This study employs a Van de Graaff generator to drive both a standard electrostatic windmill and a custom aluminum windmill with adjustable parameters, including tip angle, rotor radius, and drag coefficient. Voltage, ion wind stability, and angular velocity were measured under varying operating conditions, and a governing equation of the rotational dynamics was established. Experimental results indicate that thrust increases with voltage and reaches a maximum at tip angles of 30–45°. Rotor radius influences the characteristic time and terminal angular velocity, while the drag coefficient alters the system behavior between exponential and hyperbolic tangent saturation. Potential applications in fine particle air purification are also discussed.