Has your band sawmill been installed and made all the necessary adjustments? So it's time to proceed directly to the sawing process itself. To really get quality material, it is necessary to correctly install the log and fix it with special clamps.
The quality also depends on the correct calculation of the amount and type of material that you want to get from this log.
Having gained experience in the future, one glance at the log will be enough, and you will already know how much and what kind of material can be obtained from it. Learn to accurately determine where the top is and where the butt of the log is. The butt, as a rule, is larger in diameter than the top. And this largely affects the thickness of the slab.
How to calculate a log
So, you have measured the diameter of the log, and it is measured from the top. We calculate the approximate amount of material according to the diameter and proceed to further actions.
Firstly.
We pay attention to all the bends and bulges of the log - a perfectly even trunk is rare. Therefore, we try to turn it so as to get as little waste as possible from it, such as slabs. When the log is laid and fixed, it is worth making sure that it passes freely between the guide rollers.
Set the size on the ruler of the sawmill according to the diameter, and to this size add the greatest height of the bulge of the log. This is that bulge that is higher than the diameter of the top or narrowest part of the log.
Using a regular tape measure, measure the height of the highest part, and from this size you start counting the dimensions required material, taking into account the size of the cut, which is from 2 to 5 mm.
Secondly.
As soon as the width of the cut reaches the required size, and the remaining height of the log has reached right size, it is flipped. That is, if you saw a beam, for example, at 150, then both the width of the cut and the height of the rest of the log should correspond to this value, even be larger, taking into account the removal of the slab.
To do this, after turning the log over, start the calculation from the final size to the full use of the log height, but do not forget to take into account the size of the cut, which, as we already know, is from 2 to 5 mm.
For example - you have a log on the flyover that you cut to a size of 260 mm. Let's flip the log and continue.
The end result we want to achieve is a gun carriage with a thickness of 150 mm. Further, in a simple way, considering that 260 mm-150 mm \u003d 110 mm. We get as much as 110 mm thick additional material. And that is exactly what needs to be calculated.
We take this additional size and calculate, in order to obtain a chopping block, which has a size of 50 mm, 110-50=60, do not forget the cut, and in our case it is 2 mm, 60-2=58 mm, then the gap, equal to 25 mm, 58 -25-2=31 mm, slab 20 mm, 31-20-2=9 mm.
As you can see, from our calculations, it turns out 9 mm slab, 20 mm slab, 25 mm cleft and 50 mm chopping block. And the final size will be 150 mm.
Possible mistakes
As you can see, there is nothing complicated here. Often, inexperienced sawmillers make a mistake in the calculations when they start counting from zero. For example, if the final size of the material is 150 mm, then there is no need to add 2 mm to the cut to it, otherwise it will turn out like this 150 + 2 = 152. There should not be such an error, the cut is calculated only between the material, for example, a 50 mm board and 150 mm carriage, we obtain as described above, 150 + 50 + 2 \u003d 202 mm.
Obtain if necessary cut material rotate the log 90 degrees and perform the same manipulations that are described above.
So you sawed your first log, look at the quality of the material and the accuracy of the dimensions. Make sure your calculations are correct. The main mistake in the calculations is that they forget to take into account the size of the cut. Try to take into account this fact. And don't make those mistakes.
In the future, when you gain experience, the calculation will take place automatically in your head, it will be enough to look at the log.
We are confident that everything will work out for you, we wish you success in your work.
Find out from which part of the trunk they are cutboards or timberit is possible according to the pattern of growth rings, looking at their end, as well as by the number of knots on the boards or bars. The butt part of the trunk is always thicker than the top part and, as a rule, does not have branches, that is, it contains better quality wood.
From the middle part of the whip, the so-called technological wood raw material is obtained - wood supplied to the mechanical (for chipboard production, fiberboard) or chemical (for example, for hydrolysis production) processing. The remaining butt part of the whip is sawn into two or three parts, which are fed to sawmills.
