How to make brushes for an angle grinder

With a gas wrench

This method is considered not entirely safe, since the stopper can be broken, although in most cases, it is possible to unscrew the nut. To avoid breaking the spindle lock, do not apply too much force to the gas wrench. Retainer is designed to withstand the force of a standard wrench.

An overly tightened flange can be unscrewed using 2 gas wrenches. To do this, break off the protruding ends of the abrasive wheel with pliers so that you can reach the bottom flange with the first gas wrench. Next, tighten both flanges with wrenches and turn them in opposite directions (taking into account which thread on the spindle is right or left).

Typical disc sizes

When choosing a disc for your angle grinder, make sure that the outer diameter of the attachment does not exceed the maximum allowable values ​​for your angle grinder. For example, if an angle grinder is designed to use a wheel with a maximum diameter of 125 mm, then a 230 mm wheel cannot be fitted to it. And there are several explanations for this:

  • the linear speed of the cutting edge will be exceeded, which is fraught with destruction of the abrasive wheel and injury to the user;
  • a small angle grinder does not have enough power to work with a large tool;
  • installing a nozzle that exceeds the permissible dimensions requires removing the protective cover, and this is already a violation of safety rules.

Angle grinder discs come in standard sizes 115, 125, 150, 180 and 230 mm. In modern angle grinders, the bore diameter (diameter of the shaft on which the tool is installed) is practically the same and equals 22.2 mm. If you have an obsolete angle grinder “lying around”, then you will need to use adapters – rings of different diameters.

2 Amazing Angle Grinder Attachments | DIY Tools

All abrasive wheels of any size have a special marking, from which you can find out the following information: the diameter of the disc and its thickness, the diameter of the seat, the maximum rotation speed, as well as for the processing of what materials it is intended.

Roughing

If it is necessary to remove a layer of paint or other application, as well as rust from any surface, use a brush. They are disc-shaped or in the form of a bowl with built-in metal wire.

The wire in these attachments can be twisted or loose. Its thickness can also be different. The thicker the wire, the coarser the roughing is used for the roughing disc or bowl, and vice versa..

Disassembly of the gearbox

In the event that the retainer is broken, you will have to disassemble the gearbox to remove the tool from the angle grinder. Use pliers to break off the edges of the remaining abrasive wheel so that you can get to the bolts holding the gear cover. After that, unscrew the fasteners and open the gearbox. The cover will be removed together with the pinion shaft. Further, this shaft should be clamped in a vice, having previously laid aluminum gaskets between the steel jaws, and unscrew the flange using a gas wrench (do not forget to determine the direction of unscrewing).

Sharpening

To sharpen the tool, grinding machines (sharpeners) are usually used. But if you do not have the latter, but you have an angle grinder, then you can purchase a sharpening (grinding) wheel for it, with which you can easily sharpen almost any cutting tool.

The main difference between sharpening wheels and cut-off wheels is their thickness (at least 5 mm).

Spinning methods if the disc is jammed

What to do if the hold-down flange is stuck? This nuisance, when the nut is bitten, often occurs if, while working with thick and durable materials, the tool is jammed in the workpiece. In this case, the abrasive wheel often breaks, and the spindle continuing to rotate tightly tightens the clamping flange. There are several ways to spin the angle grinder if the disc is jammed..

Cutting discs

The most common task performed with an angle grinder is cutting various materials. The choice of tool material also depends on what material needs to be cut..

  • Metal cutting. The metal cutting disc is made from crystalline alumina corundum, as well as from a synthetic corundum called fused alumina. The main color of wheels for cutting metals is blue.
  • Cutting stone and concrete. For cutting stone, you should choose a disc made of another abrasive material – silicon carbide. This abrasive cuts white brick (silicate) and slate with ease. But to cut red brick, some types of concrete or ceramic tiles, this circle material will not work. Stone discs are available in green.
  • Cutting ceramic tiles, red brick, porcelain stoneware and concrete. For these purposes, a diamond disc is already used. This nozzle is made of metal, an abrasive mass with diamond chips is applied to the cutting edge. The illustration above shows a segmented saw blade designed for dry cutting of material. All-metal discs require water cooling during operation.
  • Wood cutting. Although there are sawing wheels for wood on the market that are no different from circular saw blades, it is best to avoid using them for safety reasons. When working with such a tool, the user often receives serious injuries due to jamming, bouncing, accidental slipping of the tool, etc..
  • Therefore, if you are still going to use a saw blade for wood, then you should adhere to safety measures. The angle grinder must be fitted with a protective cover and handle, and the user must wear a face shield or goggles. In addition, you must not use this tool to cut materials that are not intended for it..

