At large volume use of lumber, sooner or later the question arises of your own sawmill. 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 the potential danger of the structure, and the dimensions of the workpieces, 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. Can be made from steel profile or a corner, but from the point of view of the cost of the material, a tree 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 inside diameter 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 disk.
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 beating on the plane, and the tape can come off.
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 might be a countertop from kitchen furniture with 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. Connecting the web into a closed tape is the most difficult step in manufacturing. Welding of band saws is carried out by butt contact method. There should be no overlap.
After joining, the joint is polished.
However, the modern range of canvases allows you to buy a kit for any material at an 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.
Band saws are a powerful, reliable tool used in construction for cutting various materials. In order to avoid problems during operation, it is necessary to carefully approach the choice of equipment, take into account specifications. First of all, you need to find out for what purposes this or that type of saw is intended, get acquainted with the parameters of the teeth, the size of the blade, the quality of sharpening the cutting element.
Types of band saws
The band saw tool can process:
- stone,
- wood,
- metal,
- synthetic material.
For hard materials, it is recommended to use equipment reinforced with heavy-duty alloys: the cutting belt will not tear, spoil the workpiece. Before buying, determine the scope of work that is planned to be performed using the installation.
A large amount of work requires a powerful, hardy saw that can withstand increased loads. Its cost will be high. For a one-time procedure, infrequent use, cheaper equipment is suitable, with standard features strength.
Saw size
Width, length are selected according to the same parameters of the machine. Recommendations for the selection of components are in the instructions for the unit.
Additional Tips:
- Wide band saws have a smoother cut and are more commonly used for ripping.
- The thinner the workpiece being processed, the more likely it is to be damaged by a thick saw.
- When carrying out curly and contour cutting, the width of the cutting element must allow processing the product at a given angle. This type of tool is produced with a width of 14–88 mm. For standard work the average parameter is suitable - 35–40 mm.
Tooth pitch
The distance between the pointed segments of the saw corresponds to the mating part of the unit.
- Thin sheet material processed with a saw with a large uniform tooth pitch.
- A frequent constant step is suitable for working with large canvases.
- Variable teeth are designed for cutting natural and synthetic materials with a soft structure. The cutting speed increases as the saw does not clog.
The quality of cutting, the level of vibration during operation, and the wear resistance of the main element depend on the setting of the teeth. The canvas can have a different profile:
- Wavy. Used for small workpieces, thin materials.
- Standard. Differs in the alternating arrangement of all cutting elements, one segment is placed in the center. Choose for the processing of bulk workpieces, contour cutting, mounting on a vertical type of machine.
- Variable, or group. Contains paired teeth. The unit is more expensive: it is more durable, efficient, and has a reduced load on the cutting edge.
Particular attention is paid to the quality of saw sharpening. They check how sharp the cutting segments are, whether the steel from which they are made is uniform, and the evenness of the cutting edge line.
You need to find out if it is possible to re-sharpen the saw, how many cycles for updating the cutter are provided.
Drawing of a homemade band saw: 1 - tape drive pulley (lower); 2 - base; 3 - band saw; 4 - V-belt A710; 5 - damper; 6 - guide; 7 - carrier bar; 8 - belt drive pulley (upper); 9 - table (plywood s20); 10 - electric motor AOL-22-2; 11 - belt drive pulleys; 12 - bracket (steel angle 40x40); 13 - nut M12 (2 pcs.); 14 - top support; 15 - adjusting screw; 16 - slider.
Band saw machine: device and assembly
Tape-type joinery machines for wood consist of a desktop, which serves as the basis for the rest of the elements, and the elements themselves. The design provides for a constant circular motion of the web, based on two pulleys.
A full-fledged unit with a bed and a tabletop is made if there is separate room large dimensions: the equipment has impressive dimensions. In other cases, a desktop manual mini-installation is made, on which it will not be possible to dissolve whole logs.
bed
The machine frame is a load-bearing element that must support the weight of the entire structure. It is best made from metal profile, but a tree will do. Plywood, chipboard are usually not used, a board with a thickness of 20 mm is used. The frame is glued according to the rule of intersection of the fibers of each next layer relative to the previous one.. Self-tapping screws are used to reinforce the frame. The design must be rigid and at the same time elastic in order to act as a damper that dampens the jerks of the cutting blade.
