Homemade band saw with your own hands. Homemade band saw Drawing band saw for metal

Band saws are powerful industrial tools for cutting wood and metal. The cutting blade is a continuous belt moving in one direction along the drive pulleys and one side interacting with the material being cut. With a relative simplicity of design, a do-it-yourself band saw is quite real. How to make it and how to set it up correctly will be described in this article.

The band saw has been known for a long time, since the beginning of the 19th century (the first patent was in 1808). The very principle of the continuous movement of the saw blade (as opposed to reciprocating with a hacksaw) has long been of interest to engineers. It is more technological for many reasons:

• The hole saw cools naturally - a small part of it is in contact;
• The movement of the teeth in one direction damages the cut area less;
• Tape is easier to sharpen;
• The drive and tension mechanism is simplified as much as possible, as is the lubrication mechanism.

But on the way to implementation, there were some difficulties associated with connecting the saw blade into a ring. The tape must be strong, resilient and, at the same time, flexible and sufficiently elastic. Weld such metals so that there are no seams that interfere with its movement in the body of the material and cause overheating (as a result, a gap at the junction).

On band machines for wood, these difficulties were minimized, but on metalworking machines, everything was different. Only towards the end of the century in France was it possible to establish the production of acceptable saw blades, which were welded by contact welding and then the seams were carefully ground.

At the moment, several varieties of circular saw blades are produced:

• jagged;
• friction saws;
• electrospark.

As a rule, it focuses on the toothed blade of a bimetallic structure. This is a belt made of strong steel (spring or similar in properties) with teeth made of extra strong tool steel with a hardness of M42-M71. Sharpening of teeth is different for different materials.

For example, for cutting pipes and channel bars, you will need a tape with reinforced tooth backs, for stainless steel - with a sharp sharpening of 15 0 and an increased distance between them. When sawing, stainless steel forms viscous chips that interfere with the movement of the saw, getting stuck between the working edges. If you have to cut large-sized metal, then you need a blade with periodic wiring - narrow and wide alternate, to eliminate the threat of the tape getting stuck in the cut.

In order for the band saw to work properly with your own hands, count it under the factory-made tape. It is quite difficult to make it with your own hands, even if you manage to find a suitable metal and your workshop has all the necessary welding and grinding equipment.

Band saw device

The band saw is highly versatile. It can cut wood and metal

• vertical;
• horizontally;
• at an angle.

There are machines with a working console feed, when the material is fixed motionless, and the blade moves on it, and there are built according to a different principle - the saw unit is motionless, and a log, board or metal sheet is fed. The second option is more affordable for self-production.

Main knots band saw:

• The bed (frame) is made heavy and durable. It must ensure the stability of the machine during operation and the absence of vibrations;
• Working table with stop and ruler;
• Drive pulleys;
• Engine (from 2 kW);
• Remote Control;
• Lubrication system;
• Protective cover.

It should be remembered that the cutting speed of various metals is slightly different. The range is very wide - from 30 to 100 m/min. The average sawing speeds for homogeneous solid metals are shown in the table, but for each specific saw and saw band model, they may differ by 10-15%.

DIY band saw

On how to make a band saw with your own hands on the Internet, you can find a lot of materials, photos and videos. For example, the Canadian website of Matthias Wandel offers drawings of a machine tool almost entirely made of wood. But let's focus on something less exotic that can be done both in a home workshop and in a small woodworking or metal workshop.

Bed manufacturing

The initial stage is the manufacture of the frame. For a saw for wood, it can be wooden or metal, for metal - only steel. You can weld it from a channel or corner. For a small workshop or workshop, this is not a problem. The dimensions of the bed are selected depending on the expected dimensions of the material being processed. A normally sawing home-made machine can handle wood up to 350 mm thick and metal a few centimeters thick.

The carrier bar is a channel No. 8, which is welded to the frame or bolted. It must be strictly vertical and fixed at least at two points along its length in order to eliminate the risk of deflection. When biting the saw, for example (which sometimes happens) or sawing material large sizes loads are quite large.

