Causes of angle grinder failure and repair methods
Even the simplest repair of angle grinder in a service workshop can cost from one third to half of its value. Therefore, before turning to professionals, you should always try to repair it on your own. The more so, that in the machine’s passports often provide tables of the most common malfunctions and causes of their occurrence. For home repair in most cases you can do with a set of the most common tools: screwdrivers, pliers, wrenches and a multimeter. The only place where you might need to use mandrels, pullers, or similar tools is in the removal and installation of bearings. And spare parts to repair the angle grinder without problems you can buy in all the well-known online stores.
The following guidelines will help ensure successful repair of the bearing assemblies.
- You need to know the design of the controlled angle grinder. Read the technical documentation provided with the shredder. Knowing the location of components and parts will help you properly disassemble and reassemble the grinder during repairs.
- Performing work on replacing bearings will help as having the necessary tools. This tool is not complicated and is almost always available in the arsenal of home craftsmen: screwdrivers, wrenches, hammers, puller set or other hand tools (vise, extensions, punches of various designs) to fix and remove bearings.
- When repairing grinders, there is a certain order of operation. This should be taken into account, taking into account some differences related to the characteristics of a particular model.
- Replace bearings if there is even a small shaft, Since a damaged bearing can completely damage the entire power tool.
- Make sure the power tool is switched off before carrying out repairs.
Bearing open for Hammer crusher. 220V picture
The tool used must be in good condition:
- The design elements of the pullers (legs, rods, stops, screw devices) comply with the technical documentation;
- The screwdrivers have straight sides and the straight rod is firmly mounted in the handle;
- Key jaws are parallel, no cracks or indentations;
- The hammers are firmly attached to the handles.
Following these recommendations will allow you to properly and safely disassemble angle grinders, replace defective bearings, lubricate all parts, and reassemble the grinder for future use.
How to remove/remove the needle bearing in an angle grinder
It’s no problem to press in a new needle bearing, but to remove it, you need to use the original puller. The following video shows the author how to make such a device and what it does in practice.
The extractor is an expander collet with shoulder strips on the ends of the moving paddles. The collet is dimensioned on a lathe and the center hole is drilled for a petal expander rod. the extractor is inserted into the bearing and the collars, following the movement of the rod through the bore, are lifted up and rest against the shoulder of the ring. The bearing can be removed from the housing using levers of reinforced steel with ground edges, which do not look very impressive but are reliable and rest on an inserted washer.
Important: A needle roller bearing has a significantly longer operating life than a plain bearing. However, the spindle shaft wears out during operation and must also be replaced. In the video the author found a variant for replacement. But this can cause additional problems in most cases.
How to disassemble the gearbox of an angle grinder
Intensive use of such a popular and demanded in the home angle grinder (“angle grinder”) necessarily leads to the need to repair it. But, most skilled people in this situation are confronted with the question of how to disassemble the angle grinder, so as not to make major damage. Only knowledge of the device and the principles of disassembly, repair of the device allows you to carry out the repair yourself expertly.
Design modifications of angle grinders
Angle grinder is very different in several design features:
- Power. the basis of all design features: the bearings used, the type of transmission and hardness of the metals used, the quality of assembly and materials used in construction.
- Housing assembly features. the transmission mechanism is necessarily in a metal housing, which, despite the general principles of assembly, can have different modifications. In most cases, the body of the mechanism has a cover with four tightening bolts or screws. It is worth considering that before you disassemble the gearbox of the angle grinder, you need to carefully visually examine the assembly seams of the housing, showing the detailing of the design, t.е. what needs to be disassembled beforehand.
- The quality of materials used to assemble the angle grinder is very different from the manufacturer, so the celebrity and availability of branded parts indicates the quality of the device itself and its repairability.
Component parts of the angle grinder
To know how to disassemble the angle grinder, you need to clearly understand its design features, places and peculiarities of the connection of parts:
- The overall body with the handle is usually made of plastic, has two halves connected by self-tapping screws on the perimeter. Unscrewing it allows you to get to the electric motor and all the electrical components. Many models have indestructible part of the housing, which is mounted stator coils, and disassembly of the entire device is carried out by unscrewing the side “covers.
- The electric motor of the angle grinder is fixed in the housing flanges. pads, and its notching reveals the unimpeded excavation of the rotor from the stator. The motor bearings are also quite easily inserted into the housing, but their fit on the shaft has a lot of tension, which is very often a problem in the situation of how to disassemble the angle grinder.
- The rotor. not a collapsible unit for self-repair, so you need to be careful with it, so as not to damage the winding wires, armature and geometric shape of the metal components.
