What Is a Waterproof Servo?
A waterproof servo refers to a type of servo motor designed with waterproof specifications.
Products conforming to the full waterproof (IP67) standard are equipped with thorough dust and waterproof performance, enabling usage not only underwater but also in harsh environments such as contaminated water, oil, and spray painting.
Uses of Waterproof Servo
Waterproof servos, much like standard servo motors, can be applied in various industrial settings, including production lines, measurement devices, medical equipment, as well as unmanned aerial vehicles (UAVs), and radio-controlled models.
In industrial and commercial applications, even if submersion is not the primary use, waterproof servos are preferred as a precautionary measure in case of water exposure. Especially IP67-rated fully waterproof products exhibit high dust resistance, making them particularly effective in industrial applications where durability and environmental resilience are crucial.
Specific application examples include:
- Various industrial machinery
- Steering components in UAVs and UGVs
- Robots (industrial and research applications)
- Industrial unmanned vehicles such as helicopters, drones, and boats
- Outdoor facility unlocking mechanisms
- Production equipment
Another specific application of waterproof servos is in hobbyist settings, such as radio-controlled machines used in water environments like boats. They are widely used not only in clearly water-centric RC models like boats but also in various other applications. Examples of applications in electronics and RC include:
- RC boats of various scales (EP, GP)
- Seaplanes and RC airplanes of various scales
- RC cars of various scales (1/10, 1/8, 1/5, 1/4 on-road cars, off-road cars, giant-scale cars, EP cars, 1/10 GP cars)
- RC helicopters of various scales (30-90 class GP helicopters, 600 class EP helicopters, giant-scale helicopters)
- Robots and drones
Principles of Waterproof Servo
1. Operating Principles
Waterproof servos use various types of motors, including brushless motors, coreless motors, 3-pole corded motors, and 5-pole carbon brush motors, to efficiently generate torque. Additionally, they come equipped with encoders, similar to regular servo motors, allowing feedback on motor displacement to the control unit.
Brushless motors eliminate mechanical contact parts like commutators and brushes, with electronic circuits taking over the role of the commutator. DC motors rotate the rotor with the movement of magnetic fields in the stator, and the switching of current in the winding is controlled by position sensor detection, ensuring rotation at the appropriate timing.
Coreless motors lack an iron core in the rotor. With a permanent magnet inside and a cup-shaped coil encased in resin outside the magnet, the coil rotates according to Fleming’s left-hand rule when current flows through it. The rotating coil is referred to as the rotor.
2. Waterproof and Dustproof Features
The indices representing the waterproof and dustproof performance of electronic devices are referred to as the IP (Ingress Protection) rating, internationally defined by the IEC (International Electrotechnical Commission), and adopted domestically by JIS (Japanese Industrial Standards).
The IP rating is expressed with two digits, where the first digit signifies dust protection, and the second digit indicates water protection. If only one of the protective features is specified, the other is denoted by ‘X’ (e.g., IP6X).
An IP67-rated waterproof servo is completely waterproof, with the dust protection level indicated by the “6” being the highest in the standard. It is dust-resistant, except for parts requiring protection, such as connection terminals; dust does not penetrate the internal components. The waterproof level “7” denotes immersion protection, ensuring performance is maintained even when submerged in water under specified pressure and time conditions.
The external casing of waterproof servos comes in various types, including full metal cases, engineering plastics, and combinations of engineering plastics with metal, all designed with a waterproof structure to meet specified protection standards.
Types of Waterproof Servos
Waterproof servos differ in rated torque, peak torque, rotation speed, and speed based on internal motor types, such as brushless motors, coreless motors, 3-pole corded motors, and 5-pole carbon brush motors, as well as varying applicable voltages.
Controller units also exhibit differences among products, particularly in models equipped with a 32-bit MCU (Microcontroller Unit) and 12-bit ADC (Analog-to-Digital Converter), enabling high resolution and fast response.
Control signals can be transmitted using PWM or TTL (half-duplex communication) command methods in many products. Some products even offer the ability to customize the operational feel and functions through a dedicated programmer.
When utilizing waterproof servos, careful consideration of each feature and specification is essential to select the one that best suits the intended application.