Self-repair of the electric drill

The drill is widely recognized as a favorite tool among home DIY enthusiasts and is utilized in a variety of tasks. With extensive use, however, the drill’s components are susceptible to breakage, rendering the device inoperable. There’s no need to immediately seek assistance at a service center, as it is entirely feasible to fix the drill on your own and save a significant amount of money in the process.

Layout of parts

If you understand how the drill works and know its device, then repairing the product on your own will not be difficult. Regardless of the model or manufacturer, all these electric tools are composed of a standard set of basic components.

1. Power cord . Many users do not give proper attention to the cord that connects the tool to the power supply, but, according to statistics, 50% of electrical product malfunctions occur because of it. The cord can easily break during operation, with common breakage points being at the entrance to the device handle and at the soldered contacts on the power button. This defect often occurs due to the constant movement of the entire button assembly.
2. Capacitor. This small rectangular part is situated in the drill’s handle and is designed to reduce the interference caused by sparking.
3. Power button. One of the most vulnerable components – if there are any electrical issues with the device, this part is checked right after the cable.
4. Stator of the electric motor. In case of a short circuit, the winding can break down – a very unpleasant scenario that requires rewinding the entire coil. Inside the stator is the rotor or armature.
5. Armature bearing.
6. Motor brush assemblies. The brushes are made of durable graphite and wear out over time, which can lead to electrical malfunctions – during normal operation, each brush produces sparks. Common issues include dust accumulation between the brush and the rotor.
7. Product enclosure.
8. Fan. It is specifically designed to constantly cool the motor of the electric drill.
9. Mode selector.
10. Gearbox. It is always present in any model, as the chuck is not directly attached to the rotor axis.
11. The largest gear of the gearbox. Common issues include dust and foreign particles getting into the lubricant, causing it to lose its properties and the gearbox to wear out quickly and require replacement.
12. The two bearings of the chuck. They bear the heaviest load, so they require periodic inspection and maintenance – removal, cleaning, and grease replacement.
13. The shaft to which the chuck is attached. In drill-hammer models, it includes a return spring.
14. The chuck of the product has a collet mechanism that can quickly clamp the drill bit or various attachments, or be clamped with a special key.

When repairing the drill yourself, it is important to start with a visual inspection of all the parts. The approach here is simple – start with the simple things and move towards the complex. First, check the cord, wiring, contacts, and fasteners. Then, proceed to test the blocks and motor. In some cases, it may not be necessary to completely disassemble the product, but it’s always good to be prepared for such a possibility. Refer to the instruction manual for specific disassembly instructions for your model.

Frequently occurring breakdowns

Irrespective of the assembly quality and manufacturer, the following issues frequently occur:

• The electric motor fails due to armature or stator breakage;
• Excessive brush wear;
• Bearing problems;
• The speed control button malfunctions;
• The start button has contacts that are oxidized or burnt out;
• The chuck, which clamps the drill, breaks due to jaw wear.

If you choose to repair the electric drill yourself, it is important to diagnose and identify the fault first. Repairing the faulty part yourself is rare, as it is usually more practical to replace it with a new one.

Before you start taking apart the drill, it’s important to ensure that it’s disconnected from the power source. The disassembly process starts by removing the fasteners. After that, you can unscrew the screws and self-tapping screws, and remove the upper part of the device. All the components will remain in the lower part. The electrical circuitry of the drill is straightforward, so there’s no need to individually describe each element since everything is easy to understand intuitively.

Of course, when it comes to models featuring electronic adjustments, the repair process becomes considerably more complex. However, it is highly unlikely that you will be able to fix a drill with such components on your own. It is strongly advised to entrust the job to professionals at a reputable service center.

Connection cord

When power is lost after adjusting the product’s position, the issue is likely due to a broken wire in the cable. To troubleshoot, disconnect the drill from the power source and use a multimeter to check the cable. Alternatively, you can use a simple setup with a light bulb and battery in a circuit.

Important note: Never pull the cord while the drill is plugged in to prevent a short circuit and the need to replace the motor winding.

Power button

This particular component features a straightforward design; however, in the event of any malfunctions, it serves as a safeguard to prevent the drill from starting. Its operation is quite simple: a key is inserted into a specialized housing and a pusher mechanism is employed to close the contacts. Over time, dust tends to accumulate within the housing, obstructing the movement of the button and hindering its ability to establish proper contact. This issue can easily be resolved by opening up the component and removing the dust accumulation using a brush.

Important! Under no circumstances should you attempt to lubricate the sliding surfaces of the button. The combination of dust and lubricant can lead to the formation of a hazardous residue, necessitating the replacement of the entire unit.

In order to fix the drill button, you will have to take off the side wall and examine the condition of the contacts. If there is any soot buildup, make sure to carefully clean the contact with fine sandpaper. If the contact has been burnt, then it would be necessary to replace the entire unit.

Rotor brushes

Many users are unaware that electricity from the main power source is transferred to the rotor through the use of graphite brushes, which results in constant sparking between them and the rotor. On certain occasions, dust may accumulate between the armature and the brush, and since dust acts as an insulator, the drill will cease to function until the dust is removed and contact is restored.

The brushes gradually wear down over time due to regular use, specifically the lower part of the brushes. It is important to inspect and replace the brushes periodically, as it is a relatively simple task but requires having a new set of brushes on hand.

If you observe significant sparking near the brushes and you have recently replaced them, this may be indicative of issues with the rotor or its collector.

To perform a comprehensive inspection, diligently detach the rotor from the stator. It is possible that the contacts are burnt or covered with scale – diligently cleanse them with emery cloth, strictly following the rotational direction. The scale may have accumulated due to prolonged operation at high speeds. How can we assess the rotor’s functionality? Examine the adjacent lamellae using a multimeter – their resistance should be uniform.

Make sure to inspect the coil for any potential short circuits with the magnetic core housing. If you find any issues, you can either rewire the faulty coil yourself or bring it to a professional repair center.

Drill stator

It is important to carry out regular visual inspections. This is especially necessary if the product has experienced overheating or has been used at maximum loads, as the protective varnish may have melted, leading to an interturn short circuit. If this occurs, the winding will burn out and the motor will no longer be suitable for use. To check for this issue, the windings can be tested with a multimeter, in a similar way to checking the rotor. In the event of a breakdown, the stator winding will need to be rewound.

Leading manufacturers of impact drills prioritize the protection of winding wires as their products operate under unique conditions.

Mechanical damage

Is the device still not functioning despite checking everything and eliminating electrical circuit malfunctions in the drill? The only possible answer is that the product’s non-working condition is due to mechanical issues.

1. The bearings are not functioning. Dust is getting into the lubricant due to a burst packing, causing them to wear out quickly and potentially jam at some point. This can be easily fixed by washing the bearings in kerosene, replacing the oil seals, and filling them with new grease, preferably a special composition for high rotation speeds.
2. A broken gearbox is a severe issue that requires spare gears or a complete module replacement. Only the same model should be installed. If the drill is a commonly available version, purchasing spare parts for it should not be a problem.
3. One of the most challenging issues that experts identify is the malfunctioning of chuck parts.

During operation, drilling waste often accumulates in the inner part of the chuck and gets mixed with grease, causing the inner jaws to become jammed. It is necessary to disassemble the chuck, clean and lubricate all the parts before reassembling. If significant wear is observed, the affected part should be replaced, and if the base or sleeve is severely worn, the entire unit should be replaced.

We have provided an overview of common issues that can occur while using electric drills. It is important to remember that self-repair is often a more cost-effective solution compared to purchasing a new product.