- The stator is the electrical windings with a transformer steel housing. Self-repair node of the angle grinder is impossible.
- The rotor shank with the gear teeth passes into the metal gear housing where the bearing can be securely fixed, and removing it without the aid of impact force can result in cracking of the aluminum.
- The problem, how to disassemble the gearbox of angle grinder, found mainly only in one of its nodes. the fastening of idler pinion on the output shaft and pressing out of the node removable cover housing.
Disassembling the gearbox with your own hands
- In most cases, access to the gearbox transmission can be performed without general disassembly of the angle grinder, but only need to unscrew the gear cover, which is attached by four or six screws, depending on the power of the device.
- Before you disassemble the gearbox of the angle grinder, you need to unlock the screws and remove the protective cover of the cutting wheel.
- After unscrewing the screws of the gearbox cover, it is removed together with the output shaft and the idler pinion, which “opens up a view” of the structure of the unit and the wear of the mechanism: cheaper models are fitted with plain bearings of base metal (brass, bronze), replacement of which is very problematic because of the tight fit in the aluminum housing.
- fitting of new bearings on the shaft is not too much trouble, because.к. It is easy enough to press it into place by using an additional, suitable spacer. It is advisable to disassemble the old bearing from the shaft by “destroying” it, for which purpose both cages are carefully cut with a file or a cut-off wheel of a grinder-milling machine.
- The bevel gear can be cast with the output shaft or detachable. Disassembling the unit is an extremely rare occurrence, because.к. It is sold in pairs. But to accurately depress it from the housing without a puller is not an easy task, because a careless movement can split the metal housing. Disassembly can be facilitated by heating in an oil bath or, in extreme cases, in boiling water, and it is inadmissible to perform open flame heating to disassemble the reducer of angle grinder.
How to Disassemble the Gearbox Angle grinder Makita 5030
Most of the tools used in the household are not immune to failure. Angle grinders, which almost every craftsman has, eventually break down. Different models of angle grinders may be similar type of failure. But each brand has its own characteristics in design and accessories. The well-known Makita brand is appreciated for its high quality. durability. However, devices of this brand also tend to break.
how to disassemble and reassemble makita angle grinder
Repair can be done at home. Spare parts for the machine can be easily purchased. Before repairing the device, you need to read the attached diagram.
Types of Makita brand angle grinders and their features
Based on the diameter of the working wheel, the brand grinders are divided into classes:
- Lightweight. have a wheel with a diameter of 115-125 mm. They are distinguished by easy controllability.
- Medium. the diameter of the circle is 150-180 mm. There are professional models and household models, differentiated by motor power.
- Heavy. diameter of the disc 230 mm. This class is represented by models for professional purposes when working with concrete, brick, etc.п. Characterized by the latest protective systems.
Amateur devices vary in power and price. Professional equipment is designed for long-term heavy loads and has an increased power reserve. The models with power over 1000 W have a comfortable back handle, which is covered with special pads that protect against vibration.
As for the design of the bolsters of this brand, it is characterized by the presence of such additions:
- a labyrinthine device serving to protect against dirt and dust;
- armored coating of the motor windings;
- A special system for soft start and overload protection (Super-Joint-System).
How to disassemble the Makita 9555 hn angle grinder
During the entire time of using my power tool, I have “burned” it myself for the first time. During prolonged work, my Makita 9555HN angle grinder caught a lot of smoke. It happened because of haste and at the same time by negligence. In the aggregate of all my activities and events, there was a very strong overheating of the tool. Timely overheating was not observed due to the fact that the work was done in welding shoes. As they are leather, it is safer to work in them, because they won’t wind up, unlike rag or knit ones. And because the tapes are designed to protect against the temperature, and the work was carried out as if nothing had happened.
In addition to simply work long, which lasted about an hour and a half, was another aggravating moment, the tool is used a little heavy equipment in the form of a thick, six millimeter grinding disc and a metal brush in the form of a cup.
The operating time of this copy of the angle grinder is small, so it will be repaired.
Disassembling the tool. The process is simple enough: unscrew the screw that secures the black plastic cover and take it through the power cable. Then lift the spring-loaded locks of the brushes and remove the brushes (there are two, located on different sides).
We proceed to the disassembling of the front part of the angle grinder. Unscrew the four screws that fix the gearbox and remove it. Next, remove the rotor of the electric motor. Use a screwdriver for this. We set it in the technological groove and turn it carefully, controlling the process. It’s easy to pull out the rotor, without any effort (the main thing is not to forget to remove the brushes).
