How to Replace a Drone Motor: A Step-by-Step Guide

 

Among all drone components, the motor is both essential and highly prone to wear. Although high-quality brushless motors can be used for hundreds of hours under normal conditions, you need to consider replacing the motor in the following situations:

 

1. Motor Fails to Start or Stalls

If you find that a motor cannot start, or sometimes turns and sometimes does not turn, or has obvious "stuttering" phenomena, it is likely that the internal winding is burned out or the control signal is abnormal. Replacement is usually the quickest solution.

 

2. Unstable or Off-Balance Flight

The decline in motor performance may lead to inconsistent thrust, causing flight drift, vibration, and even flight control failure. This is especially common in multi-rotor drones. Once the thrust of one axis is insufficient, the overall flight control balance will be broken.

 

3. Overheating or Unusual Noises

If the motor continues to heat up, emits irregular whistling or friction noises without being overloaded, it usually means that the bearings are aging, the magnets are demagnetized, or there is internal mechanical damage. In this case, the motor should be inspected or replaced as soon as possible.

 

4. Physical damage to the motor

After a crash or collision, obvious damage to the motor, such as a bent shaft, cracked casing, or broken wires, is a direct sign that the motor must be replaced.

 

5. Upgrades or Platform Modifications

Sometimes it is not the motor that is damaged, but the aircraft load, battery voltage, or the thrust, speed and other performance indicators need to be improved, and a more suitable new motor model needs to be replaced.

 

Before replacing a drone motor, being well prepared will not only improve operational efficiency, but also avoid unnecessary damage or safety hazards. The following are the necessary preparation steps before replacement:

 

1. Confirm Motor Specifications

First, confirm the model of the motor you want to replace, including:

KV value (determines the speed)

 

Supported voltage range (e.g., 4S, 6S)

 

Dimensions and mounting hole spacing

 

Shaft diameter and propeller compatibility

 

If upgrading for performance, compare key specs like thrust, power, and current to ensure compatibility and safety.

 

2. Prepare basic tools and accessories

Depending on the drone structure, you may need:

Phillips screwdriver (common M2/M3 screws)

 

Welding tools (soldering iron, solder wire)

 

Heat shrink tubing or electrical tape

 

Tweezers, small pliers and other auxiliary tools

 

Use anti-static tools whenever possible to avoid damaging sensitive electronics like ESCs or flight controllers.

 

3. Disconnect power and remove battery

Before replacing the motor, you must disconnect the main power supply and unplug the battery. Even if the drone is not powered, some ESCs may still have residual current, which may cause short circuit or burn out components.

 

4. Clean up the work area

It is recommended to perform the replacement operation on a clean and bright workbench to prevent small screws or motor wires from being lost, and use a magnetic tray to store parts when necessary.

 

Once the preparations are complete, you can begin the actual operation of replacing the motor. The following steps apply to most multi-rotor drones, including mainstream structures such as cross-country drones and aerial photography drones:

 

Step 1: Remove the propeller

Detach the propeller using a suitable tool or by carefully rotating it by hand.

 

Purpose: To prevent accidental rotation of the motor from injuring people. This is also the first step in standard operation.

 

Step 2: Disconnect the motor cables

According to the connection method between the motor and the ESC (welding or plug), remove the three motor phase wires;

 

If it is a soldered connection, use a soldering iron to heat it and then absorb the solder or pull it apart directly;

 

Remember the original wiring sequence and colors so that you can connect them correctly when installing the new motor.

 

Step 3: Unscrew and Remove the Motor

Use a screwdriver to remove the screws securing the motor to the frame.

 

Some racks may have vibration pads or mounting rings, be careful not to lose these small parts.

 

Step 4: Install the New Motor

Align the new motor with the mounting holes on the frame and tighten the fixing screws;

 

It is recommended to use thread glue (such as Loctite 243) to reinforce the screws appropriately to prevent them from loosening during flight.

 

Make sure the motor is installed flat to avoid tilting or scratching.

 

Step 5: Reconnect Motor Wires

Reconnect the three phase wires to the ESC. The order doesn't matter-just match the original setup.

 

If you find that the rotation direction is incorrect after replacing the motor, just swap any two phase wires;

 

If it is a solder connection, please use heat shrink tubing to protect the solder joints to avoid short circuits.

