Calculation of Motor Power for a Circular Saw
DIY Circular Saw Repair
The design of the circular saw, as in other things and many other electric tools, is based on the collector electric motor. The collector motor tends to spin up to very high revolutions. Therefore, even with a small engine power, the circular saw has good performance. Previously, circular saws were made on the basis of asynchronous electric motors. They had worse characteristics and were more bulky. Most of these saws were converted into makeshift, stationary circulars. To do this, a table is made or it is also called a bed and a circular saw was screwed in a convenient place. Home-made circular can be made not only from a factory-made circular saw. To make a home-made circular it is enough to have an electric motor, a table and a familiar tokyor.
A common reason for the failure of the circular saw is the electric motor. Defects and methods for their elimination can be found in the Repair of collector motors section.
A feature of the circular saw is work in a dusty environment. Since the collector motor is cooled by the outside air, dust and even chips get in and part settles inside the engine. To prevent breakdowns, periodic maintenance is required. It includes: cleaning dust and dirt and cleaning the collector of the anchor from graphite and carbon deposits.
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Choose a circular saw
Circular (circular) saws are designed for transverse and longitudinal cutting of wood materials, non-ferrous metals and plastic. Due to the high performance of this tool, the ability to perform fast and accurate straight cuts, it will become a wonderful assistant for you when performing a variety of work with wood: laying floors, creating furniture, roofing, etc. Equipping the tool with a special saw blade, you can easily cut profiles from different non-ferrous metals. But today such profiles are very widely used in creating items of modern furniture.
Working with such a saw is very simple, but safety measures must be observed. The slightest violation of the operating rules, negligence in work can cost you very much.
Over the long years of using this unit, its design has changed little. Of course, its ergonomics became more perfect, the weight changed, the engine power increased. The biggest changes have affected the saw blade. Recently, a large variety of these disk elements has appeared, made of aluminum, and wood, and of laminated materials, etc.
The design of circular saws is quite simple. It includes the following elements: gear case electric motor protective cover platform equipped with a guide line.
As a rule, the body of the device is made of heat-resistant wear-resistant plastic. Quite rarely, but you can see on sale a model with a metal case. The design gives enough attention to the ventilation and cooling systems of the engine. In addition, many manufacturers, taking into account the fact that a circular saw often has to work in conditions of considerable dust, paid attention to the process of removing chips from the working area. First of all, this factor has a good effect on the health of the operator, since his lungs are less affected by dust. All modern models have the ability to connect to a forced dust removal system or to industrial vacuum cleaners. For this, special adapters are used.
Some manufacturers, for example, Makita (MAKITA), supply their products with a stationary device for removing dust and chips. For example, the model of the MAKITA 5017 RKB circular saw with a power of 1400 W has a special container for collecting sawdust. Such a system removes more than 90% of all sawdust generated during operation.
Some manufacturers, trying not only to facilitate the work with the device, but also to somehow isolate their products from the total mass, resort to rather non-standard solutions. Thus, for example, WORX supplied one of its saw models with a “revolving handle”. There is a start button on the handle and the angle of the handle itself can be changed within sixty degrees. Such a very solution is quite interesting and useful. Indeed, now the operator can easily adapt the instrument precisely to his anatomical features. I would like to note right away that this constructive improvement is available only on WORX brand products.
Any circular saw is equipped with a collector electric motor. Its power can be from 500W to 2.5kW. It goes without saying that engine power affects such an important parameter of the tool as the depth of cut. In addition, the speed will depend on engine power. In recent years, the number of revolutions of the saw blade on modern machines has almost doubled. Just ten years ago, the number of revolutions of units with a power of 2.2 kW ranged from 2.5 to 3.5 thousand per minute. But modern models of circular saws with exactly the same engine power give already about 5 thousand revolutions per minute.
Separately, it should be noted that today in the market of tools you can also find cordless models of circular saws.