At sawmills, lumber is produced from logs by sawing them parallel to the longitudinal axis.
Among lumber, there are:
timber (width and thickness more than 100 mm)
segmented timber or quarters (obtained from a log sawn into four pieces)
bars (thickness up to 100 mm and width no more than double thickness)
Boards (thickness up to 100 mm, width more than double thickness)
obapol - side parts of the log
slats - thin boards and bars cut during longitudinal sawing
In addition to the listed basic lumber, there are also so-called semi-finished products, in particular, grooved and profiled boards, plinth and other molded products.
The thickness of the boards coming out of the saw frame is determined by the distance between the blades of the saw frame
1 - a beam is cut out of logs from heartwood;
2 - upon receipt of half beams, the log is sawn along the longitudinal axis;
3 - upon receipt of segmented bars, the log is sawn along the longitudinal axis crosswise;
4 - during group sawing (tossed), unedged boards are obtained in one pass of a log through a sawmill frame;
5 - in case of individual sawing with a bar, during the first pass through the frame, a two-edged beam, slabs and side boards are obtained;
6 - the most difficult is the radial sawing of a log, in which floorboards with vertically arranged annual rings;
7 - during the second pass, the two-edged timber is rotated by 90 ° and sawn into
Edged boards, separating side wane from it;
8 - for boards with horizontally arranged growth rings, the front side is called the side facing the core (core), and the back side is the side facing the sapwood (peripheral part of the trunk)
1. The outer layer of the bark, which protects the tree from cold and heat, and therefore from intense evaporation of moisture.
2. Through the inner layer of the bark (bast), the tree receives the nutrients necessary for its development. In the process of tree growth, the bast dies off, joining the outer layer of the bark.
3. Between the bast and the actual wood there is a cambium, which ensures the growth of the tree in thickness and the formation of growth rings.
4. Sapwood - external, a layer of active wood adjacent to the cambium and nourishing the tree with moisture. The older inner layers of sapwood are gradually receding towards the heartwood.
5. The internal dead layers of wood, no longer nourished by moisture, form the core (core), which, due to its strength, is the bearing and supporting core of the tree
Sawing frozen wood sawmill equipment is associated with a number of problems that need to be addressed. Under conditions of negative temperatures, the physical and chemical properties of wood undergo changes.
Consider this problem in the context of working on band saw machines, because the specificity and type of the cutting tool contribute to the greatest difficulties when sawing frozen wood due to the fact that the structural parts freeze through unevenly, forming areas of different density.
Why is sawing harder in winter?
Sawing as such is possible when the wood chopped during operation is completely removed from the cutting zone. In other words, for high-quality sawing, it is necessary that the volume of the cavity between the teeth accommodate the cut chips, and they are immediately released when they exit the cut.
The degree of chip compaction directly depends on the density of the wood and its hydrothermal characteristics - the higher the moisture content of the wood, the higher the value of the chip compaction coefficient.
When the ambient temperature drops to -25 C°, the moisture present in the wood structures crystallizes, thus creating additional resistance to the load produced by the saw teeth during sawing.
What to pay attention to first of all?
The key to solving this problem lies in comprehensive measures to prepare the machine, the saw and the processed wood itself for sawing.
1. Prepare the log for sawing!
Soaking and debarking of logs to equalize the contrast of density values in the structural parts of wood is a mandatory procedure included in the technological cycle of material preparation during primary woodworking. In Russia, it is lowered as "unnecessary".
Such saws are designed with a reduced radius of curvature at the base of the tooth by 2-3 mm and a stepped shape of the teeth themselves, which prevents the sawn surface from sticking to wood dust and facilitates easy removal of chips from the cut.
3. Optimum saw tooth setting is the key to high-quality sawing
The effective type of tooth set is “complex”: one tooth is to the right, the second is not set, the third is to the left. This scheme ensures the stability of the saw in the cut and the high-quality removal of sawdust.