Pulley block
The upper pulley block does not hold the blade in tension when moving vertically. The frame requires hard wood. On the inside of the frame there is a wooden insert to which the wheel shaft is mounted. The inclination of the axis is adjusted with a threaded rod and nuts embedded in the wood.
The vertical movement is carried out along the guides fixed in the upper part of the frame, provided by a screw mechanism. For reinforcement, the adjusting nuts are supplemented with washers or welded. When turning the shaft, a flange is provided, due to which it will be fixed from the back.
Pulleys
Wheels with a thickness of about 30 mm are glued together in several layers of plywood circles, after which a hole for the bearing is formed in them. To make the sawmill stable, the bearing is fixed in the clutch. FROM inside a washer is put on the shaft, and it is fixed with a flange from the outside. In order for the tape to be able to center itself, the wheels are barrel-shaped, the treated surface is pasted over with a bicycle inner tube.
When installing the bearing, it is necessary to monitor the perpendicularity of the shaft, otherwise the wheel will hit the plane during operation. As a result, the cutting blade may slip off seat. A drive pulley is attached to the lower wheel.
table top
The tabletop is located on a pedestal base, inside which is placed a motor with a trigger mechanism. The table is usually made from a sheet of thick plywood, on the working side it is pasted over with textolite. To make it more convenient to cut at a given angle, the tabletop is made swivel. They also provide a parallel stop; for this, roller guides or a profile with clamps are used.
Saw setup
First provide parallel placement of the wheels relative to each other. Fluoroplastic washers strung on shafts are used against vertical displacement. A trial run of the system is carried out without guides, a test cut - without load. The correct setting of the saw is evidenced by the smooth running of the wheels without sharp jerks that provoke the slipping of the tape.
After debugging, the tape guide block is mounted. It consists of two halves installed along the line of the cutting element.
The video shows how to assemble a band saw yourself.
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.
To band saw I worked properly with my 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, but there are built according to a different principle - the saw unit is motionless, and a log, board or a metal sheet. The second option is more affordable for self-production.
The main nodes of the 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 a saw, for example (which sometimes happens) or sawing material of large dimensions, the 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 protects against belt beats special mechanism damper, 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 is best to make them from waterproof plywood with a thickness of 10 mm or more. 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.
DIY tape machine For an experienced locksmith, it will not be difficult. Some of the necessary parts and assemblies can be taken from decommissioned or dismantled machines of your own enterprise or bought on the market or on the Internet, some you can make 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.
A lot of tasks can be done with a custom made band saw. Using the recommendations of the proposed article, it is quite simple to reproduce this device.
1 - tape drive pulley (lower), 2 - base, 3 - band saw, 4 - V-belt A710, 5 - damper, 6 - guide, 7 - carrier rod, 8 - tape drive pulley (upper), 9 - table ( plywood s20), 10 - AOL-22-2 electric motor, 11 - belt drive pulleys, 12 - bracket (steel angle 40x40), 13 - M12 nut (2 pcs.), 14 - upper support, 15 - adjusting screw, 16 - slider
The desktop of a home-made band saw (dimensions 420x720 mm) is made of plywood 20 mm thick, pasted over with textolite on top. Around the perimeter, it is edged with hardwood slats. There are narrow grooves in the table to guide the saw band. The base is a box measuring 420x720x500 mm glued from 20 mm plywood. Among other things, it serves as a place to collect sawdust.
The carrier bar is a section of channel No. 8 680 mm long, the shelves of which are cut to a height of 20 mm for convenience. The bar is attached to the table with a bracket from a 40x40 mm corner and four M8 bolts. The saw band drive pulleys are machined from 20 mm thick plywood. On the working surface, they are pasted over with dense sheet rubber, docked at the mustache. Used polyurethane adhesive. After rubberizing the pulleys, the wood is impregnated epoxy resin, sanded and painted. The working surface is barrel-shaped, necessary to hold the running saw blade. A duralumin bushing is glued into the upper pulley with epoxy resin, in which a socket for a 60203 ball bearing is machined. The lower pulley is mounted on an axle made of 30KhGSA steel and fastened with three 5x20 screws. The axle is inserted into a box with two 60203 ball bearings mounted on the lower end of the carrier rod. At the other end of the axle, the driven pulley of the belt drive is fixed through the spacer sleeve. After installation, the belt pulleys are balanced. The principle of operation and the dimensions of the details of the saw band tension system are clear from the figures shown (section A-A).
