If the circular machine began to work worse, it is possible that the equipment has simply not been serviced for a long time. Spend a little time on preventive cleaning and make a number of adjustments with your own hands. You will immediately see the difference in the work of your "circular".

Before starting maintenance, unplug the power supply from the socket and do not turn on the circular saw until the end of work.

First of all, cleanup

Even with an efficient dust extraction system, sawdust and tar deposits will inevitably accumulate on machine parts. Pollution complicates the work of moving mechanisms and adjusting units.

Start do-it-yourself maintenance of the circular machine with a saw blade: replace the dull one, and clean the tarred one with a special tool or white spirit.

The photo shows a cleaned section of a disc that has been used to cut softwood for two months.

Now check the spindle flange - its surface should be smooth and clean, because uneven seating of the disc leads to vibration. Remove steel burrs with a file, and remove dirt with a solvent.

Advice. Purchase saw blades that fit your circular saw spindle rather than using adapter rings. The latter are made of soft alloys and often deform when reinstalled.

Using a vacuum cleaner with a crevice tool, remove sawdust and dust from the saw body. It is not necessary to clean all surfaces to a shine, pay more attention to moving elements: gears, pulleys, gear sectors, threaded parts and adjusting stops. Remove hardened deposits with a wire brush soaked in solvent, but be careful not to get liquid into the bearings.

After thorough cleaning, lubricate the threads, tilt and vertical lift mechanisms with light machine oil. After applying a few drops to the parts, rotate the flywheels so that the lubricant is evenly distributed.

Advice. Dust and sawdust quickly stick to ordinary oil. The problem is solved by using a “dry” anti-friction lubricant that hardens on the surface and does not attract pollution. With a similar composition, but on a silicone basis, you can wipe the table of a circular machine and guide bars.

Setting up a circular machine for precise work

It is clear that not every home workshop has micrometers and hour indicators. Let's learn how to do without high-precision measuring instruments.

Checking the belt and pulleys

First check if the belt pulleys are in line by applying a ruler to them. If this is not possible due to the design of the actuator, close one eye and visually evaluate the accuracy of the alignment. To correct the problem, loosen the lock bolt and move the pulley.

Check the tension of the belt by pressing in the middle with your finger. Permissible deflection at medium force - no more than 6 mm. Loosen the suspension bolts to tension the belt.

Tighten the adjusting screw to the desired number of turns and fix the motor fasteners.

Disc tilt adjustment

First, make sure that the saw insert is flush with the table surface by placing a rule or drawing square on top of it.

Correct the position of the insert with the adjusting screws; if they are missing, place washers or thin plates. You can lower the insert by sharpening a part of the material from the bottom side.

After completing the settings, check the plane with a square in several places.

Raise the saw blade all the way, turn the tilt knob all the way to 90° and check with a square.

Adjust the hexagon through the hole in the table to the exact perpendicular position.

Turn the handwheel in the opposite direction to the extreme position and make sure that the 45° stop is accurately adjusted. Adjust the position of the saw blade if necessary.

After adjusting the pivot stops, check the tilt scale and correct the pointer by loosening the screw.

Checking the saw table stops

Cuts on a circular saw will be flawless when the saw blade is parallel to the groove of the crosscut fence and the rip fence. Otherwise, burns, non-rectangularity and rough edges of the workpieces are inevitable.

Check the parallelism of the groove and the disk with a simple device consisting of an even cut fixed on the stop with a screw screwed in. Install an improvised probe until the tooth of the blade touches and fix it with a clamp. Then move the fixture along the groove to the far edge of the disk - maintaining the tightness of the touch of the screw indicates the strict parallelism of the parts of the machine.

To change the position of the table in circular carpentry machines, there are four screws at the corners of the body. In household models, parallelism is usually adjusted by shifting the motor, for which you need to unscrew the nuts from the bottom of the machine.

Advice. You can try to fix the excessively free movement of the corner stop along the groove by making holes on the side faces with a center punch. It does not help - you will have to purchase a new one or make a home-made one, at least for exactly cutting at a right angle.

When finished with the table, check the longitudinal stop with a bar that fits snugly into the groove, inserting it from both sides.

Follow the steps necessary to set the stop according to the instructions for the saw machine and adjust its scale.

Latest Checks

The previous operations performed will improve the quality of work on a circular machine, but you should also take care of safety. Take a look at the riving knife, which should be in the middle of the disk and at right angles to the plane of the table. This is checked with a flat bar and the same drawing square.

