Chainsaw chain sharpening with your own hands Chainsaw chain sharpening with your own hands The chain tooth planes wood like a plane, and the thickness of the shavings is regulated by the height of the limiter. Intense sawing results in rapid dullness
Chain teeth parameters
To achieve optimal cutting properties, the tooth blades are angled. The back of the tooth falling back at an angle forms the posterior angle of the upper blade. This angle is needed to cut the upper blade into the wood.
The backward tapering blade of the tooth forms the back angle of the end blade. This angle is needed for side cutting of the chips.
The edge of the end blade forms a rake angle with the sliding surface of the cutting link. The rake angles for different types of chains range from 60 to 85.
The back angle of the top blade refers to the backward tilt of the top blade.
This angle is measured relative to the sliding plane of the cutting link and, depending on the type of saw chain, ranges from 50 to 60. The upper blade is the main blade and the rear angle of the upper blade. This is the most important corner. The clearance angle of the upper blade is difficult to measure, and the correct value is obtained by observing other prescribed values.
The grinding or entering angle is obtained by measuring from the top cutting edge at right angles to the guide bar.
The sharpening angle can be changed, depending on the application. As a rule of thumb, the larger the sharpening angle, the higher the cutting performance when cutting non-frozen softwood. Reducing the sharpening angle when cutting frozen and / or hard wood contributes to a smoother saw blade and less vibration. However, sharpening angles greater than 35 and less than 25 should be avoided (except for rip chains, where this angle is 10).
The rake angle, sharpening angle and upper blade angle change during sharpening. These angles have a decisive influence on the cutting performance of the chain. Be sure to observe the prescribed values.
A depth gauge is located on each cutting link in front of the tooth blade. The difference in height between the top edge of the depth gauge and the front edge of the back of the tooth is defined as the distance of the depth gauge.
The depth of penetration of the upper blade into the wood (chip thickness) and thus productivity depends on the distance of the depth gauge. The distance of the depth gauge is set depending on the chain pitch and type of execution. Normally, it should be 0.5-0.8 mm, more often 0.6 mm. High values will result in an increased tendency of the chainsaw to kickback, too much grip and chain vibration. Low values lead to a drop in performance. Since the distance of the depth gauge decreases with each sharpening of the saw due to a decrease in the upper edge of the tooth, the depth gauge also needs to be filed periodically. After 5-10 chain sharpenings.
General rules for sharpening chainsaw chains
Do-it-yourself chainsaw sharpening
The chain tooth planes the wood like a plane, and the chip thickness is adjusted by the height of the stop.
Intense sawing will quickly dull the chain. Several sharpenings may be required within one day. The problem is aggravated by the fact that the tooth quickly dulls when it meets the ground. It is enough to hook the soil with the tire once or twice, and the work can be stopped. The shavings become fine and the saw stops going deep into the wood.
The sooner dull teeth are sharpened, the less material needs to be removed during sharpening, as a result. The service life of the saw chain is longer. Determining the moment when sharpening is already required is quite simple. An important feature is the feed force. A properly sharpened chain is pulled into the cut with just a little pressure. If, on the contrary, the chainsaw is forced to cut by increased feed force, then the teeth are dull. A dull chain can also be recognized if only small chips fly out of the cut instead of coarse, thick chips.
In this situation, the chainsaw must be sharpened urgently. Do not cut with a dull or defective saw chain. The consequence is high stress in the body, high cyclic load, poor cutting results. In addition, this means reduced productivity, high fuel consumption and increased wear on all parts of the chainsaw.
Hand tools
A set of tools required for sharpening saw teeth:
- Flat file, which is taught to use in labor lessons at school. With it, the depth gauge is grinded.
- A round file of a certain diameter, required for cutting a cutting tooth. It comes with an additional tool holder with fishing lines, which tell you how to properly hold the tool in relation to the chain. The holder is placed on the saw tooth, taking into account the guiding lines, the position of the file is under the cutting surface.
- A template that serves for editing and observing parameters.
- The hook is needed to remove sawdust from the chain.
Metal sharpening templates help you calculate the sharpening depth
Sharpening of cutting teeth
The question arises: how to sharpen the chain so that all the teeth are evenly even and sharp? The work is facilitated by the use of a metal template, which is applied to the chain. It is installed in a strict position according to the arrows, the ends of which are directed along the movement of the chain. The main pressure is applied to the leading edge, respecting the angle of inclination, which corresponds to the length of the chain pitch.
