Debarked round timber (logs) is a very popular material. Unlike a rounded log, a debarked log has a significant advantage, because it retains the top splint layer, which effectively protects the inner wood from various pests and bacteria. Thanks to this, a log house made from debarked logs will last much longer and will require less costs for antiseptics than a house made of rounded logs. When purchasing logs for building a house, it is necessary to determine not only their quantity, but also their volume, because all suppliers sell logs by volume. You can convert quantity into volume either manually, remembering school lessons in algebra and geometry, or using tables or special tools. In this article we will talk about various techniques calculation, which will help you correctly determine the required volume when ordering and purchasing logs.
Calculating log volume manually
The methodology for determining the volume of a log is described in detail in two documents adopted back in the Soviet Union - GOST 2292-88 And GOST 2708-75. Since then, no changes have occurred in this technology, so all the recommendations set out in GOSTs are still relevant today. Here are the basics for both measuring an individual log and determining the volume of stacked logs:
- the diameter is determined by the upper (thin) edge of the log using mechanical measuring forks (analogous to a caliper);
- the diameter of the top part of the log is measured twice, with a deviation of 90 degrees; if the values differ, then they are averaged;
- when determining the diameter of the log, the thickness of the bark is not taken into account;
- diameter is rounded to half a centimeter;
- the volume of logs for building houses is determined by multiplying the average volume of a log by the number of logs in the stack;
- Measuring the volume of logs by multiplying the height, width and length of the stack is unacceptable.
After determining the diameter and length of the log, its volume is calculated using the formula. For example, the volume of a log 10 meters long and 15 centimeters in diameter is 0.176 m³. Therefore, there will be 5.5 logs in one cubic meter.
Video - Calculator - cubaturnik
Determining the volume of a log using a computer caliper
The computer caliper determines the volume of each log by measuring the diameter and entering the length. Using this tool allows you to avoid tedious work with tables and numerous calculations. After determining the thickness and entering the length of the log, the fork independently determines its volume and displays the data on the display. Because of high cost This tool is used only at wood processing enterprises.
The cubic capacity of a log is a certain volume of lumber, the unit of measurement of which is a cubic meter. m. This parameter is used when constructing wooden houses to calculate the required volume round timber. The determined indicator is very important when calculating payment for sold lumber for building a house, since it is necessary to know the cost of each cubic meter. m of wood.
Round timber is very convenient and practical for building houses, bathhouses and other residential and non-residential premises.
Method for correctly counting lumber
Exist various options, allowing you to calculate the cubic capacity of a log, which is a round cylindrical lumber. This estimate is indicative. The methods used include initial geometric parameters, on the basis of which calculations are made.
Industrial harvesting of lumber involves quite complex calculations that are carried out to determine the cubic capacity of the forest. For accurate calculations, use a special truncated cone formula. It is built on the basis of determining the main diameters of each of the two cuts of wood and the length of the logs.
In practice, this complex method is rarely used, since world standards that determine the cubic capacity of roundwood require the use of special tables. Calculating the cubic capacity of the forest when building a house in this way is not particularly difficult. The result is quite accurate, and the calculations are based on the volume of material in the form of a parallelepiped and average value an indicator of the thickness of the cut of a log in its upper part.
How to calculate the cubic capacity of a log in a single version correctly?
Until now, the calculation of the cubic capacity of a single tree was determined by multiplying its length by the arithmetic mean total area all cuts. This method involved the use of special measuring instrument, resembling a caliper.
- Roulettes.
- Calculation tables indicating the final cubic capacity.
Before calculating the cubic capacity of the log, the size of its diameter in the middle part was increased three times, obtaining specific value cross-sectional area. It had to be multiplied by the length of the workpiece to obtain the resulting volume of material. This method was not accurate because the thickness of the tree bark was not taken into account.
The value of Pi in the circle formula was used with a very large deviation, so the distorted form of the formula did not allow accurate calculations without errors. In practice, the following formula is used: diameter divided by 2 round tree squared, then the result is multiplied by Pi and the length of the tree.
It cannot be argued that it is correct to calculate the cubic capacity of forest for building a house only on the basis of tables, special measurements and corresponding formulas. The simplest method is to determine the density of wood species.
If we calculate the cubic capacity of round timber by measuring the thickness of the bark of lumber for building houses, then it is impossible to determine the diameter of the logs without possible errors. The calculated parameters will be inaccurate. To correctly calculate the volume of a unit wooden material, measure its length with a tape measure, then measure the diameter of the cut at the top, not taking into account the thickness of the bark.
