing frozen and hard wood, and the 13/29 profile is used for freshly sawn soft wood. in particular pine and spruce.

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Tooth spread
Tooth set is the distance the tooth is deflected in relation to the saw blade. Tooth set is an important factor in saw performance. The more the tooth is spread, the wider the cut will be and the more engine power is required. The purpose of the tooth setting is to create a gap for the saw in the kerf. In other words, you need to reduce the friction between the tree and the saw so that the saw can go through the cut without overheating. The amount of spread depends on the type of wood. The softer and more fibrous the wood is, the more the teeth are set to reduce friction against the fibers. Soft woods have coarse, long fibers, while harder woods have virtually none. The latter also applies to frozen softwood, which is sawn with slight wiring.

blade, sharpening, wood

Adjustable device
To ensure the accuracy of the setting process (/.0.0025 mm (0.001 “)), Wood-Mizer uses a new screw system to replace the old lever system. Working on the new sharpener is less tiring for the operator and ultimately results in more high precision and speed of setting the saw.In addition, the stand for the setting device has been modified: now the position of the device in relation to the operator can be adjusted and thus easier to read the readings of the device.All these factors have increased the accuracy of setting, which in turn improved the accuracy and smoothness of the cut.

Wood-Mizer produces saws with 9 ° or 10 ° grasping angle. Saw sharpeners and setters can change the grip angle and tooth set.

How to find out if the saw is set correctly
The layout can be considered optimal when there is a mixture of 65-70% sawdust and 30-35% air between the saw blade and the tree it is sawing. The external manifestation of the fact that the saw is set correctly is the release of approximately 80-85% of sawdust from the cut. In cases where the saw is set too far, not enough sawdust is thrown out.

If the saw is not diluted enough, tightly compressed, hot sawdust remains on the surface of the board. In fact, the sawdust should be warm to the touch, but not hot or cold. A saw that is too far apart is more likely to cut in jerks, and when not set too far in waves. If you are sawing logs with a diameter of 30 cm at a good speed, and the sawdust is warm to the touch, then you should not try to cut a log with a diameter of 60 cm with a saw with the same layout, because it will have to remove twice as much sawdust from the cut. The wiring should be increased by about 20%.

The conclusion that suggests itself: logs should be sorted by thickness before starting to saw them. Another important point: only the upper third of the tooth should be diluted, and not the entire tooth “under the root”. Only a sharp corner at the very top of the tooth should be involved in the sawing process. It should also not be forgotten that the indicator on the wiring device is a precision instrument. It costs nothing to knock down its setting. He works in an extremely stressful mode. Therefore, the indicator wears out over time, and you should check its installation more often.

Set point on the tooth
When setting the saw, special attention must be paid to the position of the saw in the setting device. the bend line (saw blade) must be at the lowest point of the bosom or higher. The bend point (where the pusher of the adjuster pushes against the tooth) should be about half the height of the tooth. If the bend line is too low, the tape itself will bend, not the tooth. This will cause the saw to break prematurely. When the bend line is too high, the top of the tooth will bend, the saw will be unstable and the cut will be wavy. This slows down the sawing speed and can lead to premature saw failure. Incorrect sharpening and setting of the saw is the main cause of premature saw failure. The whole process of sharpening and setting serves to extend the life of the saw.

Saw Rig Problems

They start routing only after the saw is sharpened, and the edge is cleaned of burrs. Here are some basic details to watch out for. Firstly, this is the installation and verification of the indicator. Verification usually does not cause any problems. However, users often forget to install the indicator tip, which must be correct across the full width of the indicator in relation to the measuring plate supplied with the wiring device. Secondly, it is setting the height of the mainsail (mast) and determining the point of inflection of the tooth. The correct position of the mainsail is shown in the figure. It should be at 1/3 of the top of the tooth.