Tape drive pulley (upper)
The gear ratio of the belt drive from the engine is i=1, so the driving and driven pulleys are the same, except for the mounting hole, which on the driving pulley depends on the motor shaft. Pulleys are made of duralumin. V-belt - A710 (in this design).
To eliminate vibrations of the saw band, a damper (vibration damper) is provided, assembled from textolite parts on M6 bolts. The fixed element of the damper is fixed at the bottom of the desktop, and the movable bar allows you to select the required gap. It should be noted that an upper damper is also provided on the band saw, however, its installation is advisable if the upper pulley of the saw band begins to "hit in diameter". Otherwise, the upper damper only increases the friction of the belt. By design, it is similar to the main one and, if necessary, is mounted on the bar with M5 bolts using a special bracket 105 mm above the plane of the desktop.
1 - base, 2 - M6 bolt (2 pcs.), 3 - strap, 4 - nut with washer.
The guide for feeding the sawn timber is made of a steel angle 100x100 mm. It is desirable to grind its perpendicular planes on the machine. In one of the shelves, two grooves are made along the edges to adjust the gap between the guide and. tape, and in the middle - a cutout to increase the course of the bar. Safety during work is ensured by a protective casing that covers the entire assembly of the upper pulley of the saw band, which leaves the cavity of the casing only in the working area.
The saw blade itself deserves great attention. It must be sufficiently elastic, on the one hand, and durable, on the other. For its manufacture, we recommend cold-rolled sheet steel grade U8, U10 or 65G with a thickness of 0.2-0.4 mm for sawing soft woods (balsa, linden) or 0.4-0.8 mm for harder woods. By the way, many people use steel tape measures from quality metal 0.2 mm thick and about 10 mm wide. "Automatic" modern roulettes with a curved tape profile are unsuitable - only old samples are suitable. The length of the workpiece for the given dimensions of the machine is 1600-1700 mm. On the strip-blank, teeth are cut with a file in increments of about 3 mm, after which the tape is soldered into a ring, the ends at a length of 3-6 mm are sharpened in thickness by a mustache. Then the place of adhesion is sprinkled with borax and warmed up for gas burner. Solder brand PSR-40 is applied to the joint and the seam is tightly compressed with pliers with asbestos pads on the sponges (otherwise, the joint cools quickly and the metal in this zone becomes brittle). If necessary, the joint is ground. To obtain a better cutting surface, the front and back surfaces of the teeth are sharpened in the same way as a hacksaw for wood and slightly divorced. Of course, you can also use commercially available blades for branded band saws, but then the dimensions of the machine should be made in advance in accordance with the dimensions of the purchased blade.
The considered home-made band saw is used for straight-line sawing of soft woods (balsa, linden, aspen, spruce, pine). Harder woods (beech, oak, mahogany) can also be sawn when a 0.8 mm thick tape is installed on the machine.
The disadvantage of this version of a homemade band saw is a small overhang of the blade, but this greatly simplifies the design. If a small blade overhang does not suit you, then in order for the blade overhang to be like that of branded band saws, you will have to make the location of the carrier bar like theirs and use larger diameter pulleys.
Specifications of a homemade band saw:
Maximum sawing thickness, mm
soft breeds - up to 100
hard rocks - up to 40
The smallest cutting width, mm - 0.25
Tape drive pulley diameter, mm - 240
Center distance of belt drive pulleys, mm - up to 500
Gear ratio from engine to drive pulley, i - 1
Engine speed, rpm - 2800
Electric motor power, kW - 0.6
Rated voltage, V - 380
Linear speed of the tape, m/s - 35
Tape length, mm - 1600-1700
Sawing speed, m/min - up to 5
Overall dimensions, mm - 720x420x920
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 carpentry tool almost everyone has it.
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/sec.
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 required pressure and at the same time will extinguish the voltage, 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.
It is convenient to use self-centering bearings to fasten the upper pulley, 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 is not “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:
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