On the frame there is a horizontal working table with cuts for the movement of the tape, a ruler, an emphasis, clamps and other devices for feeding and holding workpieces. The height of the table from the lower stops is 0.7-0.9 meters. The height of the bar above the table is 0.6-0.8 m.

Installed at the bottom of the bed asynchronous electric motor with start-up capacitors, connected by a belt drive to a variable diameter drive pulley. If it is necessary to change the cutting speed, the V-belt is simply transferred to a different diameter. Belt tension is provided by a spring tension mechanism.

Mounting the drive

To drive the belt, wooden or metal pulleys of the same diameter (240-260 mm) are used, which are mounted on shafts mounted on bearings. The lower pulley is connected by a shaft to the motor drive. The shafts of the saw pulleys are fixed on the bar. The lower one is motionless, the upper one is in the slot of the fixed tension mechanism. This allows the use of tapes of various lengths.

The machine is protected from tape beats by a special damper mechanism, which is located under the desktop. Drawings of this device can be found on the Internet. Sometimes you can see band saws with two dampers - from below and from above working area. This is justified if the machine is designed to work with large workpieces or exceptionally high sawing accuracy is required.

Lubrication system and protection

Lubrication system (adjustable), installed above the work table. Oil flows by gravity to the saw blade in the required amount, which for each homemade machine determined experimentally.

All work units where something rotates or moves must be protected with casings. It's best to make them out of waterproof plywood from 10 mm thick. It won't cost much, and the sanded plywood, painted with enamel, looks very good.

The start system is a standard button with the possibility of an emergency shutdown. It is desirable to make the lower part of the machine in the form of a bedside table with a wide door, or even two. One is for picking up falling sawdust, the other is for accessing the pulleys and adjusting the speed of the belt.

Do-it-yourself tape machine for an experienced locksmith will not be difficult. Part necessary details and nodes can be taken from decommissioned or dismantled machines of your own enterprise or bought on the market or on the Internet, some can be made by yourself. In any case, a self-made machine will cost two times cheaper than a factory one, with the same level of performance and accuracy of adjustments.

With a large amount of use of lumber, sooner or later the question of own sawmill arises. Similar installations are commercially available, but their cost is excessively high.

Therefore, many home craftsmen make their own sawing machine. The following options are used:

Homemade band saw - how to make a sawmill

The main problem of such an installation is its dimensions. Owners of apartments with balconies need not worry. This device is not for you. Unless the desktop version is a substitute for a manual jigsaw.

If we are talking about dissolving round timber into logs, you need a spacious shed, a barn or a separate workshop. Of course, all this is located in the courtyard of a private house.

IMPORTANT! Considering potential danger designs, and dimensions of blanks - the room is selected taking into account the free space around the sawmill.

Drawings are best made using specialized programs, for example, AutoCAD. General form structures in a three-dimensional image is shown in the illustration:

This material describes the vertical tape.

Frame manufacturing

The most important part of the machine is the frame, or bed. It bears the entire weight of the structure and is a support for the desktop. You can make it from a steel profile or a corner, but in terms of material cost, wood is preferable.

The sawmill can be for wood or metal, depending on the selected canvas. At the same time, a properly manufactured frame will ensure reliable operation with any material.

It is undesirable to build a frame from plywood or chipboard. best material there will be a 20 mm board, from which any configuration of the bed can be assembled. The design is glued according to the principle - each next layer crosses the previous one with the direction of the fibers.

It is possible to strengthen the structure by using self-tapping screws to fasten the layers, however, glue remains the main binding material. The “C” shaped structure is rigid, and at the same time relatively elastic. That is, the frame, in addition to the bearing component, acts as a kind of damper, which allows you to smooth out the jerks of the blade for the band saw.

Top pulley block

The next critical part of the installation is the adjustable block of the upper wheel (pulley). The shaft must move vertically to provide tension to the web when it inevitably stretches during operation. The frame is made of durable wood (beech or oak).

Inside the frame is a wooden insert made of the same wood, in which the shaft for the wheel is directly attached. The shaft is machined according to the inner diameter of the wheel bearing.
The insert with the shaft must have one degree of freedom to adjust the axis inclination.

