Sudden stop. screwdriver In the middle of the work, it's a very unpleasant situation, but it's often remedial. If a tool stops rotating the cartridge, it hums but it doesn't rotate, or it's running with a noticeable loss of power, it's probably the heart of the car, the electric motor, that's out of order. Many users immediately send it to the service or buy a new one, unaware that they're not doing it. engine-change A procedure that is available even to a homeowner with a basic set of tools.
Self-repair allows not only to save a significant budget, but also to extend the life of your favorite tool, especially if we are talking about a high-quality model, where the cost of the engine is only part of the price of a new product. Before starting to disassemble, you need to clearly understand the type of installed engine: collector (brush) or brushless, as algorithm And the parts that you need will be different, and in this article, we'll go into detail about the process of diagnostics, component selection and step-by-step drive replacement.
Diagnostics of malfunction of the electric motor
The first step is always to make sure that the problem is in the engine, not the battery, the start button or the gearbox. Often the symptoms can be similar: the tool does not turn on or is working in jerks. collector You need a multimeter that's tuned to the resistance measurement mode (Omas), and the squirts are connected to the slats of the collector opposite each other; if the resistance is stable low and does not change when you turn the shaft, the winding is likely intact.
But visual inspection often gives you more information than measurements. graphite-brush: if they are worn to the limit or stuck in the holders, the motor will not work, and also a sign of fatal failure is blackening of the winding, the appearance of charcoal on the collector or the characteristic smell of burning, which is not to be confused with anything.
If the engine is brushless, the diagnostics are complicated because there are no brushes, and the control is done via an electronic board. In such cases, it is often not the motor itself that fails, but the controller, but if one of the sections of the stator winding is burned, then the engine is not the same as the stator. engine-repair It becomes economically inefficient and requires a complete replacement of the node.
⚠️ Warning: Before starting any diagnosis, be sure to remove the battery or disconnect the mains cord. Residual voltage in the control board capacitors can be dangerous even if the tool is turned off.
Sometimes the problem is not the electrician, but the mechanics: a jammed bearing or metal shavings that get inside can block the rotor. Check the ease of rotation of the shaft with your hand when the power is turned off - it should rotate freely, without jamming or extraneous sounds.
Required tools and choice of spare parts
Successful engine replacements require a minimum set of locksmiths that any home builder can find, and the key is to find the right new part, because you can't get it right. dimensions and the electrical specifications must strictly correspond to the original or acceptable analogues.
- 🔧 A set of screwdrivers (cross and flat) for opening the body and dismantling fasteners.
- 🔌 A soldering iron with solder and flux (or terminal clamps) for connecting the wires of the new motor.
- 🧹 A brush and solvent for cleaning the insides of the body from old lubricant and coal dust.
- 📏 A calibre for accurate measurement of the diameter and length of the engine.
When choosing a new engine, pay attention to the marking. For collector models, voltage (usually 12V, 14.4V, 18V) and type of shaft (the presence of a gear or a smooth shaft) are important. Makita or BoschIt is better to search for original parts by article, but there are universal Chinese analogues that require careful comparison of sizes.
Pay special attention to the type of shaft. On some models, the engine shaft is part of the rotor and not removable, on others, the gear is fixed with a locking ring or pin. Shaft diameter It should perfectly coincide with the landing place of the gear gear gear gear gear gear gear, otherwise there will be a backlash or jamming.
Where can I find the engine article?
The article is often printed directly on the metal body of the motor or on a white sticker. If the marking is erased, measure the length of the body (without the shaft), the diameter and length of the shaft, and the diameter of the engine itself. These four parameters are the key to finding an analog.
Step-by-step instructions for disassembling the screwdriver
The process of disassembly from different manufacturers may have its nuances, but the general logic remains the same. First, you need to unscrew all the visible screws on the case. Often one of the screws is hidden under a sticker or rubber lining in the handle area, so carefully inspect. hull from all sides.
Once the fastener is removed, the body consists of two halves connected by plastic latches. Don't use excessive force to separate them - use a thin plastic card or a special spatula, gently passing along the perimeter of the seam. A sharp jerk can break the latches, and then it will be impossible to assemble the tool back without gaps.
☑️ Preparation for disassembly
When the body is opened, you will see the internal layout: start button, engine, gearbox and cartridge. The engine is usually attached to the rear of the body or in a separate compartment of the gearbox. circuitry wires to the contacts.
In some models, for example, in the lines interscoll or dentureThe engine is inserted into a plastic glass inside the gearbox, and you need to carefully remove the entire gearbox to access the motor's fastener, and be careful about the little things like springs, balls and locking rings that can pop out when you disassemble them.
