Circular saws - a tool that is used regularly in the woodworking industry and construction. The circular saw works with different materials, and the quality of the cut is of great importance. Sooner or later, the question of restoring the teeth of the saw arises. The ability to carry out this work at a high professional level will make it possible to use the cutting tool for a long time.
The need for a procedure
Circular saws are needed both in private households and in production. When building a house, creating furniture, cutting boards, timber - everywhere a similar tool is required. Proper sharpening of a circular saw requires practical skills and knowledge.
Circular saws compare favorably with other cutting tools:
Disk circular devices have significant performance, their service life is also much higher. Sharpening of circular saws is an important necessary stage; without it, the tool will not fully work. Thanks to various carbide tipped nozzles, as well as victorious coatings, cutting can be carried out both with wood and with metals.
To sharpen discs with various nozzles, special equipment is required. If the processing of the disk is done “according to science”, this will significantly extend its service life.
Timely sharpening of circular saws is performed with several obvious signs.
- The engine begins to experience extra loads. The reason is simple - the teeth are dull, and additional resources are required to process the material. There is a danger: if the disk is damaged, if there is no engine shutdown relay, the machine may fail.
- If crevices and chips are formed on the cut, and the cut itself becomes too wide, then this is a sure sign - the tool should be repaired.
- An extraneous smell of burnt material appears, and dark spots are also visible on the cut line.
- The time required to process the part is increasing.
Varieties of drank
If the blade is correctly sharpened and the teeth are set apart according to the pattern, then it can process the workpiece in any direction relative to the wood fibers.
There are such types of tools:
- carbide saw;
- discs made of solid metal;
- disks with teeth treated with hard material;
- wheels with heavy duty brazed teeth.
Hard wood is treated with discs that have special notches. Technological breaks protect the deformation of the tool, do not allow it to overheat during the production cycle. And also vibration, noise background are significantly reduced, the quality of the line formed by the cut is improved. The saw has teeth that are machined at a certain angle, each tooth has several cutting edges.
There is a main edge, additional mates with it, and intersecting planes are formed:
The planes themselves also vary in different mates.
In order to properly and productively use saws, the material with which you have to work should be considered.
The teeth can be straight, they are usually used for preliminary cutting of the material . Such teeth provide a low incision. However, the performance of such teeth is quite high.
The teeth of the beveled configuration provide a more accurate line, such teeth are suitable for processing materials such as:
- PVC sheets;
The teeth provide a smooth cut, while the material does not crumble.
There are also discs in which there is a bevel at the leading edge of the cutter, and there is also a bevel with a trailing edge . Alternatives of alternating different teeth with different bevels are possible. Such tricks provide a clean cut, but remember: the denser the material, the faster these teeth become dull.
Trapezoidal tooth - this tooth configuration provides a long tool life. Often, a complex design is used when the teeth are alternating between trapezoid and straight. The second carry out the primary cut, which makes it possible for the teeth of a straight form to “polish" the cut.
Typically, such a tool is used in cutting a laminate, as well as PVC sheets.
Cone - shaped tooth - such teeth are auxiliary and are designed to work with materials on which a laminated surface is present. They provide the correct cut without the formation of any chips.
Independently teeth of such a configuration are practically not used.
A tooth in the form of a sickle - in this case, the teeth are bent, which makes it possible to accurately cut the material across the wood fibers.
Determining the degree of wear and sharpening angle
Saw blades, sooner or later, lose their performance characteristics during operation, it is possible to effectively extend the tool's service life if it is properly re-sharpened. This operation is not difficult, in many cases you can do the work yourself.
First of all, one should have an idea: what parameters does the working disk of the unit have. The second most important parameter is the sharpening angle, what parameters the tooth itself has.
Before you start working, you should test the tool, to understand how relevant its restoration is. You should inspect the disk by removing it from the machine. An important indicator is the change in size, this can be seen even with a quick inspection.
A special approach requires discs that are processed with special materials. The soldered disc can significantly increase the service life of the cutting tool. It can work with any tree species, even material with increased hardness.
The knobs themselves are made of heavy-duty steel of the brand:
And also some other steel grades are used.
This material is distinguished by its strength and wear resistance, however, it also requires preventive treatment.
It is advisable to start the work to have the desired template, by which you can adjust the geometry of the cutting surface. Typically, the template is made of tin or cardboard.
The teeth themselves have a standard prescribed in GOST 9768-78, however, each manufacturer has a differentiation in the angles of inclination and shape.
In the absence of a template, it will be necessary to determine the parameters of the teeth on their own. For this there is a tool - a pendulum goniometer. With this tool, you can precisely align the angle of sharpening.
Another option is to take a new disk and use it as a template . You should take a sheet of thick cardboard, draw on it with a pencil the exact shape. Then, using the pendulum angle meter, the exact configuration of the solders should be established. It is recommended to keep this sample, it will be possible to work with it in the future , using it as a reference.
After completion of the work, it will be necessary to test the obtained sample by comparing it with the standard. The angle of inclination in such saws ranges from 15 to 25 degrees .
If the model is transverse, then the differentiation can be from 5 to 10 degrees. If the model is universal, then the angle of inclination is only 15 degrees.
It should be taken into account when starting work: the rake angle can have a negative value. Similar models are used for working with PVC sheets, as well as with soft metals.
You can sharpen the instrument with your own hands (if it does not have a winning coverage) at home on your own. And also in such cases, you can use a simple machine on which you can successfully grind any edges. It is very important to choose the right circle.
They are of the following types:
It is best to use an aggregate in which the disc can be positioned at different angles.