If the position of the mainsail is already correctly adjusted, you need to pay attention to the correct installation of the limiters (counter rails). They must be positioned so that each tooth folds over at the same point. This is a very important operation because it affects the accuracy of the cut. Thirdly, the installation of the cheeks of the adjustable device. In this case, you should pay attention to two important points. This is the distance of the tape step from the edge of the cheeks, which should always be at the same level, ensuring the bend of the tooth, and not the rotation of the tape (this, by the way, is a very common mistake). And this is the state of the pressure plate guide bolt.

These bolts will wear out over time and can cause incorrect routing. The first symptom that the bolts have become unusable is the presence of free space between the pressure plate and the permanent plate. This can also be noticed at the moment of bending the tooth, if the tape first turns, and then the mainsail begins to bend the tooth. According to Wood-Mizer, by paying attention to these seemingly small details, the operator of the sawmill equipment will significantly improve control of the saw setting process.

How to sharpen a band saw correctly

Immediately, we note that if there is no experience and skills in performing such work, it is better to entrust saw sharpening to professionals. Violation of the geometry of the teeth of the cutting edge, the appearance of dross on the metal or incorrect setting will significantly reduce the life of the blade.

Having decided to sharpen the band saw with your own hands, it will be useful to first familiarize yourself with the key definitions, the knowledge of which may be required in the process. So, for the correct formation of the cutting edge you will need:

  • setting. deviation of the teeth from the plane of the main saw blade;
  • the height of the teeth is the distance between the top point and the base;
  • pitch. the distance between the teeth, usually varies between 19-25 mm.
  • sharpening angle. depends on the intended purpose of the tool; for example, the recommended sharpening angle of carpentry saws is 35 °, indexing. 18-22, intended for sawing a bar. no more than 15 °.

The sharpening angle is determined by the manufacturer, therefore, when self-dressing the saw, it is recommended to adhere to these parameters.

Here are detailed instructions that will help you sharpen a closed saw correctly without resorting to the services of specialists.

Sharpening

This is the main step in cutting edge dressing and can be done in two ways.

Full-profile saws are sharpened with an CBN wheel installed in a special sharpening machine.

This is a fully automated operation used by professionals. The work of the machine for sharpening band saws for wood is controlled by electronics, and the sharpening wheel processes the entire band in one pass. The disadvantage of this method is that the CBN wheel is selected individually to the profile of the saw, therefore, for dressing different tools, the sharpening element must be present in the assortment.

Sharpening of teeth is carried out manually or on specialized equipment.

Note! This is the method used for self-sharpening band saws. A normal emery wheel or file can be used here.

In the first case, the sharpness of the teeth can be restored in the shortest possible time, but the work requires certain skills. In the second. painstaking work: 4-5 movements along the edge of each tooth.

For automatic sharpening, diamond, CBN and corundum wheels are used. It is important to understand that when performing this procedure, only sharpness is given to the teeth, the geometry created after setting the blade should remain unchanged.

What you need to know about sharpening angles

The geometry of the teeth of band saws can be modified depending on the characteristics of the material being processed. This is expressed in the shape of the tooth and the distance between the individual elements of the cutting edge.

The saw band profile is determined by the markings applied by the manufacturer. It looks like this:

  • WM. a universal version designed for sawing soft and hard wood;
  • AV. used for longitudinal cutting and sawing of hard materials, such as frozen wood;
  • NV. has a narrow blade width, so it is ideal for shape cutting;
  • NU. a cutting edge with a wide tooth pitch, which provides high performance when cutting soft wood;
  • PV. almost a complete analogue of the previous blade, but has a flattened tooth shape;
  • KV. the profile is used for wide band saws intended for softwood;
  • PU. wide saw blade for cutting hardwood.

The pitch of the teeth is selected individually, depending on the material. For example, when cutting hardwood and metal, only fine-toothed blades are used to avoid damaging the cutting edge. Soft raw materials and thick-walled materials are processed with saws with a large tooth spacing, which allows to speed up the production process.

