How The Length Of A Chainsaw Bar Is Measured
How the length of the chainsaw bar is measured The main tire malfunctions and how the tire for the chainsaw is selected. Part design and review of the best materials. The size and variety of tires. Selection rules and an overview of the most popular tire models.
The tire itself and all the elements for securing it are consumable parts. Most of all, the tire wears out when the rules for using the chainsaw are violated.
The main signs of tire damage are a decrease in chain tension, a decrease in the smoothness of its movement. The fastening of the chainsaw bar when the part is worn out cannot provide the correct cutting angle in relation to its body.
If during the use of a chainsaw such alarming symptoms appear, then it is necessary to urgently stop working and eliminate all malfunctions, since it is very dangerous to work with such a tool.
How the length of a chainsaw bar is measured
The bar is the part of the saw that serves as the skeleton and guide for the chain. It is the tire that bears the greatest load during tool operation. For this reason, you need to know how to choose and install a new tire on your chainsaw, thereby significantly saving money on repairs or tool replacement.
Brief content of the article:
- Bus faults
- Construction and materials
- Tire sizes
- Varieties of tires
- Selection rules
- Popular models
- Chainsaw tires
It is worth knowing that the total and cutting length of the bar are different concepts. The cutting length of a chainsaw bar is measured by the distance between the tooth farthest from the sawtooth body and the body itself. This value is measured in whole inches.
Despite the fact that the length of tires from different manufacturers may be the same, the use of accessories from other companies on the tool is unacceptable, this can disrupt the correct chain movement and lead to injuries.
Varieties of tires
All chainsaws are divided into 3 classes: hobby class, semi-professional and professional models.
On hobby-class models, the guides have a length of 30 to 40 cm. Semi-professional tools have tires from 38 to 45 cm long. Professional models of chainsaws have a bar length of 50-90 cm.
Also, the differences relate to the step of the guides and the thickness of the groove for the saw chain.
Tires from an expensive brand are guaranteed to last much longer than products from an unknown company. Expensive products are made of good quality steel, which guarantees good wear resistance and a minimal chance of getting a defective tire.
It is necessary to take full responsibility for the choice of accessories for chainsaws, since low-quality parts can lead to both breakage of the tool and injury to the employee.
If this is the first time you buy guide bars on your own, then in addition to measuring the cutting length, you need to make tires for the chainsaw, which was installed before, this will help the consultants to choose the right product.
Construction and materials
A standard tire looks like an elongated oval part. At one end of the part there are special holes for threaded fasteners, and on the opposite side there is a so-called driven sprocket. Along the entire perimeter of the part, there are grooves for the shanks of the chainsaw chain.
Household saws and tires for them
This type includes a tire for the Stihl 180 chainsaw. When choosing a guide for the tool, you should pay attention to its length. The size of the pillar of the tree that she can cut down depends on it. To determine the longest free cut, subtract 50 mm from the stated guide size. For example, a 45 cm tire on a Stihl chainsaw shows that such a saw can cut a trunk with a diameter of 40 cm in one go.
Do not exceed the recommended guide size, because the longer it is, the higher the resistance values in relation to the torque of the engine crankshaft. Exceeding the recommended size can lead to a quick failure of the tool, as well as an increase in fuel consumption. You will need to repair the tire of the chainsaw, engine and other mechanisms or replace them.
Usually household saws are designed for guides of 30-40 cm. For work at height, lightweight special tires with voids filled with polyamide are chosen.
Farm and professional models
Partner and Echo are considered good farm saws. The size of the guides for such saws must necessarily correspond to the power of the unit, otherwise the saw mechanism and the engine will quickly wear out and you will need to replace the chainsaw tire and other parts. Guidelines for the selection of guides and their technical characteristics can be found in the instructions for the tool.
Professional saws from Stihl, Echo and Husqvarna are reliable helpers and have a lot of power. These tools use guides from 50 cm to 75 cm long with removable heads.
The hobby class of saws is usually equipped with guides of 30-40 cm. Semi-professional saws have bars with a length of 38-45 cm. But on professional powerful models, they install guides for a chain from 50 cm to 90 cm.With a long chain, the load on the engine increases, and then the same time, the force of movement decreases for each tooth of the chain.
Tires for husqvarna chainsaw and other brands match the installed chains and differ in such a pitch:
The thickness of the groove along which the saw chain travels also varies. The following chain guides are distinguished:
Another difference in the guides is the number of links in the chain intended for them. They bear the designation DL (from the English drive link leading link). For interest, you can independently determine the number of links by counting them. Various types of guides are presented.
How to check the length
The nominal or cutting length of the chainsaw bar is slightly different from the total. Cutting is defined as the distance between the saw body and the tip of the tooth farthest from it. The length is rounded to the nearest inch and is the number by which the guide is selected for each tool model and for a specific chain. The numbers may differ from manufacturer to manufacturer, so a tire for a Husqvarna chainsaw may not be suitable as a replacement for a Partner saw.
