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How to saw correctly on a band sawmill. Recommendations for sawing and sorting (photo gallery) How to cut timber on a band sawmill

For processing logs 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 is drawn up in advance band sawing blank 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 - movement cutting edge relative to tree rings. According to this, lumber of various qualities is formed, with a unique appearance. Not only their aesthetic qualities, but also their price depend on this.

Distinguish following types cuts:

• 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.

1. Processing the side with the cut-off edge. The result is two boards.
2. Rotate the workpiece by 90°. The cut is made from the opposite part. The number of products varies from 3 to 4.
3. 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 my 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 infeed bed sawing machine. Then you need to complete the following steps.

1. Removing the primary slab. This is carried out until the width of the base is 110-115 mm.
2. Removal of unedged boards approximately 28 mm thick.
3. 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.
4. 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 current state sawmills, saw sharpening level and 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:

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. By 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 school desk or a pipe with a square cross-section, 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.

Working with a homemade tool is not difficult; for this you will need goats, they will serve as a support. In addition, you need to prepare metal strip or a 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 structural parts.
• The leading ruler needs to be attached to the supports using staples 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.
• Do not pour fuel into hot tank tool, 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.

Wood as a product is very valuable. Wooden products are all around you. However, before becoming a table, cabinet or bench on the street, a tree must go through long haul processing. Wood materials - boards, beams, bars, are obtained by sawing. It is this work of the band sawmill that is most important.

Frozen wood - how to saw on a band sawmill?

Many operators, especially those who lack the necessary experience, encounter difficulties when sawing frozen wood with bandsaws. It is especially unpleasant if the wood is not completely frozen, and there are unfrozen areas in the log, i.e. different densities.
Meanwhile, the problem is being solved.

And yet, how to saw frozen wood on a band sawmill. Much, when sawing with band saws, depends on correct selection and preparing the band saw, much depends on the geometry of the tooth.

Firstly, saws designed specifically for sawing hard and frozen wood are very effective in this case (for example, Wood-Mizer wood band saws with a 4/32 profile, or “winter” profile saws 9/29)
Secondly, pay attention to the tooth alignment. When working with frozen logs, it makes sense to reduce it to 15-18 or even less, to 12-14.

The performance of a band sawmill is usually influenced by an individual combination of various factors, so if this is your first time working with frozen wood, it is advisable to experiment. Using three saws, make three wiring options: recommended, smaller, and even smaller. Work with all three saws, evaluate the result and then use the optimal layout

Operation of the saw blade of a band sawmill.

When using a saw blade for the first time, it is recommended to sharpen the saw after about an hour and a half of use. This sharpening should be done in three passes through the sharpening machine. The first passage plays the role of an introductory passage, the second has a leveling function, and the third passage has a nursing function. This procedure will serve to eliminate microcracks on the surface being sharpened. After sharpening, experts advise hanging the saw for six to eight hours so that it can rest.
To avoid overheating of the saw blade, as well as to avoid excessive fatigue, it is best to work with it for one to three hours (the time depends on the type of saw), then sharpen it, and then leave the saw blade to rest for approximately 12 hours.

In the process of sawing wood, high cutting parameters are sometimes set. This causes the saw teeth to overheat. Therefore, proper cooling is necessary saw blade, and also, if possible, adjust its tension, because when the temperature of the saw changes, the amount of its tension may also change. In summer, it is best to use water as a coolant; in winter, it is recommended to use diesel fuel for this purpose.

The operation in which the cutting ability of the saw blade is formed is called setting. During the setting process, the tooth is moved apart in the segment to the right, left, directly in relation to the saw body. The saw teeth must be set symmetrically, otherwise operational problems may arise. The laying begins at a height of two-thirds from the top of the blade.

For sawing hard or frozen wood, the recommended setting value to the side of the saw blade body is 0.3 - 0.4 mm. For sawing soft wood, this value is 0.5 - 0.7 mm.

Disc sawmill sawmill "Grizzly"

The Grizzly sawmill is the founder of angle sawing in Russia. The machine is designed for sawing various (both soft and hard) wood into export-quality edged boards, or timber. Successfully saws larch.