This will be required when adjusting the belt tension. The inclination is adjusted with a threaded stud and a set of nuts integrated into the wood.

Vertical movement is carried out by means of a screw mechanism with a hexagonal head. You can tighten the block with a socket wrench, or install a stationary handle for adjustment. The block frame itself moves along the guides installed in the upper part of the frame.

To do this, they are pre-milled grooves corresponding to the racks of the frame.

IMPORTANT! All nuts in the adjusting mechanism are reinforced with metal plates. Nuts can be welded on if necessary.

The shaft is machined with a flange, with which it is fixed from the back on a wooden insert. An example of such a flange in the illustration:

Manufacturing of wheels (pulleys)

Material for gluing wheels - plywood circles. Cut with a milling compass. Depending on the thickness of the material, there can be 2 or 3 layers. The total thickness of the wheels is about 30 mm. After gluing, it is necessary to cut a hole for the bearing.

For structural stability, it is better to fix the bearing in a coupling machined from fluoroplast or textolite. You can get by with aluminum if you find a circle of suitable diameter.
From the side of the block, a fluoroplastic washer is put on the shaft.

It is undesirable to use metal, due to accelerated wear. The outer side of the bearing is fixed by a flange, in the illustration it is square.

The running surface of the wheels is turned to a barrel shape. In this case, the band saw is self-centering. A bicycle camera is put on and glued to the finished surface. After the final assembly, the wheels are balanced. This can be done by changing the diameter of the holes that are drilled into the disc.

IMPORTANT! When installing the bearing, it is necessary to ensure that the shaft is perpendicular. In the event of a deviation (even a slight one), the wheel will have a runout along the plane, and tape fabric can jump.

A drive pulley is attached to the lower wheel. The shaft is installed rigidly, without the possibility of adjustment. It is better to adjust the tension of the drive belt by the position of the engine; for this, its foundation is equipped with longitudinal grooves at the points of attachment to the base of the machine.

The normal wheel speed for a band saw is 700-900 rpm. When calculating the diameters of the drive pulleys, it is necessary to take into account the operating speed of the electric motor.

The tabletop along with the base is also made of wood. The base is made in the form of a cabinet, inside which the engine with a starting device, and boxes for fixtures and spare parts will be hidden.

The table is made of thick plywood, textolite is glued on the working side. A good option may be a countertop from kitchen furniture with a durable laminate on the surface.
For convenience, the tabletop can be made swivel.

In this case, it will be possible to cut at the desired angle. It makes no sense to describe the mechanism for tilting the tabletop, since each master will decide for himself what degrees of freedom he will need.

Complete with a table, it is necessary to make a parallel stop. The design is the most diverse: from a profile with two clamps to a roller guide system.

Band saw setting

To begin with, the wheels are set strictly parallel to each other. The vertical displacement of the pulleys is removed with the help of fluoroplastic washers put on the shafts. The initial start is carried out without guides, and a test cut is made without load. Properly tuned wheels rotate without jerks, the belt does not tend to come off the pulleys.

After setting, the web guide block is installed. Without it, it is impossible to cut under load. Design feature - the module consists of two parts, but both halves must be set strictly along the line of the saw blade.

Band saw blades

There are craftsmen who make their own band saw blades. You can purchase a blank in the form of a steel strip, and sharpen the band saw according to the template. The connection of the web into a closed tape is the most difficult stage of manufacture. Welding of band saws is carried out by butt contact method. There should be no overlap.

After joining, the joint is polished.
However modern assortment canvases, allows you to buy a kit for any material according to affordable price.

So don't waste your time making Supplies- this is not the case when it makes sense to apply your skills.

Before buying, use the reference material on the selection of the width of the web, depending on the radius of curvature. Perhaps you will cut out curly wood products at your sawmill.

The video shows step by step how to make a homemade saw for wood from plywood and a hub from a Zhiguli. After assembly, a 6TPI wood blade 3380 × 0.65x10 mm is used to work on the saw. from machine JWBS-18 Jet PW10.3380.6. In general, the saw blade must be selected according to the tooth profile, depending on the type of wood. For example: hardwoods are sawn with a tape with a width of 80 mm or more.