Another interesting feature that appears is the laser pointer. She in the process shows the direction of cut. Many people know how inconvenient it is when sawdust fills the marked line of the cut with the work of the disk device. Now, having a laser pointer, you will forget about most of the inconvenience in work.
Criterias of choice
When choosing a circular saw, you must evaluate the quality of its platform. To reduce the cost of the product, many manufacturers use a stamped platform, but for professional purposes it is necessary to choose a model equipped with a cast aluminum platform. Only in this case the work will be carried out with maximum accuracy. In addition, such a platform is much less subjected to various deformations. It is convenient when the manufacturer placed special marks on the surface of the platform, which allow better control of the cutting process of the material. It turns out a kind of sight, through which accurate work is performed.
Another important point when choosing a machine is the method of changing the saw blade. To this day, there are products in which there is no spindle lock. That is, the disk here can only be replaced with two keys. And this, as you understand, is both long and uncomfortable.
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The circular saw allows a long and even cut.
If at the same time you want to do this work as accurately as possible, then you should pay attention to such additional tooling as a guide rail. Each manufacturer of disc tools for their products also produces such tires. However, there is one significant nuance here: guide rails can only fit a tool from one manufacturer. There is no escape from competition laws.
This element of circular saws should be given special attention. Today they produce discs designed for almost any material. A variety of discs for wood, you can very quickly dissolve the board. The only thing is that the quality of the cut will be low. Disc elements designed for laminate work so that subsequently the surface of the sawn material will not need additional processing. This quality of cut is achieved due to the geometry of the teeth on the disk, the frequency of the teeth, as well as the use of special carbide taps. Recent developments in this area allow you to saw boards without first removing nails from them. As a result, not only a spectacular spectacle is created, but also the ability to avoid tool breakage, operator injuries.
It will be appropriate to note here that the cost of repairing a circular saw is quite high. Replacing the anchor can be compared with the price of a new product. In general, there are several reasons for the wear of the slots on the anchor. Among them are the following:
Excessive pressure on the tool during operation.
Incorrect selection of the saw blade.
Use of a damaged saw blade (no sharpening, no carbide brazing).
If you need this tool for its active use, then it is better to stop the choice not on the battery model, but on the one that is powered by the mains. This is explained by the fact that cordless saws have a rather limited range of applications.
In conclusion, it must be noted that the use of a circular apparatus should be extremely careful. During the work, be sure to use special safety glasses.
We wish you the best choice and safe, safe work.
High-quality repair of a circular saw
- Fault location
- Dismantling and its features
- Mechanical malfunctions
- Malfunctions of the anchor and stator
The advantages of any home tool can be fully appreciated only after it fails. This axiom is known to every home master. The presence in the arsenal of a large number of devices has led to the fact that most people simply can not imagine how to do this or that operation without them.
A circular saw is used to evenly cut various materials.
In the case of a circular saw, this is especially true. The fact is that it is indispensable for longitudinal sawing of wood, it does not have a worthy analogue among hand tools. With a conventional hand saw, this cannot be done. Therefore, when the circular refuses to work for some reason, all work stops. It is urgent to do something. However, do not rush to bring it to the workshop, it is quite possible to do the repair of the circular saw yourself.
The first thing you are trying to determine is broken. This is not a specific site, but the nature of the damage. It can be mechanical or occur in the electrical part of the saw. In other words, if smoke came out of it, this is one thing, and when an extraneous noise or whistle # 8211 appears, it is completely different. It is these two criteria that are the main ones in the localization of a malfunction. There is, however, a third, when the saw does not make sounds at all. We’ll start with him.
Circular saw device.
Oddly enough, the fact that the saw is silent can be a good sign. Here it is worth mentioning those malfunctions that are usually printed on the last page of the instruction manual. At first glance, they seem ridiculous, but show a little respect for them. Check if there is voltage at the outlet and if the power cord is working. If everything is fine, then there is only one chance left to avoid a complete disassembly # 8211 to check the brushes.