    The safest are considered to be discs for wood, along the end of which a chain from a chainsaw is installed. In the event of a tool jam, the chain stays in place and the disc rotates idle, reducing the likelihood of injury to the user.

    Using a penetrating lubricant

    Liberally spray the flange-to-shaft connection with WD-40 fluid. It tends to penetrate into inter-threaded spaces and small cracks. After applying the liquid, wait about 5 minutes and try to unscrew the fasteners with a standard wrench.

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    Do-it-yourself wall chaser from an angle grinder

    A groove is a groove that must be cut in a wall to lay an electrical wire or cable. The difficulty of this work lies in the fact that the groove must be of constant width and depth. Then the wire will fit evenly and less solution for the bookmark will be required.

    A wall chaser is rarely used in practice, so it will be expensive to buy it for a home. But it can be made on the basis of an angle grinder – our favorite angle grinder..

    The main task is to install two diamond discs on the shaft of an angle grinder with a distance of at least 1 cm:

    • install the first disk and fix it with a nut;
    • install the second disk and fix it with a nut;
    • measure the resulting distance between the disks;
    • we install protection on the angle grinder;
    • checking the work.

    But, if for some reason it is not possible to install two discs on the shaft, the strobe can also be cut by the usual method with one installed disc. You just have to cut a second parallel line.

    Work with a wall chaser is carried out indoors. This creates a huge amount of dust. Even a respirator does not save from it. To eliminate this negative phenomenon, it is necessary to make a protective casing that would cover both disks and have a branch pipe on top for connecting to a vacuum cleaner. There is a similar device on electric jigsaws for collecting small sawdust..
    Sometimes lovers of the rational use of the tool adapt 2 or 4 rotating rollers to this casing. When the chaser moves along the wall surface, it will move on rollers without creating additional loads on the hands.

    To make a tool for a wide groove, it is necessary to make special bushings for attaching discs to the desired width. With such a wall chaser, it will be possible to make grooves for pipe laying..

    But the protective casing will also need to be made wider. On the cover of the chaser for both wires and pipes, you must install a screw for adjusting the immersion of the cutting tool into the wall. In this case, the casing will consist of two parts connected by a hinge and a submersion adjustment unit..

    It will take

    Most of the materials and fixtures that we need for work can be found in the home workshop:

    • steel pipe and nut;
    • reducer from a faulty angle grinder;
    • steel strip;
    • U-shaped bracket;
    • bolts and washers;
    • pieces of round and square pipes;
    • pieces of wire.

    We will have to use: welding machine, angle grinder, wrenches, drill, vise, etc..

    Sliding gate drive

    The following video shows one of the options for a sliding gate drive based on a gearbox from a burnt-out angle grinder and an old screwdriver. The operator is equipped with an automatic device for controlling the opening / closing of the gate. A chain drive with a drive spindle on the gearbox spindle operates at high speeds to perform the gate control function, therefore, increased operating noise is generated.

    On a screwdriver

    The screwdriver, which the author of the following video uses, already has to work at maximum loads when threading on the M8. The use of a reduction gear from an angle grinder increases the amount of torque, and allows you to cut threads in more comfortable conditions. A burnt-out angle grinder is used here, where the rotor is cut to a length that at the same time allows you to securely fix the end from the cut shaft in the screwdriver chuck and tightly fit the plastic case of the angle grinder on it. For a more thorough connection, the screwdriver with the housing, the angle grinder is fastened with fasteners, while the gearbox bearing of the angle grinder fits into its seat. Drilling and tapping with prepared tooling for such work does not require any additional effort.

    For outboard motor

    The gear ratio of the angle grinder gearbox allows the propeller to give the required rpm for efficient operation. Electric motors from many household devices are suitable for the production of a homemade boat motor. In the following video, an electric motor powered by a car battery through a long shaft in a pipe and a gearbox connected to it transmits the rotation of the propeller.