Rotation on the main shaft tape machine is transmitted from the electric motor, which is connected to it by means of a belt drive. The speed of movement of the tape mechanism can be adjusted, thereby changing the modes of processing parts. The belt of a surface grinder can be located horizontally or vertically, as well as at a certain angle, which is allowed by some models of equipment in this category.

When choosing a model of a belt grinder for processing a particular part, it is important to consider the length of the surface that needs to be grinded. It is much more convenient to process parts on such machines, the surface length of which is less than the length of the abrasive belt and the desktop. Under such conditions, the quality of processing will be much higher.

Tape grinding machine may have different design: with movable and fixed work table, with free belt. A separate category includes wide-belt equipment, the peculiarity of which is that their desktop, which is also a feed element, is made in the form of a caterpillar. In those models of equipment that have a working table in their design, the abrasive belt is located in a horizontal plane, and in equipment with a free belt, in which a working table is not provided, it can have a different spatial position.

Compulsory constructive element any belt grinder, including a desktop one, is an exhaust device that is necessary to remove dust that is generated in large quantities during processing. Both professional and any homemade grinder used in a home workshop or garage is powered by an electric motor.

Principle of operation

The main parameters of the belt grinder are the feed rate and the force with which the belt is pressed against the workpiece. Parameters such as the degree of grit of the abrasive belt should be selected depending on what material the workpiece is made of, as well as the degree of roughness that the surface of the machined product should have.

The characteristics of the material to be processed, in particular its hardness, primarily influence the grit size of the abrasive belt. The processing modes that are directly related to each other are the feed speed and the belt pressure. So, if grinding is carried out on high speed, but with a slight clamping force of the abrasive belt, then some areas of the surface of the part may not be processed. If, on the contrary, you increase the pressing force and reduce the feed rate, then you may encounter the fact that burns and blackening of the material may appear in certain areas of the treated surface.

Another variation of the machine is a view from the side of the working surface of the tape

The results of grinding are also influenced by how well the abrasive tape is glued together. In order to obtain a high quality finish and not to experience a malfunction of the band machine, do not use abrasive belts that are not glued correctly or have torn edges. When putting on the tape on the shafts of the equipment, it should be positioned so that the end of the seam, which is overlapping, does not lift up on the surface of the workpiece, but slips along it. Learn more about gluing the tape in the video below.

Any, including a manual grinding machine, should provide for the possibility of adjusting the belt tension, which is ensured by moving a movable shaft that is not driven. Tape tension is a very important parameter, the choice of which should be guided by the "golden mean" rule. If the belt of the grinding machine is tensioned too much, then this can lead to its breakage during operation, and too little tension will cause slippage and, as a result, its excessive heating. The main characteristic for determining the degree of tension of the tape is the arrow of its deflection, which is measured by lightly pressing on its surface in a taut state.

The manual belt grinding machine of the group can be operated by one operator, who moves the desktop with the workpiece and rotates it so as to bring all parts of its surface under the abrasive belt.

How to make a belt sander

Many home craftsmen and professionals are wondering how to make a grinder with their own hands. The reason for this question is quite simple: the high cost of mass-produced grinding equipment, which, with irregular use, not everyone can recoup. In order to make such equipment, you will need several basic components: an electric motor, rollers and a reliable frame. Naturally, the drawings of such a device or its photo will not be superfluous. Also at the end of the article you can watch videos on assembling a tape machine on your own.

The motor for belt sanding equipment is easy to find, it can be removed from a used washing machine. The bed will have to be made independently, for this you can use a sheet of metal with dimensions of 500x180x20 mm. One side of the frame should be cut very evenly, since it will be necessary to attach the platform on which the electric motor will be mounted to it. The platform for the electric motor should also be made of a sheet of metal with dimensions of 180x160x10 mm. Such a platform must be fixed to the bed very securely with a few bolts.

Another version of the bed

The efficiency of a belt grinder directly depends on the characteristics of the electric motor that is installed on it. If you are going to make a grinding machine with your own hands, then an electric motor with a power of 2.5–3 kW, developing about 1500 rpm, is quite suitable for you. In order to use such a motor to move the sanding belt at a speed of 20 m/s, the drums must have a diameter of about 200 mm. Which is convenient, if you choose an engine with such characteristics, then you do not need to make a gearbox for your grinding machine.

