How to Pick An Anchor For Angle Grinder
Angle grinder in the house. Like a telephone connection. When it is serviceable, no one remembers it. Should a breakdown happen, the fact that one day can’t do without this tool immediately becomes apparent.
Self-repair of this useful electrical appliance is within the power of even a novice master. And for this you need to know what parts for grinders can and should be changed yourself.
To begin, consider the device angle grinder:
- Anchor. Internal movable engine component. Usually it is integral with the working shaft through which the rotation energy is transmitted to the gearbox.
- Collector. Patch plate anchors. Through its contacts, operating voltage is supplied from the brushes.
- Electric brushes. Contact elements pressed against collector plates.
- Stator. External winding of the motor, inside of which the armature rotates. Located along the inner contour of the tool body.
- Gearbox. A mechanical component that slows down the working shaft while increasing torque.
- Housing, handles for holding, start key, speed control, power cable.
A detailed description of what the angle grinder consists of
Usually one of the components fails, so the expression “angle grinder has broken” is in some ways illiterate.
And you can choose the right part even for a rare model. Most components are unified.
Self-alignment of angle grinders
Typically, breakdowns in an angle grinder are associated with the electrical part. Mechanics break down only with untimely maintenance (especially the lack of lubrication).
A malfunction is cheaper and easier to prevent when its first signs appear:
- Sparking inside the case, angle grinder, in the area of electric brushes;
- Fuzzy activation of the start key;
- Revolutions spontaneously change;
- The engine turns on. Turns off when the tool position in space changes;
- The angle grinder suddenly stopped working.
No matter how trite it may sound, first you need to check the voltage in the network and in the outlet, or extension cord, from which the power tool is powered. Then check that the power cable is working.
It is necessary to open the case of the angle grinder, and check the integrity of the supply wire visually and with the help of a tester. Having reliably connected the device contacts, bend the cable intensively, observing the indicator readings on the tester.
If a break is detected, replace the entire wire, or restore the fracture site using refractory solder. Then securely insulate the repair location with a heat shrink tube. Insulating tape for this case is not suitable.
If the cable is working, we proceed to typical fault No. 2. Most often, brushes burn on an angle grinder. To see the symptoms is quite simple. The angle grinder sparkles inside the case during operation.
Why do brushes burn in an angle grinder?
The attached figure clearly shows the electrical circuit and the device components of the electric motor.
Tool motor image
The angle grinder engine operates in extreme conditions. Despite the protection, dust gets inside, most often in the form of small metal filings. Metal. As you know, is a conductor.
When it enters the contact zone of the brushes and the collector, microclosures occur and the copper plates become very hot. Melting and mechanical bonding of collector contacts may occur.
Type of motor manifold to be repaired
In this case, the brushes overheat, and the working surface burns out intensively. Hence the sparks and increased wear. Another reason brushes sparkle is the ingress of fine sand and wood dust.
When the collector is contaminated with sawdust, the contact between the brushes and the collector is broken, and under intense load sparking occurs, with all the ensuing consequences.
Therefore, for prevention, it is necessary to periodically disassemble the case of an angle grinder and clean the dust from the collector. It is necessary to periodically purge the engine with an angle grinder.
This simple procedure will extend the life of both the brushes and the armature collector. It is advisable to vacuum the angle grinder after each dusty job, especially in the area of the ventilation openings.
How is the brush replaced with an angle grinder?
As a rule, brushes together with the spring block are located inside the handle of the tool. This design allows you to save on the production of the case, and make it more compact, and therefore convenient.
The brush holder is located in the tool handle
There are instances in which the mounting screws of the brushes are placed outside the housing. On the one hand, this allows inspection and replacement faster. However, it is better to change the brushes in combination with cleaning and lubricating the power tool, so the case will still have to be disassembled.
It is also advisable to remove the rotor from the stator, and measure the resistance of the windings. It should be the same.
We measure the resistance of the windings in the rotor
Then you should clean it from dust, grease the bearing and, if necessary, grind the collector contact plates with an emery or sandpaper. After this procedure, the grooves between the contacts must be cleaned with a hard brush from copper dust. A healthy collector should look like this:
Collector after thorough cleaning
Inspect the brushes, and if there are chips, cracks, or other signs of wear on them, replace them with new ones. Included is an angle grinder; a spare kit is often present when buying.
Do not take larger brushes in order to grind them under your seat. The material is very fragile, easily breaks.
Graphite brushes need to be selected individually. Parts may not fit another tool.
In this, the wizard shows the brush replacement sequence.
How to choose the right brush for the angle grinder?
In addition to the geometric shape and size, the brushes differ in the material from which they are made. Previously, this element was made in the form of a copper wire with a conductive brush at the end.
Hence the name. Of course, the resource of such products was not high, and they needed frequent replacement.
Modern brushes are made of carbon materials by high temperature pressing.
The engine resource is determined precisely by the longevity of these interchangeable elements, with a low quality of the current collector, the plates of the armature collector are quickly destroyed.
The following varieties of brushes:
Graphite brushes
Produced by their graphite bound by special substances. Sometimes soot is added to the mixture. After molding under pressure, the product is fired to give strength.
Graphite Electric Brushes
They are made from the same composition as ordinary graphite, but at the end of the process they are subjected to high-temperature processing in electric furnaces.
At a temperature of 2500 degrees, progressive carbon saturation occurs, giving the product additional strength and wear resistance.
Production costs are higher, but performance compensates for this shortcoming. The most common option for use in angle grinders.
Carbon brushes
The production material is almost the same, but the production technology is different. After pressing under high pressure, heat treatment is not performed. Reliability is lower, therefore, such products are used in less critical electrical appliances. Benefits. Low cost.
Metal brush
They are used in critical devices, for example, low-voltage generators. They are made on the basis of various metals: copper, tin, lead, babbit.
The same graphite is added to the mixture, but in smaller proportions. After molding. Heat treatment or firing at a temperature of 250 degrees.
High strength, resistant to aggressive liquids and gases.
Disadvantage. High cost, so they are practically not used in household electrical appliances.
The choice of brush for the angle grinder is determined by the manufacturer. Information can be found in the technical data sheet of the tool, or inquire at the service center.