The principle of adjusting the riving knife is similar for most saws: loosen the nuts or screws, change the tilt of the post and the angle of the corner, then tighten the fasteners.

It remains to check the side wings-extensions and, if necessary, align the parts at table level. Try to carry out such maintenance at least once a year and your "circular" will always be in good condition. And for cheap machines, such a check is recommended immediately after purchasing the equipment.

I planned to open this topic for a long time - but I hesitated all the time, I wanted to "gather my thoughts", shoot more material and put it in a separate playlist, but today I received a question from my viewer, and I decided to start the topic right now, and the new material - I can add as it becomes available :)

So where to start? First, I want to determine the range of tasks for which the machine will be made. Let me highlight a few areas:

- The first type is a saw for "cutting firewood", oddly enough, but this type of machine is also in demand, especially in villages and cottages where there is no gas but there is a need to cut firewood for heating or a fireplace.

Why a circular saw and not a chain saw? Firstly, if it is necessary to cut a "thin gauge" and firewood of small diameter, then a simple pendulum machine (Frame, a pair of housings with bearings, a shaft, a belt drive, a disk without soldering and asynchronous motor) - will cost less than an electric chain saw.
At the same time, it is safer and easier to maintain (does not require oil to lubricate the chain), has a much longer resource (an asynchronous motor lasts much longer than a collector one).
And thanks to the narrow cut - it requires less power (respectively, it consumes less electricity)
Of course, this is a highly specialized machine and it makes sense to build it if the need for firewood is large. In other cases, you can make a simple miter carriage and use a circular saw by installing a disk for transverse cut.

Go ahead

Simple machine "balcony" type. A machine used for small jobs, such as for modellers, do-it-yourselfers and "junior technicians".

This machine does not have depth adjustment, so it is suitable only for the simplest tasks, but using the drive (motor) of the tile cutter, you can quite easily build a machine that has depth adjustment.

The second option for a donor for a home-made machine, I will call angle grinder (grinder). Why exactly an angle grinder, I will discuss below. For an "entry level" machine, you can use an angle grinder for a circle of Ф 125 or 150 mm, it is desirable that the grinder has a speed controller.

Many build home-made machines based on hand-held circular saws.

Such a scheme has its advantages - with little effort you can get a full-fledged machine with adjustable depth and angle of cut.

But such a scheme has several big, hard-to-remove drawbacks:

This is the difficulty of removing sawdust (the problem can be solved only by radically altering the standard saw guard, which will make it difficult to operate it in the "manual" mode)

Another disadvantage is the low rigidity of the structure, which makes it difficult to fix the saw so that there is no play, and the depth adjustment in such a machine is rather inconvenient.

The next type is a "general purpose" machine - Universal sawing machine for the household - do simple sawing work - cut boards for a fence, make a garden bench, cut firewood for a fireplace - but you never know what works in a private household%)

A universal machine is often built like a combine: jointer + circular saw, I also have such a machine that I built over 20 years ago. Then I considered such a scheme promising, but now I consider it rational to separate the functions of a jointer and a saw. Separate scheme has more advantages and is more secure.

A few words about the design requirements for the machine.

1 - movable ruler with quick locking system.

I showed the options for the execution of the line in my videos. More simple (with a screw) in the video about the tile cutter, More complex (with an eccentric) - in the video with a hand saw.

Options with fastening the ruler with clamps, screws (in longitudinal grooves) and in a similar way, which requires constant checking of the parallelism of the ruler - I am not considering, since the ruler should “automatically” become parallel to the saw, and be fixed in one motion.

2 - adjustment of cutting depth. This function should be without fail.

And it is desirable that the adjustment takes place as simply and quickly as possible. What type of adjustment to choose, you need to decide based on your own capabilities. There may be several options - a lead screw, a lever, a longitudinal groove with a bolt fixation.

3 - saw tilt adjustment is a useful and necessary function, but you can do without it, since it is used only in a few percent of cases.

I want to consider a more scheme - a machine from "improvised materials", using available materials. Now I will not talk about technical issues, but will focus only on 2 constructive types. Each of them has its own advantages and disadvantages.

The first option is a self-made design, consisting of an engine (asynchronous), a saw shaft, a bearing housing, a belt drive and the frame itself, on which it is all mounted.

The frame is suspended under the table and has the ability to swing in one plane - to adjust the depth of cut. The design with asynchronous motor allows you to get a machine with a long operating mode, for a large amount of work.

