How to Change the Bearing on a Small Grinder

Features of repairing angle grinders of various brands

This article offers ways to find faults in angle grinders of various models without repairing an angle grinder (angle grinder) on your own. Here you can find answers to questions about the procedure for disassembling gearboxes of grinders of the most popular models, replacing gears, bearings and their repair. Recommendations are given on the procedure for pressing in and unpressing gears and bearings, and methods for repairing devices.

Along with general malfunctions, angle grinders of various brands have their own characteristics. This occurs not so much from differences in the designs of angle grinders, but also from the non-component materials used.

It is important that at first, who made the instrument. Knowledge of the design features of angle grinders allows you to repair angle grinders yourself, but not quickly. The information below will help you repair any brand of angle grinder.

Along with original tools, the construction market is flooded with cheap fakes. It makes no sense to think that counterfeits are made exclusively in China. Power tools from Chinese manufacturers are in no way inferior in quality to those from European countries, or in other words, Southeast Asian countries.

High-quality tools from Chinese manufacturers for European consumers undergo several stages of incoming control. For third countries, Chinese manufacturers do not control tools. But the instruments are produced on the same lines, in the same factories, by the same people. This is why there is such a difference in price.

To repair an angle grinder in makeshift conditions, you need to have a diagram of this angle grinder without understanding it. Repairing a Bosch grinder differs from repairing an Interskol grinder. You can find grinders under the brands Makita, Hitachi, Metabo.

Some general useful tips for organizing the repair of an angle grinder

Before we start repairing the angle grinder, let’s look at some useful tips:

1. Before you start disassembling the angle grinder, carefully read its description, assembly diagram and the order of work.
2. Be sure to follow the sequence of technological operations.
3. Strictly follow safety precautions.

The most common reason why an angle grinder breaks down is a broken wire near the handle. First of all, you need to check the presence of voltage on the button, this is done with a regular voltage tester. Then we check the button itself for functionality.

How to choose bearing sizes online

Brief instructions for using the online search to select bearings suitable for specific sizes.

Selection of bearings online by size

• d, mm - internal diameter, measured in millimeters.
• D, mm - outer (external) diameter, measured in millimeters.
• B, mm - width, measured in millimeters.

The functionality allows you to select a bearing either by individual size, for example by width B, or together: d+D, d+B, D+B or d+D+B, which greatly simplifies the search.
Thus, to find out the bearing number by size, you need to enter the parameters in the appropriate cells and click on the search button. You can enter values ​​separated by a comma "," or a period ".". Example of entering possible sizes:

Selection of bearing by number

The search is carried out by the number (index/designation) of the bearing produced in accordance with GOST and among foreign analogues, as well as by bearings that are not in the Russian-made line.

Example input:

• 880012
• 6304
• 6304-RS
• R1-2RS
• 619/2
• K3x5x7
• F618/4-2RS

Source

How to remove a needle bearing or a damaged journal bearing race

Grinder gearboxes use various bearings. They are subjected to heavy loads and do not cause malfunctions.

Bearing failure is determined by an increase in spindle shaft play. Having disassembled the gearbox housing without dismantling the large gear shaft, the needle bearing is visible.

The needle bearing is not used in many angle grinders. In the same grinders in which it is installed, its dismantling is carried out in several ways.

Having taken out the destroyed part of the bearing , there is an option to remove the inner race using a machine tap. Clamp a machine tap of a suitable diameter into the screwdriver chuck and do not try to screw it into the bearing race until the tap rests on the bottom of the housing. Continue to slowly screw the tap into the cage. It will lift the clip along the threads.

The second method is that the remaining race of the destroyed needle bearing can be removed using a special bolt not a retaining ring.

Plain bearings - description and dimensions

Sliding bearings, also called articulated bearings GOST 3635-78 - the outer and inner rings of which have a spherical sliding surface. Designed to perceive and transmit radial, axial and combined loads in moving or fixed joints of various machines and mechanisms.