4. Rolling and forging saws are especially relevant in winter.
The processes of rolling and forging not only help eliminate defects in the saw body, but also reduce the value of fatigue wear - this is a good help, because. the load on the cutting tool in conditions of negative ambient temperatures is especially high.
Do not forget that the profile of the pulleys must match the parameters of the saw blade.
Fundamental Principle
Summing up, we want to remind you that the operation of any woodworking equipment is influenced by a combination of many factors. If you are working with frozen wood for the first time, we recommend that you contact specialists who can give specific recommendations “on the spot”.
All photos from the article
Sawn logs are boards,. The task of competent and efficient sawing of trunks is extremely relevant for independent or industrial logging, in addition, knowing the basics will help you choose the right lumber.
We will look at the main points regarding this topic, and tell you how to properly cut a log into band sawmill.
sawing logs
The main task
Important! The sawing scheme is selected in accordance with the quality of raw materials, the purpose of the board and the capabilities of the equipment.
Sawing tool
Logging is done with a special tool. For normal work by today's standards, you need a special machine for cutting logs with your own hands, which is called a sawmill.
There are two types of sawmills: disc and band sawmills. Disk use circular saws and are considered less effective, since they have a large cut thickness (from 6 to 9 mm), lower accuracy and depth.
The band sawmill is equipped with a different system: the saw is a band worn on rotating rollers. The cut thickness is approximately 1.5 - 3 mm, which is quite economical in terms of chip removal.
Modern models are distinguished by high accuracy and productivity, they are automated and have a tilting mechanism for lifting and turning logs in case of circular sawing or sawing timber.
Using a chainsaw, you can only cut a log in half, but if you use a special frame, you can dissolve the log into boards right in the forest.
Important! Band sawmill is considered the most efficient and cost-effective.
Output
Sawing a log is considered one of the most complex and important tasks in logging and lumber production. The quality of products and the income of the enterprise depend on the chosen scheme, well-designed work procedure and tool preparation.
The video in this article will tell you about the types of sawmills and how to cut wood.
For a small woodworking industry specializing in sawing wood into boards and beams, the optimal equipment to use is. It has good productivity, allows you to dissolve large-sized trunks into lumber. But in order for the equipment to work with full efficiency during the work, you need to know how to cut on a band sawmill. Taking into account certain recommendations and features of the operation of such a unit will allow you to avoid problems and get high-quality business material at the output.
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 barrel along the rails.
Preparatory stage
One of the main conditions for the normal operation of the equipment is the preparatory work before sawing on a band sawmill. And they include:
- cleaning the sawn log from dirt and sand;
- evaluation of the tree (breed, humidity);
- selection of a saw (shape, profile, sharpening angles of teeth) 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 saw the wood with proper quality.
An important factor for normal sawing is the correct sharpening and setting of the saw. These works should be carried out only on special machines. A well-sharpened saw with a properly selected tooth profile will provide high speed work and a clean cut.
Attention should be paid to the adjustment of the cutting blade. Correctly tensioned tape will ensure an even cut. Any violation of the tension will lead to a "waviness" of the surface of the boards, or to a rush of the cutting tool.
The more sand and dirt 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, as well as to sharpen and set the cutting tool in a timely manner.
sawing process
In the process of sawing, it is important to ensure a uniform speed of movement of the bed along the log. This will eliminate the possibility of idle tape movement and ensure maximum productivity.
Before sawing wood with a high resin content on a band sawmill, care should be taken to ensure that water or cleaning solution is supplied to the cutting area. This will prevent sticking of the teeth and ensure a good cutting speed.
After each pass, you should evaluate the quality of the cut and make sure that there is no “waviness”, and only then continue to cut the log. This will allow you to immediately identify problems with the configuration of the equipment 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 the operation of the unit, which may affect the quality of sawing, and will also extend the 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. should not be neglected and preparatory work, because the performance of the unit directly depends on them.