Next, you should look at a special table in which, at the intersection of rows and columns with the given values of the length of the tree, as well as its diameter, the volume of the material is determined. This method is reliable. Before calculating the cubic capacity of a forest in this way, you should know that it is not perfectly accurate, since the shape of the trunk and the conditions associated with growing forest for building houses are not taken into account. However, these little things are usually ignored.
How to calculate the cubic capacity of stockpiled round timber?
Image 1. Calculation of cubic capacity of round stockpiled timber.
If we consider the industrial volumes of round logs, then other tables and parameters are used here round log, allowing you to calculate cubic capacity. As shown in the figure (IMAGE 1), round timber in storage conditions has the shape of a parallelepiped in the form of a rectangle.
The method for calculating this volume is simple and known from school knowledge. In practice, the use of this method does not give an accurate result, since the size of the voids between individual logs is not taken into account. The dimensions of the voids depend on the diameter of the logs and can be calculated mathematically. Calculate exact values if the log blanks are stacked inaccurately, the logs will not work. This procedure is not carried out during the assessment of a forest located on warehouse storage, since the volume occupied is estimated round forest in the warehouse itself.
If you carry out a preliminary weighing of the forest, then calculating the cubic capacity will not be difficult, since it is not completely filled with wood material. The required value should be reduced using the void ratio. When carrying out construction calculations, the value of the void ratio is 0.8, which is 20% of the area of the space that is occupied by air voids, and 80% is the volume of wood.
The sequence of actions when determining the cubic size comes down to the following main steps:
- Measuring the width, length, height of a space that is rectangular.
- Multiplying certain quantities together to calculate the volume result.
- Multiplying the result by a factor of 0.8, which takes into account the number of voids between the logs, which is approximate.
- Taking the resulting value as the result.
Using this method, the cubic capacity of roundwood, which is heterogeneous in size, is calculated.
Carrying out calculations depending on the type of material
To calculate the volume of lumber by dividing the mass of the forest by its density, it is necessary to take into account the type of wood.
Image 2. Table for calculating cubic capacity of unedged and edged boards, bars, linings, slats, etc.
The result obtained will be far from ideal, since the forest may have different degrees of maturity, hence different deviations in density. The main role is played by the moisture content of the wood.
The woodworking industry is characterized by concepts associated with dense cubic meters and folding. The price list for such lumber will contain information about the volume in its dense mass; it will be necessary to convert the folded cubic meter into a dense mass. For this purpose, conversion factors are used.
The volume of coniferous or hardwood two methods:
- By measuring all units of the tree.
- Through the use of a standard, that is, a cube-turner developed in accordance with GOST.
The cubeturner is designed to calculate the volume of trimmed wood material based on standard tables. In one you can find the volume of a meter of wood, and in the second - units, which allows you to calculate the cost of the forest.
The proposed table (IMAGE 2) contains calculations of the cubic capacity of unedged and edged boards, bars, linings, slats, etc. The measurement has its own specifics, that is, the size of the width of any board is equal to half the size of the width of the narrow and wide layers, measured in the middle part of the board. Volume calculation round material is done correctly if every log is measured.
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When industrially harvesting roundwood, it is quite difficult to determine its cubic capacity. To accurately calculate the volume of each log, you can use the formula for the volume of a truncated cone, which takes into account the main diameters of both cuts and the length of the log itself.
Round timber is very convenient and practical for building houses, bathhouses and other residential and non-residential premises.
In fact, like this in a complicated way The cubic size of round timber is not calculated. It is accepted all over the world to be considered more in a fast way. Special tables are used for this.
How to calculate the cubic capacity of a single tree without additional measurements?
Just a few years ago, to calculate the volume of a single tree, they used the product of the arithmetic average of the area of the cuts and the length of the tree. Using a meter (reminiscent of an ordinary caliper), the diameter of the tree in its middle part was determined. Then it was multiplied by 3 to obtain the cross-sectional area.
Next, the resulting number was multiplied by the length of the workpiece, and a volumetric result was obtained. This method of calculation is inaccurate, since the thickness of the bark is not taken into account. The number Pi was taken with a large deviation from the real one, and the formula in its distorted form gave large errors.
The formula itself looks like this: the diameter of a rounded log is divided by 2 and squared, then multiplied by Pi and the length of the log.