Example of designation: GOST; ShSP 40 K / Import designation: GE 40 ES

ShSP - A spherical plain bearing with a slot on the outer ring. 40 — internal diameter, mm. K - with holes and grooves for lubrication in the inner and outer rings.

Plain bearings with a steel/steel sliding surface are designed to withstand alternating heavy, shock or static loads. They are made from high-quality bearing steels ШХ15, ШХ15СГ or stainless steel 95Х18Ш.

Movable joints, a connection in which spherical bearings operate with the mutual movement of one ring relative to the other, at a relatively low sliding speed;

• Ш, ШП, ШЛ – spherical plain bearing without holes and grooves for lubrication;
• ShS, ShSP, ShSL - with holes and grooves for lubrication on the inner ring;
• Shs. K1, ShSP. K1, ShSL. K1 - with holes and grooves for lubrication on the outer ring;
• Shs. K, ShSP. K, Shsl. K - with holes and grooves for lubrication on the outer and inner rings.

Fixed joints, mounting joints in which spherical bearings operate with periodic single shifts of one ring relative to the other; designed mainly to compensate for misalignment of the shaft and housing.

• ShM, ShMP, ShML - without holes and grooves for lubrication, with minimal internal clearances.

Main design features and designations of imported spherical bearings:

• GE - standard series;
• GEH - heavy series;
• E - without holes for lubrication in the outer and inner rings;
• ES - with holes and grooves for lubrication on the outer ring;
• 2RS - protective seals on both sides.

Modifications of the outer ring of plain bearings:

• Sh, shs, shs. K1, ShS. K - type of spherical plain bearings with a one-piece outer ring;
• ShP, ShSP, ShSP. K1, ShSP. K, ShMP - with one slot on the outer ring;
• SSL, SSL, SSL. K1, ShSL. K - with a split outer ring (two slots on the outer ring).

Other designs of plain bearings:

• ShN - spherical bearings for moving joints with a sliding surface steel / metal fluoroplastic;
• SLT - spherical bearings for moving joints with a sliding surface steel / organofiber;
• Sh. E - spherical bearings with inner rings made of composite material - a mixture of polyamide and fluoroplastic;
• ШУ - angular contact spherical bearings;
• ShSR - spherical plain bearings with two outer half rings.

The spherical bearings are operational at temperatures up to +120°C. Short-term operation of bearings is allowed at temperatures up to +150°C. For more severe temperature conditions, bearings of special designs are produced.

Application. Sliding bearings are capable of operating in conditions of increased dust and limited lubrication. Plain bearings are used in control mechanisms of aircraft, mounted components of agricultural machinery, excavators, and suspensions of heavy mining dump trucks.

Source

How to remove helical gears of an angle grinder gearbox

Repair of the grinder gearbox begins with the dismantling of the helical gears. It is the gears that become the main cause of malfunctions of the grinder gearbox. In grinders, you most often have to change the small drive gear attached to the rotor shaft.

The helical gear can be attached to the rotor shaft in two ways:

1. The gear is fixed with a key connection and is not clamped with a nut.
2. The gear is attached using a threaded connection. Moreover, both right-hand and not left-hand threads are used.

The large driven helical gear is mounted on the spindle shaft in two ways:

1. The gear is pressed onto the shaft.
2. The gear is attached using a keyed connection.

In addition to replacing gears in angle grinders, it is often necessary to replace one or other bearings. And there are at least three of them in the design of an angle grinder.

Mechanical damage

The Bosch angle grinder is designed to perform cutting, grinding, and polishing work. Operating a tool in dust under heavy loads has a particularly detrimental effect on the durability of the gearbox, namely its gears.

In addition to wear and breakage of gear teeth, mechanical failures include destruction of bearings and housings. Repairing a Bosch angle grinder in terms of replacing failed bearings and restoring the housing is not difficult to do if there is a desire and need.