What should be a tire for a chainsaw
Chainsaw bars serve as a guide for the saw chain. They can have different lengths, chain pitch, groove width, depending on the device model. The choice also depends on the number of links in the saw chain. To find out what should be a tire for a chainsaw, you should read this article.
Before starting work with the tool, check the saw headset. If you need lubrication of the chainsaw tire or minor repairs, then you need to do this.
Every part of the tool requires a routine inspection, lubrication and replacement if necessary. It can be concluded that the tire for Stihl, Husqvarna and other chainsaws is selected according to the make and model of the tool. It must fit clearly with the saw chain for the tool to serve for a long time and reliably. If you do not follow the rules for operating the tool at low temperatures, then soon it will need repair.
The guide groove of the bar of a household chainsaw has a width of 1.1 or 1.3 mm. The same figure for professional models is 1.5-1.6 mm. The discrepancy between the thickness of the chain shank and the width of the groove can initiate overheating of the headset and its premature failure. In another variant, the chain may exit from the groove or break.
Similar consequences can occur if the pitch of the chain and the crown of the drive mechanism does not match. In many chainsaw models, replacing the drive sprocket is associated with time-consuming dismantling of the clutch assembly. In some cases, equipment of a service and repair level is required.
The most demanded sprocket and saw chain pitch for saws up to 3 HP. 0.325 in. For professional chainsaw technology, the use of a 3/8 inch pitch is characteristic.
The tire driven sprocket is not centrally lubricated. This disadvantage is compensated by the high quality of the bearing, which must be smeared every 8-10 hours of operation. A full replacement of the driven tire sprocket is possible only in an equipped workshop.
Choice of bus length taking into account drive power
The length of the new guide rail is determined by the power and torque ratio of the power unit.
Professional-grade chainsaw technology is equipped with powertrains, the power of which allows you to take advantage of tires up to 75 cm long. Often times, the tire size in centimeters and inches is applied to its side plane.
How to eliminate the possible risks of acquiring counterfeit tires?
In the information field, signs are given by which it is easy to distinguish an original branded chainsaw from the most reliable fake. As for tires, their advantages and disadvantages are manifested directly in operation.
On the domestic market of household appliances, about 15% of the total sales of chainsaw components are of unknown origin, third-rate counterfeit, which develops a standard resource in half at best.
It is economically unprofitable and unsafe to operate a chainsaw complete with a fake tire and chain. A significant part of traumatic situations is created when using tire and chain counterfeit.
Bar and chain installation
The tire is dismantled to clean the oil line, check the technical condition or replace it. The sequence of work is described in the instruction manual. Upon completion of the installation, make sure that there is no backlash and that the threaded fasteners are tightened.
With the right skill, it only takes a few minutes to remove and install a new or sharpened chain. The technology prescribes the inclusion of an unauthorized start blocking and, in some cases, an emergency stop mechanism.
After installing and adjusting the saw headset, it is advisable to start the engine and keep the saw at medium speed for several minutes. During this time, you can check the operation of the lubrication system.
After turning off the power unit, you must turn on the start lock and check the headset for local overheating of the bar and changes in the degree of chain tension.
Tire selection criteria for quality characteristics
Tires standardized in fit dimensions are presented in a small assortment. As a rule, each manufacturer uses its own standards, which excludes the possibility of using a chainsaw with saw equipment of other brands.
Less popular are cheap, short-lived Chinese-made tires, which are installed on chainsaws of the lowest price range. Most of these products are marketed under the trademarks of well-known brands.
Design features of household and professional tires
The design of modern saw sets is constantly being improved. As a result of a partial modernization, a so-called narrow tire was developed.
Structurally, such models are distinguished by the shape of the tip, which prevents kickback when the headset enters the cut. Domestic-class petrol saws are mostly equipped with narrow tires. The wide toe is a characteristic feature of the tire, designed for high-complexity sawing work, as well as professional chainsaws.
Chainsaw manufacturers, for each specific model, recommend using a saw bar of a certain size and technical parameters. For the right choice, it is worth considering these parameters and then there will be no problems.
The tire for a chainsaw is a very important part of it, if for some reason it is faulty, the operation of the tool is not possible. There are many reasons why it requires replacement. We will try to figure out in what cases a replacement is necessary, and also consider the question of how to choose the right saw tire for a chainsaw. Let’s start with the most important thing, choosing a headset.
Why does it wear out
This is one of the questions that chainsaw owners are constantly asking. The answer is easy. Friction occurs on the surface of the headset, which is the cause of wear.
There is another pressing question: why does a tire wear out prematurely? You can answer it if you study the design of the tire and the principle of operation of the lubrication system, which we will try to do.
The lubrication system begins with an oil tank, where oil is filled and then, using an oil pump, is transferred to the point of contact of the tire shank with the chainsaw body. To adjust the oil supply, the tool pump is equipped with a special screw. There is a special slot in the place where the tire is installed, which coincides with the hole for receiving grease on the tire. The cause of premature wear may be insufficient lubrication of rubbing parts, which in turn occurs with the following faults.