The household often lacks a circular saw, especially if major repairs or construction are underway. Not everyone can afford industrial products - they are too expensive. But you can make a circular yourself, using the materials that are available in the household.

Design - the main nodes, their purpose

A do-it-yourself stationary circular saw is created with advancement in several possible directions:

• adaptation of an existing hand tool, using an engine and a circular saw for new opportunities;
• improvement of industrial products to expand functionality;
• assembly from separate parts, made mainly in-house.

A stationary circular machine includes several main components: a table, a shaft, an engine, and some others, the characteristics of which are not so important.

The table serves for fixing woodworking mechanisms. It can be assembled completely from metal, which is preferable, especially for machine tools with a large engine. Wood also makes good circular tables. But it must be borne in mind that the countertop should be covered with a sheet of metal, otherwise the wood will soon wear out. Tables must be very rigid and stable, capable of withstanding a considerable load during work. The surface is made perfectly flat; protective shields must be installed above the rotating parts.

For a homemade circular, the engine from the washing machine is well suited. Portable tools are less suitable: their collector motors are designed only for short-term work. They have very high speeds, low efficiency, they are afraid of clogging. You can use a three-phase electric motor, but if there is no 380 V on the farm, you will need to purchase capacitors to make it work from 220 V.

The most responsible node is the shaft. Use ready-made, if available, or machined from round metal. Work on a lathe is performed in one setup, then, together with the working bodies, the centering is checked. Even the minimum beat is unacceptable, otherwise it will become stronger in work, at which it is unacceptable to work. Seats are provided on the shaft: for a circular saw and for pulleys on the other side. You can also make grooves for planer knives.

Basic parameters - calculation of power, revolutions, transmission

The characteristics of the saw blade, the engine and the maximum thickness of the lumber that can be cut are interrelated. On the purchased circular disk, the maximum speed for which it is designed is indicated. The number of revolutions transmitted by the engine to the shaft should be less. The power of the motor influences the maximum allowable sawtooth diameter. The diameter must be at least three times the thickness of the material, otherwise sawing will be difficult. It is believed that for sawing materials with a thickness of 100 mm, you need a motor of at least 1 kW of power.

The transmission is made only by a V-belt - if foreign objects get under the saw, the material is jammed, the belt slips on the pulleys. Traumatism in such cases is practically excluded. It is important to choose the right gear ratio. We take into account two indicators: engine speed and the maximum allowable number of revolutions of the circular saw. We calculate the required diameters of the pulleys. A pulley with a large diameter is installed on the engine, and a smaller one on the shaft for the circular to increase the number of revolutions.

The revolutions of the shaft with a circular saw are as many times greater than the revolutions of the engine, how much smaller the diameter of its pulley is from the diameter of the pulley on the engine.

Woodworking machine - a capital product for the home

For working with wood in large volumes, it is better to have a machine that allows you to cut the material, plan, choose a quarter. Requires a sufficiently powerful electric motor, hard table. We present a structure made of steel angle and sheet steel. It provides a cutting depth of 60 mm, it is possible to plan boards with a width of 200 mm. A three-phase motor 1.1 kW, 2700 rpm is used. Capacitors are required for connection to 220V.

1 - machine frame; 2 - panel; 3 - starter; 4 - a device for adjusting the height; 5.7 - desktop of two halves; 6 - base; 8 - engine; 9 - platform; 10 - studs M10; 11 - circular disk; 12 - shaft; 13 - stops of the lifting mechanism; 14 - driven pulley; 15 - belt; 16 - drive pulley; 17 - switch.

The working table has dimensions of 700×300 mm. In the drawing we see that the height of the entire structure is 350 mm. The height is insufficient for comfortable work, the circular will have to be installed on an additional platform, it weighs only 35 kg. You can increase the length and width, increase the height up to 1200 mm. We adjust the rest of the dimensions to fit them, but the design features remain unchanged.

First, we make the bed frame from steel corners 25 × 25 mm. If we are not going to increase the height, we make another same lower frame. For a frame with a greater height, first we weld four legs from the same corners to the upper frame, and then we tie them at a height of 15–20 cm from the bottom. The lower frame has slots for the motor platform locking bolts. Two studs are welded to the back side of the platform, which go into the holes on the back of the lower frame. Tightening the studs, tighten the belts, then lock the platform by tightening the nuts on the studs that go into the grooves.