Assembling the grinder

The assembly of the grinder begins with an examination of all parts, assemblies, bearings, and gears.

Pre-prepare the workplace with proper and good lighting, place tools, lubricants, and napkins.

What lubricant to use for a Bosch angle grinder

Bosch ear repairs will not be of high quality if you do not change the lubricant during the repair. For high-quality lubrication of Bosch angle grinder components, it is recommended to use those lubricants offered by the tool manufacturer. But their high price forces us to look for another way out, and there is one.

Domestic manufacturers of lubricants have developed special lubricants for gearboxes and components of angle grinders.

In terms of quality, they are in no way inferior to foreign lubricants, and are much cheaper. The only negative is that our lubricants require more frequent changes.

Rotor assembly

Assembling the rotor consists of pressing bearings onto it and installing the impeller. Lubricated bearings are pressed onto the shaft using a wooden extension. The bearing near the collector is covered with rubber protection. This is the general algorithm for assembling the rotor shaft.

Some models of Bosch angle grinders have their own characteristics.

Gearbox assembly

Assembly of the gearbox begins with the installation of the rotor shaft into its housing. Once the shaft is inserted into the housing, the drive gear, washer and locking nut are placed on the shaft. The gearbox housing with the inserted shaft must be placed in the stator housing.

Once you have the commutator bearing in place, press the gear housing against the stator housing. Check the ease of rotation of the rotor in the bearings.

A spindle assembly with a mounted bearing and gear is mounted in the gear housing cover.

All that remains is to insert the cover into place and check the quality of rotation of the spindle shaft. If the shaft rotates easily by hand, it is possible to tighten the screws securing the rotor housing cover. The screws are pre-lubricated with sealant.

This is a general algorithm for assembling a gearbox. For some models, the repair of the Bosch angle grinder gearbox is slightly different.

Conclusions:

• Knowing the general layout of Bosch angle grinders, you can safely begin disassembling the tool for lubrication;
• The ability to repair a Bosch angle grinder with your own hands will allow you to extend the life of the tool, replace the lubricant and carbon brushes yourself;
• By observing the operating mode and technological maintenance of the tool, you will extend its trouble-free operation for many years.

Good luck in job!

Bosch angle grinder repair

Bosch grinders are a reliable tool that does not cause much trouble to the user. Unfortunately, it is a rare user who treats the instrument correctly. Bosch angle grinder repair most often involves replacing bearings.

Structurally, our client is left with Bosch angle grinders made according to the same design. The spindle shaft pos. 25 is pressed into the driven helical gear pos. 26 and does not rest in the gear housing pos. 821 on the needle bearing pos. 51.

When a bearing is destroyed, a bearing race remains inside the housing, which is not easy to obtain. We recommend two methods for removing the needle bearing race. They are described in the section “How to remove a needle bearing”.

When the teeth of a pair of gears become worn out or licked, both must be replaced, not only in pairs. When dismantling the gears, remember that the drive gear is attached to the rotor shaft on a thread, and the LEFT gear is not secured with a nut. The driven large helical gear, pos. 26, is pressed onto the spindle shaft, pos. 25.

Recommendations from experts

Experienced specialists give recommendations on the best way to lubricate the gearbox of an angle grinder. They claim that if it is impossible to service the tool with a proprietary lubricant, you can choose a different composition. The second most popular lubricant in our country is recognized as CV joint lubricant. It is most often used for domestically produced tools. Some craftsmen choose lubricant for CV joints and for foreign angle grinders. However, the quality of the original compositions will be much higher.

It’s worse if the master gave preference to compositions such as litol or grease. These are universal tools. They are not capable of efficiently servicing the grinder’s gearbox system. If they are used, the operation of the tool will not be complete. At the beginning of operation, the difference will not be noticeable. But over time, serious problems may appear in the operation of the unit.

