Sharpening band saws for wood: maintaining the angle, making a set, sharpening on a machine and manually

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Band saws are designed for cutting various materials, including wood of varying levels of hardness. Their working part is a closed steel belt with teeth.

The cost of sharpening band saws in special workshops is relatively low. But often the speed and quality of order execution are not very satisfying. Based on this, the work can be done on your own.

Band saws require periodic sharpening.

Characteristics

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

The cutting width of a band saw blade is much narrower than its counterparts. As mentioned above, this is a key factor when processing fine wood and commercial timber.

The saws are capable of processing parts of any length and diameter without any problems. At the same time, a properly sharpened band saw ensures high production productivity.

It should be clarified that the reliability of hole saws is due to the heterogeneity of the material from which the blade is made.

In particular, the body of the sawing tool is usually made of spring steel, which has incredible tensile strength and dynamics. For the manufacture of cutting edges, steel grades with a high content of tungsten and cobalt are used. Individual parts of the tape are welded with high frequency currents. Tools made using this technology can be used for cutting metal.

DIY grinder: drawings with dimensions + assembly instructions

During development, special attention is paid to the configuration of the rollers, the method of fastening the product and the optimal power of the power unit. Read more about this.

Making rollers

Particular attention should be paid to the manufacture of the main drive roller, which acts as a pulley! It should be quite massive. This will avoid unnecessary jerking during the starting torque due to the presence of inertia at rest. The speed gradually reaches the desired values. If we take into account the use of a standard motor in the drive design, with a slip of no more than 9%, at a rated speed of 1500 rpm, the speed will not exceed 1400 rpm maximum.

Steel or cast iron are not suitable for making the main part because the motor will be stressed when starting up or will not be able to turn the overly heavy workpiece at all.

There are two options to solve this problem:

1. Manufacturing a hollow steel roller to reduce weight according to the principle: larger diameter - deeper cavity. The exact dimensions can be calculated from a reference book, but special accuracy is not required.
2. Second option: make a duralumin roller of grade D16 and higher.

It is recommended to make an end groove on the pulley, the dimensions of which will be identical to the dimensions of the belt intended for use. This will help prevent uncontrolled belt slippage if the rollers are not positioned correctly in the plane of rotation.

It is recommended to do the same with the remaining rollers, including the tensioner. The use of duralumin for their manufacture will eliminate the work of grinding cavities to regulate weight.

The degree of roughness of the roller surface is of no small importance. Recommended limit values: Ra1.25-Ra2.5. Increased roughness will lead to premature wear of the belt base, and roughness below the specified limit will contribute to unnecessary slippage during long-term operation.

The rollers must be installed using sealed bearing sets based on self-aligning bearings with a fixed outer ring. With this installation, abrasive or other particles cannot get on the roller shaft. When choosing bearings, it is necessary to take into account the correspondence of their bearing parameters to the maximum speed of the power unit.

The rollers can be secured with regular cotter pins or with a shoulder on one end of the shaft, as required by the standard. The drive shaft must have a keyway in common with the drive shaft.

Motor and turntable

When planning to assemble a belt grinding machine with your own hands, you should pay special attention to the choice of unit. The most commonly used engine is 0.75 kW (although up to 1.5 kW is not prohibited) with a rotation speed of 1500 to 3000.

Please note that the belt may not be able to withstand high speeds. As a rule, engine power is selected based on planned operations on the assembled machine. If rough work predominates, with a high load on the drive, a more powerful control unit is installed, but with a lower number of revolutions, and if only surface grinding is required, the parameters remain within the above limits.

The grinding process is characterized by significant contamination in the form of microscopic dust particles, so the motor must be of a closed type with its own fan. It is better to ignore the recommendations of “experts” on using a motor from a used washing machine.

To design a homemade grinder, you will need dimensional drawings; in addition, it is good to think about safety and ease of use on the assembled device. It requires:

1. Rotating table.
2. Pressure plate on the back of the belt for support.

To accomplish the first task, the stage bracket must be movable, capable of being rotated 90 degrees and fixed at the extreme points. Recommended table thickness: at least 15 mm, preferably duralumin.

The machine frame, sanded near the bearing surface, is suitable for the bearing surface.

Do-it-yourself grinder from an angle grinder: drawings

Drawing of an angle grinder with dimensions for self-assembly

This is one of the simplest DIY grinders. The design of such a mechanism is primarily intended for cleaning weld seams. However, if it is firmly fixed to the table, it can be successfully used as a sharpener for sharpening cutting tools or knives, axes, etc.

Grinder for drill

A drill-grinder is a special accessory that can be made in several stages. There are hundreds of options for what this could be. We chose a non-standard model.

To work, you will need a shaft with gears, bearings and sheet metal.

These grinders can help sharpen knives or flat parts.

Homemade grinder - making a belt grinder with your own hands

A grinding machine is a belt sanding machine used for dry grinding of metal products, various alloys, wood, artificial stone, plastic and other materials.