Blow out the rotor with compressed air and examine it. There is nothing to find fault with externally. it is perfect. The enamel on the visible parts of the wires is not darkened and retains its integrity. Unfortunately, there is no way to check it for short circuits yet. Set it aside and continue disassembling.
Now we need to get to the stator. After removing the rotor, we have access to the fasteners of the plastic stator guard. Remove the two long screws and pull it out. Before you remove the stator you should first detach the stator winding and straighten out the wires. To remove the stator, you can use a rubber mallet. The process is as follows: apply light hammer blows on the front end of the housing angle grinder, and because of the rather large mass, the stator will begin to move out of its seat. When removing the stator, make sure that the wires go through the technological windows freely and do not catch on anything.
Inspection of the stator reveals burnt-out winding conductors. The enamel on them is considerably darkened and damaged. The stator to be replaced.
We still have an open issue with the rotor. I remember that in some big stores where they sell spare parts for power tools, they can tell you and check some parts. We take the stator and the rotor and go in search of spare parts.
Assembly begins with the preparation of all parts and assemblies of the angle grinder. First of all we need to blow out all dusty elements with compressed air. Next, wash the gear parts in gasoline. After that let’s arrange all the components of the angle grinder and proceed to assembly.
Makita! Repair of a Makita 9555hn angle grinder, Makita angle grinder, work sound has changed!
It can be installed without any effort and special tools. Simple hand effort is enough. The main thing in this process is to correctly direct the four wires that are connected to the terminals. You should also pay attention to the red wire. jumper (the one that connects the two windings). When installing the stator, this wire tends to take a position right in front of the fastening hole of the plastic protection. If it is not taken into account, then during the further assembly, when screwing in one of the screws, the wire is sure to be broken.
After the stator has taken its place we install its shield.
Now you need to prepare the new rotor for installation.
Here you must install the previously removed plate, bearing, pinion nut, and do not forget to reinstall, from the old rotor with a rear bearing, a rubber ring. It is marked with number 3 in the diagram and is called a labyrinth rubber ring.
After completion of the above-mentioned works place the assembled rotor in its place. Then, using four screws, screw the gear housing. Tighten the screws evenly crosswise.
The rotor is now locked in place and the brushes can be mounted. We place them in the special channels of the brush holders, fix them and connect the flexible contacts.
How to repair an angle grinder yourself
One of the most common household appliances for repair and construction work is considered an angle grinder, or angle grinder (angle grinder). It is not uncommon for heavy loads and careless handling when operating the machine, leading to component wear and breakage. But it is possible to repair the angle grinder yourself. To do this, it is worth looking at how to do the repair of angle grinder with his own hands on video.
- The angle grinder anchor (rotor) is the most overloaded element of the angle grinder mechanism. It is subject to temperature, electromagnetic and mechanical damage, so its failure is not surprising. The armature winding can burn out when heated, causing a short circuit. Therefore, the repair of the angle grinder armature with their own hands. a frequent practice.
- If the collector fails during operation, the brushes are burned by strong vibration, so there is a very noticeable spark. Brushes conduct current to the collector.
- The bearings on the rotor shaft are also subject to heavy wear, and can be completely destroyed if not replaced in time. They need to be checked in the case of extraneous noise from the machine.
- The fixed part of the angle grinder motor is the stator, which contains the winding. The stator itself is seldom the cause of angle grinder failure.
- Gearbox is a mechanism for transmitting rotation, which requires timely cleaning and lubrication.
- The easiest thing on the angle grinder to replace the brushes, but it is also the most frequent procedure in the repair, t.к. they are made from graphite.
Recommendations before starting a repair
It is worth considering that the technology repair angle grinder different models and manufacturers may differ. So, the repair of the Interskol angle grinder with their own hands is different from the repair of faults of the Bosch machine.
That is, it is important to know the features of your angle grinder and have on hand the scheme of it, then the repair of the angle grinder with your own hands is possible to perform easily and efficiently.
Repair of angle grinder with their own hands
Only after familiarizing yourself with the detailed description and diagram of the angle grinder, you can proceed to its disassembly. Repair should have a certain sequence of actions. And the most important thing is to observe safety precautions.
Break of electrical wire at the handle. the most common problem of failure of the device to work. To make sure of this malfunction on the button, you need to use a standard voltage tester. Only after that should you check if the button itself works.
Replacing the bearing
If you notice an increase in play of the spindle shaft, it means that the needle bearing must be replaced. By the way, it is not in all models of angle grinder. To disassemble it, disassemble the housing, and pull out the large pinion shaft.
Use a machine tap to remove the inner ring in the damaged bearing.
