How to grind the brushes of a washing machine motor

The washing machine's collector motor is reliable and simple in design, but it periodically needs repair. This mainly concerns replacing the electric brushes - they need to be replaced with new ones every few years. Otherwise, the engine starts to spark, overheat and fail. Before replacing, it is necessary to grind the brushes of the washing machine's electric motor. How to do this and why - let's look at it in more detail.

Options for fitting brushes

New brushes have long carbon tips, which are best "adjusted" to the washing machine's motor in advance. There are several ways to grind the "carbons" . The choice depends on the type of motor installed in the machine, the user's preferences and the available tools. The first "adjustment" option is the most common. The instructions are as follows:

• Use a file and coarse-grained sandpaper to sand down the electric brushes, adjusting the size of the tips to the engine,
• Fix the rods on the engine,
• Place a piece of sanding glass paper under the brushes (it is fixed with the working side to the coals over the entire surface of the motor),
• Manually adjust the anchor so that the paper touches the electric brushes,
• Clean the collector from coal dust (with a dry cloth, ideally with an air flow),
• Start the mechanism with a load of no more than 30% of the operating capacity,
• Remove dust from the engine body again with compressed air (otherwise there is a risk of the mechanism short-circuiting).

In the second method, the adjustment of the electric brushes is carried out using a strip of glass sandpaper. It is wound on the engine and securely fixed to the body. After that, the carbon rods are inserted into the cases and rotated around the fixed anchor. It is important to maintain the direction in which the mechanism rotates in the generator.

There is a third option for lapping: place the sandpaper with the grain side up on the motor and run it over the housing 2-3 times. At the same time, press the carbon brushes to the canvas. The adjustment is complete when the rods lie flat on the collector. Be sure to pay attention to the size of the sandpaper - it should be wider than the carbons.

Why is this necessary?

Adjustment of the electric brushes is required both when installing new rods to replace worn ones, and in case of uneven wear or incorrect bevelling of the carbon tips. This is necessary for the engine to work properly, without sparking, noise and vibration. Otherwise, a short circuit or other motor failure is possible.

In order to replace the brushes in time, you need to regularly diagnose the motor. First, evaluate the length of the carbon tips. Second, measure the elasticity of the spring mechanism in the cases. The springs are checked using a lever dynamometer. If the clamps are not elastic enough, the rods vibrate more strongly, and the engine fails faster.

An important nuance is to choose the right electric brushes. They must match the brand of the collector, rotate freely on the axis and fit tightly to the motor body.

How can you tell if the brushes are not worn in?

Lapping in of brushes is a mandatory procedure when replacing them. If the carbon rods are not adjusted or are adjusted incorrectly, the engine will operate with failures. Thus, the following "symptoms" indicate insufficient adjustment:

• Sparking,
• Uncharacteristic hum,
• Overheating of the mechanism,
• Increased vibration of the machine.

When lapping is done correctly, uniform voltage distribution is ensured across the working surfaces. Due to the latter, the engine works quieter and better, the power improves, and the service life of the mechanism increases. You can deal with the electric brushes yourself, without resorting to the help of specialists. The main thing is to strictly follow the instructions and observe safety regulations.