Homemade assembly of an angle grinder

The question of how to make a belt grinding machine with your own hands is asked by many home craftsmen, because with the help of such equipment you can perform various technological operations with products made from various materials. Using a belt grinding machine, you can remove burrs, eliminate surface defects, clean rust, remove scale, eliminate the effects of plasma and laser cutting, and clean welds.

Making your own grinder

It would seem that buying branded equipment and using it in your workshop for more than a year is much easier than making it yourself. However, not everyone can afford to pay a decent amount for a production car from a well-known manufacturer. In addition, it is not difficult to make such a machine yourself, which will have the necessary functionality.

Main parts of the machine body with dimensions

To become the owner of a homemade belt sander, you should first sketch out a drawing, and also stock up on a drill, grinder and jigsaw. Some parts for a belt sander will need to be ordered from a lathe, but this is not a problem these days.

It’s better to immediately focus on making an angle grinder that will work in both vertical and horizontal planes - such equipment is highly functional and allows you to process parts at the required angle.

What you need to know about tooth sharpening angles

The geometry of the band saw teeth can be changed in accordance with the characteristics of the material being processed. This is expressed in the shape of the tooth and in the distance between the individual elements of the cutting edge.

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

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

The tooth pitch 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 large tooth spacing, which speeds up the production process.

Typology of paintings

The basis for the division of saws of this type is the material of manufacture and the elements being processed. In accordance with such aspects, the following types of canvases can be distinguished.

• Wood saws. The key materials for their manufacture are carbon and alloy steels; their hardness reaches 40–45 HRC. All teeth are subject to mandatory hardening with high-frequency currents. It should be noted that this blade material can be used for cutting thin non-ferrous metals or carbon steels.

• Canvases for metal. Such tools are made from high-speed or spring steel (cobalt and tungsten are added to the structure). These saws already carry a strength of up to 69 HRC. To obtain high hardness and broad capabilities, stellite or other types of durable alloys can be welded onto the teeth.

Manufacturing process

To manufacture the power parts of the machine, it is necessary to use sheet metal 10 mm thick. To draw the outlines of such parts for their further cutting, you can use the drawing as a guide. It is not necessary to adhere to exact dimensions, since only the dimensions of those parts that you are going to process on a belt sander will depend on them. You can draw the outlines of the parts on a sheet of metal with a marker and use a grinder and jigsaw to cut them out. It is much easier to cut such parts with a plasma cutter, but not everyone has such equipment at home.

Base, body parts and engine before assembly

To make the base of a homemade grinder more reliable, it is best to use a sheet of metal 12 mm thick for its manufacture. You can use screw connections to assemble the base of the angle grinder, but then you will have to drill a lot of holes, which will greatly weaken the entire structure. Assembling the base of your machine using electric welding will be much easier and more reliable.

Machine base

The semi-circular grooves on the belt sander parts, rotating the platform on which the rollers are located, will take a long time. To make such grooves yourself, you will have to tinker with a drill, cutters and files, and also use a drill. You can make your task much easier if you have a qualified milling machine make these grooves.

Plastic model of the machine: thanks to the rotating group, the angle grinder can be in a vertical position.

It is best to use titanium or duralumin (D16) to make the rollers of your homemade mini-machine. If it is impossible to find gaps from these materials, then steel can also be used, but the rollers must be made as light as possible by choosing metal from their interior. To make the rollers of a homemade machine, you will need the help of a qualified turner, just take care to prepare a drawing for it.

Sharpening machine rollers

The roller of a larger belt grinder, which will be mounted on the electric motor shaft, will still have to be made of steel, since a titanium rod of this diameter is very difficult to find, and duralumin may not withstand significant loads. For the entire homemade machine, you will need to make 4 rollers, the dimensions (diameter) of which are as follows: one drive roller - 150 mm, one tension roller - 100 mm, two small ones - 70 mm. If you plan to make a mini machine, the diameters of the rollers may be smaller.

When assembling a homemade machine with ready-made rollers, it is very important that they lie strictly in one row. Otherwise, you will constantly experience the tape slipping. The width of the rollers depends on the size of sanding belt you will use on your equipment. When making a drawing for the manufacture of rolls, be sure to take into account that they must have a barrel shape, this will ensure reliable retention of the sanding belt on them during operation. To give the rollers this shape, a small chamfer is made from each edge: 1–2 mm.

The finished rolls of your homemade belt sander should have a smooth surface, this must be reported to the turner who will make them. The bearings on which they will rotate must only be of the closed type, otherwise they will quickly become clogged with dust generated during operation of the grinding machine. In order for your homemade equipment to work for a long time and without interruptions, you need to choose bearings that have a class of at least 6a. The rollers of the grinding machine rotate at a high frequency, so the bearings for them must be of the highest quality.

Grinder ready in horizontal position with additional table

Recommendations from experts

1. If a tool sharpening machine is used, it should be inspected before use to determine whether the wheel is in the correct position relative to the saw.
2. This layer of steel must be removed from the sinuses to ensure that all microscopic cracks are removed.
3. If the saw has been used without maintenance for longer than the period allowed by the manufacturer, the amount of metal removed during sharpening should be increased.
4. To check the results of the operation, always use the new product as a reference.

