Cutting logs into boards at home. The main types and methods of cutting wood

Wood, like natural stone, is one of the oldest building materials. Despite the huge selection of various artificially created materials that exists today on the construction market, timber products are still very popular. In order to obtain high-quality lumber, a log must be sawn into boards. In this article we will talk about how to cut a log into boards.

Types of sawing logs

Sawing a log into boards is carried out in two main ways:

• radial
• tangential.

In addition, additional methods are possible:

• mixed
• semi-radial (rustic)
• central.

Radial sawing is a type of sawing, during which the axis of the cut runs through the core of the log and, as a result, the annual rings in the section of the board form an angle of 76 - 900. The lumber obtained by this sawing has a uniform color and texture. Timber almost does not undergo deformation during shrinkage and does not swell when moistened, because the dimensions of the wood change mainly along the line of the rings (across the fibers). In radial sawn lumber, annual rings are arranged in thickness. Such materials have the highest performance in comparison with other types of lumber.

Tangential sawing is carried out along the tangents to the lines of annual rings at a small distance from its core. The surfaces of the resulting boards are distinguished by a pronounced texture and a bright wavy pattern of annual rings. Such lumber is characterized by higher coefficients of shrinkage and swelling from moisture, compared to radial sawn boards. As a result, they are strongly deformed under the action of moisture. Such boards are in demand for use in dry conditions.

Rustic (semi-radial) and mixed types of sawing have signs of two main types of sawing at the same time: radial and tangential. Therefore, they show average shrinkage and swelling ratios. Rustic sawn boards are distinguished by straight lines of annual rings, which are located at angles of 46 - 75 degrees. to the layers. Mixed sawn lumber is distinguished by the fact that the lines change from straight at the edges (in width) of the board, to arched towards the middle.

The central cut is made right in the center of the trunk and contains its core. Taking into account the fact that the core of the trunk is the wood with the most low scores strength, sawn timber of the central cut is characterized by a structure that is heterogeneous in strength.

Wood balance when sawing

Log cutting tools

Tools and cutting methods depend on the total volume of logs, such indicators as length, thickness. In addition, the quality of the future lumber must be taken into account. Sawing logs involves working with different tools and specialized equipment. In order to get a small amount of lumber at home, a manual method of processing logs with a chainsaw or traditional hand saw-hacksaws with teeth for a longitudinal cut type is suitable.

The sawmill is perhaps the most famous type of sawmill equipment. This is a woodworking machine in which there are frame saws. At the sawmill, longitudinal sawn lumber is obtained, for example, edged boards or timber. Sawmills allow processing logs with a diameter of 15 to 80 cm and a length of up to 7 m.

Sawing logs into boards using circular saws is carried out by means of a saw disk type. Such equipment can be single-saw (single-disk) and multi-saw (multi-disk). Devices containing a single disk are suitable for working with small and not High Quality initial raw material. With the help of multi-disc machines, it is possible to cut round workpieces of large diameter.

Band sawmills are the most popular today. They are of two types: vertical and horizontal. cutting tool in such equipment is a tape fabric that is put on the pulleys. Work on tape machines guarantees the production of quality longitudinal and mixed lumber, such as boards and beams. This generates the least amount of waste.

On large industrial enterprises use lines for sawing wood. They allow to achieve very high surface quality and precise geometry of the final products. Such lines are characterized by the highest productivity.

In addition to all of the above equipment, such types of highly specialized sawmill equipment are also used, such as debarking, edge trimming, band-cutting and other types of machines.

Very often there are situations when you need to make a very small amount of boards or beams for your own needs. Of course, buying machines in this case is absolutely not an option. Having certain knowledge and skills, it is much more profitable to cut logs with my own hands, using a chain saw, electric or petrol. Despite the fact that this work is quite laborious, the result is quite justified.

Most experts believe that a chainsaw is better suited for this purpose. Such equipment has high power and can operate without interruption for a long time. In addition, the operation of the chainsaw does not require electricity, so you can work far from the power supply, for example, right on the plot.

In order to cut a log into boards with a chainsaw, you will also need special tools, such as a mechanism for fixing the log, a frame attachment for a chainsaw, and a guide for cutting. The attachment frame must be attached to the chainsaw bar so that it is possible for them to adjust the gap between it and the chain. This will make it possible to create boards having different thicknesses. The chain should be purchased special, for longitudinal sawing. It has a special sharpening angle of the teeth. A ruler can be made from metal profile the required length or a flat rigid board.

Before starting work, you need to remove all the bark and remaining branches from the blanks, as well as carefully examine the log for various flaws. In this way, you will be able to choose the most suitable cutting pattern and, consequently, reduce the amount of possible waste.

If you are ripping trunks, you need to make sure that the resulting lumber is of the same density across the entire width. Since the density of wood from the northern part of the log is much higher than from the south, the cut is carried out in a plane directed from east to west (or vice versa).

