Does the commutator on the grinder pull an arc? We eliminate it with our own hands

The collector on the grinder pulls an arc. We fix it with our own hands.

As the angle grinder, and other power tools, wear out, sparking appears inside its body, which can be seen through the ventilation holes. If the problem is not corrected, the electric motor will quickly fail. You can eliminate sparking at home.

What you will need:

bearings;
new brushes.

The grinder maintenance process

It is necessary to unscrew the screws on the rear handle of the angle grinder and open it. After this, the sparking when turned on will be even more noticeable.

Immediately you need to remove the brushes and evaluate their wear.

Self-tapping screws are unscrewed from the gearbox side of the angle grinder to get to the rotor. This will allow you to inspect the removed manifold.

If it has a groove, then the lamellas will need to be sharpened, leveling their plane. In addition, carbon deposits are also important, so in any case it is necessary to sand the linings to a shine. Before work, you should check the armature and stator with a multimeter for short circuits in the windings. (Read how to do this with a regular multimeter here - https://neo.washerhouse.com/en/5260-polnaja-proverka-rotora-jelektrodvigatelja.html)

Next, you need to disassemble the gearbox to remove the armature with the bearing.

There is a nut and a locknut on its shaft that must be unscrewed.

Then it is knocked out from the gearbox housing with a plate. If it doesn't come out, you need to drill through the impeller and get to the two screws located behind it. If you unscrew them, the rotor will come out of the housing.