The result of incorrect operation is burnt out tool teeth.

1. The shape of the teeth is a characteristic developed and tested by specialists. If you change it, you will not be able to process parts efficiently. Based on this, sharpening must be done so that the shape of the teeth and the profile of the blade remain the original ones, manufactured at the factory.
2. If all operating and maintenance rules are followed, the band tool will serve you faithfully until its width is worn down to 65 percent of its original size.

There is an opinion among amateur craftsmen that there is no particular need to remove burrs formed during processing. This is fundamentally incorrect, since microscopic cracks may appear on the canvas.

After completing the work, the tape device must be immediately cleaned of tree sap, sawdust, and resin. Before starting maintenance, the tool must be carefully inspected, otherwise the wheel will clog. This will lead to a significant reduction in sharpening efficiency.

Basic Information about Band Saws

A band saw is a cutting tool made in the form of a toothed belt with a closed loop. To service it, you will need a special sharpening machine for band saws. In addition, band saws have a number of other significant differences from traditional circular saws. The most significant of these differences is the ability to cut with such a tool with a minimum width. It should be noted that this is especially true when it is necessary to saw valuable wood and blanks made of expensive metals.

Equipment equipped with a band saw can be successfully used to process parts made of different materials and different configurations. This processing is characterized by a minimum amount of waste of the processed material, exceptional cutting quality and high process speed. However, such processing parameters can be achieved provided that the sharpening of band saws on the machine is carried out not only correctly, but also regularly. When servicing a tape tool (especially if you handle it yourself), you should strictly adhere to the recommendations of qualified specialists.

Automatic band saw BOMAR

Tooth geometry

Depending on the characteristics of the material being processed, band saws can be made from different materials and differ in the geometry of the cutting teeth. If we talk about the separation of semi-finished metal products, then the two most common types of steel used for the production of saws are 9HF and B2F. Equipment for sawing wood is equipped with homemade saws, the hardness of which on the HRC scale is at least 45 units.

Band tools for sawing wood are also divided into three types: carpentry, dividing, and for processing logs. Different types of tools naturally have different parameters (blade size, shape and sharpening angle). Harder wood species are processed with a tool with a smaller sharpening angle.

Today, bimetallic band saws are increasingly used to separate hard steel parts. These saws are called bimetallic saws because they are made of two different metals: the cutting teeth are made of steel with a high content of tungsten and molybdenum, and the blade itself is made of spring steels. Of course, such canvases are much more expensive than standard models, since their production requires special equipment in which the connection of two dissimilar metals occurs under the influence of a laser.

Bimetal Band Saw

Application of tapes

The key component of every band saw is the band saw (blade). Band saws are widely used when working with wood, metal, rubber, plastic and various flexible materials.

There are three types of these products.

• Manual tape devices - these machines can be called household ones; they are most often used at home.
• Desktop modifications - these units are often purchased for small industrial facilities, woodworking companies, and workshops.
• Stationary units - such installations are classified as professional; they are used in large industries, factories, factories, large workshops, and so on.

Teeth and sharpening angles

Blade profiles depend on their purpose and the properties of the materials being cut. The main distinctive parameters: sharpening angle, tooth shape, installation distance. Profiles are labeled as follows:

• HB – used for curly or decorative haircuts;
• PV – analogous to NU, but with flattened teeth;
• KV – for soft materials, suitable for wide saws;
• NU – for soft materials, has a large pitch;
• AB – for longitudinal cutting along wood fibers, used for hard grades;
• PU – for hard materials, used for mounting on wide blades.
• WM – universal, for materials of different hardness;

The sharpening angles for band saws are selected as follows:

• from 180 to 220 for dividing lines;
• up to 150 for sawing lumber.
• 350 for joiner's saws.

Sharpening methods

Sharpening a band saw for wood can be done in one of the following ways:

• full profile;
• only edges.

Full profile turning has the following advantages:

• operations are carried out with high precision, as they are performed on automated machines;
• specially shaped emery passes the entire surface of the space between the teeth simultaneously with the planes of adjacent cutting edges in one movement;
• tops of regular shape without angularity are formed.

Sharpening of edges can be done in the following ways:

• A machine with a flat abrasive wheel or a special shape is selected, depending on the profile of the cutting edges.
• At home, it is recommended to carry out processing with an engraver or regular sandpaper of suitable sizes. To operate, you will need to wear goggles and gloves.
• In the absence of tools from points 1 and 2, the use of needle files is allowed.

How to properly sharpen a blade?

According to statistics, more than 80% of device failures occur due to improper sharpening. The need for sharpening is revealed visually - by the appearance of the teeth themselves or by the state of the cut (increased unevenness of the plane).

Stones for sharpening band saw blades are selected based on the hardness of the teeth. Corundum stones are used to sharpen products made of carbon and alloy steel. Bimetal blades require borazone (CBN) or diamond blades. The cutting blade configuration should be determined based on the characteristics of the tool. It can be in the form of a plate, flat, cup, profile.