The first step is to remove the slabs from two opposite edges of the log. As a result, a two-edged beam will be obtained, which is then cut into boards or other lumber of equal thickness, according to the planned sawing pattern. The end product is an unedged board, from which the edges are necessarily removed.

For many centuries, timber has been the most popular raw material for housing construction. Today, primitive processing methods have been replaced by modern equipment. For example, for cutting timber and processing them to the desired size, craftsmen use a sawmill. The disadvantage of such a machine is the cost. For this reason, many people make mini sawmills based on chainsaws.

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Technology of woodworking production

Circular and band saws for sawing logs and beams

Circular saws. The device of machine tools and their characteristics. Circular saws are divided into log sawing machines and beam sawing machines.

Log sawing machines can be single-saw, double-saw and multi-saw. Single saw machines are designed for sawing beams, sleepers and boards. They belong to heavy-duty machines, they consist of a cutting mechanism and a feed mechanism in the form of a mechanized trolley moving along rails. The cutting mechanism of single saw circular saws is simple in design. It consists of one or two shafts on which the saws are mounted.

Rice. 1. Scheme of a two-way light and sound alarm for double-deck sawmills: 1 - light and sound red signal from below "Do not release the brakes", 2 - response signal from below "Start", 3 - red signal from above "Start", 4 - control button of signals 2 to 3, 5 - the door of the guard of the parcel mechanism, 6 - the door of the guard of the connecting rod

Modern single-saw circular saws are equipped with a loading device consisting of a transverse accumulative conveyor and mechanisms for piece-by-piece delivery of logs to the trolley, and a remote control. These machines include the TsDT6-4 machine. The maximum cutting height of this machine is 800 mm, the maximum saw diameter is 1250 mm.

The main purpose of two-saw and multi-saw machines is sawing thin logs. The machines differ in the design of the loading device, for which some of them use longitudinal conveyors, on the chain of which stops are installed, pushing the logs to the end. To hold the log, the upper or lower part of the conveyor is shaped like a chute.

For longitudinal sawing of beams and segments, multi-saw circular saws are designed. They usually have a roller material feed and are equipped with a front-stay table. The saw blades of the cutting mechanism are mounted in movable and fixed blocks on one saw shaft. Machines differ in the number of saws and power.

Rice. 2. Circular saw machine TsDT6-4 for sawing logs: 1 - cutting mechanism, 2 - dial indicator for measuring the transverse feed of logs, 3 - trolley, 4 - rack, 5 - rail track

Work on machines. Single-saw circular saws model TsDT6-4 have remote control from the remote control, taken out of the zone of possible departure of the sawn material.

First, a log is piled on a cart and unfolded. This operation is carried out with the help of the piece-by-piece issuance of logs installed on the accumulative platform, and the mechanism for turning logs, which are controlled from the same control panel as the machine.

After installing the log on the trolley, the machine operator turns on the machine. When the saw blade reaches full speed, the machine operator turns on the cart feed. Having finished the cut, the machine operator puts the trolley on reverse and returns it to its original position. By turning on the mechanism of the transverse movement of the log on the cart and setting the log for the next cut, he repeats the cycle.

The material intended for sawing on the Ts8D-8 machines is fed to the storage platform located on the side of the front machine table. With the help of the chain sections of the storage platform, the material moves to the non-drive rollers of the table, where it is oriented relative to the saws with a guide ruler. The material is fed into the machine by means of a drive roller, which descends on the material after it has been installed and the guide bar has been retracted. The control of the machine table and the machine is concentrated on the control panel at the machine table.

Machine productivity. Circular saws have significant productivity. The speed of the working stroke of the trolley for the TsDT6-4 machines is 80 m/min, and the idle speed is 120 m/min.

Band saw machines. The device of machine tools and their characteristics. Band saws are designed for sawing large-sized, mostly low-quality raw materials and logs of valuable species. On fig. 52 shows a diagram of a band saw for sawing logs.

The vertical band saw machine has a bed on which two pulleys for a saw band are located. The lower pulley is the leading one. The brake device of the machine is connected with it.

Upper pulley - driven; it can move vertically, due to which the tension of the saw is ensured. The saw blade is put on the pulleys and stretched using the load linkage 9, which causes the upper pulley to rise. The working branch of the saw blade runs in two guides designed to reduce the free length of the working section of the saw and increase its lateral stability when sawing. The more stable the saw blade is in operation, the better the cut. The lower guide is fixed fixedly on the foundation

Rice. 3. Scheme of a band saw plant for sawing logs: a - equipment layout plan. 6 - diagram of a band saw; 1 - vertical band saw machine. 2 - roller conveyor, 3 - rail track, 4 - trolley, 5 - trolley drive, 6 - platform with control panel, 7 - device for accumulation, piece delivery and pile of logs on the trolley, 8 - lower pulley, 9 - cargo mechanism, 10 - upper pulley, 11 - saw blade, 12 - mobile racks with grippers, 13 - mobile cart frame, 14 - saw blade guides

stove. The top guide can move vertically and be set depending on the diameter of the sawn log.

An integral part of the band saw installation is a trolley on which the sawn log is fixed. On the trolley there are mobile racks with grippers (hydraulically driven) for fixing the logs. The racks move in the transverse direction with respect to the trolley frame along the guides for installing the log relative to the sawing plane. Rack drive mechanical (reducer, electric motor, rack and pinion). When the trolley reverses, its frame with uprights and a log moves away from the cutting plane.

The trolley moves along the rail track with a winch driven by a hydraulic motor with stepless speed control over a wide range.

A mechanized device is installed in front of the machine for accumulating, piece-by-piece issuance, heaping logs onto a trolley, as well as for turning logs. Behind the machine there is a roller conveyor for receiving sawn boards.

One of the most important parameters of band saws is the diameter of the pulleys, which determines the largest diameter of sawn logs, the thickness and width of the saw, and the power of the machine. Increasing the thickness and width of the saw allows you to increase the feed rate and at the same time maintain a stable position of the saw during sawing, which is necessary for high-quality sawing of logs.

On band saws it is possible to cut logs with a diameter of up to 1.5 ... 2 m. The thickness of band saws does not exceed the pulley diameter Vlooo, and the width is 350 ... 400 mm.

Modern band saws models LB125-1 and LB150-1 have a pulley diameter of 1250 and 1500 mm, respectively. The machine LB150-1 is designed for sawing logs with a diameter of 20 ... 125 cm. The speed of the working stroke of the trolley for these machines is 80 ... 125 m / min, the reverse - 125 m / min. On the LB150-1 machine, saws with a thickness of 1.6 and a width of up to 230 mm can be used.

The main advantage of band saws is less (compared to sawmills and circular saws) waste of wood into sawdust and high productivity.

The considered band saw machines belong to single saw machines for individual sawing of logs, since sawing of logs is carried out on them in successive cuts. For group sawing, band saw lines are created on the basis of double, quadruple, etc. band saw machines, which are distinguished by high cutting performance of raw materials.

At present, the LBL150-1 line has been created for cutting logs based on dual band saw machines with program settings. The line consists of a store for creating a stock and piece-by-piece issuance of logs, a device for receiving, turning and centering logs, a mechanism for clamping a log and feeding it into sawing, a double bandsaw sawing machine for sawing logs by sequential pairwise heating of slabs and boards, a roller conveyor for removing sawn timber from the machine and the line control panel.

Pulley diameter 1500 mm, working speed 5 ... 60, idle - 80 m / min.

Work on the machine. The band saw machine, including the trolley and near-machine mechanisms, is controlled by one person from the central console located on the platform.

First of all, the mechanisms that feed the log to the trolley and turn it are turned on, then the trolley mechanisms that ensure the installation and fixing of the log. After that, the trolley drive is turned on to feed the log for sawing.

When the log passes the machine, a command is given to reverse / trolley to return it to its original position. Then the mechanisms that move the log to the thickness of the sawn part are turned on, and the cycle repeats. For the transverse installation of the log, a servo drive on non-contact selsyns is used. As the log approaches the predetermined position, the travel speed is automatically reduced, which ensures more accurate installation.

The sequence of operation of the LBL150-1 line is as follows. The logs arriving at the command of the operator from the store are turned by a tilter around the axis and are clamped in the movable rods with the help of a pneumatic cylinder. At this time, the saw blocks are set to the required cut size, and the stops of the roller conveyor are set to the working position.

After the first pass, the log stops, the saw blocks are automatically retracted from the cut line by 10 mm and the mechanism

log feed returns to its original position. For the next pass, the saw unit is shifted by the thickness of the sawn board.

At the end of sawing, the core board is dropped onto a roller conveyor, and the spread bars return to their original position to clamp the next log. Sawing is controlled by the operator from the remote control.

The productivity of the machine depends on the diameter of the sawn logs and the number of cuts in the log. It is advisable to use the machines when sawing logs of large diameters (over 50 cm) and with a small number of cuts in a log (for example, when sawing out beams).

The number of cuts that can be made on band saws per unit of time (for example, per hour) depends on the qualifications of the worker, the degree of mechanization of near-machine work, and the condition of the equipment. The performance of the machine is determined in the same way as a circular saw with a trolley; line LBL 150-1 - as a circular saw machine with roller feed.

Wood is the most popular material given to humanity by nature itself. Furniture is made from it, houses are built and even dishes are made. But in order to use wood as a building or finishing material, requires special machines for its processing.

The most popular material from wood, this is a bar with boards, from which many construction blanks are made, but this requires sawing round tree. It is for this purpose that band sawing machines (sawmills) exist.

Band sawmills

This type of sawing machine allows you to get from round wood construction material in the form of a board and a bar of various cross-sections and sizes with minimal waste. The board may not be edged, the edges of the board have a curved line, and edged (the edges make up a straight line). The bar can be square or rectangular.

The modern tool market today offers a variety of woodworking machines manufactured by domestic and foreign manufacturers. Among them a large number of machines designed specifically for the longitudinal cut of round wood.

One of these is the tape model of the Taiga sawmill., which is by far the most demanded among entrepreneurs manufacturing lumber for construction, furniture industry and for other industries.

Band sawmill "Taiga"

Peculiarities

Distinguishing properties

"Taiga T-1"

This sawmill model It has small dimensions and is driven by an electric motor. It is used for sawing round logs, as well as large timber into boards.

It has a durable metal frame. When sawing, there is no oscillation of the saws (waves). Sawing logs of small diameter. Differs in the low price, and low consumption of the electric power. small dimensions allow it to be transported even in a minibus.

"Taiga T-2"

It's practically an inexpensive machine. , whose power is only 7.5 kW. Its metal frame has a large margin of safety, which is designed for quite a long operation. The performance of the model depends on the type of product being processed, and can be approximately 5-10 cubic meters per meter. in shift.

Can be additionally equipped electronic ruler type Micron - 4, with the help of which full automation of control of almost all production operations is carried out.

The use of Micron - 4 helps the operator accurately, without errors, make a sawing map, mathematically calculate and make corrections for the thickness of the cut. In this case, all calculations are stored by an electronic ruler, which has 8 memory cells.

"Taiga T-2B"

According to their technical properties and performance, this model can be considered unique equipment. It is equipped with an economical drive from a four-stroke gasoline engine with a power of 10 kW (13 l / forces). When fully loaded, the engine consumes only about 1.5 liters of AI-92 gasoline.

To warm up the engine before the expected load, idling is provided, thereby extending its service life.

The design of the sawmill consists of a standard frame of the Taiga sawmill, but it provides fasteners for installation electric motor instead of petrol engine.

The T-2B machine can work in the field directly on a deforestation plot, where, of course, an electric line cannot be present.

Depending on the diameter of the sawn logs, Taiga-2B can cut about 10 cubic meters per one shift.

"Taiga T-2M"

This model band sawmill has a fairly powerful, 11 kW, electric motor, so you can saw large-sized logs with dense wood.

Its design has a fairly large margin of safety, therefore it is designed for long-term, multi-shift operation with a capacity of up to 10 cubic meters / m. in one shift.

At this sawmill, as well as on the T-2 model, an electronic ruler of the Micron-4 type can be installed, which automates many work processes.

"Taiga T-3"

The T-3 sawmill is designed for multi-shift work with wood of any density. Power

its electric motor is 11 kW, it has a reinforced design of the sawing carriage, due to which the diameters of the sawing pulleys are increased up to 60 cm, which increases the resource of tape blades several times.

The design of this model is designed for fairly high loads, with minimum fast settings. This allows you to work without long breaks to adjust the equipment.

The performance of the T-3 model is, when cutting large round timber, about 12 cubic meters / m. in one shift.

The function of moving the sawmill along the log being processed can be separately configured and additionally equipped to automate the workflow with a multifunctional electronic ruler of the Micron-4 type.

The design of tape models "Taiga"

The basis for the sawmill can be a concrete platform or thick wooden beams laid on a flat area of ​​dense soil. Rails are laid on the bars or a prepared platform, which are rigidly fastened to each other. They also have a system for attaching processed logs.

The rails can be extended with an additional section, which makes it possible to cut logs, the length of which can exceed 8 meters.

The frame of the sawmill can be mechanically or electrically driven vertically and run on rails. with support rollers in manual mode. Removal of saw cut is made manually one or two support workers.

The movement of the sawing mechanism along the vertical plane is carried out using a two-row chain transmission simultaneously with the lowering / lifting drive gearbox, and is controlled by a metric scale located on the frame. Thanks to this, the sawing mechanism is fine-tuned in height and firmly fixed on the frame of the sawmill.

On the sawmill of the T-1 series, the sawing mechanism is moved manually by rotating the gearbox with a special handle. And on the rest of the machines, the vertical movement of the sawing mechanism is carried out by an automatic switch, but if it becomes necessary to adjust the saw in height, then it is done using a manual closer.

The sawing mechanism is equipped with two balanced rollers (leading and driven) on which the cutting saw is fixed. The drive roller is driven by a belt drive from a pulley electric motor. The driven roller is attached to the tension system and rotates from the movement of the belt.

The speed of the band saw can increase with the increase in the diameter of the pulley, which can be a maximum of 520-600 mm. This improves the quality of the cut surface of the log and increases the service life of the cutting blade.

After installing the band saw, its tension is made with a special key with a dynamometer. Tension control is carried out on a scale located on the dynamometer sensor mounted on the tension wrench.

Constant tension and prevention of oscillation of the saw blade is carried out by the damping rollers of the sawing mechanism. The saw blade is equipped with a special lubrication system so that the saw blade does not get caught in the cut of the log, which can be caused by wood resin accumulated on the band. The system has a lubricant flow regulator, which simultaneously cools the cutting blade.

All moving and rotating parts of the sawmill are protected by a metal protective casing, and the machine is controlled through the sawmill keypad, which is installed on the saw frame.

Purpose and consumer groups

Preventive Maintenance

Preventive maintenance of sawmills consists in daily cleaning them of sawdust, lubricating the resting rollers and periodically inspecting all working mechanisms.

During service, worn parts are changed, mainly resting, as well as driving and driven rollers.

Blanks for the manufacture of parts for products of carpentry, construction and furniture industries are obtained by cutting edged and unedged sawn timber from coniferous and deciduous trees. With the correct organization of production, cutting into blanks is carried out according to a pre-compiled specification, which indicates the dimensions of the blanks, set in accordance with the dimensions of future parts and allowances for processing in length, width and thickness.

Achieving the highest possible efficiency in the use of materials already at the stage of their cutting is the most important task of any production.

Cutting methods

In general terms, the efficiency of material use is estimated by the blank yield coefficient Kv, which is determined by the percentage of the volume or area of ​​the cut material to the volume or area of ​​the blanks obtained. Increasing this ratio is always a difficult problem. The yield of blanks depends on many factors: the presence of wood defects in the material (visible and hidden), the size of the blanks, the requirements for their quality, as well as the qualifications of workers, working conditions, the equipment and tools used, etc.

According to the degree of participation of personnel in the control of the work process, individual and group cutting are distinguished. Individual cutting is carried out with the direct participation of skilled workers who constantly keep records of the quality of raw materials, the required dimensions and the number of blanks. right size and using the most rational cutting scheme.

Group cutting is carried out without taking into account the quality of raw materials, according to a predetermined scheme. Of particular importance is the correct preparation of the specification and the order of the original boards, the width of which must correspond to the width of the blanks, taking into account the cuts and ensure the formation of a minimum amount of waste (narrow slats). With group cutting of unspecified lumber, the yield of blanks is reduced by about 7% compared to individual cutting.

When cutting boards with a large curvature, the volume output is reduced by 20-30%. Before facing, it is recommended to cut them into parts, the curvature of which has a lesser effect on the volumetric yield of the workpieces.

Cross cutting of lumber, called facing, is carried out by dividing lumber into blanks of the required length by sawing with circular saws. Longitudinal cutting of lumber involves the division of material into blanks of the required width or thickness using circular or band saws.

Depending on the sequence of these technological operations, there are three main cutting patterns: transverse-longitudinal, longitudinal-transverse and mixed - transverse-longitudinal-transverse (Fig. 1).

Some enterprises practice preliminary milling of boards in order to reveal the defects of wood, which are poorly distinguishable due to its darkening during drying or poor-quality sawing in the process of cutting a log, which led to the formation of hairiness on the layers of the boards.

Longitudinal-transverse individual cutting provides the highest yield of blanks due to less material loss when cutting out defects and is especially effective for boards of low grades. Moreover, preliminary marking provides an increase in the yield of blanks by about 3-9%. Marking is carried out along the surface with the largest number of defects, starting from the butt end of the board. The use of preliminary milling with the opening of invisible defects can additionally increase the yield of blanks by 3%.

In order to make better use of the suitable part of the board, it is advisable to cut it in accordance with the existing specification for blanks of different sizes. In this case, it is possible to choose the dimensions of the blanks so that the defect-free part of the board is used as fully as possible. When cutting, preference is always given to obtaining the longest blanks.

When visually evaluating the quality of the boards, the number of realistically assessed options for placing an outline of blanks of given sizes on them is limited by the physiological characteristics of a person. In the process of cutting, a skilled worker can memorize and use no more than 4-5 standard sizes, provided that the difference in length between them is more than 100 mm.

An increase in the number of standard sizes while cutting blanks from one board drastically reduces productivity and can lead to errors.

Additional marking and milling increase the cost of processing, but easily pays off by increasing the yield of blanks.

According to the technological purpose, circular saws for preliminary (rough) cutting of lumber into blanks, called trimming, are divided into those intended for transverse and longitudinal cutting, as well as universal ones.

Cross cutting machines

To universal machines include machines for transverse, longitudinal and mixed cutting, which also provide sawing at an angle to the wood fibers. These are manual feed circular saws equipped with a longitudinal guide bar and a movable carriage with a transverse stop bar. Sometimes they are equipped with an automatic feeder. Once upon a time, such machines were called circular. Due to their low productivity, today they are used mainly in workshops.

Machines for cross cutting, also used for leveling the ends of boards, are divided by design into machines with an upper (above the table) and a lower (under the table) spindle location.

Machines with an upper spindle arrangement are divided into pendulum, balancing and straight-line movement of the caliper.

pendulum machines represent a swinging metal frame, the upper end of which is hinged above the machine table on the shop wall or on a separate stand. An electric motor is mounted at the bottom of the frame, on the horizontal shaft of which a saw is mounted.

During operation, the machine operator, holding on to a specially provided handle, pushes the lower end of the frame with the saw blade onto the board laid on the desktop. At the end of the cut, the frame is released and, together with the saw, under the action of a spring or counterweight, returns to its original position. These machines got their name because during the working cycle the saw makes movements resembling the swing of a pendulum.

Balancing machines are equipped with an electric motor with a saw mounted on an articulated-lever suspension. The worker, holding on to a special handle, pulls the saw towards himself, as a result of which the workpiece placed on the machine table is trimmed. The return of the saw to its original position is carried out by a spring or by means of a counterweight.

In machines with rectilinear movement of the caliper trimming is carried out by horizontal or vertical movement of the electric motor with a saw along the beam with guides relative to the table. Such machines are equipped with a hydraulic drive for moving the caliper, which is activated by a pedal.

The productivity of machines with rectilinear horizontal movement of the caliper is 2-3 times higher than that of pendulum or balancing machines, and is up to 10 thousand cuts per shift.

However, in modern production the most widely used are circular saws with a lower spindle location (Fig. 2).

By design, they are divided into machines with saw lifting or saw moving parallel to the table. In the first case, the saw, located under the machine table, rises when sawing. In the second case, in a non-working position, it is located at the table and moves parallel to it, advancing onto the board from the edge. The saw spindle can be moved manually (pedal machines), as well as using a hydraulic or pneumatic device. For machines with a saw lift, productivity is slightly higher due to a shorter actuation cycle.

The working width of all cross cutting machines is between 300 and 500 mm. However, when choosing equipment, it should be taken into account that the largest actual width of the cut lumber is directly related to their thickness, which is why the characteristics of these machines of each model are supplemented by a certain diagram.

Near-station equipment

Cross-cutting machines of all types are equipped with driven or non-driven roller tables at the entrance and at the exit for placing the material to be cut and removing workpieces. The length of the tables should be sufficient for laying the board to be cut completely and can be 10 m or even more.

In addition, each table is equipped with a longitudinal guide ruler for basing boards in the transverse direction. If the trimming machine is used only for leveling the ends and preliminary removal of obvious defects, then the rulers may not have stops for basing the boards in the longitudinal direction. If the machine is also used for cutting boards into measured blanks in accordance with a given specification, then rulers with folding or recessed stops for measuring the length of sawn blanks and parts are required.

The design of the stops should ensure their movement along the ruler to establish the desired size (Fig. 3). But if these stops are forced to be outside working area machine operator, he will be constantly distracted by managing them and interrupt work.

To eliminate the loss of time and ensure the correct position of the board or workpiece at the time of sawing, stops have been developed that are automatically extended to the working position at the command of the machine operator who presses the buttons on the control panel located in front of him. In this case, the order of their extension can be programmed.

There are also pull or push units that grab the board at one end and automatically move it in a longitudinal direction in step mode to the positions necessary to cut the blanks of the desired length in accordance with the specification.

Longitudinal cutting machines

Longitudinal cutting of boards and blanks is carried out on one-, two- and multi-saw machines with mechanized material feed.

By purpose, they are divided into the following main groups:

● edged single-saw with shaft
tsovo-disk and caterpillar feed for cutting one edge of unedged boards or longitudinal cutting of boards and blanks according to the ruler installed on the machine;

● cut-in single- or multi-saw with caterpillar feed for precise cutting of boards and blanks in width;

● gang saws with roller feed for cutting boards and blanks into bars, planks and laths.

Here it is necessary to explain the difference between edging and slicing machines. Their design can be exactly the same, but the first one does not include a longitudinal guide line, which allows them to perform only straight cuts, the position of which along the width of the material is set by the machine operator who is loading. Slicing machines are equipped with such a longitudinal guide ruler, along which the cut material is based on the edge, which allows you to get Exact size blanks corresponding to the distance between this ruler and the saw blade. On slicing machines, it is also possible to perform preliminary longitudinal trimming. So, if there is a wane on the board, the first cut is made by eye, and at the second, third and other cuts, the already sawn edge is pressed against the ruler.

The working width of machines for longitudinal cutting for most models is from 300 to 600 mm. To make it easier to change saws, all these machines have the spindle on top. In this case, the maximum thickness of cut boards and beams, as a rule, is 120 mm.