Ideal for valuable wood species.
The design of the machine is unique.

The cut is made using a movable carriage along a fixed log. At the same time, on the carriage, at an angle of 90º, there are: one vertical and up to two horizontal disks, which allows you to obtain a maximum radial cut. In one pass of the carriage, up to two edged products are obtained, which are fed into the hands of the operator by reversing the carriage.

The disc sawmill allows you to cut logs with a diameter of up to 1 meter without turning them. This is done by sawing from top to bottom and from left to right, step by step, board by board. The operator can obtain timber and boards from the log various sizes: vertically up to 250 mm in any configuration of the machine vertical saw blades, namely a Ø765mm disk with removable teeth, and a Ø630mm disk with carbide tips. And horizontally up to 100mm, up to 170mm, when the machine is equipped with one vertical disk with a diameter of 630 mm, and one horizontal disk with a diameter from 305mm to 450mm (with removable teeth or with carbide tips). This configuration of the machine allows you to save on cutting.

To obtain dimensions on sawn timber up to 250 mm vertically and up to 200 mm horizontally, the machine is equipped with one vertical disk with a diameter of 765 mm, and one horizontal disk with a diameter of 500 mm.

Comments

Wood as a product is very valuable. Wooden products are all around you. However, before becoming a table, cabinet or bench on the street, wood must go through a long process of processing. Wood materials - boards, beams, bars, are obtained by sawing. Exactly this band sawmill operation is of greatest importance.

When sawing logs into boards, strive to obtain boards with a uniform wood density. It is important that the direction of the cuts goes from east to west or vice versa. Because the northern side of the log has greater density, while the southern side is looser. Medium boards have a uniform structure and are preferred when working in carpentry.

If the log is absolutely round, approximately the same thickness along its entire length and does not have any significant flaws on the outside, cutting is done quickly and with virtually no loss of valuable wood. First cut down the top and bottom sides, and then cut the rest of the trunk into boards of equal thickness.
In most cases, it is necessary to think through suitable sawing methods in order to increase the yield of the most more high-quality and wide boards, regardless of their thickness and hidden advantages. When cutting on a band sawmill, this can be done by rotating the log 90o or 180o. First remove the slab. Next, remove unedged board. If there is a false core or defects on the bottom of the board in an amount exceeding the permissible, the log is rotated 90o or 180o.

Remove the board again. If there are no defects, remove the additional board, etc. After you have removed all the side boards, you will be left with timber, which is also sawn into fixed width boards. Turn the logs over on the bed whenever the other side of the log when cutting will produce better quality boards than the one you are currently cutting.

Band sawmill Taiga T3 and its features

The Taiga T3 band sawmill is an electric sawmill designed for sawing logs into beams, carriages, edged and unedged boards, and so on.

We recommend purchasing additionally

Main consumables for band sawmills are saws. Band saws require special attention; they need to be periodically sharpened and thinned so that the resulting lumber is high quality. Therefore, we additionally recommend purchasing with the Taiga T3 band sawmill:

Taiga adjustable machine for band saws.
Automatic sharpening machine 220 V Taiga for Taiga band saws.
Bimetallic band saws 4,290 m long, for the Taiga T3 sawmill.

And also, to adjust the rail track level, we recommend purchasing a set of anchor bolts:

Box with adjustable supports for installing rail tracks.

Technical characteristics of Taiga T3
Maximum diameter of sawn log, mm 900
Minimum diameter sawn logs, mm 100
Length of sawn log, mm 6500
Diameter of saw pulleys, mm 600
Capacity, m3 6-12
Saw blade speed, m/s 30
Dimensions machine, mm
Length 930
Width 2000
Height 1700
Overall dimensions of the rail track, mm
Length 7900
Width 1060
Weight, kg 633
Volume, m3 3.55
Engine power, kW
Saw drive 11
Voltage, V 380
Lifting and lowering 0.55

Band sawmills and their work

In industry, three types of sawmills are most often used: frame type, circular circular saws and band saws (for example, Ritm-M, PLP-1, PLGR-700-6300). Let's take a closer look at each of these three types.
Frame-type sawmills are characterized by high energy consumption, low coefficient exit finished products, a large amount of waste, the need to sort lumber by diameter, require a massive foundation. As a rule, on the basis of this equipment, stationary sawmill complexes are created with access roads equipped with lifting mechanisms, sorting areas that occupy a large area for sorting and packaging finished products, equipment for removal, temporary storage and disposal of waste. Thus, these complexes require serious financial investments to equip the sawmill site with the necessary additional equipment for the necessary uninterrupted operation of production.