Equipment for sharpening soldered discs is not cheap, it can only be found in specialized technical centers.
It is advisable to move the sharpening yourself:
- it is worth the extra work;
- manual movement accuracy will be poor;
- if there is no skill for sharpening circles, it is recommended to contact professionals.
There are rules:
- the main defect occurs on the edge from above, that is, the edges are rounded within the range of 0.11-0.31 mm - this is the starting point from which to start sharpening;
- should be processed both front and rear, this should be done at least 26 times;
- size does not exceed 0,051-0,151 mm;
- front and rear faces are treated identically;
- after the cycle, the finishing process should be implemented, that is, clean the surface with “zero” sandpaper.
Work on creating a new configuration requires compliance with the regulations and has its own complexity.
- To get acquainted with the requirements, in particular, to specify the number of revolutions. It is clear that for metal this indicator will be noticeably less. Wooden elements are processed at a high speed.
- The material from which soldering is made can withstand heavy loads, its service life is significant, but even sooner or later it gets defects, chips and cracks appear.
- A sure sign that the material begins to "get tired" is the appearance on the surface of microarrays, roughness. In these places after some time defects will occur.
To correctly implement sharpening, you should know what kind of teeth are:
- tooth with a bevel from the back;
- in the shape of a cone;
How to sharpen:
- thoroughly clean the disk using alcohol or chemicals;
- all work planes are processed;
- it is permissible to remove metal 0.051-0.151 mm;
- sharpen, perhaps no more than twenty-five times;
- can be sharpened with a special file if practical experience exists;
- carbide teeth are recommended to be sharpened on separate equipment;
- winning tricks can be "taken" only using a special machine in which there is a diamond wheel.
Marker should make markings, mark the reference point. The teeth are arranged in such a way that they are in a single plane. After passing the grinding cycle, each tooth is tested and processed separately.
Tooth sets are of several types.
- Wavy, each tooth is flattened at a certain angle of inclination, thus, a semblance of a wave arises.
- Protective, two teeth have tilt angles, the third tooth is present without tilt. This method is effective when working even with mahogany and oak.
- A classic when the teeth are variable - tilt angles to the left and right.
- An inclination is made at the frontal plane.
- An inclination is made at the rear plane.
There is another parameter - this is the point angle, but it usually “works” as an additional tool.
For manual sharpening you will need:
- wooden bars (2 pcs. size 52x32 mm);
- drill, screwdriver;
- screwdriver crown;
- hacksaw to process ceramics;
- screws or screws.
The middle of the bars is cut out, they are fixed on a solid plane using self-tapping screws. A mark is made on the bars, so that a crown for processing ceramics is placed in the cut-out markings, which, in turn, is attached to a screwdriver.
The surface of the stand matches the surface of the disc. The circle lies on the stand, the sharpening plane must be at an angle of 90 degrees to the saw blade. Such a simple device is equipped with a rotary assembly. This reliable fastening allows you to evenly process all the teeth of the tool. Using a marker, make markings, which makes it possible to correctly determine the angle of inclination.
All equipment that provides sharpening has one principle of operation. Differences are present only in the performance of the equipment.
Household units can work for half an hour, then they should be disconnected from the network for a while. A professional tool is able to function almost without stopping the entire shift (8-10 hours).
The tool kit includes an abrasive wheel, as well as grinding material.
Using machines to sharpen teeth provides several advantages:
- the ability to adhere to a given angle;
- increases the efficiency of production operations and their speed;
- it is possible to use a variety of discs.
Using the machine, you can even work with coatings of hard alloys. Grain grinding wheel varies. As an example, we can say that if the diameter is 126 mm, then the speed can be 2300 rpm.
The speed of rotation of the disk can deviate between 510-720 rpm, it all depends on what kind of fragility the disk has.
The harder the material, the greater the speed required to process it.
The functionality of the installation determines whether the workpiece or spindle will move. It is also possible the movement of the entire device.
The angle of inclination can be measured using a pendulum protractor; some units have a built-in scale to determine the angle of inclination of the teeth.
The teeth are usually ground first from the front, then from the rear.
To sharpen the teeth with victorious soldering, a diamond wheel is required. Discs that have soldering should be sharpened using special nozzles or with a diamond wheel on which diamond spraying is present.
Units have circles of the following parameters:
- thickness is from 15 to 42 mm;
- outer diameter 11-252 mm;
- hole for fasteners (16, 20, 33 mm).
A lot depends on the performance characteristics of the abrasive, special attention should be paid to them.
Standard cutters are not always suitable for work, so there is a tool with special heavy-duty soldering (corundum, diamond spraying).
And finally, some tips from experts:
- the front should be monitored more closely;
- when working with massive elements, the lateral planes are subjected to heavy loads;
- Radial rounding not more than 0.21 mm;
- it is most reasonable to treat teeth both in front and behind;
- metal removal parameters should not exceed 0.151 mm;
- the disk is cleaned before starting work; you should also check all the appropriate angles;
- sharpening the teeth at the right angle requires practical experience, for lack of such it is better to take the disk to the workshop;
- circles on which there is diamond spraying should be cooled using a special coolant;
- the unit designed for sharpening circular knives is able to work with the workpiece in only one plane;
- the teeth must not be allowed to wear out before rounding by more than 0.21 mm, otherwise normal grinding will be difficult;
- usually a disk has a resource of no more than 36 sharpenings, and it does not matter on which unit the processing takes place;
- It is important to ensure that the metal does not receive defects during processing (chips, cracks, nicks), their appearance can provoke further destruction of the material.
About how to sharpen carbide tipped saws - the next video.