    The angle grinder gearbox is not intended for work in the water element. It is imperative to revise it. Firstly, make a seal at the spindle outlet from the gearbox, and secondly, plug the place from where it is necessary to remove the fixing mechanism of the angle grinder from turning when changing the tool. Such measures do not guarantee 100% water penetration into the gearbox. However, a more frequent change of lubricant will make it possible to work with the gearbox of an angle grinder as a unit of a boat motor for a rather long time..

    Homemade products, what you can do with your own hands, where to adapt the gearbox

    A significant number of mechanisms operate at the number of shaft revolutions after the gearbox of the angle grinder. Therefore, there are more options for using the angle grinder for the operation of other devices. Together with non-standard ways of using a whole angle grinder for homemade products, the masters of technical creativity create interesting compositions. Some are presented by the authors in specially filmed videos.

    Signs of a malfunctioning mechanism

    In the process of using the angle grinder, it is impossible to avoid the ingress of small debris into the mechanism. This leads to the fact that a short circuit and overheating occurs in the area of ​​the copper plates. The rise in temperature causes the brushes to melt and burn. And as soon as the dimensions become close to the minimum specified by the manufacturer, the master may observe the following warning signs:

    • metal brushes on an angle grinder start to sparkle;
    • when working, the tool jerks or jerks;
    • if the brushes are heavily worn, a burning smell may appear.

    Some manufacturers of angle grinder use special types of safety brushes. They are equipped with a special device that controls their length. As soon as the parameters of the parts do not meet the requirements, it blocks the operation of the mechanism until the malfunction is eliminated. This measure helps to protect the entire tool from failure..

    How to make brushes for an angle grinder

    An angle grinder (or an angle grinder, abbreviated as an angle grinder) is an indispensable tool for construction and renovation work. The result of the loads during the operation of the device is the need to replace parts. If the repair is negligent, the entire mechanism can be damaged..

    Brushes need to be replaced especially often. Therefore, it is worth considering what is the cause of the breakdown. And how to change the brushes for an angle grinder.

    Brief content of the article:

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    Rules for replacing brushes in angle grinders from different manufacturers

    A wise craftsman will not wait for a tool to show signs of breakage. Since the replacement of brushes is part of the maintenance of the angle grinder, it will regularly clean the manifold for contamination and inspect these parts..

    It is worth remembering that manufacturers of brushes for an angle grinder always indicate the minimum size at which the product still retains its performance. This figure may differ slightly depending on the manufacturer..

    Most tool models offer two options for the location of the electric brushes. In the first case, they can be inside the handle. In the second option, the brushes are placed on the body. However, regardless of the location of these parts, in order to prevent it, it is worth disassembling the tool and lubricating all its components..

    Before starting the analysis of the angle grinder, you need to de-energize it. Then you need to disconnect the tips, inspect the holder. After removing the brushes themselves, a thorough check is required for mechanical damage, which will indicate wear, requiring replacement of the part.

    Here are examples of repair work on angle grinders from leading manufacturers:

    Repair of Interskol models begins with removing the stator cover, after which it is necessary to unscrew the screws from the holder. The minimum residual length of brushes on the mechanisms of this company cannot be less than 5 mm.

    On Bosch angle grinders, you just need to open the handle of the stator housing to remove the brushes. The device of this brand will not work with the length of the working brushes less than 8 mm.

    When you buy an angle grinder, you will find in-demand spare parts in the starter kit. From them you can decide which brushes to choose.

    How to choose brushes for your angle grinder

    New technologies involve the production of brushes by pressing carbonaceous material at high temperatures. This method increases the life of the parts due to less wear..

    There are several main types of this part:

    The most common are graphite brushes. For this, the main material from which the part is made is shaped. Then it is covered with a graphite layer and fired at temperatures from 2500 degrees. The result is a strong, durable connection that pays for the high cost..

    Carbon brushes are considered the cheapest and most short-lived option. Low indicators of wear resistance are formed due to the lack of heat treatment.

    The most reliable option is metal-graphite brushes. The composition of the coating, in addition to the carbonaceous material, includes copper with the addition of lead, tin or silver. Such parts are rarely purchased for household appliances due to the high price..