Circular saw disc units have lower energy consumption than saw frames, there is no need for a massive foundation, it is possible individual cutting each deck. Complexes using this equipment have sufficient high performance. Unfortunately, the question arises about the need for waste disposal, since the cutting width of circular saws is 6-7 mm, therefore a large amount of sawdust is formed, just like with frame saws. In addition, the cost of the machines themselves and the circular saws for them is quite high. Saw sharpening should only be carried out by highly qualified personnel.

Band sawmills can be horizontal (Ritm-M, Ritm-1 PLGR-700-6300), vertical, or with the band saw machine positioned at an angle. Installations using tapes up to 40 mm wide are, as a rule, relatively inexpensive and small-sized. These are sawmills with a capacity of 10-12 cubic meters of saw logs per shift. In principle, they are designed for professional sawing and working with large-sized sawlogs (800-1000mm). Sawmills using 35-50 mm wide belts are the most popular among consumers, since these saws are relatively inexpensive. Their maintenance comes down to timely sharpening and periodic teeth alignment. Performing these operations does not require special qualifications of personnel. And the most expensive in this group of equipment band saw with tape larger than 60 mm. It requires a more serious approach to preparing the premises for work. The band saws themselves are produced with carbide tips, which requires the personnel to have special training and qualifications, since in addition to sharpening, such saws require periodic rolling of the blade on special equipment. All band sawmills are designed so that the cutting width does not exceed 2.4-2.6 mm, that is, a minimum of waste is produced. A necessary condition work on a band sawmill - work with one band for no more than two hours. According to the recommendations of all band saw manufacturers, it is necessary to change the band every two hours of operation, regardless of whether it is dull or not, and then give it a “rest” for 18-24 hours. During normal inspection, one belt (timely, correctly sharpened and spread) processes 60-80 cubic meters of lumber).

There are many different methods of cutting wood, including straight or clear sawing, square sawing, straight sawing, grade sawing, which is rarely used in Europe, and very interesting way cutting the log into quarters. Read a description of each of these methods, including their names in English, which may be useful when searching for information on the Internet later.

Live sawing or continuous sawing
The straight or clear cut method is one of the easiest ways to cut a log on a band saw. In English, this method is called Live sawing or Slab sawing, that is, sawing off a slab, or another option is Through and through sawing, that is, sawing through. The essence is that the log is laid on the frame, clamped and several boards are sawn off from it sequentially on top, and then, when it is formed horizontal surface, the log is turned 180 degrees and again sawn one board at a time from top to bottom to the very end.

Although this cutting method is the easiest and fastest, it has a significant drawback, since the result is unedged boards, and therefore another operation of longitudinal cutting of the board is needed to obtain a product of proper quality. Generally, clear sawn lumber is heavy, wide, low grade boards that are likely to become seriously distorted if placed in the kiln. Because of these disadvantages, the clear sawing method is recommended only for low quality logs.

Cant Sawing or Sawing timber
When sawing timber, the first cuts are made on top of the log, after which it is turned 180 degrees and sawn with opposite side until the specified beam thickness is achieved. Then the log is turned again, this time by 90 degrees, sawn on the third side, turned again and the last edge of the beam is formed on the fourth side. Thus, a beam is cut from the center of the log, which is subsequently either processed on other equipment or sold in finished form as a support beam, post or other heavy and durable building material.

In terms of production volume, this method of sawing logs maximizes productivity and is often used as the initial stage of wood processing in large sawmills. Typically, the beam sawing method is used for logs of medium and low quality, since its advantages are saving time and effort.