Before starting work, it is recommended to leave the canvas hanging unscrewed for 10-12 hours.

Conditions for sharpening blades with your own hands:

• Avoid putting excessive pressure on the disc (this can cause annealing);
• the indispensable presence of liquid for cooling;
• checking for clogging;
• ensure the integrity of the height and shape of the tooth section;
• ensure systematic removal of metal according to the cross-sectional shape of the tooth.

In general, despite the abundance of rules and conditions, these devices are quite undemanding in terms of sharpening. They can be operated either using a special sharpener for band blades or manually. In addition, mugs of various configurations and substances can be used for processing.

Before sharpening the blade, it is advisable to familiarize yourself with the basic methods of performing this procedure.

Full profile sharpening

This method is considered to be of particularly high quality and is performed on automatic equipment. The Elborov disc (Borazon), ideally adapted to the configuration, processes the entire interdental cavity along with the corresponding planes of adjacent teeth in one pass. In this case, it is impossible to obtain an incorrect configuration at the base of the teeth.

What can you sharpen with?

A small blade with small teeth can be sharpened with a special needle file or a regular machine attachment. However, such sharpening is very time-consuming and low-productive, and also very often causes a number of saw breakdowns. Taking these problems into account, many craftsmen have long been using an electric sharpening machine, which quite quickly and equally sharpens all the teeth of a band saw.

Such machines are divided into several groups.

• Fully automatic centers , they use a specialized feeding and sharpening program; such machines are used mainly by large workshops for sharpening or restoring large and massive band saws. The process takes place using cooling chemical liquids and under strict control.
• Semi-manual machines with special tool consoles.
• Small automatic centers , in which the step of moving the web is adjusted and the process is controlled.

A sharpening machine is a unit that helps sharpen a saw efficiently using a sharpening wheel. Most often, a specific unit is selected for a certain type of saw.

The machine includes:

• base and external structure;
• tool holder;
• special drives used to move the blade and rotate the grinding wheels.

How to sharpen a band saw correctly

Let us immediately note that in the absence of experience and skills in performing such work, it is better to entrust saw sharpening to professionals. Violation of the geometry of the cutting edge teeth, the appearance of burrs on the metal, or incorrect installation will significantly reduce the service life of the blade.

When deciding to sharpen your band saw yourself, it will be helpful to first familiarize yourself with the key definitions that you may need to know during the process. So, to properly form the cutting edge you will need:

• the height of the teeth is the distance between the highest point and the base;
• pitch - the distance between the teeth, usually ranges from 19-25 mm.
• sharpening angle – depends on the intended purpose of the tool; for example, the recommended sharpening angle for carpentry saws is 35 °, for splitting saws - 18-22, intended for sawing timber - no more than 15 °.
• installation - deviation of the teeth from the plane of the main saw blade;

The sharpening angle is determined by the manufacturer, so when sharpening the saw yourself, it is recommended to adhere to these parameters.

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

Wiring

Inserting bandsaw blades into the wood is the first step in restoring the edge profile. During operation, the position of the teeth may change, so until the correct geometry is obtained, there is no point in sharpening the saw part.

The saw can be opened in three ways:

• stripper - the first and second teeth deviate in different directions, the third remains straight. This profile is designed for sawing hard materials;
• wavy - the most complex option, similar in shape to a wave. Here, each tooth is given an individual shape, and such installation is usually performed only in specialized workshops.
• classic - teeth alternately deviate to the right and left;

It should be noted that when setting, not the entire tooth is bent, but approximately 2/3 of the apex. The procedure is carried out on a special band saw. The cost of such a tool is quite high, so buy it if there is a need to adjust several tools. Its availability can become the basis for sharpening activities.

Of course, you will be able to do everything correctly the first time, even on an adjustable machine, it may not work, so at least the profile geometry should remain the same as before starting work.

Sharpening

This is the main step of modern dressing and can be done in two ways.

Full profile saws are sharpened using a CBN wheel mounted in a special sharpener.

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

Teeth sharpening is done manually or using specialized equipment.

This method is used for self-sharpening band saws. Here you can use a regular grinding wheel or file.

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.

Diamond, CBN and aluminum oxide wheels are used for automatic sharpening. It is important to understand that during this procedure, only sharpness is given to the teeth; the geometry created after installing the blade must remain unchanged.

Myths and reality of band sawing.

Part 2.2

Do this several times and check with a protractor what you got.

For clarity, you can combine these sheets. Please note that a data discrepancy of just 0.5° already leads to inaccurate profile grinding.

And an inaccurate connection of the left straight line also leads to a change in the pitch of the saw. Now imagine that the sharpener should do all this not on paper, but on a rotating circle, where it is even more difficult to maintain the exact dimensions. But it is not enough to form it once.