Characteristics

Band saws have three distinctive features. They are made only of special grades of tool steel, which ensures high strength and wear resistance of the teeth. Russian manufacturers usually use steel grades 9HF and B2F, foreign companies prefer the C75 series. In any case, the hardness of the material must be at least 45 HRS.

The cutting width of the band saw blade is much narrower than that of circular counterparts. As mentioned above, this is a fundamental factor in the processing of precious woods and industrial wood.

The saws are able to handle workpieces of any length and diameter without any problems. At the same time, a properly sharpened band saw ensures high production productivity.

It is necessary to clarify that the reliability of closed saws is due to the heterogeneity of the material used to make the blade.

In particular, the body of the saw tool is usually made of spring steel, which has incredible tensile and dynamic resistance. Grades of steel with high m of tungsten and cobalt are used for the manufacture of cutting edges. Individual parts of the web are welded together by high-frequency currents. Tools made using this technology can be used for cutting metal.

Rules for sharpening band saws for wood

Band saw. closed-type cutting tool used on sawmill equipment.

The undoubted advantages of these elements are high productivity and a minimum amount of production waste. It is possible that when sawing ordinary boards, the latter fact does not play a significant role, but when it comes to processing valuable wood species, the kerf width and cut quality directly affect the economic benefits.

Correct sharpening of a band saw for wood is a guarantee of production efficiency and tool durability. Usually such services are provided by specialized companies, but if you know the procedure and the subtleties of the procedure, you can sharpen a blunt saw yourself.

  • Characteristics
  • What you need to know about sharpening angles
  • How to sharpen a band saw correctly
  • Wiring
  • Sharpening
  • Common mistakes
  • Wiring

    Setting band saws into wood is the first step in restoring the profile of the cutting edge. During operation, the location of the teeth can change, so until the correct geometry is achieved, it makes no sense to sharpen the saw part.

    There are 3 ways to open the saw:

    • classic. the teeth alternately deviate to the right and left sides;
    • stripper. the 1st and 2nd teeth deviate in different directions, the third remains even. This profile is created for sawing hard materials;
    • wavy. the most difficult option, resembling a wave in shape. Here, each tooth is individually shaped, and this type of setting is usually performed only in specialized workshops.

    It should be noted that when wiring, not the whole tooth is bent around, but about 2/3 of the upper part. The procedure is performed on a special band saw setter. The cost of such a tool is quite high, so they buy it if you need to adjust several tools. Its presence can become the basis of a sharpening business.

    Of course, the first time you can do everything correctly, even on an adjustable machine, it may not work, so at least the geometry of the profile should remain the same as before the start of work.

    Common mistakes

    If a person tries to sharpen a saw for the first time, it is difficult for him to fulfill all the requirements and remember the nuances of the technological process. However, violation of these rules leads to the fact that the efficiency of using the band saw is noticeably reduced, the load on the blade increases, which leads to premature rupture.

    Professionals recommend avoiding such mistakes:

    • with mechanical sharpening, the abrasive stone is not positioned correctly relative to the saw profile. In this case, the sharpening of the teeth will be uneven;
    • excessive force when the saw and the grinding wheel contact. As a result, the metal overheats, dross appears, which leads to premature wear of the cutting edge;
    • burrs remain on the canvas. After sharpening, all roughness must be eliminated, otherwise microscopic cracks will appear on the metal during operation;
    • using your own sharpening angles. Many inexperienced craftsmen believe that only sharpness is important for saw teeth, therefore they shamelessly violate the geometry of the cutting edge profile recommended by the manufacturer. It is important to understand that the shape of the tooth has been tested over the years; it is useless to try to experiment here.

    Instead of a conclusion, we add that each band saw has a certain resource, so the blade cannot be sharpened indefinitely. Manufacturers guarantee the correct operation of the tool until the total blade width is reduced to 65% of the original size.