Waveshare Servo RSBL85-12 – 85kg·cm

The RSBL85-12 is a programmable RS485 serial servo motor with a locked-rotor torque of 85kg·cm. It features a full aluminum alloy case, a brushless motor, a steel gear box, a 360° high-precision magnetic encoder, and an external stainless steel primary multi-servo disk. The servo motor allows for programming to set any angle as the servo motor's middle position, enabling 360° controllable angles and multi-turn continuous rotation. It includes a built-in acceleration start/stop function for smoother movements.

Each servo motor has two interfaces, allowing multiple servo motors to be connected in series. Theoretically, up to 253 servo motors can be controlled simultaneously, with each servo motor capable of reporting its current angle, load, voltage, mode, and other information. This servo motor is suitable for robotic arm projects, hexapod robots, humanoid robots, wheeled robots, and other robot applications requiring closed-loop control, easily handling heavy loads. Additionally, Waveshare provides a robotic arm model for this servo motor. You can download the open-source structure model and engineering files from the "Resource" section of the Wiki page.

Key features

• Can be used in series, controlling up to 253 servo motors simultaneously (provided sufficient power supply) and obtaining feedback information from each servo motor
• 360° magnetic encoder allows for a wider range of angle control
• High precision with angle control accuracy reaching 360°/4096
• Any angle can be set as the servo motor's middle position, making assembly more convenient
• Acceleration start/stop function provides smoother movement
• Compact structural design and more nice-looking appearance
• High torque, RSBL85-12 reaches up to 85kg·cm at 12V respectively.
• Programmable working modes: servo mode for angle control or motor mode for continuous rotation

Brushless motor & steel gear box

To ensure the strength and durability of servo motor power transmission.

High precision 360° magnetic encoder

Adopts 12-bit high-precision magnetic encoding angle sensor. Compared with the carbon film potentiometer, the angle of the magnetic encoder is enlarged to 360°, and the resolution is increased by 4 times. Since there is a gap and no friction between the magnetic encoder and the radial magnet, the lifetime of the servo is effectively extended.

Small size, large torque

Up to 85kg·cm torque on typical voltage, suitable for building quadruped robots, hexapod walkers, robotic arms and other robotic projects requiring multiple motors.

UART serial bus control

Up to 253 servo motors controlling at the same time, with simple wiring, reducing the occupation of the serial port. Note: though one channel UART can control up to 253 servo motors, due to the high power of the motors, it is necessary to consider whether the power supply solution is enough when using too many motors.

Acceleration start-stop function

The speed and acceleration values are settable to make the motion effect softer and reduce impact from inertia.

Technical data

Aluminum alloy case & CNC processing

To improve the heat tolerance, size stability, rigidity, and mechanical performance of the case.

One button to calibrate the middle position

360° installation at any position, one button to set the current position as middle position. Easy to install and debug.

Closed-loop feedback with real-time protection

The servo will provide various feedback like position, load, speed, input voltage, current and temperature in real time, with unloading force protection when the servo is overheated or overloaded.

Multiple operation modes

Suitable for more application scenarios.

Multi-Loop angle position control

Supports angle position control in both positive and negative directions up to 7 loops under the default precision setting, but the number of loops will not be saved in case of power loss. Lowering the angle resolution can double the number of control loops.