Plain sawing or Simple sawing
The simple sawing method is very similar to sawing timber. In the same way, at the first stage, the log rotates and a beam is formed from its center the right size, but the sawing doesn’t stop there: the operator cuts the timber on a band sawmill into boards of a given thickness. If the customer's specification specifies boards of different widths, then it is necessary to make timber of the maximum size in width, and then pass the finished boards through an edger. Simple sawing is one of the most popular ways to get the highest yield and the best quality boards.

Grade Sawing or Sawing by Grade
This method is used in the USA and Canada, it is not popular in Europe, however, it is useful to know how American sawmills cut logs into lumber different varieties.

Look at the picture. This method involves sawing off several slab boards from a log, then turning it over 90%, sawing off the boards again and turning it over again, and so on at least five times. From a financial point of view, this is the best method for dissolving valuable wood, although the productivity of the machine is low.

Quarter Sawing or Quarter Sawing
Here is another interesting way to cut a log. There are several reasons to use the quarter sawing method when dealing with expensive valuable species wood, because this method allows you to obtain boards with improved strength characteristics due to a certain pattern of annual rings in the finished lumber. The cost of such boards is higher and the demand for them is higher than for lumber obtained by simple sawing. Typically, carpenters, furniture workshops and craftsmen prefer to work with this material because of the obvious advantages in its properties.

However, with this method of cutting logs, the benefit in the price of the product may not pay off due to the large labor costs and time spent on sawing.

Quarter sawing takes into account the angle at which tree growth rings intersect the surface of the lumber. Although there are different opinions In relation to this term, quarter sawn lumber is distinguished by the fact that the growth rings are located at an angle of 80-90 degrees to the surface of the board. This method can also be used to cut boards in which the growth rings will be at an angle of 45-80 degrees to the surface.

Advantages of the quarter sawing method
- Increased strength of lumber.
- Width shrinkage during drying is half that of plain sawn boards (3% instead of 6%).
- Less risk of surface cracking during drying.
- Lumber is more stable in a humid environment.
- The pattern on the surface of the board looks more uniform, which is important, for example, when laying a floor.

Disadvantages of the quarter sawing method
- The yield of finished lumber is 20% less than with simple sawing.
- Productivity decreases.
- Drying time increases by 15% compared to plain sawn timber.
- Thickness shrinks twice as much during drying.
- A different pattern of branches (not round, but spiky), which may reduce strength.

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 angling, 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, it 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 yield gives 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 amount of lumber, differing 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 blades and processes different diameter forests according to their quantity.

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:

1. 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.
2. 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, the double-edged timber and boards on the sides are cut, and then a certain amount of edged lumber is obtained from the timber.
3. 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.
4. 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 all the necessary work with a conventional 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 of fruit trees, and it also becomes possible to additionally produce material for outbuildings, without resorting to the services of specialists, so anyone zealous owner would prefer to buy a chainsaw. Most often they are prepared for the home conifers, which this tool does an excellent job of cutting. 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 or a manual device is intended for processing the trunk, 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 solution is an 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. The following indicators are typical for lumber obtained from coniferous trees:

• 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%;
• When used with a chainsaw, an unedged board leaves up to 30% waste.

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 over a large area. Average price sawing wood at a regular sawmill will cost approximately 150-180 rubles per cubic meter of boards.

Sawing map

The cutting map represents the calculation optimal quantity finished lumber from one log. You can calculate it yourself for each specific log diameter, or you can use a computer program that 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 should always be oriented to 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, wood processing methods have evolved, and in addition, new, more productive equipment, allowing you to obtain the necessary lumber quickly and with a minimum amount of production waste.

Features of wood processing

Cutting chart for automated wood processing

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 the point of view of the quality of the finished product. 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 materials 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.

1. 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.

1. 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 of processing 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 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 is practically not used on an industrial scale.
• The aggregate method involves preliminary milling of a wooden log, after which the resulting beam is square section 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 it is used cross-cutting machine in the form of a frame with a saw with a lower location. 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 We manufacture 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 optimal combination workpieces that can be cut in one pass to a 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 industrial wood processing is carried out. Still have questions that require clarification? In this case, we recommend watching the video in this article.