Hello everyone, I'm Theodore Li, Technical Director at HONPINE. Today I'd like to share a real customer case that demonstrates how our engineering team helps customers select and customize the right robot joint actuator for demanding applications.
At HONPINE, we don't simply recommend products from a catalog. Every year, we provide more than 2,000 customized robot joint actuator solutions for customers worldwide. Whether the application is a humanoid robot, collaborative robot, service robot, medical device, or industrial automation system, our engineering team works closely with customers to optimize performance, size, wiring, and integration.
The customer was developing a compact robotic system and required an integrated harmonic joint actuator with extremely challenging specifications.
The key requirements included:
Outer diameter smaller than 56 mm
Overall length shorter than 61 mm
Rated torque of 3 N·m
Starting (peak) torque greater than 3 N·m
Motor cable routed from the rear of the motor
Extremely low operating speed of approximately 0.2 rpm
Positioning accuracy capable of achieving 0.2° per movement
Gear reduction ratio greater than 50:1
Compact integrated design combining a harmonic reducer and servo motor
These requirements demanded a highly integrated solution that could deliver high torque, high precision, and compact dimensions simultaneously.
For many robot manufacturers, balancing torque output, structural size, cable routing, and positioning accuracy is one of the biggest engineering challenges during product development.

After carefully reviewing the customer's specifications, our engineering team selected the most suitable HONPINE HAG Harmonic Joint Module and immediately provided detailed engineering drawings for evaluation.
Instead of only recommending a standard product, we analyzed:
Mechanical dimensions
Torque requirements
Gear ratio
Motor performance
Cable routing
Installation constraints
Future customization possibilities
This allowed the customer to verify compatibility before prototype development.

During the evaluation, the customer raised an important question regarding cable routing.
The customer asked:
Is it possible to have the cable exit from the top of the motor instead of the side? What would the required cable length be?
This is a common concern when robot joints are installed in confined spaces where cable management directly affects the overall structure.
Our engineers explained that the standard HONPINE HAG Harmonic Joint Motor uses side cable خروج (side cable routing).
For the bottom cable version, approximately 20 mm of cable bending radius is reserved to ensure reliable cable protection and long service life.
Rather than stopping there, our engineering team proposed an optimized customized solution.
The customer then asked another important question:
Instead of providing only drawings, our engineers supplied actual product photographs and demonstrated how the motor is assembled.
We also proposed a customized cable configuration.
By directly soldering the power cable to the motor according to the customer's requirements, the cable bending radius could be greatly reduced.
As a result:
Overall actuator length becomes significantly shorter
Installation becomes easier
Internal wiring is cleaner
More space is available inside the robot joint
The customer can achieve a more compact mechanical design
Although the actuator itself remained largely unchanged, this customized cable solution solved the customer's space limitation while maintaining performance and reliability.
This is a good example of how small engineering improvements can create significant value for robot manufacturers.

Many actuator suppliers only provide standard specifications.
At HONPINE, our engineering team focuses on solving real integration problems.
Depending on customer requirements, we can provide customization including:
Cable exit direction
Cable length
Connector type
Encoder configuration
Brake options
Communication protocols (EtherCAT, CAN, CANopen)
Gear ratio selection
Torque optimization
Mechanical interface customization
This engineering support helps customers reduce development cycles while minimizing design risks.
The rapid growth of the global humanoid robotics industry has created unprecedented demand for high-performance robot joint actuators.
Governments, venture capital firms, and technology companies around the world continue investing heavily in humanoid robot development.
As more companies enter this market, compact, lightweight, high-torque, and high-precision joint modules are becoming increasingly important.
Driven by this trend, HONPINE expects to provide more than 3,000 robot joint actuator solutions during 2026, representing substantial growth compared with previous years.
Customers work with HONPINE because we combine manufacturing capability with engineering expertise.
Our harmonic joint modules offer:
High torque density
Compact integrated design
High positioning accuracy
Low backlash harmonic drive technology
Customized cable routing
Multiple encoder options
Servo motor integration
Reliable performance for demanding robotic applications
Every application is different, and our engineers work directly with customers to ensure the selected actuator fits both the mechanical structure and the motion control requirements.
This project demonstrates that successful robot joint design is not only about selecting the right actuator.
It also involves optimizing every detail—from mechanical dimensions and cable routing to assembly methods and customization—to achieve the best possible system performance.
At HONPINE, we are more than a manufacturer of harmonic joint actuators.
If you're developing humanoid robots, collaborative robots, industrial automation equipment, medical robots, or any precision motion system, our engineering team is ready to help you find the most suitable joint actuator solution.
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