The drive shaft is connected directly to the motor shaft, and the second - the driven one - must rotate freely on the axis, which is installed in the bearing units. In order for the abrasive belt to more smoothly touch the surface of the workpiece, the section of the bed on which the driven shaft is installed should be made with a slight bevel.

It is possible to make shafts for a belt grinder with minimal financial costs from a chipboard plate. You simply cut square blanks 200x200 mm in size from such a plate, drill central holes in them and put them on the axle with a package with a total thickness of 240 mm. After that, you just have to grind the resulting package and make a round shaft out of it with a diameter of about 200 mm.

Drawings and a detailed analysis of some parts of a machine made of wood.

Wood belt sander (click to enlarge)

Table Tilt Adjustment Mechanism Plate Unit Belt Tensioner

Any construction or major repairs are unlikely to do without boards and various bars. In this case, all this material must be cut to the desired size.

Of course, you can buy ready-made boards or bars. But this will require large financial costs. Therefore, many home craftsmen and professionals prefer to do everything themselves.

And for this you need the right tool, for example, a band saw. And in this case, you should not immediately run to the store to buy a machine.

If you have a little experience, then you will definitely get a homemade band saw. And the technology of its manufacture will be discussed in this article.

Preparatory stage

A do-it-yourself band saw will cost less than its factory version. But in order to make everything right, you should first deal with the design itself. The band saw is designed for sawing large diameter wooden workpieces. As a rule, with its help, boards or bars are made from logs.

The design itself is a frame on which the electric motor and pulleys are mounted. The first is necessary for the rotation of the pulleys on which the cutting blade is fixed. It is with its help that the workpiece is cut.

Before starting work on creating a band saw for wood, it is worth making a drawing. With it, all further work will be faster and clearer for you.

1 - lower drive pulley; 2 - bed; 3 - band saw; 4 - V-belt A710; 5 - damper; 6 - guide; 7 - carrier rod; 8 - upper drive pulley; 9 - table, 10 - electric motor (AOL-22-2); 11 - belt drive pulleys; 12 - bracket; 13 - nut M12, 14 - upper support; 15 - adjusting screw; 16 - slider

• metal corners, profile pipes, channel bars and rolled products;
• electric motor;
• pulleys from old agricultural machinery. Best suited are those that have a diameter of 30 centimeters;
• sheets of plywood or chipboard to create a cabinet;
• the cutting blade itself;
• welding machine and metalwork tool

You must first make a frame (according to the previously drawn up drawing). It is made from a channel (100) by welding. The height of the frame should be about one and a half meters. It is also desirable to make a box under the frame, chips will be collected in it. This design is easy to make from sheets of plywood or chipboard.

carrier bar

Upper belt drive pulley

The damper is necessary to dampen the oscillations of the tape. Made from textolite.
1 - base, 2 - M6 bolt (2 pcs.), 3 - strap, 4 - nut with washer

The guide is for correct filing workpieces

A homemade band saw consists of several basic elements. First of all, it's a frame. It is on it that the rest of the components will be attached. An electric motor is mounted on the frame, which is connected to the pulley. You also need to make a device for feeding a log (or other wooden blank) for cutting.

Let's move on to the pulleys. They are used in the design of two pieces. In this case, the right pulley will be driven, so it does not require rigid fixation. It must be equipped with a spring, which is responsible for the tension of the canvas. The left pulley, which is the leading one, is fixed rigidly in its place.

The pulleys themselves are mounted on special guides made of pipes. In this case, it is necessary to provide for their fixation with bolts. The pulleys must be sharpened so that the edges of the tape protrude a couple of centimeters. Also, the cutting blade itself is installed with a slight slope. In this case, it will stretch itself, which will prevent the tape from falling off during the operation of the machine.