Therefore, experienced craftsmen do not recommend saving on gearbox lubricant. The costs of purchasing original or other high-quality products are paid off by the long service life of the equipment.

Hitachi angle grinder repair

Hitachi grinders have gained particular popularity among Russian consumers. All this is natural. There are practically no handicraft fakes of Hitachi angle grinders on the economic market. The simplicity of the design makes it easy to carry out repairs of varying complexity.

Hitachi grinders have increased reliability and do not often come to the attention of repairmen. The main reason why a Hinachi angle grinder needs to be repaired is a breakdown of the gearbox, specifically, the wear of gear teeth.

Control

Having studied how to lubricate the gearbox of an angle grinder, you should consider the procedure for monitoring the correct maintenance of the tool. The angle grinder must be assembled and connected to the network. When starting the engine, the quality of filling the gearbox with lubricant is assessed. To do this, the grinder is placed in idle mode for a short time.

If the gearbox begins to heat up after the test, and traces of lubricant appear from the gaskets, it means that there is too much substance in the mechanism. After disconnecting the tool from the network, you need to open the gearbox cover. There will be excess oil on the walls. They are removed from the equipment cavity.

If extraneous noise appears in test mode, insufficient lubricant was applied. In this case, the tool is disassembled and an additional amount of compound is added to the gearbox. Then the verification procedure is repeated. If everything is in order, the tool can be used as usual.

Having considered how to lubricate the gearbox of an angle grinder, as well as the procedure for this process, each master will be able to service his equipment independently without any problems.

Any power tool contains rotating parts in its design that are subject to increased wear as a result of friction. It is possible to prevent their premature destruction and extend the service life of the tool if you carry out timely preventative maintenance of rubbing parts. In an angle grinder, the main wear and tear is on the gears of the gearbox. The harmful effects of friction can be reduced by applying lubricants to the surface of parts. Let's consider which lubricant for an angle grinder gearbox is best to buy.

Replacing bearings on an angle grinder. Replacement of bearings angular polishers.

Replacement considered

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bearings
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the grinder
, with disassembly and reassembly I tried to maximize the income

The grinder gearbox is easy to disassemble. To disconnect the gearbox housing, pos. 3, from the stator housing, pos. 37, the carbon brushes must be released.

Unscrew the four screws, item 1, securing the gearbox housing and stator housing. Separate the gearbox housing and the stator housing. The gearbox housing will be disconnected together with the rotor, pos. 8.

To remove the gearbox cover pos. 23, you need to unscrew the four screws pos. 24. The driven helical gear pos. 33 is fixed on the spindle shaft pos. 26 using a key pos. 25 and is driven off with a puller. Bearing pos. 21 is removed with a puller.

Bearing selection

Makita angle grinder repair

A special feature of the Makita family of angle grinders is the quick-release protective cover pos. 19.

Makita grinders are more likely than others to be repaired. But the reason is the high percentage of counterfeits that have flooded the Russian market.

A true Makita is a reliable, durable tool. But, like all angle grinders, it suffers from failure of the gearbox and its gears.

Reducer gears are replaced if they become jammed or destroyed.

To repair a Makita 9069 or Makita 9558 HN angle grinder, you need to disassemble the angle grinder.

If the gearbox is faulty, and this is determined by the appearance of play in the spindle shaft, jamming of the gearbox, or slipping of the driven gear, then the gearbox should be disconnected from the stator housing. Release the carbon brushes, pos. 35, unscrew the four screws, pos. 10, and disconnect the gear housing from the stator housing, pos. 37.

At the next stage, unscrew the four screws pos. 18 holding the rotor cover pos. 15. The driven gear pos. 14 is removed using a tool. The drive gear, pos. 43, is secured by a keyed connection and secured with a nut, pos. 42. The rotor shaft bearings pos. 3 are removed using pullers.