It is necessary that when re-sharpening after sawing, the profile of the end of the wheel should be exactly the same as during the previous sharpening, which is practically impossible. Therefore, it is not so important what quality you sharpen around. Even if you have a very good wheel and you can sharpen a set of band saws for an entire shift without additional profiling, you will almost never be able to repeat exactly the same profile of the end of the wheel the next time you sharpen it, which means you will not be able to accurately sharpen the profile of the saw teeth after its dullness.

Now you understand why accurately shaping the end of a circle profile is not just difficult, but an extremely difficult task. To somehow make its solution easier, you can sharpen with bakelite reinforced circles 3-4mm thick.

But they are difficult to find in the required quality. Therefore, the profile of the circle must be monitored very carefully. Otherwise, this leads to the following changes in the body of the band saw: A change in the radius at the base of the tooth, which entails a change in the pitch and the impossibility of normal sharpening of the saw on the next pass.

The circle begins to unevenly cut into the front edge without touching the back, or vice versa, that is, it becomes impossible to grind the full profile of the saw at once. The sharpener tries to sharpen at least the cutting edges of the teeth in just two or three passes, but at the transition point a microhump or microcavity appears, which leads to the appearance of microcracks, and microcracks that have already arisen during sawing are not removed, which leads to premature rupture of the saw along the body.

Sharpening blades in winter

If everything is clear about sharpening blades under normal conditions, then sharpening in the cold season needs to be said separately. There is a difference in sharpening band saw blades in summer and winter. It consists of changing the degree of sharpening. The permissible angle of inclination in winter should be 90 degrees, in contrast to summer, when the sharpening angle is 120 degrees.

When sharpening a blade on a machine, before starting the process, you need to make sure that the grinding wheel is positioned exactly in relation to the tool.

It is extremely important to remove such a volume of metal from the recesses that all microcracks are reliably eliminated. If the blade operates without normal maintenance longer than the manufacturer allows, the amount of metal removed in one step should be increased. Always use a new blade as a reference to check the sharpening effect.

• The configuration of the teeth is an indicator that has been worked out and adjusted over the years. If operating standards are maintained, the belt will operate properly until the width is reduced to 65% of its original width. When sharpening, the width of the blade decreases.

• There is one completely incorrect piece of advice that says you don’t need to remove abrasion marks after sharpening. If you take this into account, the occurrence of microcracks in the saw is guaranteed;
• At the end of the work, the tape blade must be cleaned of chips and resin, without putting it in a box, and carefully inspected before sharpening. Otherwise, there is a very high risk of contamination of the abrasive discs. And this will certainly lead to a poor-quality sharpening process.