 

Step 6: Confirm the rotation direction

After power is applied, the rotation test is performed without installing the propeller;

 

Check whether the motor rotates clockwise or counterclockwise correctly through the flight control/ground station/ESC;

 

If there is any deviation, swap the phase lines or set the rotation direction through the software.

 

Step 7: Install the Propellers and Test Flight

Install the propeller in the correct direction;

 

Perform a brief takeoff test to check that the motors are running smoothly and that vibrations are normal.

 

Q1: What if the motor wires are connected in the wrong order?

It won't damage the system, but the motor may spin in the wrong direction, affecting flight control.

 

Solution: Swapping the positions of any two motor wires can change the direction of rotation.

 

Q2: What should I do if the thrust becomes smaller after replacing the motor?

Possible causes include:

The KV value or voltage adaptation range of the new motor does not match;

 

Incompatible propellers or overloads used;

 

The ESC is current limited or not calibrated.

 

It is recommended to confirm the motor parameters and refer to the maximum thrust and power of the original motor before making the selection.

 

Q3: Do the ESCs need to be recalibrated?

In general:

If you are just replacing the same model motor, it is not necessarily necessary;

 

If you replace a motor with a significantly different KV value/specification, it is recommended to recalibrate the ESC;

 

Especially in racing or load scenarios, more precise adjustments can avoid instability at the moment of takeoff.

 

Q4: Can the motor be replaced with a different brand or model?

Yes, provided the following parameters remain compatible:

The installation hole spacing is consistent with the rack;

 

The voltage range is consistent;

 

The thrust/power meets the flight requirements;

 

It is recommended to replace all motors on a quadcopter/hexacopter drone as a set to avoid unbalanced flight.

 

Q5: Is it necessary to use thread glue?

Highly recommended, especially for drones and long-duration flying platforms.

 

The motor screws are very easy to loosen under high-frequency vibration, which may cause thrust loss at the least and even fall off directly at the worst.

 

When replacing a drone motor, choosing the right model is more important than the replacement operation itself. The following points are what you must consider when choosing a motor:

Key factors in motor selection

Voltage Compatibility (Based on Battery Configuration)

The voltage range supported by the motor must match the drone battery. Otherwise, there may be insufficient thrust or the motor may overheat.

 

KV value selection

The higher the KV value, the faster the motor's no-load speed, which is suitable for light load and racing scenarios; the lower the KV value, the more suitable it is for high torque and heavy load platforms.

 

Thrust Output vs Load Requirement

Choose a motor with at least twice the aircraft's total weight in maximum thrust for optimal flight stability.

 

Structural dimensions and installation holes

Confirm whether the motor outer diameter, shaft diameter, screw hole spacing, etc. are compatible with the original frame.

 

Application scenario matching

Different flight missions have different requirements for motor response speed, efficiency, life, etc. When selecting a model, you must be clear about your drone application goals.

 

VSD UAV motor model full range recommendation

VSD offers a variety of high-performance brushless outer rotor motors, covering all application scenarios from lightweight drones to large multi-rotor platforms:

Model	KV value range	Voltage support	Maximum thrust	Recommended application scenarios
5315 Drone Motor	380KV	6S ~ 12S	9034g	Industrial-grade multi-rotor, large-load UAV
4720 Drone Motor	420KV	6S ~ 8S	7232g	Commercial aerial photography, multi-rotor flight platform
3115 Drone Motor	900 / 1050 / 1520KV	5S ~ 8S	4185g	Medium-sized aerial photography and mission drones
2808 Drone Motor	1300 / 1500 / 1950KV	6S	2910g	Medium-load aerial photography platform, multi-purpose aircraft
2812 Drone Motor	900KV	6S	2710g	Small and medium-sized platforms with high stability requirements
2807 Drone Motor	1350 / 1750KV	4S ~ 6S	2728g	High performance light payload aircraft
2306 Drone Motor	1800 / 1960 / 2400KV	4S ~ 6S	1683g	Cross-country drones, racing drones
2207 Drone Motor	1960KV	6S	1702g	High-speed FPV, competitive platform

 

Feel free to contact us for detailed manuals, technical consultation, or sample requests. VSD also offers KV customization, voltage tuning, and matching ESC recommendations. OEM/ODM services are available to meet a variety of drone project needs.