Gearbox maintenance

Having chosen how to lubricate the grinder gearbox, as well as preparing the mechanism for this process, you can begin servicing the tool. The product must be mixed thoroughly. It is applied in a thin layer to the gearbox parts. The mass is applied to the bearings using the packing method.

If the product is packaged in a tube, its neck is placed on the side of the bearing cage. The composition is poured inside until it flows out from the other side. Enough grease is filled into the gearbox so that it covers the gear teeth. The excess will flow out when the grinder is in use. Lack of lubrication leads to increased heat and friction inside the mechanism.

Angle grinder repair Interskol

With proper use, Interskol grinders can work for years.

Along with the infrequent failure of the grinder gearbox, in which the weak link is a pair of gears and a bearing, there have been cases of malfunctions in the stator.

To replace the gears of the gearbox, it is necessary
the gearbox housing, pos. 19, by releasing the cover, pos. 6.
The driven gear pos. 11 is pressed onto the shaft pos. 8 and is removed using a press. The bearing pos.9 is removed with a puller.

You can repair the stator of an Interskol angle grinder yourself if you know the necessary data. When disassembling a burnt stator, you must count the number of turns of the wire used and its cross-section.

Specifications

To have an idea of ​​how to lubricate the gearbox of an angle grinder (“Interskol” or products from other manufacturers), it is necessary to consider the features of this tool. They affect the technical characteristics that the lubricant should have.

The main and most loaded unit of the grinder is the gearbox. It consists of gears of a certain configuration. Proper lubrication can reduce friction and heat the moving parts. To do this, the consumable material must have a viscosity of no more than 800 Pa*s. Its dropping point must be at least 120ºС. The tensile strength is recommended at 120 Pa. This allows the product to form a durable film on the surfaces of the parts.

The lubricant must consist of naturally soluble components. It should not harm the environment or human health. Products from trusted well-known manufacturers have appropriate quality certificates, so they are recommended to be used for tool maintenance.

Repair of angle grinder Lepse

Grinders under the Lepse brand are marked with the LPS Lepse Kirov 1.8-230-A. These grinders trace their history back to the famous Soviet-made grinder IZH. An amazingly durable tool with the most vandal-proof design.

The advantages of the Lepse grinder are the ability to replace worn carbon brushes without disassembling the body of the machine.

Repairing Lepse angle grinders in terms of replacing brushes is simple. Through special windows pos. 45, closed with caps pos. 48, carbon brushes pos. 47 are inserted into the brush holder housing pos. 46.

When repairing the gearbox of a Lepse angle grinder, it is necessary to dismantle the gear pair.

The driving small helical gear is mounted on the rotor shaft on a key and secured with a nut.

The driven gear, pos. 15, is screwed onto the spindle shaft, pos. 10, and secured with a nut, pos. 18.

Required Tools

Hammer with wooden handle. Photo ForgingPRO

The quality of repair largely depends on the correctly selected tool. The best option for replacing gears in an angle grinder is to have the following:

• a set of screwdrivers, or better yet a screwdriver;
• pliers for removing circlips;
• set of wrenches;
• when replacing worn gears, you have to press out the bearings, where it is difficult to do without special pullers;
• in some cases, in their absence, disassembly of parts with press fit can be performed with metal, wooden, or rubber hammers using special extensions;
• to assemble the gear unit after replacing the gears, the technological operation of pressing is best performed on a press - this guarantees high-quality assembly;
• a bench vise with the ability to use soft jaws is not the last device when repairing an angle grinder gearbox.

Repair of angle grinder Fiolent

Recently, Fiolent grinders have become especially popular. What attracts us is not only the affordable price, but also the reliability of the tool.

repairing the Fiolent angle grinder with your own hands by studying emerging faults. If you need to disassemble the Fiolent angle grinder, then in order to remove the driven gear, pos. 11, it must be pressed out from the spindle shaft, pos. 8.

To remove the spindle shaft bearing, you must first remove the large helical gear. These are minor inconveniences.

