The chainsaw and guide bar should be in a fixed position to ensure good stability, and in order for you to have both hands free for filing. It is easiest if you use a vice on a workbench to secure the guide bar. Secure the chain by activating the chain brake.
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Cutting tooth angles
The cutting teeth on the chain must be filed according to three different angles: filing angle, side plate angle and top plate cutting angle. The angles vary depending on the type of chain you have. If you use a filing gauge you do not need to think about the different angles to ensure a good result. Just follow the instructions and you will get the right angles on the cutting tooth.
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1. Start with the cutting teeth. Use the round file and filing gauge designed for the type of chain that you have (see table in the section Maintenance of cutting equipment).
2. Place the filing gauge on the chain. The arrows on the filing gauge should point in the chain’s direction of rotation (towards the nose wheel). Make sure the gauge has contact with the chain.
3. File with both hands. Place the file at an 90-degree angle in relation to the rollers on the filing gauge. The file should rest on both rollers. The filing angle is then 25–35° depending on the type of chain. File the cutting tooth away from you with smooth strokes.
4. Now proceed to file every other tooth. Each cutting tooth is to be filed so that it is sharp. It is important that all the cutting teeth are of equal length.
5. Once you have finished filing all the cutting teeth on one side, loosen the vice and then attach the guide bar from the other direction.
6. Then sharpen the cutting teeth in the same way from the opposite direction.
Hook. The side plate angle is too small.
If you are used to filing you can also file without the filing gauge. Be sure to maintain the original angles for the cutting tooth. To maintain the correct angle and depth of the cutting teeth, we still recommend that you use the filing gauge when you have filed with a free hand a few times. Avoid filing in a way that produces hook. The chain will be too “aggressive” as a result. This means that the saw is exposed to unnecessary strain and the user to increased vibration. Correctly sharpened cutting tooth are pictured in the section Maintenance of cutting equipment.
Replace the chain
It is time to replace the chain when the longest portion of the cutting tooth is less than 4 mm or if you find cracks.
The height difference between the position of the depth gauge and the tip of the tooth (depth gauge clearance) determines how much the cutting tooth will cut. It works much like a plane. When the plane is set up with minimal cutting blades, the plane takes a very little amount of wood. The same thing happens with the saw chain if the distance between the depth gauge clearance lip and the tip of the tooth is too small. It is also not good if the depth gauge clearance lip has been filed down too much. The cutting tooth will then cut too deeply into the wood. The cut is more aggressive with high vibrations as a result. The risk of kickback increases and the chainsaw is exposed to unnecessary stress.
Filing the depth gauge
We recommend that you file the depth gauges after you have filed the cutting teeth 3-5 times during normal wear. After filing following sawing through stone, for example, where you have filed each cutting tooth a lot, you should also file the depth gauges.
The depth gauge has the words “Soft” and “Hard” stamped on it. “Soft” stands for soft wood (conifers) and “Hard” stands for frozen and hard wood (leaf trees). If the depth gauges are filed using the “Hard” setting, each tooth takes slightly less wood than when filing with “Soft”.
When the timber is hard, you cannot saw off as much wood at one time as you can with soft wood. The measure of the depth gauge varies with the type of chain, see the saw’s user manual.
1. Add the gauge and hold it firmly with one hand. Select “Soft” or “Hard”, depending on the wood you are sawing. The depth gauge varies with the type of chain.
2. Take a flat file in your other hand and file the depth gauge until the file engages the gauge.
3. Now continue to file all the depth gauges on the chain. The gauge mounting varies with right and left-handed filed cutting tooth.