To adjust the height of the table in relation to the saw, we use a simple lifting mechanism. It consists of racks, in the upper part of which we cut grooves at an angle of 45 °. In total, eight racks are needed - four on each side. We weld them to the frame with grooves located in a mirror image. We attach the crossbars to the outer racks. In the middle of each of them we drill holes, weld nuts. Threaded shafts will move along them to control the rise.

At the end, they rest against the racks welded to the drawers assembled from the corners of 75 × 50 mm. On the side, we weld the studs into them opposite the grooves for the adjusting mechanism. The table consists of two equal halves and is attached to the sides with countersunk bolts. The adjustment mechanism works like this:

• loosen the nuts on the racks;
• turn the screw that presses the stop, raising or lowering the table;
• tighten the stud nuts;
• perform a similar adjustment for the second half of the working surface.

The design can be simplified without installing the adjusting shaft. Raise and lower the table manually. If you assemble the table not from two halves, but as a solid one, you will need only four racks for the lifting mechanism.

Hand-held circular saw - turning into a stationary one

It is easy to make a stationary one from a manual circular saw, expanding its capabilities. The first thing you need is a table. Finnish plywood will serve as a convenient material, which, unlike ordinary plywood, is laminated - the workpieces slide well over the surface during processing. It is thick enough to withstand a lot of weight, moisture resistant, and can be processed well. You can use ordinary plywood 20 mm, only it needs to be painted, and it is better to cover it with sheet steel or textolite.

It must be understood that the depth of cut will decrease by the thickness of the cover. You will need a large diameter disc so as not to reduce functionality compared to a portable tool. We make the dimensions of the countertop sufficient so that the workpiece fits in width. It should be added that an electric planer and a jigsaw can be additionally strengthened on a wide table, which will make the machine universal.

Using drawings and explanations, it is not difficult to make accessories for a circular saw that will expand its capabilities.

We mark a rectangle of the required dimensions on a sheet of plywood, cut it out, process the edges. With the sole we apply a hand circular to the surface and mark the attachment points with a pencil. We make a slot for a circular saw. You can slightly deepen the attachment point using a cutter, but not more than 10 mm, so as not to weaken the countertop. This manufacturing method will bring the depth of cut closer to the circular saw indicated in the passport.

We make a frame (tsargi) from the boards, which we will install from below to strengthen the structure. We fasten four boards into a box, glue it to the countertop, securing it with clamps. Through the table we screw screws into the boards. The holes for them are countersinked on top so that the heads of the self-tapping screws are hidden. We fasten the legs to the sides of the stationary saw, preferably with bolts with washers and nuts. The table should be provided with additional rigidity, so we make spacers at the bottom of the legs.

We make a restrictive bar equal to the length of the working surface. In it we drill two grooves perpendicular to the disk, in which the bar will move and be fixed at a certain distance from the saw blade. It remains to make changes to the control system: we fix the control button in the on state with electrical tape. We install a socket connected to the network on the drawer. In the break of the wire going to the saw, we mount the switch.

Some moments of the execution of home-made devices

No matter how well the circular is made, individual errors can lead to the fact that its performance will be limited. This concerns, at first glance, seemingly trifles. Let's start with the bearings for the shaft. The installation of conventional is justified if the machine is used from time to time. For a homemade device with constant use, it is better to install self-aligning bearings. They consist of two rows of balls, adjustable by tightening the clamping nut. Install a cover to protect against dust, chips is mandatory.

On the working surface, we put a scale in centimeter increments. This will make it much easier to work with the tree when determining the width of the cut. Many neglect to install a protective shield over the disc, but in vain - treatment from chips getting into the eye or in more serious situations is more expensive.

When working with different materials, it is often necessary to adjust the speed of the circular saw. A self-made design, as a rule, does not have the ability to control the engine speed. There is only one way out - the use of pulleys of various diameters. They are mounted on the motor shaft. If you undertake to order pulleys from a turner, immediately make a solid pulley with two or three different diameters.

Many people want to install a three-phase electric motor on a sawing machine without having 380 V. You will need capacitors rated for a minimum operating voltage of 600 V paper or oil-paper type.

We calculate the capacitance of capacitors based on the power of the electric motor: for 1 kW - 100 μF for a working capacitor Cf. We take the capacity of the starting Cn twice as large. The SB trigger is a button that automatically returns to its original position. The start is simple: SQ is turned on, SB is pressed for a couple of seconds. After starting, the button is released, as soon as the engine picks up speed, you can cut.