You need to try to have an equal number of movements for each tooth. The teeth are sharpened in turn: one on the left, the next on the right, and so on. For the convenience of performing the actions, the tire is clamped in a vice, and then processed through the prong on one side, then the same on the other.
During sharpening, the fixture must be held at a certain angle
When is it time to sharpen the saw?
The periods between two sharpenings depend on the frequency of use of the tool. Some use it daily, others several times a year.
You can understand that the teeth are dull by some signs that come to light during operation:
- The chain stretches and sags, causing the saw blade to function inaccurately and slow down in the cut. Working with such a chain requires additional effort.
- The sawing process slows down, productivity drops, and you have to spend twice as long on work.
- The type of sawdust changes: they become uneven, sharp, and smaller. Shavings from a sharpened saw looks different: the same pieces of an even rectangular shape.
If the saw loses accuracy and gets stuck in the cut, it’s time to start straightening the chain teeth.
Repair work should not be postponed for a long time. The sooner you sharpen, the less material you have to grind, and accordingly, the longer the service life. And you don’t have to work with a blunt instrument for a long time, increase its wear and tear and waste your own physical strength.
Two swarf samples: first result with a sharpened saw, the second with a blunt one
Files and tools
The main one with which the saw tooth is sharpened is round. Flat is used to adjust the height of the cutting depth gauge tooth.
File holder
The round file is installed in the holder and fixed with special clips. There are several markings on the plane of the holder that indicate a specific sharpening angle. When straightening the chain with a file with a holder, the markings on the device are placed parallel to the chainsaw tire, which allows you to accurately maintain the required angle.
Description of the sharpening process
Let’s take a closer look at how to sharpen a chainsaw chain. The first thing to do is to prepare a place for installing the clamp, or if the process takes place without it, then it is convenient to use a regular log as a stop for fixing the tire in the horizontal plane. The chainsaw is installed on a flat surface, the log is placed under the tire, the brake is activated.
The next stage is direct sharpening of the tooth. To do this, a round file is made to move from the inside of the tooth to the outside.
It is very important at this point to maintain the correct sharpening angle. The standard angle is thirty degrees from the file perpendicular to the plane of the tire. How to arrange it correctly is shown in the photo below.
In the process of sharpening a chainsaw for a non-standard cut, for example, longitudinal. The sharpened angle is changed to a less acute one. As a rule, it is no more than 10. It is in such cases that a holder, hand-held lathes or filing gauges are used to control the sharpening angle.
Some manufacturers of chains for chainsaws, to facilitate sharpening, as well as to indicate the maximum possible sharpening, a special mark is made on the upper surface of the tooth.
By keeping the file parallel to the mark, you can be sure that the correct angle is being observed.
In the process of straightening the chain, it is customary to sharpen the teeth first on one side, and then on the other, this is convenient since there is no need to constantly change its position in relation to the chainsaw.
After the working teeth have been sharpened, it is necessary to adjust the height of the limiting tooth with a flat file. To do this, the filing gauge is placed on the chain in such a way that the limiting tooth coincides with its slot, after which the protruding part is grinded with a file. This procedure is performed on all restraining teeth.
Electric sharpening machines
They are equipped with special adjustment functions to help you position the chain at a certain angle. At the same time, it is possible to accurately and accurately bring the disc to the chain teeth. There are machines equipped with automatic vices. They are switched on when the disc approaches the sharpened edge. Convenience and functionality are certainly high. You can also find models at lifting prices.
How to understand that the chain is dull
- Increased physical effort;
- Sagging (stretching) of the chain;
- Vibration and retarding cutting passage;
- Inaccurate sawing and change in the type of sawdust (they become uneven with sharp needle-like edges, small and dusty). This is already the answer to the test.
According to experts, and in my opinion too: well-sharpened teeth are more important than engine power.
Why dull? The reasons are generally known, but I will name the main ones:
- Intense or voluminous work;
- Accidental contact with stone, earth, hard knots, etc.;
- Mishandling (broad term).
First about horror stories
If you cut with a blunt chainsaw, you will get three negative factors:
- Reduce the efficiency of your process. For example, instead of two cubes, cut one (at the same time);
- Expose the mechanism to intense wear, with the risk of destroying the drive sprocket and tire;
- Get increased fuel consumption;
There is also a fourth, perhaps not so significant factor, the ragged cut of the saw cut.
And of course, you will get tired more, you will (perhaps) be angry with yourself, what kind of fool should I not sharpen in advance, now suffer
Here is a test question for you (photo on the right). Guess what kind of shavings came out from under the sharp and dull chain? (the answer will be below).