Belt tension mechanism: 14 - upper support, 15 - adjusting screw, 16 - slider, 17 - cover, 18 - M4 screw, 19 - bearing 60203, 20 - gland seal, 21 - end washer, 22 - Grover's washer

Saw band attachment unit (lower pulley)
1 - lower belt drive pulley, 4 - V-belt, 7 - carrier rod, 11 - belt drive pulleys, 19 - bearing 60203, 23 - washer, 24 - M6 locking bolt, 25 - spacer bushing, 26 - axle box housing, 27 - axle box cover, 28 - shaft.

Box for the tape machine

Drive shaft of the tape machine

After preparation, all parts are mounted on the frame. The pulleys are connected to the electric motor using a belt drive (you can mount a chain drive). Next, the power buttons are installed and the manual band saw for wood is ready for use.

Highly important element such a machine is a cutting blade. Some craftsmen make a saw with their own hands. To do this, you can purchase special blanks from steel strips. Further, using templates, sharpening is done.

Place of soldering

Blanks are produced in the form of strips, and a “ring” is needed for the machine. For this, the workpieces are welded. This requires a complex method. The fact is that the overlap should not work out. The connection of the strip into a single ring is done end-to-end. After welding, the joint is carefully polished.

Such complexity of manufacturing a cutting blade forces many to buy ready-made saws. Today, there are a wide range of such products in stores. The main thing is to choose the size of the cutting blade so that it fits your pulleys.

In addition, when choosing a saw, you should pay attention to the thickness. The larger this indicator, the greater the radius of curvature of the canvas. For a more accurate selection, you can use special tables.

A DIY band saw can quickly recoup the time and money spent on its production. But this will be true if you follow the recommendations for the operation of such equipment. Experts give such advice:

the cutting blade must be properly tensioned. The magnitude of this tension will depend on the grade of steel used in the manufacture of the saw, as well as its width. This indicator can be measured using special device- "Tyrzometer";

do not think that the saw will be able to work continuously for a long time. Experts recommend the following mode of operation - two hours of sawing, then the canvas is removed and hung out in a free state for 12-24 hours. In this way, you can extend the life of the saw;

always use a lubricant, especially if you are sawing fresh wood. Freshly felled trees produce abundant resin. Its mass begins to clog the incisors. As a result, the saw begins to warm up and quickly fails. For lubrication (and simultaneous cooling), you can use ordinary water with the addition of a simple detergent. AT winter period experts recommend using a mixture of diesel fuel and engine oil;

Loosen the cutting blade after finishing work. When cut, it heats up and expands a little. After the end of work, the canvas begins to cool and decrease in size. If you leave it in a taut state, then marks from the pulleys will form, in place of which scuffs will subsequently turn out;

follow the rules for sharpening teeth. Both the speed of the work itself and the service life of the cutting blade will depend on this. Also, make sure that the teeth are always well sharpened and their correct divorce is observed.

It is also necessary to strictly observe safety precautions. A band saw is a rather traumatic piece of equipment. It is best to equip it with a protective cover. Such an addition will increase the safety of work, and help to improve the removal of sawdust.

Also, carefully consider the choice of the installation location of the machine. Of course, a homemade band saw does not take up much space. But still, there should be enough space around for free movement.

In addition, take care of high-quality lighting of the workplace. Quite often, such a machine is installed on the street. In this case, try to work only during daylight hours or with a good street lamp.

From the video you will learn how to make a band saw with your own hands from available materials.

Making your own saw is a painstaking and difficult, but quite doable task. The easiest way to make a homemade band saw is to wooden frame- you don’t have to cook anything, and almost everyone has a carpentry tool.

For the frame, it is better to choose strong and hard wood, otherwise the structure will turn out to be unreliable and will vibrate. Some elements, such as a desktop, can be made of plywood, and the ribs are edged with slats for rigidity. Most cheap option- disassemble old furniture, putting plywood on the pulleys and the table. A maple beam will do for the carrier bar.

First of all, you need to decide on the drawings, according to which the frame will be assembled in the future. So, the size of the band saw itself will depend on the height of the working room. It is necessary to think in advance about the convenient height of the table, the length of the rod and the diameter of the pulleys. The drawings can be either conditional, reflecting only the general dimensions, or detailed, as in the photo.