    To summarize, changing brushes is an important part of maintaining your angle grinder. Inattentiveness in this regard can lead to more serious damage, such as destruction of the armature collector plate. When replacing, it is important to properly disassemble and assemble the mechanism, along the way, lubricated its main components.

    When deciding which brush is better in a particular case, it is better to refer to the instructions or those passport of the device. If you have additional questions, it makes sense to seek advice from the service center..

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    How to make brushes for an angle grinder

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    Terms

    Anchor – a rotating element of an electric motor containing windings.
    The collector is the place at the anchor, to which all the windings are brought out. Looks like a row of plates isolated from each other.
    Stator – the stationary part of the electric motor containing windings.
    Brushes – carbon parallelepipeds supplying current to the collector.
    Gearbox – a mechanical device for transmitting rotation with changes in power and rotation speed.

    The most popular tool in everyday life after a drill is an angle grinder or, as it is often called, an angle grinder. The angle grinder is used for cutting metals, wood, concrete, grinding various surfaces, cutting openings, doors, niches. If there is an angle grinder, then it can always be used and it is especially offensive when it ceases to function normally, jerks, twitching, burning smell appear …

    the angle grinder is all arranged in the same way: an elongated body in which the engine and gearbox are located, a handle and a protective cover are screwed on the side.

    A sticker with initial data is located on the body of the angle grinder. Here you can find both the personal number of the angle grinder and the supply voltage – 230 V. This refers to the maximum permissible mains voltage. The frequency of the current in the network is 50 Hz. Consumption current – 5 A. Power consumed from the network – 1100 W, it is obtained as a product between voltage (220 V) and current (5 A) multipliers. The rotational speed of the disk installed on the angle grinder is 2800-11000 rpm. The armature itself rotates at a higher speed than the disc. Specifically on this angle grinder, step regulation of the rotation speed is possible. The disc mounted on the angle grinder has an outer diameter of 125 mm, the fastening nut of the disc has an M14 thread.

    A household tool designed for a phase voltage of 220 V has an armature winding and a stator winding. The transfer of energy from the network to the armature is carried out using graphite brushes. Mains voltage is applied to a switch, which is mechanically connected to the power button of the angle grinder. The stator winding consists of two halves that are not electrically connected. The armature winding consists of many windings, but at any given time, the brushes connect only two armature windings.

    When the angle grinder is turned on, the current is supplied to the input of half of the stator winding, the output of the stator winding is connected to the brush holder into which the brush is inserted with the help of a spring. The brush transfers current to half of the armature winding, on the other hand, the other brush receives current and through the brush holder transfers current to the other half of the stator winding. The current went in and out of the angle grinder. If the entire electrical circuit is in good working order, then the armature will begin to rotate..

    make, brushes, angle, grinder

    Reverse, i.e. the change in the direction of rotation of the disk can be carried out by interchanging the wires going to the brushes from the stator windings. Just disconnect the wires on the brushes and swap.

    At the end of the case of the angle grinder there is a red wheel for stepwise control of the armature rotation speed and a screw for removing the casing.

    make, brushes, angle, grinder

    In this type of angle grinder, the brushes themselves are located inside the case and there is no access to them, but the developers have simplified the replacement of the brushes when removing the casing. After unscrewing the screw, the plastic plate is removed and the outer casing moves towards the cord, exposing all the insides, including the brush holders.

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    The speed control mechanism is electronic. The entire circuit is filled with epoxy resin and only the speed control wheel and radiator are taken out. What’s hidden inside. the trade secret of the company. When the unit fails. the speed ceases to be regulated, but remains at the maximum level. In any case, you should not despair, but in series with an angle grinder, you can turn on the most ordinary dimmer. dimmer. It can be used to adjust the speed of any AC collector motor, the main thing is that the engine power does not exceed the dimmer power.

    On both sides of the body there are steel brush holders with springs in the form of a curled steel strip. The spring is needed to keep the brush pressed against the armature collector even with strong vibrations and heating of the armature itself.