The tap must be clamped into the chuck of an electric screwdriver and screwed into the bearing cage. When the bottom of the housing is reached, you need to continue slowly screwing in so that the cage rim rises on the threads.
Disassembly of helical gears
Gearbox failure occurs because of damage to the helical gears. Often the small drive gear attached to the rotor shaft is replaced, which is attached in two ways:
The driven large pinion can also be attached by means of a keyway, but also by pressing it onto the shaft.
Differences in repair angle grinder Interskol
Under the correct operating conditions, the Interskol angle grinder can rarely be repaired by hand.
To replace the gears, the gearcase is disassembled and the cover is removed. Since the idler pinion is attached by pressing it on, it must be removed with a press. Then remove the bearing with a puller.
If the stator is burned out, you need to calculate how many turns of wire, and what is its cross section.
It is not superfluous to see the repair of Interskol angle grinder with their own hands on video.
Repair features of the Bosch angle grinder
The design of all models of the Bosch line has an identical scheme. Repair of angle grinder Bosch with their own hands is usually reduced to replacement of bearings.
The spindle shaft is pressed onto the idler pinion. Held in place by a needle bearing in the gear housing, which leaves only the cage inside when worn. The drive pinion is fastened to the rotor shaft with a left-hand thread, and then secured with a nut.
Repair of a Makita angle grinder
The Makita angle grinder is distinguished by its protective housing, which can be quickly removed. This can be called a plus, because.к. Angle grinder this firm most often subject to failure. This applies mainly to counterfeit products that have flooded the domestic market.
Real Makita angle grinder is famous for its durability and reliability. Regardless of whether a fake or real angle grinder fell into your hands, the most common cause of failure will still be the gearbox and its gears.
This becomes noticeable when slippage of the idler gear appears, the gearbox jams and the shaft backlash increases.
When repairing first disassemble the angle grinder. Disconnect the gearbox from the stator housing by loosening the brushes and unscrewing the screws. Next, the screws holding the rotor cover are removed.
An idler pinion can be removed with a press, and the pinion is keyed with a locking nut. Use pullers to remove bearings of the rotor shaft.
Thus, no matter what angle grinder you have, with proper study of the problem you can repair the main faults with your own hands. The main thing is to correctly understand the scheme and have the necessary tools for repair.
Despite this, the angle grinder is a complex mechanical power tool, and it is not uncommon to damage the more difficult to access components of the mechanism. In this case, if you have not previously encountered such breakdowns, it will be more effective to first consult with experts on your particular problem.
How to disassemble the gearbox of an angle grinder
The process of disassembling the angle grinder is inextricably linked to the disassembly of the gearbox of the angle grinder, since they form a single. angle grinder has the option of disassembling without having to disassemble the gearbox, but here such disassembly will not
Servicing a Makita GA five thousand thirty \ Fixing a Makita five thousand thirty \ Repair of power tools \ maintenance tool
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Possible electrical faults
Electrical faults of a Makita angle grinder can be divided into control circuit faults, rotor faults, and stator faults.
How to troubleshoot the control circuits of a Makita angle grinder
If your Makita angle grinder does not turn on, the biggest reason may be a breakdown in the power and control circuits.
To get to the control circuit components, you have to remove the back cover of the housing pos.38 by unscrewing the 4×18 self-tapping screw pos.39. Switch ST115-40 K9565 pos.28 is secured in the switch holder pos.27. The switch holder is closed with a cover pos.29, which is attached to the motor housing pos.33.
Power cable is connected to the switch pos.37. Using a tester, check continuity of circuits from the plug contact to the switch terminals. Switch pos.28 is operated by the lever pos.30. From the switch contacts, check the circuit to the carbon brushes pos.42.
Grinder Repair – How to Replace the Gear Bearing
The weakest link in the control circuits is the carbon brushes. The Makita 9565 angle grinder uses CB-318 carbon brushes with automatic shutoff, so check the brushes.
Professional grinders have speed controllers. Makita angle grinders over 1000 W have a soft-start system. The Makita 9077SF angle grinder is equipped with this system.
If the switch fails, the problem can be solved by replacing it completely. If the power supply wire is broken or broken, the fault is eliminated by replacing the entire wire or by removing the damaged parts.
The switching process is carried out with the lever pos.30. If you disassemble the body of the angle grinder for repair or maintenance, before reassembling lubricate the grooves of the lever movement with silicone grease.
How to disassemble the gearbox correctly: Guidelines
When a gearbox completely fails to work, it requires a complete disassembly to replace parts not thoroughly clean. To do the work, prepare a bench vice. Work must be carried out in a specific order of procedure:
- Use wrench to loosen bolt holding gear housing.