Replacing the rotor bearings requires the removal of the small helical gear, pos. 22.

Disassembling an angle grinder for prevention

I would recommend disassembling your sander not only for repairs and replacement of worn parts, but also for regular maintenance. This will significantly extend the operating time of the electrical device. Any mechanism works longer and better if it is properly cared for. The Bulgarian is no exception.

Disassemble the tool as described in this article. Only now you are doing this not for repairs, but in order to thoroughly clean and lubricate such a necessary tool in the household.

The most ideal option for cleaning is to use compressed air and a blower attachment in compressors. You will have to take into account that the angle grinder is cooled through the distance in the middle of the armature and stator.

Excessive amount of construction dust, various particles on the engine. All this needs to be cleaned from time to time.

And if you have already disassembled the angle grinder for prevention, apply fresh lubricant to the parts, as described earlier.

As you can see, maintaining and repairing an angle grinder is not such a difficult task!

What repairs can a user make to an angle grinder with his own hands?

Although the grinder is not a particularly complex tool, the user cannot perform repair work on all components.

Along with simply replacing the bearings or gears of the gearbox, there are malfunctions that cannot be made without special equipment or devices.

• To press out the driven gear you will need a press. It will not be possible to wind the rotor without tools.
• Such malfunctions include rotor failure. For the average consumer, such a malfunction ends with a trip to the service center.
• Advanced users can revive a burnt out rotor with certain skills and concepts. But sometimes it’s easier to buy a new one than to rewind.

For most users, repairing an angle grinder with your own hands is limited to a certain range of faults.

Preparing to change the lubricant

Having studied the options for how to anoint the gearbox of an angle grinder, you need to delve into the process of applying a new composition to the elements of the mechanism. This procedure is carried out according to the power tool maintenance plan established by the manufacturer. This must also be done when replacing gearbox parts or rotor bearings.

The waste will have a dirty color. This is due to the ingress of metal particles and dust into it. Before lubricating the gearbox, it is necessary to remove old oil from the surfaces of the mechanisms. The waste is removed completely.

To perform this procedure, automotive engine cleaning products are suitable. You can also use kerosene or gasoline. Using these products, traces of old lubricant are completely removed from the surfaces of all parts. After treatment, the gearbox must be thoroughly dried. Only after this you can start refueling.

Systematization of faults in the electrical part of angle grinders

1. The simplest fault that causes the angle grinder to not turn on is a broken power cord. Most often, a break occurs in the power cord near the plug or at the entrance to the instrument. The malfunction can be easily resolved by replacing the power cord or removing the broken piece of wire.
2. Increased heating in the area where carbon brushes are installed. Most often, such a malfunction occurs due to shortening the carbon brushes below the nominal size. The length of carbon brushes cannot be shorter than 8 mm.
3. The grinder's power button goes down. The malfunction is due to burnout of the internal contacts in the button. Eliminated by completely replacing the switch with a new one.
4. Some models of angle grinders use a device that allows you to smoothly regulate the speed of the angle grinder. The angle grinder's speed regulator improves the smooth operation of the angle grinder and prevents the working tool from biting. Repair of the angle grinder speed controller consists of completely replacing it.

Homemade mixtures

If the required lubricant is not available for sale or if the user considers the price of the product to be unreasonably high, you can try to make the lubricant mixture yourself. There are several formulations using different bases. One of them is the common Tsiatim-221.

Transmission oil TAD-17 is added to the container with Tsiatim. Continuously stirring, add oil one drop at a time until the required consistency is achieved. The mixture should adhere well to the parts, not be too thick and not flow like liquid oil.

Another base can be CV joint lubricant in combination with MS-20 liquid oil.