A circular hand saw is a fairly practical tool with which you can quickly saw a wooden blank of any length and width along or across, cut any wood-based sheet material. In addition, after changing the equipment with a circular saw, you can cut plastic, metal corrugated board and corrugated board. Despite the simplicity of design and high reliability of this unit, it is prone to breakdowns, like any power tool. But in most cases, the repair of a circular saw can be done independently at home.

A hand-held circular saw differs from a miter saw in that it does not have a turntable bed, as well as the placement of the handle. But in general, both models are similar in internal structure, the principle of operation and do not differ in the complexity of the design. The following figure shows the device of a hand-held circular saw.

The unit consists of the following main elements.

1. The top protective casing having an opening for ejection of sawdust.
2. The housing in which the electric motor and the start button are located. Some models of electric saws can run on batteries. In this case, the battery pack is also placed on the case.
3. The lower (movable) protective cover, which automatically closes the cutting element after it leaves the workpiece.
4. Saw disc. Mounted on the gearbox shaft with a nut or bolt.
5. Parallel stop. Allows you to make a smooth cut without the use of additional devices.
6. Base plate (sole) of the unit. Thanks to it, the tool is installed on the workpiece or tire at different angles.
7. Depth adjuster. With it, you can adjust the reach of the saw blade relative to the base plate.
8. Sole angle adjuster. Allows you to tilt the sawing unit at an angle.

This tool works according to the following principle. Power from the mains or battery is supplied to the start button, which breaks the circuit. When the start button is pressed, current begins to flow to the electric motor. Below is unit wiring diagram.

The electric motor starts and transmits rotational motion through the gearbox to saw blade. The unit is installed with the help of a sole on a workpiece or a guide rail, after which the process of both longitudinal and transverse sawing is performed.

Main malfunctions and their symptoms

Typical malfunctions of manual circulars include the following situations.

1. The saw does not turn on. The mains cable, electric plug, start button or electric brushes may be faulty.
2. The motor of the tool gets very hot. Such symptoms may be the result of an interturn circuit (open circuit) in the armature or stator coils, as well as too intensive operation of the unit.
3. Gear box overheats. Overheating of this assembly may occur due to bearing failure or lack of lubrication on the gears.
4. Brushes sparkle. This is usually due to their excessive wear.
5. Burning ring visible around the engine manifold. If during the operation of the unit a circular spark is observed around the engine collector, then its appearance can cause a malfunction of the armature winding or clogging of the space between the collector lamellas with graphite dust.
6. The unit does not develop the required power. A drop in power may be due to a voltage drop in the network, a malfunction of the motor windings, wear of the electric brushes, and a malfunction of the start button.
7. A rattle is heard during operation of the unit and other extraneous sounds. These symptoms may be caused by broken gear teeth or bearing failure.
8. The engine hums, but the unit does not work. Perhaps there was a jam in the gearbox.

Tool disassembly

Almost all malfunctions of electric circular saws cannot be eliminated without disassembling the device partially or completely. Complete disassembly of a manual electric saw using the example of the Interskol unit is performed in the following order.

1. Unscrew the angle and depth adjustment screws fixed on the base of the machine.
   
   
2. Press the gearbox shaft stop button and use the hex wrench to unscrew the bolt holding the saw blade.
   
   
3. Slide the lower protective cover aside and remove the circular disc.
   
   
4. To remove base plate, first unscrew the fasteners on its underside.
   
   
5. Next, use two screwdrivers to remove the Sieger ring that locks the stem on which the sole rotates to change the angle.
   
   

   

6. Insert a screwdriver into the gap between the body of the shield and the sole, then move it away and remove it.
   
   

   

7. In the next step, unscrew all the fixing screws located on the upper casing of the unit.
   
   
8. Also unscrew the screws holding the movable saw cover.
   
   
9. Disconnect both protective covers from the saw.
   
   

   

   

10. Using an open-end wrench, unscrew the bolt holding the riving knife and remove it.
    
    
11. Unscrew the rod holding the movable mechanism of the casing, and disconnect all its elements.
    
    

    

12. Next, you should disconnect the gearbox of the unit by unscrewing 2 screws.
    
    

    

13. When the mechanical part of the device is disassembled, you can proceed to electrical disassembly devices. Loosen the fasteners holding the engine cover and remove it.
    
    
14. After removing the cover, you will see two electric brushes. If they need to be completely disconnected from the engine, it is recommended to mark one of them with a marker, as well as the place where it was removed from.
    
    
15. Next, you should unscrew the screws with which the motor housing is attached to the gearbox housing.
    
    
16. After unscrewing the fasteners, disconnect both nodes.
    
    
17. In the detached part of the engine housing you will see stator coil.
    
    
18. Next, you should unscrew all fasteners from the handle of the unit. But before disconnecting it, you need to remove the rubber pad by prying it with a screwdriver.
    
    

    

19. After removing one half of the handle, you will see motor soft start module and start button.
    
    

    

This completes the disassembly of the saw blade.

Do-it-yourself circular saw repair

When starting to repair the unit with your own hands, it is not necessary to completely disassemble it to find out the causes of the breakdown. Some malfunctions are characterized by specific symptoms, by which you can identify the problem and already purposefully disassemble one or another part of the apparatus.

The saw does not turn on

If, when you press the start button, the engine of the unit is “silent”, then the first thing to focus on is network cable, provided that there is electricity in the socket (plug the device into another socket to check).

Advice! Before checking the cable, you need to disassemble the electrical plug and make sure that the cord conductors are connected to its pins.

To check the electrical cable, you need to disconnect the handle. This will help you get to the pins to which the power cord wires are soldered. Next, using a tester, ring each wire by pressing one probe to the soldered contact, and the second to the plug pin.

If the network cable is intact, then in search of a malfunction, do the following.

1. Ring the entire circuit with the tester, starting from the cable entry into the unit to the start button. You should also check the contacts of the button at its input and output when the key is pressed. Normally, an open circuit should close. Call all wires after button going to the motor brushes.
2. If everything is in order with the conductors, check how worn brush electrodes. After the electrode has worn 2/3 of its original size, it should be replaced. The brushes, no matter how worn out each of them, are changed in pairs.
3. If the brushes are in good condition, then most likely engine failed. In its windings, an open circuit or an interturn circuit could occur. In this case, it is better to entrust the repair of the engine to specialists who will rewind the stator or armature coils.

The engine is warm

The unit may become excessively hot, for example when intensive use, as well as when sawing hardwoods or using a saw blade with a large number of teeth, when the load on the engine increases significantly. Also cause overheating of the motor malfunctions associated with the stator and armature windings, which are eliminated only in the service center.

Burning brushes

Strong sparking from under the brushes is caused excessive wear and tear when the spring can no longer press the electrodes against the collector with the required force. To replace the brushes, you need to disconnect the motor cover or remove them through special holes in the motor housing (depending on the saw model).

Stuck shaft during operation

This problem may occur when, for any reason, the stopper is pressed while the tool is running. It is designed to fix the shaft when changing equipment and should be used after the engine has completely stopped. Otherwise, the stopper rod breaks, and its fragments fall into the engine, causing jamming. It is not uncommon for this to lead to armature shaft deformation. Also, the result of pressing the stopper may be a split in the gearbox housing, the fragments of which can damage the gears and cause them to jam. To solve the problem, it will be necessary to replace the anchor, stopper, drive (large) gear of the gearbox and its housing.

In some cases, the gearbox may jam when the bearing is completely destroyed.

The saw stops during operation

Stopping the engine in most cases is caused by a cavity worn out electric brushes. When the contact between the brush electrode and the collector lamellas is broken, the unit is turned off.

Often, when buying brushes for this device, you come across products with short conductor, connecting the electrode to the plate. This conductor is located inside the spring and does not allow it to fully open. When the electrode wears out to a certain length, then pressing it to the collector stops, since this is prevented by a short conductor. If you, inspecting the brush, find that it is not yet worn out and the spring is not unclenched, then the part should be replaced.

The gearbox housing gets very hot

Rapid heating of the gearbox occurs if shaft bearing failed, on which the gear is fixed and the equipment is attached. In this case, in addition to heating, you can replace the appearance of extraneous noise in this unit of the apparatus. It is necessary to disassemble the gearbox and change the bearing. Also, the gearbox will heat up if it contains not enough lubrication or it is completely absent.

Advice! Periodically, the gearbox should be disassembled and checked for lubrication. If necessary, generously lubricate the interior of the assembly. For these purposes, you can use a special lubricant for grinder gearboxes.

The saw does not gain power

If during the use of the unit you notice a drop in its power, it is first recommended check the voltage level in the network. Sometimes even a slight drop can adversely affect the power of the power tool.

Also, power loss can be observed when wear of armature bearings or gearbox bearings. In this case, extraneous noises that were not previously characteristic of this unit will be heard. By their localization, you can determine where the problematic bearing is located - in the gearbox or engine. To replace the bearings, you will need to disassemble the saw blade. How to do this was described above.

If no extraneous noise is heard during the operation of the unit, and the engine still develops poor speed and power, then pay attention to its manifold. Usually you can see a circular spark (ring of fire) on it. This may be due to an interturn circuit of the armature coil or the accumulation of dirt between the collector lamellas.

Open the motor housing and carefully inspect the collector (the place over which the brush electrodes slide). It consists of parallel strips (lamellae). There is a small gap between them. When this gap gets clogged conductive graphite dust formed during wear of the brushes, then a short circuit occurs between the lamellas, and a burning ring appears around them.

The problem will be solved by replacing worn brushes and cleaning the gaps between the lamellas with a toothbrush, cotton wool and alcohol, followed by polishing the plates with fine sandpaper.

In some cases, a power drop can be caused by a faulty start button. If the check by the tester confirmed its malfunction, then the part should be replaced with a new one, since it cannot be repaired.

Extraneous sounds appeared during operation

The appearance of grinding and other extraneous sounds can be caused by faulty bearings or gears of the gearbox and shaft with worn or broken teeth. In the following figure, the arrow shows where the armature gear is located.

The gear located on the motor shaft can be licked when the saw jams in hard or loose wood. Usually the gearbox gear does not suffer. To eliminate this breakdown, you will have to completely change the anchor of the engine. In the event of bearing failures, it is easy to remove them with a puller and replace them with new ones.

A homemade circular saw is a kind of handy tool that can cope with a number of construction tasks at home. In principle, it will not be difficult to make a circular yourself even if you do not have any special skills, the main thing is to have at least a little idea about working with metal. The necessary material can usually be found in a garage or home workshop, and a steel corner, a rectangular profile pipe and an engine are suitable here. The assembled circular saw can be put on an existing workbench, or, in the absence of such, you will have to build a table for a circular saw with your own hands. As for the motor, you can use the unit from the old washing machine or walk-behind tractor, but first things first.

Hand held angle grinder

If there is a “grinder” on the farm, then there is no better device for a hand-held circular saw. Don't know how to make a mini circular saw at home from such a popular tool? Do not despair, because its manufacture only involves providing a sliding stop and an axial handle to an existing unit. The sliding stop includes in its design two pieces of a metal corner of a small section located on both sides of the saw blade. With the help of bolts and nuts, the corners are connected on the front and back sides with a cross ligament, and the technological gap between the sidewalls of the thrust structure and the working element will be provided with washers.

It is necessary to put on a metal band clamp on the grinder so that its screw tie is located at the bottom, and a strip of galvanized metal with a hole for the sliding stop, folded in half, is already fixed to it. In principle, a special clamp with a stand can be made as a single unit, but in this case, the thickness of the metal strip will ideally be at least one and a half millimeters. Further, in the gearbox housing of the future circular, you will have to make a couple of holes for the bolts, for which it is disassembled, and the drilling points are determined. Through the holes made, an axial handle for a circular saw assembled from a grinder is attached, since the existing handle will not allow high-quality cutting, even if the master has remarkable physical strength.

The axial handle, which will be supplied with a circular grinder, is made of a metal rod or tube. The design in shape can be a transverse bracket or a kind of horn. The ends of the metal part, with which the handle is attached to the gearbox, are provided with holes for fasteners. There is one important point here: the ends cannot be riveted in order to eliminate the deflection of the handle during the operation of the hand-assembled circular. It is also necessary to make an adjusting rod from a piece of metal rod (4 - 6 mm), for which we bend one end into a loop, rivet a little and form a hole for the front stop bolt. The uniformity of the gap, as usual, is regulated by washers.

At the other end of the rod, a thread is cut, thanks to which it will connect to the handle. First, one nut is screwed onto the thread, and after assembling the structure, the second one. By tightening and lowering the nuts of this fixture for a homemade hand-held circular saw, the depth of cut is adjusted. This is how at home you can convert the grinder into a full-fledged disk tool designed for cutting various materials. By the way, by remaking a circular from a drill, you can achieve a similar result.

Miniature Tabletop Circular Machine

The mobility of the element is achieved by sawing a horizontal segment into two uniform parts, which, after installation, are fastened with clamps. A circular saw is fixed to the vertical part of the frame on the clamp. A table from a hand-held circular saw assembly can function as a cutting machine if a standard cutting disc is installed on the grinder. It is worth noting that the through cut here will not exceed 80 mm, and for processing larger lumber, a more serious home-made circular machine will be required, which will be discussed later.

Stationary machine

Circular machine, as close as possible to factory models, requires a competent approach to assembly, therefore, before making a stationary type circular saw, you need to think through everything to the smallest detail. In principle, a desktop mini circular saw differs from a stationary one in the height of the bed, which directly depends on the nature of the work performed and the dimensions of the workpieces that the device will process. One-time work can be carried out on a compact table saw, while a circular saw from a hand-held circular saw can be easily hidden in a barn or pantry, and a carpenter who constantly manipulates lumber will need a stationary home-made circular saw. Below is a diagram that details all the elements and fixtures for a circular saw of this type.

As can be seen from the figure, home-made circulars of this type have a clear design, and drawings similar to the one presented above greatly facilitate the process of their assembly. Before you make a circular, as well as mount a circular table with your own hands, we will consider each detail of the unit separately in order to know all the intricacies of its operation and installation.

Circular table

A table for a manual circular saw with a slot in the center is sometimes remade from an ordinary kitchen table or assembled from bars or metal profiles. Experts strongly recommend covering the table for a circular saw with a sheet of galvanized metal, since without a coating, the base is threatened with abrasion in the center from constant friction of the lumber, which in turn will negatively affect the quality of the cut, and the depth of cut will be uneven. The cross ties that reinforce the saw table are best made from a 60 - 80 mm steel angle with the horizontal segment outward in order to simplify the installation of the side limiter. A home-made table on which a circular saw will be installed must be strong and stable, and it must also be securely fixed in a fixed position.

saw blade

The toothed disc should rise above the surface of the circular table by a maximum of a third of its diameter, otherwise it will not saw the wood properly, and the process itself will become dangerous. If you need to cut a beam with a diameter of, for example, 100 mm, a similar cutter parameter should not exceed 350 mm, however, an engine with a power of 1 kW or more is also required here. For workpieces with a diameter of more than 150 mm, a mini circular made by hand is hardly suitable. On some factory circular machines, a riving knife is provided, which is installed behind the disk at a distance of 2 - 3 mm from the saw teeth. It eliminates the jamming moment due to the closing of the parts of the sawn workpiece, therefore it can be very useful in the case when a home-made circular is assembled.

Side stop adjustable

It is possible to put a high-quality emphasis from a steel corner with a section of about 80 mm, which is 3–4 cm longer than the table structure. The flat sides of the corner are bent down so that their width is one and a half cm more than the thickness of the table. After installation, the stop is fixed on a homemade circular table in a predetermined position with the help of bolts. The adjustment of this element is carried out according to the template placed between it and the cutter.

Shaft

The shaft mounted on the circular is the most critical unit, therefore, only a specialist using special equipment should be engaged in its turning and testing as an assembly with a disk. A pipe product with a carelessly fixed circle is excluded immediately, because the slightest errors in the operation of this element will result in major troubles such as equipment breakdown, damage to the workpiece and injury to the operator. The best solution would be to purchase a finished shaft with a seat for the cutter. It is better to give preference to self-aligning ball bearings with a curved inner surface, otherwise the self-made assembly will quickly collapse and the shaft mounted on a homemade circular will become unusable.

Broadcast

In our case, a V-belt drive would be an ideal option, but it is better to refuse a rigid gear mechanism, since such a homemade product does not guarantee safety. If a nail is suddenly caught in the lumber, the motor rotor will provoke the destruction of the disc, which can lead to injury. If the inner diameter of the belt drive pulleys is small, then slippage will be ensured, and the tensioned belt will serve as a kind of damper. The gear ratio is usually chosen based on the engine speed, always taking into account the allowable number of disk revolutions. The smaller the diameter of the saw blade, the greater the frequency of its rotation, and the cleaner the reworked unit will cut.

Motor

Among home-made devices, the most popular is a circular assembled from an engine from a washing machine. This choice is explained by the fact that its operation scheme is best suited for such purposes. Unlike collector units, which are usually supplied with power tools, the engine from the washing machine runs at lower speeds, which means that it shows longer operation, has increased efficiency and is not so prone to all sorts of clogging. You can also use a three-phase motor, but then additional costs will be required for the purchase of a starting and running capacitor, so it is more economical to get by with a device from a washing machine. Here, in general, and all the wisdom.