Installation of the rod and supports for pulleys

The simplest do-it-yourself band saw is on a wooden C-shaped frame, where the support bar is made of a bar with a thickness of at least 8x8 cm, to which two supports are attached from one (conditionally rear) part.

Pulleys will be held on them. It is better to make such supports from strong material; multilayer plywood with a strong core is allowed.

The distance between the supports must be selected so that the logs needed for sawing fit there. In any case, it is recommended to make the distance “with a margin” so that there are no problems in the future.

Desktop Assembly

The height of the table should be comfortable for working on it, and at the same time accommodate the lower pulley and drive pulley, motor and a large number of shavings. The form itself can be any, but often it is made in the form of a closed cabinet that serves as a container for sawdust.

It is advisable to provide an easy way to open the table and the waste tray - this way it will be much more convenient to clean the saw.

Cutting pulleys and attaching them to supports

The diameter of the belt drive pulleys can be chosen arbitrarily, but the larger the pulley, the longer and better the saw works. In this case, it is necessary to select the blades correctly, the ideal ratio is 1/1000 of the blade to the pulley diameter. Thus, for forty cm pulleys, the tape should be 4 mm. But with proper operation, even on narrow pulleys, you can safely work with 6 mm blades.

The diameter of the belt drive pulley must be selected depending on the diameter of the main pulleys, the length of the belt and the engine speed.

1. The circumference of the saw pulley is calculated: D = 3.14 * pulley diameter.
2. On average, the web speed should be 30 m/s.
3. The number of revolutions is determined: O = 30 / D;
4. The ratio (C) of the motor revolutions (OM) to the revolutions of the belt drive pulley is calculated: C = OM/O;
5. Drive pulley diameter = D/S.

The diameter is selected one or two sizes smaller than the pulley. This rubber cover prevents the canvas from slipping.

The upper pulley is mounted on a movable block, which must move horizontally, providing tension to the belt.

For this, a special lifting mechanism. The simplest option is a bar located under the block and attached to the lever with a very tight spring. By pressing the lever, the beam raises the block with the pulley, providing the required tension.

It is necessary to provide a way to fix the lever in a given position, for example, with several bolts located at different levels. The spring will provide the necessary pressure and at the same time will dampen the tension, preventing the tape from tearing.

It is important to correctly balance the upper and lower pulleys in the same plane, minimizing the "eights" when the wheels move.

For fastening the upper pulley, it is convenient to use self-centering bearings, which will allow you to quickly remove and put on the wheels.

But they need to be attached to the pulleys as tightly as possible, otherwise the bearings will loosen very quickly. After attaching the wheels to the frame, test run the saw with the utmost care.

Mounting the blade guides

In order for the band saw on wood to make an even cut and the blade not to be “squeezed” by the sawn tree, guides are mounted along the blunt end of the saw on a narrow beam.

The easiest option is to screw three roller bearings to the beam. The flat side of the canvas rests on one, the other two hold the tape tightly on the sides.

Be sure to perfectly align the guides at the attachment point on the support, otherwise even a microscopic vertical deviation can result in 3 mm at the opposite end. It is best to mark the position of the beam with the canvas stretched to the maximum and the guides already mounted. This ensures their exact position relative to the saw blade.

Instead of two bearings on the sides, you can make wooden stops. Also, it will not be superfluous to install additional guides under the countertop, and not just from above.

It should be borne in mind that the guides should be as close as possible to the workpiece, ideally at a distance of 3-4 cm from the log. Therefore, if you plan to cut workpieces of different thicknesses, it makes sense to adjust the height of the guides.

Finishing

This is not so much for aesthetic purposes as for safety - even if the tape slips off the pulley, it will linger in the casing.

It is better to take out the belt drive from under the table so that sawdust does not fall on it. To protect the motor, it is also recommended to arrange a cover to prevent the ingress of dust and other particles.

Finishing wood with varnish or paint will not only prolong its life, but also protect your hands from unpleasant rolling pins and chips from untreated wood. Previously, all surfaces must be sanded and treated with antiseptics that prevent decay.

The video provides an overview of a homemade wooden saw and describes the advantages of such a solution: