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We learn to saw on a band sawmill. Methods for cutting wood on a band sawmill. "Band sawmills" - operation and design

Boards and timber are one of the main building materials. But not everyone has the financial means to purchase ready-made boards. In such situations, one of the solutions is to independently harvest wood on a plot taken from the forestry.

The advantage of a chainsaw as a tool for sawing logs

You can saw a log using a sawmill, gas or electric saw and additional accessories. When choosing one of these tools, you should consider the amount of work ahead. The cost of the cheapest stationary sawmill along with all components is 150 thousand rubles. A chainsaw is much cheaper. It is more convenient than an electric saw for the following reasons:

Electricity is not required to operate the tool - this makes it possible to use a chainsaw on plots.
It is more powerful compared to an electric saw.
It starts smoothly and allows you to conveniently adjust the speed, which reduces the likelihood of a chain break.
The inertial brake operates faster than that of an electric saw.
Long working time without interruption – up to one hour.
Can be used in conditions of high humidity.

Types of working attachments

When sawing logs with a chainsaw, various attachments are used.

Attachment for longitudinal sawing. It is used for sawing logs lengthwise, the process takes place in a horizontal position. After work, the master receives the same thickness of the product. The finished materials undergo a drying process, after which the boards are used in construction. In appearance, the device is a frame small sizes, it is attached to the tire on each side.

Drum debarker (debarker). With the help of such an attachment it is easy to dissolve the log; it works due to a V-belt drive. Attached to belts on both sides, special pulleys are used for this. The speed of rotation of the shaft depends on the size of the pulleys, so the performance of the attachment is easy to change. This technology forces the master to carefully monitor each stage of the process; some specialists use an assistant during this cutting. But this option requires increased security measures.
Sawing with a lightweight nozzle. The method is not highly 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.

Features of sawing using a homemade tool

You can easily saw a log into boards using a self-made tool. It's easy to make. To do this you need to do the following:

As a support, you need to use a frame from a school desk or a pipe with a cross-section in the form of a square, its optimal size is 20x20, more is allowed.
It is necessary to build two clamps, mount a cross member with two holes for coupling bolts at one end, and make a protrusion for the tire in the middle.
To cut logs longitudinally into boards, you need to make a support frame; its width should be seven to eight centimeters less than the length.
Then two parts ten centimeters long are welded to both sides, holes are made for the bolts, and a handle is attached in the middle for ease of operation.
Then you need to insert the clamps into the grooves, install the tire, and secure everything carefully.

To Work with homemade instrument It’s not difficult, for this you will need goats, they will serve as a support. In addition, you need to prepare a metal strip or board to use as a guide. A log is placed underneath and the required height for work is set.

The procedure for performing preparatory work

To cut a log lengthwise, you need to perform the following sequence of actions:

Take two straight boards and attach one to the other at right angles. The result is a strong guide line.
To support the manufactured ruler, you need to make stops from boards.
Moving the trunks must be done using a tilter.
The log should be placed on a comfortable base.
You need to secure the frame to the chainsaw bar using nuts.
The supports of the leading ruler must be attached to the ends of the log, checking the horizontal position with a level.
Self-tapping screws must be used to secure all brackets and structural elements. Nails are not suitable for these purposes, since they are difficult to remove in the future without causing damage to the structural parts.
The leading ruler needs to be attached to the supports using brackets and its height adjusted taking into account that the cut will not go along it, but approximately one centimeter higher.
The log needs to be rotated and the second board secured so that it rests on the ground and supports the log.

Procedure for performing basic work

Now you need to start the chainsaw and make the first cut.
Next, you need to free the log from the stops and boards and attach a guide ruler to the cut surface of the log in the direction of the next cut. The ruler is attached directly to the surface or to the ends of the log using supports. The second cut is made perpendicular to the first cut.
The log needs to be turned and secured with a board against the ground.
A ruler is not required to perform the following steps. One of the cut sides serves as a guide.
It is necessary to adjust the thickness of the cut on the frame and saw off the log from the other side so that you get a beam with bark remaining on only one side.
This beam must be turned over and secured so that the attachment point of the fixing board is as low as possible.
Then you need to adjust the frame to the required thickness of the board and saw the timber into boards.

Safety rules when performing work

The circular saw should not be used without a protective guard.
It is necessary to wear headphones, gloves, glasses, thick clothing and a respirator.
You should not pour fuel into a hot tool tank; you need to wait until it cools down.
Children should not be allowed to be present at the work site.
It is necessary to start the tool on the ground with the chain brake engaged, which must be released only before starting to cut.
You should always have a first aid kit on hand.
When working, you need to hold the chainsaw by the arc handle, moving it forward along the guide. You should not put too much pressure on the chainsaw - it should move freely.
Right-handed people should position the log with right side from yourself, for left-handed people - from the left.

For a small forestry industry specializing in sawing wood into boards and beams, the optimal equipment for use is. It has good productivity and allows large-sized trunks to be cut into lumber. But in order for the equipment to work to its full potential during the work, you need to know how to saw on a band sawmill. Taking into account certain recommendations and operating features of such a unit will allow you to avoid problems and obtain high-quality business material as a result.

The process of sawing timber with this sawmill comes down to the fact that the log is placed and fixed on a special frame, which also acts as a guide. A frame with a cutting tool mounted on it, driven by an electric motor or internal combustion engine, moves along the slats along the barrel.

Preparatory stage

One of the main conditions for the normal operation of the equipment is to carry out preparatory work before sawing on a band sawmill. And they include:

cleaning the sawn log from dirt and sand;
wood assessment (species, humidity);
selection of a saw (shape, profile, tooth sharpening angles) depending on the material being cut;
correct performance of adjustment work (tensioning of the cutting element, drive belts).

Proper preparatory work will allow you to quickly cut wood with the proper quality.

An important factor for normal sawing is the correct sharpening and setting of the saw. These works should be performed only on special machines. A well-sharpened saw with a correctly selected tooth profile will ensure high speed and clean cutting.

Attention should also be paid to adjusting the cutting blade. A properly tensioned tape will ensure an even cut. Any violation of the tension will lead to “waviness” of the surface of the boards, or to tearing of the cutting tool.

The more sand and dirt there is on the wood, the faster the saw will become dull, which will greatly affect the performance of the equipment. Therefore, it is better to prepare the material before sawing, and also sharpen and set the cutting tool in a timely manner.

Sawing process

During the sawing process, it is important to ensure a uniform speed of movement of the frame along the log. This will eliminate the possibility of idle belt movement and ensure maximum productivity.

Before sawing wood with a high resin content on a band saw, care should be taken to ensure the supply of water or cleaning solution to the cutting area. This will prevent the teeth from sticking and ensure good cutting speed.

After each pass, you should evaluate the quality of the cut and make sure there is no “waviness”, and only then cut the log further. This will allow you to immediately identify problems with equipment setup and eliminate them in a timely manner.

Periodically it is necessary to clean the moving elements of the sawmill from sawdust. This will eliminate unnecessary vibrations during operation of the unit, which can affect the quality of sawing, and will also extend the service life of the units.

In general, sawing on a band sawmill is not difficult; the main thing is to fully adhere to the manufacturer’s recommendations regarding operation. You should not neglect the preparatory work, because the performance of the unit directly depends on it.

The specification of sawn raw materials is given in the assignment for the course project.

According to specification required edged lumber, a significant part of which is of a certain width. Therefore, the timber method of cutting logs is chosen. In addition, logs with a diameter of 34, 32, 30, 28, and 26 cm are intended for cutting, which can be sawed using this method. In the lumber specification, the most difficult (main) assortment is boards with a thickness of 50 mm and a width of 275 mm. When producing lumber of a certain section in accordance with the rules for drawing up deliveries when sawing with baling, the thickness of the maximum volume of timber is equal to 0.6-0.8 of the top diameter of the log. Therefore, to produce lumber with a width of 275 mm, sawn raw materials with a diameter of 34 cm are selected. For logs of the selected diameter, supply No. 1 is compiled and calculated for sawing lumber with a thickness of 50 mm and a width of 275 mm. Simultaneously with the main assortment, sawing of lumber with a thickness of 25 and 19 mm is provided.

In table 8.1 shows delivery No. 1 for boards with a cross-section of 50275 mm, boards with a thickness of 25 and 19 mm from logs with a diameter of 34 cm.

Let us determine the volumes of boards of the main and associated assortment from logs with a diameter of 34 cm and a volume of 94.16 m 3:

The obtained values are recorded in the corresponding columns “Plan for cutting logs into lumber.”

Total lumber by supply (m 3). The correctness of filling out the “Plan for cutting logs into lumber” is determined by comparing the calculated volumetric yield with the actual delivery yield P = 65.41%.

In this example, the task for producing lumber of the main assortment was exceeded. The remaining volume of logs can be sawn into the following lumber required according to the specification. To fulfill the planned target for the volume of p/m with a cross section of 50×200, we need the following volume of raw materials:

We record the resulting value in the log cutting plan, because There are raw materials of this diameter left, we use it to produce the next main assortment of 50x200 mm. and the calculations are repeated.

We carry out calculations similarly for subsequent sections, and write the calculation results in the table. 8.1.

Forest sawing is a cycle of actions using a variety of technologies aimed at obtaining lumber from round timber suitable for further use in industry. The duration and labor intensity of the process depend on the chosen method of processing round timber, as well as the time of year.

Tools and equipment

Trunks and large branches are used for production. All material is divided into groups according to thickness and presence of bark. Often, timber processing enterprises have workshops near the harvesting site, in which machines for the initial processing of wood are installed.

Manual debarking of wood

Wood that has not passed the debarking stage can be used on floors or as ridge beams in the corresponding interior, or as a supporting device during construction.

Industrial debarking of forests

If another option for using the wood is planned, then sawing is carried out, resulting in the following segments:

unedged and semi-edged (rough material from which the bases of the floor, walls or ceiling are mounted);
edged (intended for finishing flooring).

The cutting can be carried out by a mobile organization that has all the necessary tool.

Wood cutting map

Rational use of the material is ensured by compliance with the cutting map. This allows you to reduce costs due to waste, the percentage of which the card can significantly reduce. The tools and types of forest processing equipment used depend on the volume, desired quality and size of the finished lumber.

Wood sawing machine

The most commonly used are a circular saw and various machines:

circular due circular saw allows you to make precise cuts in various directions. Suitable for both professional and home use, copes well with above-average round timber diameters;
chainsaw;
machines for clean bark removal;
sawing on a band sawmill makes it possible to process dense logs; it is considered the most popular, since the output is high-quality material and a small amount of waste;
disk machine: production of double-edged timber and unedged boards;
a frame sawmill does not require a foundation, the technology using it allows you to install the equipment in close proximity to the felling site;
the fine gauge is processed by universal machines, the output is high-quality building materials even from low-grade logs;
sawing round timber at a large woodworking enterprise should be produced with the largest number lumber that differs from the rest in its special quality and precise dimensions. For this purpose, special lines are installed for sawing.

At the sawmill, timber and edged boards are obtained by cutting logs up to 7 m long and 15-80 cm in diameter along the longitudinal line. A circular saw has one or more disks and processes wood of different diameters according to their number.

If you need to process a small amount of wood at home, you can use a regular chainsaw.

Cutting wood

Before choosing a tool, you need to decide on the type of cut, focusing on the annual rings of the log. There are several types:

radial (along the radius);
tangential (the cut is parallel to one radius and touches the annual rings);
the fibers are located parallel to the cutting being performed.

Among the cutting methods, the one that is most suitable for a particular case is selected:

Waddle. Sawing wood in this way is carried out for deciduous trees with a small trunk thickness, and is considered the simplest processing. Output: unedged elements and slabs.
If you have another forest processing machine, then it is possible to cut up to 65% of the material to produce edged boards of equal width. First, double-edged timber and boards on the sides are cut, and then a certain amount of edged lumber is obtained from the timber.
More specific methods are sector and segment sawing. The number of elements in the first method varies from 4 to 8, and depends on the thickness of the trunk. After dividing, elements are cut from each sector along a tangential or radial line. The second method begins with the timber coming out of the central part, and boards are cut from the side segments in a tangential direction.
For individual cutting of wood, the circular method is suitable. It is based on turning the log along the longitudinal line by 90° after each sawn board. This allows you to monitor the quality of the wood and promptly remove affected areas of the trunk.

Manual work: using a chainsaw

For home cutting of several trunks, it is not advisable to purchase a tool whose cost is several times higher than the price of finished products. If you have the necessary skill, then it is more efficient and cheaper to do the whole necessary work a regular chainsaw, or chain equipment powered by electricity. Of course, such work requires much more physical effort and time, but the cost of the issue is significantly reduced.

Work for garden plot requires pruning fruit trees, and it also becomes possible to additionally produce material for outbuildings without resorting to the services of specialists, so any thrifty owner will prefer to buy a chainsaw. Most often, coniferous wood is harvested for the home, and this tool does an excellent job of cutting it. Thanks to straight trunks, it is easier to mark cutting lines, which increases the speed of work. Professionals, by the way, most often use a chainsaw, since it is more powerful than an electric one and can be used anywhere, regardless of whether there are power sources at the cutting or cutting site.

To use a chainsaw to cut logs, you will need a device such as a saw attachment, as well as cutting guides and base-trunk fasteners. The frame-shaped attachment is attached to the tool so that it remains possible to adjust the distance between the chain and the frame itself. This is done to make it possible to produce finished lumber of different thicknesses. For the role of a guide, you can take either a profile of the required length, or a flat wooden plank with sufficient rigidity. A special chain is selected for the tool, designed to cut the trunk lengthwise. Its difference from the others lies in the teeth sharpened at a certain angle.

Before you start work, you need to not only prepare all the necessary tools. Regardless of whether a woodworking machine is intended for processing a trunk or hand tool, the first thing you need to do is familiarize yourself with the cutting map. This is done in order to minimize the percentage of waste and increase the yield of useful products.

The first thing you need to worry about when cutting longitudinally is the uniform density of the finished boards. To do this, a competent sawyer directs the tool from the east side of the log to the west, or in the opposite direction. This is explained by the higher density of round timber in its northern part than in the southern part.

Next, use a chainsaw to remove the slab from both sides so as to obtain a double-edged beam. It, in turn, is sawed in accordance with the cutting pattern chosen at the beginning of the work. The exit gives unedged board. If there is a certain percentage of defects in the trunk, then a circular cut is possible with the trunk turning at a right angle or 180°.

Quantity of finished material, cutting price

Exit useful material from coniferous and deciduous species differs in percentage. For lumber obtained from coniferous trees, the following indicators are characteristic:

provided that the operation is carried out by a professional and a circular sawmill is used, the percentage of finished wood will be the highest (80-85%);
the edged material produced by the machines averages 55-70%;
An unedged board leaves up to 30% waste when used with a chainsaw.

The figures are given without taking into account the finished culled timber, the amount of which can reach 30%. However, such material is used for products that allow certain defects.

Finished wood products after sawing

Deciduous round timber produces 60% of the finished unedged timber and about 40% of the edged timber. This is explained by the initial curvature of the round timber. It is possible to increase the amount of products obtained: this will require forest processing machines of various types. A certain kind of device can increase the amount of lumber by 10-20%. For one cube of lumber you will need about 10 cubes of deciduous round timber. The cost of installing additional equipment will be recouped by the cost of the finished timber. Special lines provide greater volume, but their use is only advisable for large plot. The average price of sawing wood at a regular sawmill will be approximately 150-180 rubles per cubic meter of boards.

Sawing map

The sawing map is a calculation of the optimal amount of finished lumber from one log. You can calculate it yourself for each specific log diameter, or you can use computer program, which greatly facilitates the calculation, and the price of which is quite affordable.

Material yield after cutting wood

Or the source could be a regular sawmill reference book. The result is a table that is used as a basis. The sawmill attachment must always be oriented towards its data in order to obtain more lumber of any type of wood.

In this article we will talk about how to cut logs on a band sawmill. In addition, we will consider what are the criteria for selecting one or another method of wood processing and how this affects the characteristics of the finished lumber.

Methods for cutting logs to produce various lumber have been developed and improved for a long time, since this is the only opportunity to obtain edged boards, timber and other categories of similar products from a single tree trunk.

An example of what can be obtained from an ordinary log

From ancient times to the present day, methods of wood processing have evolved, and in addition, new, more productive equipment has appeared that makes it possible to obtain the necessary lumber quickly and with a minimum amount of production waste.

Features of wood processing

Cutting map for automated processing wood

The instructions for processing raw materials and obtaining lumber products consist of a number of technological operations, including longitudinal cutting of logs, trimming lumber and cutting to width, sorting by standard sizes, sorting by quality of workmanship, drying and storage.

Each of the listed stages is important from a quality point of view finished products. But cutting is the most labor-intensive and critical stage, during which the main characteristics of the finished lumber are formed.

Slicing diagram for common lumber products

Drawing up a plan for cutting logs into lumber (choice suitable method processing) depends on the type of wood, the size of the raw material, the degree of humidity, the density and hardness and many other factors. Of course, the method of processing raw materials is determined to a large extent based on the level of technical equipment of the enterprise.

Let's consider what equipment is used for industrial sawing of wood and what methods are relevant for each category of this equipment.

Cutting equipment and features of its use

An example of wood processing with group circular saws

The following categories of equipment are used for longitudinal cutting of logs:

Single band saws or circular saws are a traditional solution that has been used for a long time.
The group of frame saws is a more progressive solution that can significantly increase the productivity of raw material processing without compromising the quality of the finished product.

Let us consider in more detail the features of the application of the listed categories of equipment.

Custom sawing is a method that uses single saws. In this case, only one cut can be obtained in one saw pass. Therefore, the entire tree trunk can be cut in several passes.

Important: The advantage of individual cutting is the independence of each subsequent cut from the previous one.
That is, sawing can be carried out in different planes.
As a result, it becomes possible to more rationally use certain properties of different parts of the log.

At the same time, this method is low-productivity and therefore not suitable for use in large woodworking enterprises.

Group sawing is a technological process in which a group of frame saws is used.
The advantage of this method is that the log is completely cut in one pass. This saves time and, as a result, reduces the cost of production. But you need to remember that group sawing is performed in one plane.
Today, the following categories of equipment for group sawing are most widespread:

narrow-clearance vertical frames, machines with circular saws, milling saws (diameter of processed raw materials from 14 to 22 cm).
medium-clearance vertical frames (diameter from 24 to 48 cm)
wide-clearance vertical frames, double and quadruple bandsaw-type units (diameter of processed raw materials over 50 cm).

Basic methods of longitudinal sawing

This is what the log cutting table looks like on a band sawmill

So, now that we have examined the current methods of processing wood raw materials using special equipment, let’s consider the features of the implementation of these methods.

In the modern woodworking industry, the following cutting methods are used:

“Waddle” is a method of sawing logs in which the cutting planes are parallel to each other. In accordance with the arrangement of lumber in the log, the core board or timber is distinguished; central boards, one of the planes of which runs along the longitudinal axis of the log; side boards.

The photo shows a tree trunk installed in a slitting machine

Important: This method processing of wood raw materials is considered the simplest and least labor-intensive.
But you need to take into account that ready wooden boards unedged, and therefore you will additionally have to make a cross-section of the log.

“With lumber” - this method allows you to get a lumber with two edges. The rest of the log is sawn into unedged side boards and flooring. That is, cutting is performed not in one, but in two passes. Moreover, the type of saws used for the first and second passes differs both in the number of cutting surfaces and in their direction.

Band saw cutting edge

The equipment on which the timber is made is called the first row machine, and the equipment by which the timber is cut into individual boards is called the second row machine.

The “sector” method, during which the log is cut into separate sectors, from which boards are subsequently made.
Sawing using this method is performed in one pass, when the cutting tools go sequentially or in several passes, when initial stage longitudinal sectors are obtained, and at subsequent stages these sectors are divided into lumber.
The sector method is relevant for the production of lumber for radial and tangential sawing. In accordance with the diameter of the log and the required dimensions of the workpiece, sawing is performed only into quarters or into quarters, followed by cutting into smaller sectors.
The disadvantages of this method include labor intensity, since the log cutting map is drawn up individually. In addition, when processing wood raw materials, a large amount of waste is generated.
The segment method involves sawing the trunk into longitudinal segments, which, in turn, are cut into boards of the required size.
The segment-breaker method involves the simultaneous production of segments and sawing them into lumber of the required size in one pass
The segment-beam method, in which the side segments are simultaneously sawed out, while a double-edged beam is obtained from the middle (central) part.
The method involves cutting in two passes. During the first pass, the log is divided into beams and side segments. During the second pass, the segments are divided into smaller boards.
Circular sawing involves processing a log in which the boards are sawn off sequentially. During processing, the workpiece rotates around its axis after the next board is sawn off.
Due to the labor intensity and individual approach, circular sawing in industrial scale practically not used.
The aggregate method involves preliminary milling wooden log, after which the resulting square-section timber is cut into the required number of boards. During milling, a large amount of technological chips is formed, which, in turn, is used for the production of particle boards or fibreboards.

Features of cross cutting

The most common configuration of cross-cutting machines

The cross section of a log is called trimming and is performed with special circular saws. Despite the fact that the price of lumber increases due to trimming, this stage is mandatory during industrial wood processing. Cross cutting is performed after the longitudinal sawing of the log is completed.

Lumber, upon completion of drying, often has simple, transverse and wave-like curvatures. Such deformations are difficult to correct with your own hands. To reduce the degree of deformation of lumber, trimming is performed, during which part of the wood that has undergone curvature is simply cut off.

Automated line for cutting lumber

To perform these works, a cross-cutting machine is used in the form of a frame with a bottom-mounted saw. During cross-cutting, technological waste is generated, which can be processed into chips and used for the production of particle boards. The location of the cut is determined in accordance with the type of assortment and taking into account the defects of the processed lumber.

Methods for performing cross cutting

Cross-cutting machine in an industrial workshop

Currently, domestic and foreign manufacturers is being manufactured a wide range of cross-cutting machines.

In accordance with the configuration of the equipment and the degree of its automation, several trimming options can be performed:

Trimming beams and boards in a stack at a given constant length. This option is used in the manufacture of various carpentry products (doors, windows, stairs, etc.), laminated veneer lumber and structural elements for wooden house construction.
Trimming boards of different lengths. During this technological process, the boards are fed to the working tool, where they are automatically measured. Next, the control unit selects the optimal combination of workpieces that can be cut in one pass in accordance with the given specification.
Trimming with removal of defects with variable length of finished products. This equipment configuration allows you to minimize the volume of knots, rot, pigment spots and mechanical deformations by cutting off problem areas from the end of the workpiece.
This option is widely used in the manufacture furniture facades, where gluing of lamellas to obtain a solid slab is allowed. Choosing this trimming option allows you to reduce the volume of production waste to a minimum and thus reduce the cost of the finished product.
Trimming with removal of defects with fixed standard sizes of finished products. In this case, all workpieces are cut to the same length according to specification.

Taking into account the peculiarities of the technological process, it should be noted that the products obtained in this way are the most expensive, since a large amount of waste remains.

Conclusion

Now we have general idea about how and with what equipment it is performed industrial processing wood Still have questions that require clarification? In this case, we recommend watching the video in this article.

To process logs on a band sawmill, it is necessary to adhere to the accepted technology. This way you can get the maximum amount of high-quality materials - boards and timber. But first you should familiarize yourself with the basic cutting rules.

Types of wood cutting

At the first stage, a carriage is formed from a log. To do this, cuts are made on both sides of it. In some cases, processing is performed on four sides. A map of the band cut of the workpiece is first drawn up, on which the dimensions of the components are indicated.

The determining parameter when choosing a scheme is the direction of processing of the log. In particular, the movement of the cutting edge relative to the annual rings. According to this, lumber is formed various quality with unique appearance. Not only their aesthetic qualities, but also their price depend on this.

The following types of cuts are distinguished:

tangential. The cut is made tangentially to the annual rings. As a result, oblong patterns in the form of arches and rings are formed on the surface;
radial. To perform it, perpendicular processing along the annual rings is necessary. A special feature is the uniform pattern;
transverse. Processing occurs across the fibers, the cut pattern is an even cut of annual rings;
rustic. Can be made at any angle, contains a certain number of knots, sapwood or other similar defects.

The woodworking industry often uses waste from band sawing logs - slabs. On one side there is a flat plane, and the other remains unprocessed.

To create the most accurate cutting, it is recommended to use special programs. They take into account not only the dimensions of the source material, but also the type of wood.

Sawing on a sawmill with log rotation 180°

To form the maximum number of boards, it is recommended to use a technology in which some belt processing processes are rotated 180°. This allows you to achieve the maximum amount of lumber with different types of cuts.

The principle of processing is to make initial cuts along the edges of the log, located at an angle of 90° relative to each other. They will serve as the basis for further tape cutting. The work is carried out on equipment with a vertical arrangement of cutting elements. The diameter of the trunk must be at least 26 centimeters.

Step-by-step order of work.

Processing the side with the cut-off edge. The result is two boards.
Rotate the workpiece by 90°. The cut is made from the opposite part. The number of products varies from 3 to 4.
Repeated turn 90°. The main part of the source material is processed. Depending on what you plan, you may end up with 7-8 pieces.

Despite all its positive qualities, this method has one significant drawback - low production speed. It is recommended to use it on equipment that has a block for automatically changing the position of the log relative to the cutting part of the machine.

The detailed diagram is most often used for the production of rustic boards, which have lower quality requirements.

Sawing on a sawmill with log rotation 90°

For the manufacture of tangential and radial boards, it is recommended to use a different technique. It consists of systematic strip processing of logs with simultaneous analysis of defects. In this way, products of the required quality can be obtained.

After delimbing, the workpiece is placed on the feed bed of the sawing machine. Then you need to complete the following steps.

Removing the primary slab. This is carried out until the width of the base is 110-115 mm.
Removal of unedged boards approximately 28 mm thick.
If the number of defects on the surface exceeds the required level, the material is rotated 90°. If the quality of the board is sufficiently high, the next one is cut.
Repeating the operation.

A similar technique is applicable for processing units that have one cutting surface or have the function of temporarily dismantling the rest.

If there is a sufficiently large number of defects, you can not put the workpiece aside, but rather process it by turning it 180°.

The above-described strip processing technique can be used to create any configuration of wooden products. Often the core area is used to form timber, and the remaining parts are used to make boards. But there may be exceptions - it all depends on the required shape of the blanks.

The quality of work is affected by the current state of the sawmill, the level of sharpening of the saws and the processing speed. These factors must be taken into account before starting the production process. If necessary, preventive maintenance or repair of equipment is carried out.

The video shows the technique of sawing logs on a homemade band sawmill:

Wood, along with natural stone, is one of the oldest building materials. Despite the huge variety of all kinds of artificially created materials currently present on the construction market, wood is still in constant demand. Wood – versatile and available material, and not a single construction project can be completed without its use.

The main raw material for the production of lumber (timbers of various sections, edged and unedged boards, etc.) is a log - freed from branches and twigs, as well as from the thinnest upper part of the tree trunk. Logs can be used as a completely independent building material as pillars, piles, masts, etc., however, in most cases they must be sawed to obtain beams and boards. How to cut a log into boards, beams and other lumber will be discussed further.

Sawing logs can be done in various ways:

manually, using a saw tool;
on sawmills;
on woodworking machines and specialized lines.

The price of lumber largely depends on its thickness and the amount of production waste.

In order to make the most efficient use of available raw materials and correctly saw a log, the woodworking industry uses special sawing schemes to reduce the percentage of waste and thus reduce the cost of the final product. Therefore, before cutting a log yourself, it would be useful to familiarize yourself with similar diagrams.

Tools and equipment for sawing logs

Depending on the total number of logs, their length, thickness and the expected quality of the future lumber, various tools and specialized equipment are used for sawing. For getting small quantity lumber at home is quite acceptable manual method processing trunks using chainsaws and conventional hand saws with teeth for longitudinal sawing.

The sawmill is a fairly common type of sawmill equipment. It is a woodworking machine with frame saws, designed for longitudinal cutting of logs to produce edged boards and timber. Sawmills can process logs with a diameter of 15 to 80 cm and a length of up to 7 m.

Sawing tree trunks on circular saws (circular saws) is carried out using a circular saw. Such machines can be single-saw (single-disc) and multi-saw (multi-disc). Single-disc circular saws usually work with small-sized and low-quality source material. Multi-disc machines are designed for cutting large-diameter round timber.

The most popular currently are the so-called band sawmills, both vertical and horizontal. They use a belt cloth mounted on pulleys as a cutting tool. Band machines provide high-quality longitudinal and mixed sawing of logs into boards and beams with a minimum amount of waste.

Wood sawing lines are used at large enterprises in the production of lumber on an industrial scale. They provide high surface quality and precise geometry of the final product and have the highest productivity.

In addition to the above, other types of highly specialized sawmill equipment are used in the mass production of lumber: debarkers, edgers, band-dividers and other machines.

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Types and methods of cutting logs

Before sawing a log into boards and beams, it is important to choose the most the best way sawing, which is determined by the size, geometry and surface quality of the future lumber, necessary technical requirements, as well as the type of wood. By orientation to the growth rings of the trunk, types of sawing can be distinguished. This:

radial, carried out precisely along the radius of the growth rings;
tangential, when sawing is done tangentially to the growth rings, parallel to one of the radii;
parallel-forming, when cutting occurs parallel to the direction of the fibers (this way, a minimum inclination of the fibers in the lumber is achieved).

Depending on the direction of sawing, there are several ways to saw logs:

waddling sawing;
sawing with beams;
segment method;
sector method;
circular sawing.

Tumble sawing is carried out using several parallel cuts along the entire cross-sectional plane of the log and produces an unedged board and two slabs at the output. Tumble cutting is the most in a simple way processing of logs and is used mainly for cutting hardwood round timber of small diameter, since other methods greatly reduce the width of the finished lumber.

Sawing with beams involves cutting out double-edged timber and side boards at the initial stage. The timber is subsequently sawn into edged boards the same width. Up to 60% of all raw materials are cut using lumber. The disadvantage of this method is the need to use two sawmills simultaneously.

The above methods are the main ones. Special methods are used much less frequently: sector and segment. When sector sawing, the log is first divided into several fragments - sectors, numbering from 4 to 8, depending on the diameter of the trunk. These sectors are then sawn into boards along radial or tangential directions.

With the segment method, a beam is cut from the central part of the log, leaving two so-called segments on the sides. The resulting segments are then cut into tangential boards.

The circular sawing method is used for individual cutting of logs and allows you to separate healthy wood from damaged wood. When circular sawing, after sawing off another board or several parallel boards, the trunk rotates around the longitudinal axis by 90° each time.