    The spring presses the brush and as the brush is erased, the spring sinks lower and lower into the steel brush holder. Brushes wear off and shrink. When their length becomes insufficient, the angle grinder stops working. In expensive models, there is a spring inside the brush that pushes the brush away from the armature collector. In cheap models, the brushes are not supplied with a built-in spring.

    When choosing new brushes, it is better to contact the service centers of your specific manufacturer of the angle grinder. The fact is that just as a graphic artist chooses twenty different simple pencils with different softness, so manufacturers of an angle grinder specially develop brushes for a specific type of collector. If you use other brushes, for example from a generator for a VAZ, then the anchor will most likely burn out soon, but for the first time, such brushes will fit in as a solution to the problem..

    The power button of the angle grinder is a plastic box with a mechanical lever transmission. The box is bulky enough to assume that it commutes high turn-on currents and that the button goes not only into this equipment.

    The head of the angle grinder has a reducer that increases the rotational speed of the disc to 11,000 rpm. The stem of the gearbox on which the disc is put on contains a sheared washer, which firmly sits on the shaft and has a support pad with a rubber ring for seating the disc.

    Nearby there is a foot with cuts, which fixes the protective cover. For added safety, the protective flap can be slid and then locked. The foot is pressed down to the angle grinder and the flap is moved to the desired level, after which the foot is released and it fixes the flap.

    Nuts for fastening the disc are self-locking SDS and conventional with wrench holes.

    The gearbox is supported by four screws. If you unscrew them and open the cover carefully with a screwdriver, you will see the parts of the gearbox. The gear wheel on the armature shaft has a left-hand thread and is threaded to the armature shaft.

    The gearbox uses rolling bearings, i.e. ordinary bushings abundantly lubricated with grease. The teeth on the 1100 W model are straight, apparently this is quite enough for locksmith work, but in the 1500 W models gears with curved teeth are used.

    In order to remove the armature, gently remove the brushes, remove the gearbox and pull the armature out of the housing using the gear. At the other end of the armature, closest to the cord, a rolling bearing is put on, which is recessed into the plastic of the body. Pull firmly and carefully to remove the anchor..

    The anchor is a steel rod on which a steel cage made of plates is pressed. Coils of insulated copper wire are laid in the grooves of the cage. All the ends of the windings are brought out to the rear end of the armature, called the collector. At the front end of the armature is a gear for transmitting rotation.

    To gain in the force that needs to be applied to the disc for operation, a gear transmission is used. For a 2KW angle grinder, the armature gear has 10 teeth and the wheel gear has 41 teeth. It turns out that at a wheel speed of 8000 rpm, the armature rotates 8000X41 / 10 = 32800 rpm. If we take into account that the number of collector contact plates is 36, then 32800X36 / 60 = 19680 Hz. This is approximately the frequency that interferes with the network and to eliminate which ferrite rings are needed..

    The disc gear is located on the shaft. In production, the gear was heated and the shaft was cooled. After that, the gear was put on the shaft. The resulting connection is cheap, simple and practically does not make it possible to remove the gear without damaging the gearbox housing. Heating the assembled part will cause expansion of both the shaft and the gear. The only thing that can be used to remove the gear is a puller. In this case, the grips of the puller paws must be thin and strong enough to go into the small gap between the body and the gear.

    The shaft gear is threaded. Probably, the manufacturers calculated that the armature gear flies more often than the gear gear. On this model, the gears are helical to increase the power output.

    The gear has a RIGHT thread. To spin the gear, you need to wrap it with a rag so as not to break the teeth when unscrewing it, clamp it with a gas wrench and turn it COUNTER-CLOCKWISE.

    After removing the gear, it becomes clear that the thread is not made all the way through the height of the gear. but only in a small area. The section without thread allows you to put on the gear evenly, without distortions.

    Malfunction

    Cause

    Elimination

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    Manifold sparking, odor, body heat, pops

    Disassemble, get the anchor, clean the collector

    Angle grinder does not start

    Disassemble and replace both brushes

    Disassemble, replace the button

    Power cable defective

    Splicing the breakdown site and isolating

    Mechanical sound when rotating the disc

    Disassemble, replace the gear, lubricate with cyatin (grease, lithol)

    The disc is constantly gaining momentum and the angle grinder goes into gear

    Turning closure of stator windings angle grinder

    Disassemble, replace windings (if possible)