Machines that can saw material with a thickness of 160 mm or more are equipped with two saw spindles: lower and upper. Saws are located in the feed direction from below and from above. The lower saws capture one part of the cut in height, the upper saws the remaining part, finishing sawing. In such machines, saws of small diameter and thickness are used, which reduces the amount of waste (sawdust). This is especially important with a large cutting height and a small thickness of the sawn workpieces.

For safety reasons, all circular saws in without fail there should be claw protection at the entrance.

Adjustment of saws for the processing width in multi-blade machines is carried out by installing spacer rings of the required thickness on the spindle, between the saws. However, with frequent changes in the specification of workpieces, this leads to significant losses of time for reinstalling the saws. Therefore, the design of some machines allows you to replace the entire spindle with another - with saws that already have a new position. To move such shafts around the workshop, for example, to the tool area, such machines are equipped with special transport trolleys.

In order to further reduce the setup time, many manufacturers have developed gang saw machines with devices that allow, at the command of the machine operator from the control panel, to move the saws along the spindle to a new working position. These positions are set on the control panel in advance and are programmed.

There are also gang saws with a working width of 1300 mm, designed primarily for longitudinal cutting of board materials into strips. But they can be effectively used without changing saws and for longitudinal cutting of short boards in accordance with the specification.

To do this, the saws on the spindle are mounted so that the distance between them corresponds to the dimensions provided in this specification. In this case, laser devices are placed above the machine, indicating the cutting line of each saw (Fig. 4).

The machine operator evaluates the location of defects in the material being cut, selects two suitable lines of laser marks, between which there will be the smallest number of defects, and directs the material forward - until the rollers capture the machine feed mechanism. After cutting, the rest of the material is transferred back by the return conveyor and the cycle is repeated.

Machines for longitudinal cutting are served by two people: a machine operator and an auxiliary worker. The first controls the machine and feeds the pieces into it, the second receives them and, if necessary, returns them for re-cutting.

Cross cutting on automatic machines

In many woodworking factories, you can see huge containers full of waste left after cross-cutting, and many pieces could well be used for subsequent splicing along the length. The fact is that the implementation of the enterprise program requires a large number of parts of the same section, but of different lengths. However, when cutting boards or bars, the machine operator cannot physically remember the number of already cut parts of a given length, determined by the specification, and fulfills these specifications sequentially, first sawing parts of the same length or two lengths from the boards. As a result, due to the discrepancy between the distance between the defects in the board and the given length of the parts to be cut out, lumpy waste of excessive length is formed, bringing very significant losses to any enterprise.

Their reduction by increasing the useful yield of material is most easily achieved by using "smart" equipment that can remember the specified specifications for cutting blanks in length and in the number of parts obtained as a result of cutting.

Machines and lines for cross cutting of lumber, equipped with optimization devices, have been known for a long time, but are not used at all Russian enterprises. The reasons for this are the seemingly high initial cost of the equipment and its high productivity. However, electronic equipment that automatically calculates the length and number of blanks in accordance with a given specification is being used more and more often.

When working with a cross cutting machine equipped with electronic system, the board is placed on the roller table, and the operator manually, using a fluorescent chalk or a special pencil, marks the location of the defects and the places for future cuts. Then the board is moved by the feeding conveyor to the circular saw. The marked cut points are recognized by a photocell. At the same time, the machine computer determines the distance between two adjacent cut points and compares it with the length of the workpieces included in the specification entered into it in advance. The machine software calculates how many different pieces of the largest total length can be placed between these two adjacent marks, giving preference to the longest. After that, cross cuts are automatically performed, and the number of parts included in the specification is reduced by the number of blanks received.

The sequence of dimensions along the length after the cutting is immediately remembered by the computer, and the blanks leaving the machine are automatically dumped from the receiving belt conveyor into certain pockets.

As the pockets are filled, the worker manually releases them, placing the cut blanks in the foot. The scraps remain on the conveyor and, moving further along it, fall into the collection or are immediately sent to the crusher.

The speed of the longitudinal feed of the material in such a machine can exceed 200 m / min., And the maximum speed can be set in 0.13 s. The machines are equipped with a control panel and a built-in computer with a graphical interface, which greatly facilitates the use of optimization software.

The design of the machine combines innovations used in the manufacture of mechanical and electronic components and devices. Such machines can significantly save working time and reduce the number of workers employed in sawn timber cutting operations. In addition, all the working parts of this equipment are covered with noise-absorbing casings, which ensures complete safety of work on it.

Experience has shown that the use of such machines when cutting boards, in comparison with conventional trimming machines, reduces overall length cuttings by machines more than twice and reduces the amount of wood waste by 15%.

Andrey PETROV,
company "Media Technologies"
commissioned by LesPromInform magazine

Sawing logs into boards with a chainsaw is quite convenient and simple method wood work. Due to the presence of various nozzles, the master receives materials that have a smooth and flat surface. It is easy to make boards on your own, it is not necessary to contact specialized stores.