On the vast majority of circulars, in order to get to the brushes, two bolts must be unscrewed. This assembly is two carbon elements that abut against the collector. Since it constantly rotates, the brushes are subject to wear and “freeze” over time, i.e. don’t reach it. This should be noted first. In addition, carbon brushes are connected to the stator terminals. At this point, the contact sometimes disappears. Check this. If everything is fine, disassembly can not be avoided.
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Dismantling and its features
The operation itself is quite complicated, some workshops charge money for it regardless of the result of the repair. Each saw has its own device, and precise advice cannot be given. You can figure it out on your own. But what to disassemble in the first place, we consider in more detail.
A very common damage regardless of brand is a malfunction of the switch button.
Circular saw device with separate motor.
For all models, it is in the handle, which, when untwisted, diverges into two parts.
It cannot be halved to the end, it will rest on other details, but you can already get to the button, however it will be a little inconvenient. Despite this, the tester’s probes must check the operation of the circuit breaker.
If it turns out to be faulty, the repair is completed. However, to put in place a new one, the saw will have to be disassembled completely. But if the button is working, you will have to do it too.
Remove the disc. Now you can remove the protection, which is what you are doing. Under it 4 long bolts, unscrew them. The sequence and number of parts may be slightly different, but in the end, the engine with the gearbox, handle and electric cord should remain in the hands. Disconnect the gearbox, and then it’s time to remember how the malfunction manifested itself.
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Symptoms of such malfunctions can manifest themselves in different ways, but almost always the work is accompanied by extraneous noise. It can be whistling, rattle or clicks. Now, while the engine and gearbox are still assembled, it is necessary to establish which of them is faulty. Try turning the engine by the shaft. It should rotate quite heavily, but evenly, i.e. should not wedge.
Line-up of a circular saw.
If the motor shaft does not rotate or jerks, the engine is faulty. Disassemble it and see the bearings. The first is in the engine housing, the other on its rotor. With full confidence, we can assume that one of them is to blame. It would be good if the first one is quite easy to change.
If the bearing at the motor anchor is to blame, you can safely carry it for repair. It is almost impossible to remove it yourself without a special device. In addition, all attempts to do this can damage the armature. It’s not necessary to carry the entire saw to the workshop, but only the rotor. It is lighter and cheaper.
The main failure of the gearbox is the wear of the gear teeth. In this case, it must be replaced. You should also pay attention to the slots of the anchor. They should not be damaged either.
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Malfunctions of the anchor and stator
These malfunctions are the most common. During operation, sudden sparking appears in the brush area. Smoke may come out and smell of burning. Such damage is sometimes very difficult to diagnose. Let’s start with the simplest and most expensive case.
Circuit test performance of a circular saw.
After opening the engine, it turns out that on the rotor and on the stator burn marks. Everything is clear here. It is necessary to change both that, and another. The option is expensive, but the probability of error is excluded. Worse when the stator is smoked, and the anchor is like new. At first glance it seems just # 8211 you need to change the stator. Not at all necessary. The rotor may also be faulty, but be “in a cliff”. over, it could serve as the cause of a more serious breakdown. To determine its malfunction in this case is quite simple.
- Disconnect the stator terminals from the brushes. In their place, fix the tester probes, it should show a little resistance.
- Slowly rotate the motor shaft, if at some moment the resistance increases, then the anchor is faulty.
And the last, most difficult case, when visually everything is in order. Even if you apply the method described above, this will not guarantee that the rotor is working. However, if the device shows an open, then you can try to change it. But basically in this case it is better to contact the master. You can’t do without special devices.
Very often, a circular saw is bought for a specific purpose. At the same time, a person does not even wonder if she is suitable for this. The fact is that there are professional circulars designed for long-term work, and there are those that can work only 3 hours a day, and even then with interruptions.
Therefore, before actively operating the circular saw, read the instructions and consult with specialists. The same applies to the operation of chainsaws, other tools. Maybe after that a repair is not required. Good luck