Grouping of faults according to the mechanical part of the angle grinder

1. The appearance of extraneous noise in the grinder gearbox, heating of the gearbox. The malfunction is associated with the destruction of the support bearing, wear of the gear teeth of the gearbox, and drying out of the lubricant. Eliminated by replacing gears when tooth wear is high. If there is slight wear on the gear teeth, you can try to fix it. The tooth profile is corrected manually by filing using a round file and a drill. The lubricant is replaced with a new one every time the gearbox is repaired. New lubricant is applied to thoroughly washed parts.
2. Bearing replacement is required when it is damaged or large play appears. In some models, the bearing is mounted on the spindle with interference. Replacement requires special equipment, in particular a press. Parts need to be cooled or heated.
3. Replacing the bearings on the rotor is required when large runout occurs. The presence of increased runout can be easily seen on the rotor commutator and by the wear rate of the carbon brushes.

How to disassemble an angle grinder and remove bearings. Step by step steps

After disassembling this device, you can replace broken bearings, re-lubricate all parts, dismantle damaged brushes and install new ones.

In order to separate the rotor and stator housings, it is necessary to first remove the handle housing in the machine. This is done so that it is possible to remove the carbon brushes. They hold the rotary manifold.

The second step is to unscrew the four screws that secure both housings - rotor and stator.

Take out the gearbox along with the starter and start disassembling it. There are also screws on the gearbox that need to be removed. There are four of them in total. This procedure will require some effort on your part, since the factory assembly involves the use of sealant.

Grinders of different models have different types of gears. In low-power models, spur gears are used. With a power of more than a thousand watts - the use of helical gears.

Once you remove the gear cover, you will be able to remove the assembly that houses the helical gear. To remove it, use a press or puller.

To do this, you will have to use special thin tubes. For this reason, it will be inconvenient to use the puller.

Simple faults and methods for diagnosing and eliminating them yourself

If your grinder does not turn on when you press the “Start” button, then the test begins by inspecting the power cable at the point of entry into the tool.

Unscrew the lid of the angle grinder and check the integrity of the power cord using a tester or phase. Strictly follow safety rules.

If the power cord is intact and the angle grinder does not turn on, replace the “Start” button.

If the grinder does not work when installing a new button, check the quality of fastening of the carbon brushes and their tight fit to the rotor commutator.

see also

Comments 30

I sawed out two pieces like this, clamped them in a vice and pressed them together

Beautiful. You simply, without strain, pressed it out with a vice. Respect and respect. This is the most practical advice, I will definitely draw a bold cross over the workbench so as not to forget this advice. One problem, how to make such a wedge? You can't cut it off with a grinder, you need to polish it, otherwise it will bite. I have three sandpapers in the garage, but I doubt that I can keep such a part on the plane of the stone. You need a familiar milling machine. Previously, I would have had one like this, made me a vice with a magnet for a drilling machine. But overall the idea is cool. Good luck with your inventions.

A few words about lubrication

The reliability of the gearbox and its durability largely depend on the timely replacement of lubricant and its correct selection.

The Russian fuel and lubricants market offers a wide range of lubricants. Among them, lubricants from Russian manufacturers stand out.

Modern tool manufacturers strongly recommend using only their own lubricants. This is the manufacturer's policy.

Among Russian lubricants, we recommend using lubricants specially designed for gearboxes.

But the quality of work of an angle grinder is affected not only by correctly selected lubricant, but, to a greater extent, by its timely replacement! Do not delay replacing the lubricant; monitor its condition.

Tool elements

Knowledge of the general principles of angle grinder design helps to better diagnose the causes of failure . It is important to know that each of the components of the grinder (mechanical or electrical) has its own specific features. Based on the presence of characteristic signs in the work, you can always decide in which part to look for problems.

Scheme of operation of the grinder. Source here

For example, increased sparking of the brushes in the area of ​​the commutator unit of the electric motor indicates that the electrical part should be inspected. A sharp metallic noise coming from the gearbox will give reason to determine the condition of the bevel gear pair and the presence of lubricant in this mechanical unit of the angle grinder.