During prolonged use, carbide tipped saw blades can lose their original qualities. But this does not mean that a new cutting tool should be purchased. In most cases, grinding can be done at home using any suitable machine.
Need for sharpening a saw
First you need to decide whether to sharpen or not. There are several obvious signs that indicate the relevance of this procedure. If you ignore them, then in the future the disk may become unrepairable and will cause the failure of an expensive machine.
The advantage of using a soldered saw blade is its extended life. It is also intended for the processing of hard wood. Surfacing is made of steel 9HF, 50 HVA, 65G and similar compositions. They are characterized by high hardness, but at the same time, with significant operation, the probability of their breakdown will increase.
Timely sharpening of circular saws with a do-it-yourself machine is performed with the following obvious signs:
- increased engine load. The reason for this is the deterioration of sharpening and, as a result, the power unit needs more power for cutting wood. If protective relays are not provided in the engine design, its failure is possible;
- deterioration in cut quality. The first sign is an increase in the width of the cut, as well as the formation of chips and bumps along its edges;
- increase the processing time of the workpiece. For the formation of the cut takes more time than usual.
The best way is to periodically check the status of the soldered disk on the tree. To do this, temporarily leave the machine and dismantle the cutting tool. If its geometric parameters do not coincide with the initial ones, sharpening is necessary.
How to determine the angle of sharpening a circular saw
The best option would be to have the original template, according to which you can fix the geometry of the cutting edge. Often it is made of thin-walled stainless metal, less often. of thick cardboard.
Carbide teeth are made according to GOST 9769-79. But their geometry and geometric dimensions are determined by the manufacturer based on the purpose of the saw. If the template is missing, you must independently determine the required sharpening angles. To do this, it is recommended to use a pendulum goniometer.
DIY manufacturing template technology.
- Take a new soldered disk, which is completely identical to the dull one.
- Draw the exact contours on a solid sheet of cardboard.
- Using the pendulum protractor, determine the initial geometry of the carbide taps.
- Enter data on the template.
Video: How To Sharpen A Circular Saw On A Tree
In the future, it can be used for self-sharpening on the machine or provided as a model for companies providing similar services.
In addition, it is recommended to compare the obtained data with the reference. In saws for longitudinal shearing, the rake angle is usually 15 °.25 °. For transverse models, this indicator ranges from 5 ° to 10 °. In universal models, the rake angle is 15 °.
It is important to remember that the rake angle can be negative. Similar models are used for cutting plastic sheets and non-ferrous metals.
Methods for sharpening circular saws
To form a new cutting edge, you can use any grinding machine. It is important to initially choose the right emery wheel and use it to sharpen the edge. For this it is necessary to use corundum or diamond models.
The best option is to use special equipment designed to perform this work. But due to its high cost, in many cases its acquisition is impractical. An alternative way is to use a grinding machine with the ability to change the angle of the corundum disk.
In no case can you sharpen manually yourself. Firstly, it will take a very long time. Secondly, the result will not meet the standards. If it is not possible to sharpen the saw blade on a tree, it is recommended that you use the services of specialized companies.
Do-it-yourself professional sharpening of circular saws is performed according to the following rules:
- the main deformation occurs on the upper edge of the tooth. Rounding of the faces from 0.1 to 0.3 mm. It is from this place that it is necessary to begin processing;
- sharpening is performed on the front and rear edges. This will provide the opportunity to repeat the procedure up to 25 times;
- the amount of removal should not exceed the value of 0.05-0.15 mm;
- The level of processing of the front and rear faces should be the same.
After the sharpening of the discs on the tree is completed. it is recommended to bring it with fine-grained emery paper. This can be done manually or using a special machine.
Specialists advise using special corundum disks, the end surface of which has a groove of a special shape. It will facilitate the implementation of the procedure.
Ways to increase saw blade life
The process of forming a new cutting edge is laborious and time consuming. Therefore, it is recommended to fulfill a number of conditions to increase the life of the disk.
First of all, you should familiarize yourself with the manufacturer’s recommendations. They indicate the number of revolutions (maximum and minimum) for various types of processed materials. For metal, this parameter should be less than for wood.
Hard solders have a long service life. However, they often chip and break off. Alternative soft is practically not affected by such defects. But her service time is shorter than that of a solid one.
Roughness on the cutting surface is not allowed. In the future, they can lead to the appearance of chips and cracks.
The video shows an example of a do-it-yourself machine for sharpening disks:
Drawings and tooth geometry
Sharpening of circular saws should be carried out clearly in compliance with the norms and requirements for the geometry of the teeth of each individual disk. To properly sharpen a circular saw with your own hands, you need to know the shape of the tooth and its geometry.