Six rules for sawing

1. Tension Your Band Saws Correctly To ensure that your band saw is properly tensioned, perform a vibration test. Hakansson Sawblades band saws are low tension saws, i.e. operate with 35-50% less tension than competing carbon saws. A slight tension of the belts, ensuring sufficient stability, reduces the effect of fatigue during constant bending by 70% or more, therefore, significantly extending their service life. Energy consumption is reduced by 20%. The tension force for Silco saws should be about 100-150 kg/cm2, in particular, saws with a width of 32-51 mm for band saws should be tensioned with a force of about 130-150 kg/cm2. To measure the tension of the band saw, your machine must have some kind of device (dynamometer, pressure gauge, etc.). If you don't have one, use our strain gauge. The tension force used also largely depends on the design of your machine or sawmill. To get the most out of your band saws, whenever possible, always try to follow the guidelines below. A. For machines with mechanical tension. Remove the guide rollers - you cannot perform this test if the band saw blade has limited horizontal movement. Make sure the saw wheel surfaces are in good condition. If equipped with straps, the straps must not be hard, twisted, splintered or broken. On machines with loose V-belt fits, replace them with a smaller size to ensure a tight fit. This will reduce vibrations on your machine or sawmill by more than 80%. Place the blade on the machine and tension it with the tension recommended by other manufacturers for saws made of other steels. Close the cover for safety reasons. Start the machine by setting the switch to high speed cutting mode. Stand in front of the machine, hand on the tension mechanism, eyes on the band saw. Very slowly begin to loosen the canvas without taking your eyes off it. You must reach a position where the canvas begins to vibrate. When you see that the blade begins to vibrate, you have reached the zero position. Now start adding tension by turning the tension screw a quarter turn. Slowly until the saw stops vibrating and starts to function smoothly again. At this point, add another full turn of the tension screw. Your canvas is now properly tensioned. Turn off the machine and put your guides back in place. You are ready to go. Always release the belt tension between jobs. When you loosen the tension, remember that to completely relax the saw, it is enough to turn the screw 8-10 full turns. To tighten it, you just need to turn the screw in the opposite direction the same number of revolutions. If you follow these procedures as above, you will only need to perform the vibration test once. B. For machines with hydraulic tension. Perform the above operations. At the same time, reduce and increase the pressure in steps of 10-12 kg. Once you have eliminated the vibration, add another 25 kg. Note the pressure on the pressure gauge scale. ALWAYS REMOVE THE TENSION ON THE BLADE BETWEEN USE The next time you use the blade again, use the settings you remember so you don't have to repeat the vibration test. B. For machines with pneumatic tension. Perform the above operations. At the same time, reduce and increase the pressure in steps of 5 kg. After you have eliminated the vibration, add another 5 kg. Note the pressure on the pressure gauge scale. ALWAYS REMOVE THE TENSION ON THE BLADE BETWEEN USE The next time you use the blade again, use the settings you remember so you don't have to repeat the vibration test. WARNING: IF YOU DO NOT PERFORM A VIBRATION TEST ON OUR SPECIAL SILICON STEEL SAWSAWS, YOU WILL BE OVERTIGHTENING THEM AND WILL NOT ACHIEVE THE WEAR RESISTANCE AND DURABILITY OF WHICH OUR HIGHLY DUTY STEEL SAWS ARE CAPABLE OF. 2. Selecting the correct lubricant for the band saw blade. Never use water as a lubricant for band saws. Water is not a lubricant and should not be used for many reasons. Not only is water unacceptable as a lubricant, but it also causes the blade to rust, causing corrosion, and inappropriate chip blowing. This prematurely destroys the body of the band, and the grooves between the saw teeth. Water is also wet tires or V-belts. There is no need to lubricate the blade unless the resin sticks to the saw blade. If sticking does occur, we can suggest the following: For proper lubrication, mix high-adhesive chainsaw oil with half and half kerosene or diesel fuel. Apply the mixture using a spray bottle to both sides of the blade every four minutes while the machine is running. After lubrication, sawing noise is reduced by more than 50%. Do not apply lubricant until the noise begins to increase. You should lubricate both sides of the saw. Belt lubrication increases belt life by more than 30%. By using lubricant sparingly, you will be able to saw high-grade wood without getting it dirty; We also believe that this extends the life of the rubber gaskets. 3. Always loosen the band saw tension. When you are finished, release the tension from the saw. As bandsaw blades operate, they always heat up and lengthen, then shorten as they cool down during each cooling period. Therefore, saws left on the pulleys in a tense state overload themselves, and an imprint from the two pulleys forms on them, which causes cracks to appear in the spaces between the teeth. When you leave the belt on the machine under tension, you not only distort the rim and surface of the belts (making them very rough), but you also apply excessive stress to the bearings and shafts. Believe it or not, you can sooner or later damage the geometry of the pulleys and significantly reduce their service life. You also destroy your rubber gaskets and V-belts. 4. Selecting the correct tooth set. The spread is correct if in the space between the saw blade and the wood being processed you have a mixture of 65-70% sawdust and 30-35% air. A sign that you have chosen the right cut is the removal of 80-85% of sawdust from the cut. If your teeth set is too wide for the thickness of the wood available, then you will have too much air and not enough sawdust in the cut. You will have excessive sawdust loss, and this may be accompanied by tooth marks on the surface of the board. If you don't have enough clearance, you won't get a strong enough air flow to remove sawdust from the cut. A sign of this is hot sawdust. This can cause the most devastating damage to the bandsaw: operating intervals will be short and the saw will fail prematurely. The sawdust should be cool to the touch, not warm or hot. And finally, if the cut is insufficient and the sharpening angle is incorrect, the saw will cut a wave on the board. Typical example: If you are sawing a 35 cm log, the sawdust is warm to the touch, the feed speed is normal, long working intervals are maintained, and at least 85% of the wood dust is sucked out - the saw teeth are set correctly. Then you take on a 60-centimeter log. It would be logical for the widow to increase the spread of teeth when the mass of the tree increases by 100%. In fact, in this