How to maintain and repair second-hand electric impact drills?

Understanding Electric Impact Drills

Key Components of an Electric Impact Drill

1. Motor: The heart of the impact drill, the motor converts electrical energy into mechanical energy to drive the drill bit or driver bit. Electric impact drills typically use either brushed or brushless motors. Brushed motors are more common and less expensive but have a shorter lifespan and require more maintenance. Brushless motors, on the other hand, are more efficient, have a longer lifespan, and generate less heat, but they are usually more expensive.
2. Gearbox: The gearbox reduces the speed of the motor and increases the torque, allowing the impact drill to generate the necessary force to drive screws and drill holes. Different gear ratios can be used to provide different levels of speed and torque, depending on the application.
3. Impact Mechanism: The impact mechanism is what sets an impact drill apart from a regular drill. It consists of a hammer and an anvil. When the drill is in use, the hammer strikes the anvil, delivering a series of high-force impacts that help to break up the material being drilled or driven, reducing the resistance and making the job easier.
4. Chuck: The chuck is used to hold the drill bit or driver bit in place. There are two main types of chucks: keyed chucks and keyless chucks. Keyed chucks require a chuck key to tighten and loosen the jaws, while keyless chucks can be tightened and loosened by hand, providing quick and easy bit changes.
5. Trigger and Speed Control: The trigger controls the power and speed of the impact drill. Squeezing the trigger more firmly increases the speed, while releasing it reduces the speed. Some impact drills also have a variable speed control dial that allows you to set a specific speed for more precise control.
6. Clutch: The clutch is used to prevent the drill from over-tightening screws, which can strip the screw heads or damage the material. When the set torque is reached, the clutch disengages, allowing the drill to continue spinning without applying additional torque.

Popular Brands and Models of Electric Impact Drills

DeWalt

1. DeWalt DCF880C2 20V MAX XR Lithium-Ion Cordless Impact Driver: This is a highly popular model among professionals and DIYers alike. It features a brushless motor for increased efficiency and longer tool life. With a high torque output of up to 1,400 in-lbs, it can handle a wide range of fastening and drilling tasks. The 18+1 clutch settings allow for precise control over the torque, reducing the risk of over-tightening. It also has a compact and lightweight design, making it easy to maneuver in tight spaces. The 20V MAX XR battery provides extended runtime, and the tool comes with two batteries and a charger.
2. DeWalt DCD996P2 20V MAX XR Lithium-Ion Cordless Hammer Drill/Driver: This combination drill/driver is a workhorse. It has a powerful brushless motor that delivers up to 570 unit watts out (UWO), providing excellent performance for heavy-duty drilling and driving applications. The three-speed transmission allows you to select the appropriate speed and torque for different materials and tasks. The all-metal gearbox ensures durability and reliability. It also features a high-strength aluminum housing for added protection and a built-in LED work light to illuminate the work area.

Milwaukee

1. Milwaukee M18 Fuel 2753-22XC High Torque Impact Wrench: Although primarily an impact wrench, it can also be used for many impact drilling tasks. It is part of Milwaukee’s M18 Fuel line, which features a brushless motor for maximum efficiency and power. With a torque output of up to 1,000 ft-lbs, it can easily remove and install large bolts and nuts. The friction ring anvil provides quick and easy socket changes. The REDLINK PLUS intelligence system protects the tool and battery from overloads, overheating, and over-discharging. It comes with two high-capacity XC batteries and a rapid charger.
2. Milwaukee M18 Fuel 2606-22XC Hammer Drill/Driver: This cordless hammer drill/driver is known for its outstanding performance. The brushless motor delivers up to 700 UWO, making it suitable for tough drilling and driving jobs. It has a four-mode drive system that allows you to switch between drilling, hammer drilling, driving, and self-tapping modes. The all-metal transmission and durable housing ensure long-lasting use. The tool also features a bright LED work light and an ergonomic design for comfortable operation.

Makita

1. Makita XDT16Z 18V LXT Lithium-Ion Cordless Impact Driver: This impact driver offers a high level of performance and reliability. It has a powerful motor that delivers up to 1,460 in-lbs of torque, enabling it to handle even the most demanding fastening tasks. The variable speed trigger and two-speed transmission provide precise control over the speed and torque. The compact and lightweight design makes it easy to handle in various work situations. It is part of Makita’s LXT series, which is known for its long battery life and fast charging times.
2. Makita HR181Z 18V LXT Lithium-Ion Cordless Rotary Hammer Drill: This rotary hammer drill is a great choice for heavy-duty drilling in concrete, masonry, and other hard materials. It features a powerful motor and a hammering mechanism that delivers up to 4,800 impacts per minute. The three-mode operation (rotation only, hammering with rotation, and chiseling) provides versatility for different applications. The tool also has a built-in LED work light and an anti-vibration handle for comfortable operation.