Dismantling the old engine and preparing for installation
Removing the engine is the most important step, which requires care. In collector models, the motor is either mounted with screws through the gearbox body or is tightly inserted into plastic slots with projections fixed. If the engine is held on the screws, just unscrew them. If it is clamped in a plastic case, carefully tuck it in with a screwdriver, trying not to damage it. plastic-wall.
The next step is to disconnect the wires. They can be soldered directly to the motor contacts or connected through connectors. If the wires are soldered, use a soldering iron and a tin suction to gently release the contacts. Don't pull the wires by force - the copper inside the insulation breaks easily, which will create problems when you connect a new unit.
Years of operation leave behind carbon dust from the brushes and old grease, which can cause short circuits or overheating. Use a brush and a degreaser to clean the area thoroughly. Also inspect the gear that sits on the motor shaft; if its teeth are worn along or chipped, replace it with the motor.
If the gear on the shaft of the engine is pressed and not removed, and the new engine comes with a smooth shaft, carefully heat the gear with a hairdryer to 100-120 degrees - this will expand the metal and allow you to remove it without damage.
It's important to check the condition of the bearing bushings in the gearbox body. If there's a backlash, the new engine will quickly fail or beating. If necessary, replace the bushings or add a little more. graphite-lubricant to reduce friction.
Installation of a new motor and assembly of tools
If the shaft is missing a gear, gently put on the old (or new one of the remixes) to make sure the teeth are in the right direction. Lock the gear with a locking ring or pin if the design provides for such a fastener. Make sure the shaft sits tightly and does not rotate under load.
Put the engine in the seat, observing the orientation of the contacts. Connect the wires: in collector engines, polarity is usually not critical for rotation (if you confuse it, the engine will spin in the opposite direction, which is solved by soldering the button wires), but it is better to follow the original scheme.
Assemble the gearbox and body, remembering to lubricate the gears with a special lubricant for the power tool. Before the final twisting of the screws of the case, conduct a test run without the lid (exercise care!).
| Parameter | Collector engine | Brushless engine |
|---|---|---|
| Presence of brushes | Yes (requires replacement) | No. |
| Sparkling. | Present (norm) | Missing. |
| Efficiency | 75-80% | 90-95% |
| Cost of replacement | Low. | High. |
| Difficulty of repair | Low. | High. |
The key to durability is not to overheat the tool, so let it cool down every 15 to 20 minutes of active work, especially when drilling hard materials, and that will prolong the life of the new engine.
Typical errors and precautions
When you make self-repair, you often make mistakes that make all the effort go away. One of the most common is using the wrong lubricant. Litol-24 Or solidol at high revs can thicken or, conversely, drain without providing protection. Use only specialized lubricants for power tools that withstand high speeds and loads.
Another mistake is ignoring the state of the start button, so if the contacts inside the button burn, the new engine will get intermittent power, which will cause it to fail quickly. Always check the resistance of the button and replace it or clean the contacts if necessary.
⚠️ Warning: Never use gasoline or aggressive solvents to degrease your contacts, which can melt plastic wire insulation or the body of a button. Use isopropyl alcohol or special contact cleaners.
It's also important to build the body properly. If the halves of the body don't fit tightly and there's a gap, dust and moisture will get in, which will quickly kill the new engine. Make sure that all the wires are stacked in their channels and not clamped by the screws of the body.
Frequently Asked Questions (FAQ)
Can I put a more powerful engine in the screwdriver?
Theoretically, it can, but it requires a deep modernization, a more powerful engine can consume more current, which will overheat the button, wires and battery, and may not match the overall dimensions, without replacing the electronics and strengthening the design, such modernization is risky.
Why does the new engine sparkle more than the old one?
A little sparkling on the manifold of the new engine is normal, it's a brush grinding process. If the sparks are blue and strong, maybe contaminated, the brushes are not tightly attached or the centering is broken. Let the tool work idle for 5-10 minutes.
Where to buy the original engine for a screwdriver?
Original parts are best ordered from the brand’s authorized service centers or on the official websites of manufacturers. Markets and brick-and-mortar stores often sell cheap, low-quality counterparts, whose resource is unpredictable.
What to do if the shaft of the new engine is thinner than the seat of the gear?
You can't use this engine, you can have a backlash and a beat, and you can try using a brass sleeve, but it's a temporary solution, so you'd better find an engine with the right diameter shaft, or order a gear for the existing shaft, if possible.