A UAV propulsion system combines the motor, electronic speed controller, propeller, power source and mounting structure. Maximum static thrust alone does not reveal efficiency, temperature rise, transient response or vibration risk. An integrated test bench synchronizes mechanical, electrical and vibration measurements for motor-propeller matching, ESC optimization, endurance evaluation and structural resonance analysis.

1. Parameters Measured

• Thrust and torque;

• Voltage, current and electrical input power;

• RPM and mechanical shaft power;

• Motor, propeller and total propulsion efficiency;

• Motor, ESC, connector and ambient temperature;

• X, Y and Z vibration for imbalance and resonance analysis.

2. Range and Mechanical Configuration

A small or medium UAV bench may be configured for approximately 30 kg thrust, 20 N·m torque, 5–65 V, 0–150 A and 30–15000 rpm. Heavy-lift UAV and distributed electric propulsion projects can be engineered for ranges up to approximately 1500 N thrust, 150 N·m torque and 500 A. The frame should provide high stiffness, an adjustable motor mount, propeller containment and adequate airflow clearance.

3. Sampling and Calibration

Thrust, torque, voltage, current and RPM must share one time base. Steady-state efficiency testing can use averaged data, while step response, ramp, sweep and vibration tests require higher sampling rates. Calibrate all measurement channels and perform a zero check before each test configuration.

4. Test Modes

1. Manual throttle testing;

2. Automatic step testing with stable averaging;

3. Ramp or sweep testing for efficiency and resonance peaks;

4. Constant-thrust closed-loop testing;

5. Endurance cycling and mission-profile replay.

5. Operating Procedure

1. Verify propeller type, rotation direction, fastener and maximum RPM;

2. Install the motor and check alignment, guard and emergency stop;

3. Run without a propeller to confirm direction and RPM sensing;

4. Install the propeller and perform a low-throttle trial;

5. Set current, RPM, thrust, temperature and vibration limits;

6. Run an automatic step test and generate performance curves;

7. Perform sweep, transient or endurance tests at critical points;

8. Save raw data, processed data, alarms and sample configuration.

6. Efficiency and Vibration Interpretation

Electrical power is calculated from voltage and current, while shaft power is calculated from torque and angular speed. Useful indicators include thrust per watt, thrust per ampere, motor efficiency, total efficiency and temperature rise. FFT analysis can identify rotational frequency, harmonics, blade-passing frequency and structural natural frequencies.

7. Automation and Python API

Professional software can support manual control, automatic step tests, ramp or sweep tests, endurance cycles, data export and report generation. A Python API allows users to create custom sequences, control CAN ESCs, read external sensors and replay flight missions.

8. Safety and Selection

High-speed propellers require enclosed guarding, remote operation, emergency stop, overspeed, overcurrent, overtemperature and excessive-vibration interlocks. Provide maximum propeller diameter, thrust, torque, voltage, current, RPM, test duration and automation requirements when selecting a system. Shenzhen LSKFT Testing Instruments Co., Ltd. can configure test benches for small UAVs, industrial drones, heavy-lift propulsion and distributed electric propulsion.