case you should increase the tooth set by approximately 20%. From our point of view, you cannot work with logs of different diameters, timber and beams using the same tooth set. You must sort the timber. For every 20-25 cm increase in size, you should increase the setting by approximately 18% depending on whether the wood is hard or soft, wet or dry. The only way to achieve the desired layout is to carry out test cuts on a specific log. Increase the setting by 0.05-0.10 mm on each side until tooth marks become visible. This means that you are working with a 50/50 mixture of air and sawdust. After this, reduce the tooth set by 0.75 mm on each side and you will achieve the desired result. VERY IMPORTANT: YOU MUST ONLY BREAK THE UPPER THIRD OF THE TOOTH, NOT THE MIDDLE OR LOWER. YOU DO NOT WANT THE GAP BETWEEN THE TEETH TO BE COMPLETELY FILLED WHEN YOU SAW. When you work with softwood, whether wet or dry, the chips expand in volume to 4-7 times their cellular state. Hard wood, wet or dry, increases in size only 0.5-3 times when freed from its cellular structure. This means that if you are sawing 45cm pine logs, you will need to set the teeth 20% further apart than when cutting the same oak logs. Always spread the teeth before sharpening. It is necessary that the end of the tooth is perpendicular to the tape. Set the teeth 0.02-0.03 mm more than required, and after sharpening the set will be what you need. It is important to know that there is a real formula for correct tooth set. For sawing logs on Avangard-LP band sawmills, we offer a series of “Silco” saws with a width of 31, 38, and 51 mm and a tooth pitch of 19, 22, 25 mm, respectively. The thickness of the canvas is 1.07 mm. The saw teeth are hardened and set by the company with an accuracy of 0.04 mm. There are four types of wiring (on both sides): - for dry hardwood (oak, beech, ...) - 2.03 mm; — for wet hardwoods -2.18 mm; — for dry coniferous and soft-leaved species -2.29 mm; — for wet coniferous and soft-leaved species -2.53 mm. Saw 32 mm, pitch 19 mm Soft wood Soft wood with a lot of knots Medium Hard wood Hard wood Very hard, frozen wood Recommended sharpening angle 10° 8° 10° 10° 8° Cutting width, mm Set to side, mm Set to side , mm 0-150 0.53 0.48 150-300 0.60 0.53 300-560 0.74 0.60 560-760 0.86 0.74 more than 760 0.96 0.86 Saw 38 mm, pitch 22 mm Soft wood Soft wood with a lot of knots Medium T hard wood hard wood very hard, frozen wood Recommended sharpening angle 10° 8° 10° 10° 8° Cutting width, mm Setting per side, mm Setting per side, mm 0-150 0.48 0.43 150-300 0.53 0.48 300-560 0.60 0.53 560-760 0.68 0.60 more than 7 60 0.78 0.68 Saw 51 mm, pitch 25 mm Soft wood Soft wood with a lot of knots Medium Hard wood Hard wood Very hard, frozen wood Recommended sharpening angle 10° 8° 10° 10° 8° Cutting width, mm Set to side, mm Set per side, mm 0-150 0.48 0.43 300-560 0.53 0.48 560-760 0.60 0.53 more than 760 0.68 0.60 5. Sharpening procedure There is only one way to sharpen band saws. The stone should travel down the surface of the tooth, around the base of the cavity between the teeth, and up along the back of the tooth in one continuous motion. There is no need to touch the cavity itself. The space between the teeth (gallette) is not a sawdust bin. In fact, it is the second hardest part of the saw. A good gallet is like an upside-down airplane wing. The power flow of air, cooling of steel and removal of sawdust depend on it. If you have the correct tooth set, air is forced along the log at the same speed as the saw, causing sawdust to be sucked into the gullet. The sawdust cools it significantly as it passes around the inside and outside of the next tooth. You need to ensure that the space between the teeth is filled to 40%, which will provide the desired degree of cooling and increase the operating time of the saw. If you only sharpen the front and back of the tooth, you will compromise the integrity of the tooth, which will cause the saw to break. So, you have checked your indicator and the accuracy of the teeth set, which are actually set 0.02-0.03 more than what you need. You've double-checked the angle of the sharpening device and it's exactly what you want. Now you can start sharpening your saw. 6. Correct sharpening angle. Thanks to deep gallets, we can use reduced sharpening angles, which transfer less heat to the tip of the tooth. The Silco series of tapes use a 10 degree tooth angle that is capable of penetrating most medium hard to medium soft wood surfaces. If you are working with very hard wood (such as oak, walnut, ash, or frozen wood), the saw may lift as it cuts. This is called repulsion. The tooth angle must be reduced again to 8°. You will notice that as the angle goes from 10° to 8°, the tooth becomes more perpendicular, thus increasing the penetration factor. If the tip angle increases from 10° to 12°, this results in decreased penetration into hard rock. If you use an 8° bevel angle on soft wood, the saw may vibrate from overexertion if the wood is not knotty. If there are hard knots, the angle of inclination should be 8°. On the other hand, when working with very hard wood, if the angle of inclination is 12°, the tooth will break off the hard surface because the end of the tooth is pointing too far forward. The 12° hook angle causes a pushing effect, which causes the saw to lift upward. The saw band is clamped in its movement, cuts straight across and lowers at the end of the process. This also leads to overheating of the tape and its overvoltage. By making sure that you have set the correct angle of inclination of the tooth, and the gallet mathematically exactly matches this inclination, you will achieve a straight cut. You must understand that tooth set and tooth angle are interconnected, they work together. We produce band saws with four types of tooth set with a tooth angle of 10°. Whatever you cut, 70% of the time this bevel angle is perfect for the job. Caution: You trust the templates and gauges on your sharpening machine. But they are hardly accurate. Cars wear out. The pins and guides that run the back of the belt on the sharpening machine wear out. The belt begins to slide at an angle, just an angle of a few degrees, and you are not able to notice it, but you feel that something is wrong as soon as you start working on the sharpened belt. To get an idea of ​​the wear and tear on your sharpening machine, consider the following. A saw blade with a length of 4000 mm will pass along the sharpening device at least twice during each sharpening. Six sawing rules. Tooth angleYou have sharpened 50 bands. In total, this will be 400 m of length of the tapes, which rub their back side against the alignment pins, loosening them. How do you know if the tooth angle is set correctly? Using a protractor. Without it, you can assume that the inclination angle is set correctly. We have analyzed over 4,000 saws since 1992. And more than half of all problems stemmed from the incorrect assumption that the sharpening angle was set correctly.