- The rotor body is clamped with great care in a vise.
- Strike lightly with the hammer to remove the body.
- Find a convenient position of the rotor to remove the bearing. Clamp the vice again.
By placing a wooden bar, the bearing is knocked out. To remove the pinion from the gear axle
- The rotor is wrapped in rags and not secured by the jaws of the vice.
- Gear also wrap rags, using a gas wrench, turn it counterclockwise.
Drilling machine from a washing machine engine and a gearbox from an angle grinder
Materials and tools used by the creator:
The list of materials:- Motor from a washing machine 650W / 1350 speed,- Gearbox from the 180th angle grinder,- Angle,- Round pipes,- Sheet steel,- Bolts and nuts,- Springs,- Switch. Cable with a good insulation.
The manufacturing process of the drilling machine:
Step 1. Gearbox modificationFor the machine you need gearbox
from an angle grinder to 180, it lowers the speed of the motor more than thegearbox from 125 angle grinder, as a consequence, we get the highest torque, and the axle in such a gearbox is thicker. The maker uses an angle grinder to cut off a piece of the armature and knock the rest of the armature off the axle. It’s also useful to cut off a piece of angle grinder body to screw this part with bearing bracket to the gearbox. If you do not have such a part, it can be welded from sheet steel, using a piece of pipe as a rim.
Step 3. BaseWe make the base for the drilling machine, it must be very strong, so that the entire structure will not fall off. You can use a suitable piece of channel as a base. If a channel is not available, it can be welded from thick sheet steel. To attach the machine to the base we weld on the lugs, for bolting it to the base.
Also, 4 stands, which can be pipes or iron bars, are welded to the base. Insert the bars into the carriage first, and then tack them to the base. This is the only way to install the uprights correctly.
Step Seven. Finishing touches and testsSet on the shaft of the gearbox drill chuck to screw in a chuck, you can weld a nut to it for angle grinder or cut the thread directly in the chuck.
Paint the frame so it does not rust, now the machine looks great. Set a smart isolator switch to swiftly switch off the machine in case of emergency. The machine is ready, the creator put in a chuck a huge drill bit and drills with his monster of all in succession, from timber beams, and ending with a thick sheet steel.
The machine is great, a machine for the real man. At this point the project is over, I hope you liked the do-it-yourself machine, and you found some useful thoughts. Good luck and inspiration, if you decide to repeat a similar one. Do not forget to share with us your ideas and self-made!
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Angle grinder repair with your own hands. fixing typical malfunctions
The main principle in the repair of any electrical equipment is the postulate “move from simple to complex.
Whether it is a domestic electric cartridge or a turbine at a hydroelectric power plant. the repair sequence should exclude elementary faults in the first place. Electricity and electronics are called “the two sciences of contacts” for a reason. Typical malfunctions of bolt cutters, along with the methods of their elimination are as follows:
- The tool suddenly stops beeping. With 90% probability, you can conclude that the current from the socket does not reach the electric brushes. In other words, the problem is either in the power plug, the cord itself, or in the mechanism of the start button. It is enough to disassemble the housing and “test” the cable with an ordinary tester for breaks. very often it is enough to replace the wire, and the angle grinder will work like new;
- The wire and plug are guaranteed intact and the tool is still immobilized? It is necessary to disassemble the starting mechanism, and it is desirable to mark the removable contacts. if you later connect them incorrectly, it can burn out the winding or jam the armature. It is possible to replace the starting button on any similar, working parameters are marked on it quite legibly;
- The start button and power cord are in good working order but the angle grinder does not want to work? It’s time to take care of the brush holders. Very often it is enough to clean the contact plates on the collector, and there is a long-awaited spark and a steady humming of the mechanism. If it is not, you need to replace the brushes. The service life of these devices is usually limited to several years. Some models of lathes are produced with soldered connection of electric brushes, solder and put new ones in a set, their partial replacement is not allowed;
- After replacement, carefully inspect the old electric brushes. if they have uneven wear, it is a clear sign of a shift in the center of gravity of the tool or its movable inner part. It is better to apply to a specialized firm for repair of complex electrical equipment. you can hardly adjust the balance yourself without experience.
Brush replacement is the “top of the first tier” when troubleshooting electric grinders on your own. You can and further describe repair recommendations, how to disassemble the reducer of angle grinder, to rewind its winding or reconfigure the electronic stuffing. But serious breakdowns require a serious approach to work. If you have never seen the gearbox, how can you repair it?? The chance to turn on the angle grinder depends on your common sense. saving on professional repair will cost you the entire tool.