To increase the service life, manufacturers recommend the use of special oils with high adhesion.
Thanks to this property, at high speeds of the chain movement, the lubricant is distributed and retained throughout the tire, and not only on the upper part of it, as is the case with conventional oils.
Reasons that lead away from a straight cut
Sometimes there are situations when it is almost impossible to make a straight cut with a chainsaw, the tire goes to the left or right. The reason for this behavior of the tool may be the following:
When choosing, consider the main five parameters, these are:
Depending on the power of the chainsaw, it is permissible to install a headset of different lengths on it, which allows you to adjust the performance and load on the saw. Manufacturers can indicate the length in both centimeters and inches and, as a rule, this is not the entire length of the tire, but only a characteristic of the length of its working part. Choosing the right tire for your chainsaw should start with reading the instructions for your chainsaw and finding out the permissible length for your particular model. For example, for the Stihl MS 180 chainsaw, the recommended lengths are 14 or 15 inches.
The width of the guide groove, like the pitch of the sprocket on the bar, must correspond to the same parameters of the saw chain, otherwise the installation of the chain on the bar will not be possible. The groove width for household chainsaws is 1.1 and 1.3mm for professional models 1.5. The most common sprocket pitch sizes are 0.325 and 3/8 inches.
Depending on the type of shank, the tire can only be fitted to certain chainsaws. This is because the chain lubrication hole on the bars for certain brands of chainsaws may be located in different places. For example, a tire from a Stihl chainsaw cannot be installed on Husqvarna and vice versa, be sure to take this into account when choosing.
A qualitative description of the selection process can be found below. In this, a specialist in the sales department of gasoline-powered tools talks about the main characteristics of the saw headset, its types and sizes.
Which bus is better to install
It is quite simple to answer the question of which tire is better to install on a certain model of a chainsaw. It is worth installing the model recommended by the tool manufacturer. As a rule, leading chainsaw companies, in parallel with the release of the tool itself, are engaged in the production of consumables that are specially designed for their tool.
Accordingly, the choice of a tire for a chainsaw is best done in the direction of products designed specifically for your model and made by the manufacturer who assembled the saw itself.
If this is not possible, a good choice is chainsaw tires, which are made by leading companies in the saw chain and chainsaw tire industry, such as Oregon.
- Guide in 0.375 ” pitch for low chain profile;
- Guide rail with 0.325 ” pitch;
- Guide rail with 0.375 inch pitch;
- Guide rail in 0.404 inch increments.
- Guide for a saw with a slot thickness of 0.043 inches;
- Guide for a saw with a 0.050 inch slot;
- Saw guide with 0.058 inch groove thickness;
- Saw guide with 0.063 ” groove.
- Chainsaw models of small and medium power range are equipped with tires from 30 to 40 cm long.
- Longer saw sets create excessive loads on the engine and tool kinematics, which negatively affect its traction characteristics and service life.
- The enclosed application manual contains the recommended guide bar length. This means that the installation of a shorter headset is not excluded, but there are a number of restrictions on the operation of the tool with an extended length bus.
- Depending on the design of the tensioner, the chain is loosened to the desired degree by turning the adjusting screw or setting disc, until the shanks freely exit the groove of the guide bar.
- After checking the direction of rotation, the shanks of the new chain are inserted into the guide groove and onto the crown of the drive sprocket. Tensioning is done upside-down.
- To check the tension, just pull the chain in the middle of the bar. The exit of the link shank in this place should not exceed 2/3 of its height. A properly tensioned chain should run along the bar with little effort.
- The selling price of guide rails is determined by dimensions, material quality and brand awareness. The most expensive, highest quality and durable products from leading manufacturers.
- The high cost of branded tires is fully compensated by the high wear resistance and long service life.
- In the middle price range, there is an assortment of budget-level tires, which are equipped with gas and electric saws for household use. With proper operation and qualified maintenance, tires of the Standard category develop the resource specified by the manufacturer with a large excess.
- Excessive contamination of the oil filter (the first thing to pay attention to);
- Contamination of the oil supply channels on the headset or on the instrument itself;
- Incorrect adjustment of the oil supply by the pump;
- Malfunction of the pump itself;
- The use of low-quality lubricants or oil that does not meet the requirements of the chainsaw manufacturer.
- Incorrect chain sharpening. The chain teeth are sharpened more on one side than on the other. You can fix the problem by sharpening the chain correctly.
- Uneven wear of the chain links, the support pads of the chain links on one side have a large output, because of which the chain tilts slightly and it is no longer possible to obtain a straight cut. The problem can be solved only by replacing the chain.
- Last but not least, uneven wear. As in the previous case, for this reason, the chain will change the slope and it will no longer cut exactly. The problem can only be solved by replacing the tire.
- Guide groove width.
- Tire sprocket pitch.
- The number of chain links assigned to it.
- The type of shank and the models of chainsaws on which it is permissible to install it.