Maintenance of Second-Hand Electric Impact Drills

Regular Cleaning

1. Exterior Cleaning: After each use, use a clean, dry cloth to wipe the exterior of the impact drill to remove dust, debris, and dirt. This helps to prevent the build-up of contaminants that can enter the tool and cause damage. For more stubborn dirt, you can use a mild detergent and a soft brush, but make sure to dry the tool thoroughly afterward to prevent rusting.
2. Chuck Cleaning: The chuck can accumulate metal shavings, dirt, and debris, which can affect its performance and the grip on the drill bits. Use a small brush or compressed air to clean the inside of the chuck. If there are any stuck particles, you can use a thin tool, such as a dental pick, to carefully remove them. Avoid using excessive force, as this can damage the chuck.
3. Air Vents Cleaning: Most electric impact drills have air vents to dissipate heat generated by the motor. Over time, these vents can become clogged with dust, reducing the cooling efficiency of the tool. Use a can of compressed air to blow out the dust from the air vents. Make sure to hold the can upright and keep it at a safe distance from the tool to avoid damaging the internal components.

Lubrication

1. Gearbox Lubrication: The gearbox of an impact drill contains gears and bearings that need to be lubricated regularly to reduce friction and wear. Refer to the manufacturer’s manual for the recommended lubricant and the lubrication intervals. Typically, you need to open the gearbox cover (if possible) and apply a small amount of high-quality grease to the gears and bearings. Be careful not to over-lubricate, as excess grease can attract dirt and debris.
2. Impact Mechanism Lubrication: The impact mechanism also requires lubrication to ensure smooth operation. Some impact drills have a dedicated lubrication port for the impact mechanism. If your drill has one, use the recommended lubricant and follow the instructions in the manual to lubricate the mechanism. If there is no dedicated port, you may need to disassemble the tool (which is more complex and should only be done if you have the necessary skills and experience) to lubricate the relevant components.

Battery Maintenance (for cordless models)

1. Charging: Always use the charger that came with the impact drill or a compatible charger recommended by the manufacturer. Overcharging or using an incorrect charger can damage the battery. Avoid charging the battery in extreme temperatures, as this can also affect its performance and lifespan. Charge the battery fully before the first use and recharge it when the battery level is low. However, don’t let the battery discharge completely before recharging, as this can also shorten its lifespan.
2. Storage: If you’re not going to use the cordless impact drill for an extended period, it’s important to store the battery properly. Charge the battery to about 50% – 80% of its capacity and store it in a cool, dry place. Avoid storing the battery in direct sunlight or near heat sources. Recharge the battery every few months to prevent it from self-discharging too much.
3. Battery Inspection: Regularly inspect the battery for any signs of damage, such as cracks, swelling, or leakage. If you notice any of these issues, stop using the battery immediately and replace it. A damaged battery can be dangerous and may cause a fire or explosion.

Checking and Tightening Fasteners

Common Issues and Troubleshooting

The Drill Doesn’t Start

1. Power Source Issue: If it’s a corded drill, check the power cord for any signs of damage, such as cuts, frays, or exposed wires. Plug the drill into a different electrical outlet to see if the problem is with the outlet. For cordless drills, make sure the battery is properly inserted and charged. Try using a different battery if available to rule out a battery issue.
2. Switch Problem: The power switch may be faulty. Inspect the switch for any visible damage or signs of wear. If the switch appears to be damaged, it may need to be replaced. You can test the switch using a multimeter to check for continuity. If there is no continuity when the switch is in the “on” position, it’s likely defective.
3. Motor Issue: A damaged or burned-out motor can cause the drill not to start. If you suspect a motor problem, you may need to disassemble the drill (following the manufacturer’s instructions) to inspect the motor. Look for signs of overheating, such as a burnt smell or discolored windings. If the motor is damaged, it may need to be repaired or replaced by a professional.

The Drill Runs but Lacks Power

1. Battery Issue (for cordless models): A weak or partially discharged battery can cause a cordless drill to lack power. Try charging the battery fully or using a different fully charged battery. If the problem persists, the battery may be worn out and need to be replaced.
2. Gearbox Problem: Worn gears or low lubrication in the gearbox can reduce the power output of the drill. Check the gearbox for any signs of wear, such as damaged teeth or excessive play. If the gears are worn, they may need to be replaced. Also, make sure the gearbox is properly lubricated as described in the maintenance section.
3. Clutch Setting: If the clutch is set too low, the drill may not be able to deliver enough torque. Check the clutch setting and adjust it to a higher setting if necessary, depending on the task at hand.

Excessive Vibration

1. Worn Impact Mechanism: The hammer and anvil in the impact mechanism can wear out over time, causing excessive vibration. Inspect the impact mechanism for any signs of wear, such as damaged surfaces or excessive play. If the components are worn, they may need to be replaced.
2. Loose Components: Loose screws, bolts, or other components inside the drill can cause vibration. Check all the fasteners and tighten any that are loose. Also, check for any loose internal parts, such as the motor mount or gearbox housing, and secure them if necessary.
3. Unbalanced Drill Bit: An unbalanced or damaged drill bit can also cause vibration. Inspect the drill bit for any signs of damage, such as bent shanks or chipped tips. Replace any damaged drill bits with new, balanced ones.