Benefits of sawing logs with a chainsaw

The method of sawing logs with a chainsaw has several advantages.

The ability to work under any conditions - the chainsaw is not afraid of moisture, so specialists can saw logs during rain, the equipment will not deteriorate in this case.

High productivity - it is allowed to work on wood throughout the day, but keep in mind that the power of the device must be at least 7 horsepower.

Autonomous device - the equipment runs on gasoline, does not depend on electricity, workplace mounted on any site where it will be more convenient to carry out the process.

Ease of use - the chainsaw is equipped with soft start and by adjusting the speed of rotation of the chain, these conditions provide a high-quality result for beginners in this matter.

The undoubted advantage is that the equipment is much cheaper than a small sawmill. During a breakdown, repairs are inexpensive and do not take much time.

Types of working nozzles

Sawing logs with a chainsaw is carried out different ways, masters work with wood along the fibers, as well as across it. It all depends on what nozzles are used in the chainsaw.

Longitudinal cutter

It is used for sawing logs along, the process takes place in a horizontal position. After work, the master receives the same thickness of the product. Finished materials are exposed, after which the boards are used in construction.

By appearance the device is a frame small sizes, it is attached to the tire on each side.

Sawing with a light nozzle

The method is not very productive, but is used quite often. The element is fastened on one side, but the workpieces are slightly uneven. Such materials are necessary for the construction of sheds or fences.

Drum debarker

With the help of such a nozzle it is easy to dissolve the log, it works due to the V-belt transmission. It is attached to the belts on both sides, for this purpose special pulleys are used. The speed of rotation of the shaft depends on the size of the pulleys, so the performance of the nozzle is easy to change.

This technology forces the master to carefully monitor each stage of the process, some specialists use an assistant during this cut. But this option requires increased security measures.

Features of a homemade sawing option

Cutting a log into boards is easy with a do-it-yourself tool. Making the equipment is easy:

• As a support, it is necessary to use a frame from a school desk or a pipe with a section in the form of a square, its optimal size is 20 × 20, and more is allowed.
• Build two clamps, mount a cross member with two holes for tie bolts at one end, make a protrusion for the tire in the middle.
• For longitudinal sawing of a log into boards, it is important to make a support frame, its width must be 7-8 cm less than the length.
• Then two elements 10 cm long are welded to both sides, holes are made for the bolts, a handle is attached in the middle for ease of operation.
• After that, insert the clamps into the grooves, the tire is installed, everything is carefully fixed.

Work with homemade tool it’s not difficult, this will require two goats, they will serve as a support, and it is also necessary to prepare a metal rail or board, the element will be a guide element. A log is laid from below, the required height for work is adjusted.

Log sawing technique

Longitudinal sawing is carried out using a horizontal nozzle. To get the boards even, it is important to use a specially prepared guide, its role is played by a metal rail or a high-strength board.

The most difficult thing in this process is to make the first cut, for this you need:

• Mount the leading ruler, it consists of two boards fastened together at an angle of 90 degrees.
• Install the log on supports, firmly fix its position.
• Check if the log is lying flat with a level.
• Using self-tapping screws, fix the leading ruler to the supports.
• In a horizontal position, fix another guide, the element will rest against the ground, but at the same time fix the log.
• Saw the log.

During the second cut, specialists may not use the leading ruler, the resulting board will serve as a guide. The second cut is carried out perpendicular to the first.

Cross cutting secrets

The cross saw is used to obtain firewood or decorative elements interior. Sawing is carried out according to the following principles:

• Place the log in a horizontal position on wooden supports, the height should be 0.5 m.
• To clean it from the bark.
• Using an ax or a saw, make small marks along the entire length, they should be located at the same distance from each other.
• Make cuts along the cuts.

Cross cutting does not require the use of special tools or nozzles. An ordinary chain is perfect for such work, but its rings must be strong.

Safety

When working with a chainsaw, you must follow the safety rules, they will help to avoid injuries and unpleasant situations:

• Do not allow people, especially children, to enter the work area.
• When working with a circular saw, be sure to put on a special protective cover on it.
• During the process of sawing logs, you should use means of protection against sawdust and noise.
• It is necessary to have a first aid kit with medicines to treat the wound during cuts.
• Do not pour gasoline into the heated tank of the chainsaw.
• It is necessary to use a chainsaw only for its intended purpose, it is forbidden to turn it on at full power if it is not in operation.
• Installation of logs is carried out only on the right side.
• While working with the equipment, it is strictly forbidden to put pressure on it with force.

If safety precautions are observed, the work will be simple, and as a result, high-quality material will be obtained without harm to health.

The chainsaw is a versatile piece of equipment that is easy to use. Its masters can use on personal plot, in a private house. In addition to receiving boards, it is used for repair work outbuildings and wooden decorative elements. A large number of boards is not needed, it is enough to take a couple of logs.

Video: Cutting the forest into boards with a chainsaw