Working belt

On a belt sander you can always see a spring, which is necessary to ensure automatic tension of the sander belt. If you use such a spring, changing the tape will be very convenient, and its tension will be adjusted automatically. It must be said right away that you will have to change the tape even when processing the product several times. When processing any metal part, you need to start with a tape with a larger abrasive, gradually changing it to a smaller one.

Very important attention should be paid to the adhesion of the tape. There are options for proper gluing on the Internet, and you can also watch this process on video. To make it, you need to use fabric-based sandpaper. The seam on the braid is made only from one end to the other and must be reinforced, for which a strip of dense fabric is used, placed on the back side of the area to be glued. When gluing the sanding tape, you should only use flexible adhesive and it should be of the highest quality.

For reliable and high-quality gluing of the sanding belt, it must be properly prepared. You can glue the tape using glue for a heat gun - this method can be clearly studied in the video above. For heating, you can use a regular technical hair dryer.

If desired, you can make your homemade grinding machine even more versatile; to do this, it must be equipped with an additional table located on the side of a larger pulley. This allows the parts to be sanded on a belt sharpening machine by pressing them against the sanding belt on the side of the larger pulley. If you decide to make such a table, it will be necessary to provide for the possibility of changing the direction of movement of the sanding belt, which should always move towards the desktop, and not far from it.

A simpler design of an angle grinder can be seen in the video below:

Setting up band saw equipment

Correct and high-quality work of carpentry installation directly depends on the settings of the equipment. There is an installation and configuration diagram. First, the wheels are parallel to each other. Next, fluoroplastic washers are installed, which are necessary to prevent vertical displacement.

For the first time, the launch is carried out without guides. At this stage, the smooth start-up and cleanliness of the engine are checked, then a test cut is made with a knife, but with minimal loads. To work with a larger load, a block with guide belts is used. This design consists of two halves that are installed along the line of the cutting blade.

Previously, craftsmen made not only machines, but also cutting blades with their own hands. It is difficult to close a tape assembly into a ring on your own, and this requires at least some initial experience in assembling the machine. Sharpening according to the model is also done manually. You can do all this yourself, saving money, but the modern market is simply filled with all sorts of devices and parts that improve the quality of material processing or make the equipment multifunctional. The main thing in this matter is to remember about safety precautions, because serial or home-made models pose a great danger to human health.

Preparing the device for work

In the process of constant use of a tool, a decrease in the quality of the cutting edge is inevitable. It becomes dull and the width of the teeth decreases. Based on this, sharpening and tuning a wood saw is a necessary part of band saw maintenance.

It should be noted that teeth adjustment must be done before sharpening them, and not vice versa.

Tool layout

Using an adjustable machine.

Embedding is the process of folding the teeth in at the sides. This is necessary to ensure that the saw blade does not get stuck in the workpiece, and also to reduce friction during operation.

There are 3 main types:

1. With the classical method, the teeth are bent to the right and left in strict sequence.
2. With the stripping method, every third of the teeth remains in their original position. Ideal for tools designed to cut particularly hard wood.
3. With a wave setting, each tooth is assigned a different bend size. In this case, the profile of the canvas takes on the shape of a wave. This method is the most difficult.

When setting, you should not bend the entire clove, but only one-third to two-thirds from the top. Manufacturing companies recommend carrying out the operation in such a way that the bending range is 0.3-0.7 mm. The work is carried out using a specialized distribution tool.

Sharpening the saw

Elbor circles of different shapes.

1. The need for surgery is determined visually. In this case, it is necessary to pay attention to the condition of the teeth and the quality of the incision walls (for example, their increased roughness).
2. Wheels for the tip of a band tool are selected according to the degree of hardness of the teeth. Aluminum oxide discs are required for tool steel attachments. Bimetallic saws are sharpened on borazone or diamond wheels.
3. The shape of the emery for tape devices must be selected based on their parameters. Known circles are cup-shaped, profiled, disc-shaped, and flat.
4. Before carrying out the operation, it is necessary to unscrew the saw and leave it in this suspended position for about 10-12 hours.

Manual sharpening of saw teeth.

The wood saw sharpening scheme should take into account the following provisions.

1. Metal removal along the tooth profile should be uniform;
2. It is necessary to suppress excessive pressure from the sharpening device. This may result in annealing;
3. The blade profile and tooth height must remain unchanged;
4. Liquid cooling must be provided during operation;
5. There should be no burrs on the teeth.

The theoretical instructions for sharpening band saws for wood say that this should be done on the front side of the teeth or on the back and front. However, in real life, most specialists and amateur craftsmen perform the operation only from the reverse side, because it is more convenient.

Saw maintenance

To maintain the blades, it is not enough to sharpen the teeth; they also need to be set apart. These two procedures are performed in order of succession: they begin with setting the teeth, and end with sharpening them. This chronology of work must be strictly observed. Dilution is carried out in order to reduce saw friction in the process of cutting a particular material (wood, metal, plastic, etc.). There are several methods of breeding, which depend on what elements need to be obtained after processing and the strength of the starting piece.