Overheating

1. Overuse: Using the impact drill continuously for long periods without giving it a break can cause it to overheat. If you’re working on a large project, take regular breaks to allow the drill to cool down. Follow the manufacturer’s recommended duty cycle for continuous use.
2. Clogged Air Vents: As mentioned earlier, clogged air vents can prevent the drill from dissipating heat properly. Clean the air vents regularly to ensure good airflow and prevent overheating.
3. Motor Problem: A malfunctioning motor can generate excessive heat. If the drill is overheating even when used within the recommended limits and the air vents are clean, there may be an issue with the motor. It’s best to have a professional inspect and repair the motor if necessary.

Repairing Second-Hand Electric Impact Drills

Replacing the Battery (for cordless models)

1. Safety First: Before starting any repair work, make sure the drill is unplugged (for corded models) or the battery is removed (for cordless models) to avoid the risk of electric shock.
2. Locate the Battery Compartment: On most cordless impact drills, the battery compartment is located at the bottom or back of the tool. Open the battery compartment cover according to the manufacturer’s instructions. This may involve sliding a latch, pressing a button, or removing a screw.
3. Remove the Old Battery: Gently pull the old battery out of the compartment. Some batteries may be held in place by a locking mechanism. If so, release the lock before removing the battery.
4. Install the New Battery: Insert the new battery into the compartment, making sure it is properly aligned and seated. Push the battery in until it clicks into place or the locking mechanism engages.
5. Close the Battery Compartment: Replace the battery compartment cover and secure it according to the original method.

Replacing the Power Switch

1. Disassemble the Drill: Refer to the manufacturer’s manual to carefully disassemble the drill to access the power switch. This usually involves removing screws from the housing and separating the different parts of the drill. Be sure to keep track of all the screws and small parts to avoid losing them.
2. Remove the Old Switch: Once you have access to the power switch, disconnect the wires connected to it. The wires are usually attached to the switch using terminals or connectors. Use a screwdriver or pliers to carefully remove the wires. Then, remove the screws or clips that hold the switch in place and take out the old switch.
3. Install the New Switch: Place the new power switch in the same position as the old one and secure it with the screws or clips. Reconnect the wires to the appropriate terminals on the new switch, making sure to match the correct wire colors or markings.
4. Reassemble the Drill: After installing the new switch, carefully reassemble the drill in the reverse order of disassembly. Make sure all the parts are properly aligned and tightened.
5. Test the Drill: Before using the drill for actual work, plug it in (for corded models) or insert the battery (for cordless models) and test the power switch to make sure it works properly.

Replacing the Chuck

1. Remove the Old Chuck: First, remove the drill bit from the chuck. Then, if it’s a keyed chuck, use the chuck key to loosen the jaws as much as possible. For keyless chucks, use a pair of pliers or a chuck removal tool (if available) to hold the chuck body and turn the chuck nut counterclockwise to remove it. Some chucks may also be held in place by a retaining clip or screw. If so, remove the clip or screw first.
2. Install the New Chuck: Place the new chuck on the drill’s spindle, making sure it is properly aligned. If there is a retaining clip or screw, install it to secure the chuck. For keyless chucks, tighten the chuck nut clockwise until it is snug. For keyed chucks, use the chuck key to tighten the jaws slightly.
3. Test the Chuck: Insert a drill bit into the new chuck and tighten the jaws. Try to pull the bit out to make sure the chuck has a good grip. Also, rotate the bit by hand to check for smooth operation.

Repairing the Impact Mechanism

1. Disassemble the Drill: To access the impact mechanism, you’ll need to disassemble the drill further. This is a more complex process and may require specialized tools. Follow the manufacturer’s detailed instructions carefully. You may need to remove the gearbox, motor, and other internal components to reach the impact mechanism.
2. Inspect the Impact Mechanism Components: Once you have access to the hammer, anvil, and other related components, inspect them for wear, damage, or excessive play. Look for signs of cracks, chips, or uneven surfaces. If any components are damaged, they will need to be replaced.
3. Replace Damaged Components: Order the replacement parts from the manufacturer or a reliable supplier. Make sure the parts are compatible with your specific impact drill model. Install the new components, following the proper assembly procedures. Pay attention to the alignment and orientation of the parts to ensure the impact mechanism works correctly.
4. Reassemble and Test: After replacing the components, reassemble the drill in the reverse order of disassembly. Make sure all the parts are properly lubricated as described in the maintenance section. Once reassembled, test the impact drill to see if the impact mechanism is working properly. Check for the correct amount of impact force and smooth operation.