Even if you measure the thickness of the bark and take this into account to determine the diameter of the tree, deviations from real indicators will be inaccurate, although with a smaller error. More accurate calculations showed that the actual deviations in the calculations of the cubic capacity of a round log during primitive measurements have a certain dependence on the parameters of the tree, which was taken into account when compiling the corresponding tables to determine the volumetric parameter. Let's try to figure out how to calculate the cubic capacity of the forest. For this you will need:
- roulette;
- corresponding calculation tables, where there is a finite cubic capacity.
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Peculiarities .
How much does a cube of board weigh?Technology for calculating the volume of a single log
First, you need to use a tape measure to measure the length of the tree and its diameter at the top of the cut (excluding the bark). After this, let’s look at the tabular parameters: at the intersection of the line indicating the length of the tree and the column indicating the corresponding diameter, we find the volume of the measured body. Everything is simple and reliable.
Such calculations also cannot be called absolutely accurate, since the features in which the forest was grown and the shape of the trunk are not taken into account. But with large volumes of workpieces, it is customary not to pay attention to such trifles.
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Calculation of cubic capacity of stored timber
For industrial volumes of round logs, other techniques and tabular data are used. In essence, a round forest in a stored state has the shape rectangular parallelepiped. Calculations of its volume are familiar to everyone from school. But this method cannot be used, since the size of the voids between the logs will not be taken into account. By the way, they also directly depend on the diameter of the logs, which can be calculated mathematically.
Through numerous calculations, a coefficient was determined, with the help of which a special table was compiled. It works similarly to the previously described table, with the only difference being that the volume of the mentioned parallelepiped and average thickness of the upper cut. The cubic capacity of the forest can be calculated with great accuracy.
But one cannot hope for good accuracy of calculations when stacking forest products inaccurately. This procedure is not used when storing timber in a warehouse, since in this case the volume that round timber occupies directly in the warehouse is estimated.
It is very easy to calculate the cubic capacity after preliminary weighing of the forest.
Next, you need to calculate the volume by dividing the mass of the forest by the density, which corresponds to the type of wood. This calculation also cannot be considered ideal, since the forest has a deviation in density at different degrees of maturity. The moisture content of the wood can also play a special role here.
For many builders, the topic of calculating the number of logs in a cube is familiar. But for an unprepared person this may seem not only very distant, but also incomprehensible. And very often disagreements arise between the builders themselves, as well as between the builders and the customer, about how many logs there should be in a cube.
In order to deal with this problem, a mathematical method is usually used, which in a few minutes can give a clear answer about how many logs are needed for a certain number of cubic meters.
Typically in construction wooden buildings rounded logs are used. But this material may differ in size, that is, in length and diameter. The unit of measurement is usually centimeters. There are one million centimeters in one cubic meter. Thus, first you need to decide on the size of the logs.
In order to measure the size of the logs, you will need a regular centimeter tape measure. All logs, as a rule, should initially be the same size, and later, depending on the project, they are sawn into the necessary elements.
So, by measuring the size of a log using a tape measure, we obtain the length and diameter in centimeters. For example, let's try to calculate how many logs are needed for one cubic meter, if the logs are six meters long and their diameter is eighteen centimeters.
To calculate, you will need the following formula:
Volume = Pi * Radius * Radius * Length.
six meters in in this case equals six hundred centimeters. Pi is always 3.14. We get the radius by dividing the diameter by two. Thus, our formula acquires next view: Volume = 3.14 * (18:2) * (18:2) * 600 = 3.14 * 9 * 9 * 600 = 152604 centimeters. To convert to cubic meters, divide the resulting number by one million: 152604: 1000000 = 0.1526. This result tells us that one log of this size will occupy only a little over 0.15 cubic meters.
Now you need to figure out how many logs are in a meter. This is our main task. To do this, we divide one cubic meter by the result of our calculations - 0.1526. It turns out: Quantity = 1: 0.1526 = 6.55 logs. It turns out that for one cubic meter we need to take about seven logs of a given size.
If we consider logs of larger diameter, for example, twenty-four centimeters, then the calculation results will be different:
Volume = 3.14 * 12 * 12 * 600 = 271296 cubic centimeters = 0.2713 cubic meters.
This means that in one cubic meter there will be: 1: 0.2713 = 3.69 logs. In this case, there will be fewer logs in one cubic meter.
To calculate the number of logs per cubic meter, it is used simple formula, which allows you to calculate the result in a matter of minutes. For calculations, of course, it is better to arm yourself with a tape measure and a calculator.