Costr offers two specialized servo gearbox families spanning from compact Ø32mm to powerful Ø110mm systems, delivering micro servo joints for collaborative robots across industries. Whether you're developing robotic joint modules for industrial automation, designing precision actuators for medical devices, or building flexible servo joints for humanoid robots, our integrated solutions provide unmatched performance and reliability.

Our servo joints serve diverse applications including collaborative robot arm joints, automated assembly line actuators, prosthetic limb control systems, robotic surgical instruments, underwater ROV joint mechanisms, educational robot platforms, and service robot articulation systems. With built-in servo drives eliminating external controllers, these integrated servo reducers simplify integration for industrial robot joint replacement and custom robotic arm development.

Meet Our Two Servo Joint Families

Planetary ProServo: Versatile and Robust (Ø32mm - Ø52mm)

Best for: Educational robotics, bionic applications, and cost-sensitive automation

The Planetary ProServo series features high-precision planetary gearboxes combined with Costr Planet Series brushless motors, creating an optimal pairing for diverse applications. These planetary servo reducers utilize motors from our proven Planet Series lineup (VE5010, MA3010, EA6010), which deliver flat-design efficiency and compact torque density perfectly suited for servo joint actuators for educational robots and bionic robot joint mechanisms.

Motor-Gearbox Integration Benefits: The Planet Series motors provide critical specifications that directly impact servo joint performance:

• High torque density motors (0.32-1.24 N·m) enable compact joint designs

• Flat motor profile reduces overall joint thickness for space-constrained applications

• 48V operation capability allows higher power in smaller packages

• Integrated encoder feedback ensures precise position control for the gearbox output

These planetary servo reducers excel in dexterous manipulator fingers, rehabilitation robotic devices, and research platform actuators.

Available models:

• PP05-36: Ultra-compact Ø32mm, 35W - ideal for miniature robot joint assemblies

• PP08-36: Balanced Ø40mm, 36W - perfect for collaborative robot wrist joints

• PP08D-36: Dual output version for dual-axis robotic applications

• PP11-36: High-power Ø52mm, 60-72W - excellent for industrial robot elbow joints

What makes them special: Modular design, integrated servo drives, and excellent price-performance ratio for affordable robot joint solutions.

Harmonic ProServo: Precision Powerhouse (Ø40mm - Ø110mm)

Best for: High-precision automation and industrial robotics

When you need ultra-precise positioning with zero backlash robot joints, Harmonic ProServo delivers unmatched accuracy. The revolutionary advantage of our Harmonic ProServo series lies in its ultra-low backlash performance of just 15 arcsec - making it ideal for applications where robot joint backlash reduction is critical.

Understanding Robot Joint Backlash: Traditional robot joints suffer from backlash issues that compromise positioning accuracy. Our low backlash servo gearboxes eliminate this problem through precision harmonic drive technology, ensuring repeatable robot joint positioning and high-precision robotic applications. This robot joint accuracy improvement is essential for demanding tasks like semiconductor assembly, precision welding, and medical procedures.

These harmonic drive servo gearboxes utilize strain wave gearing technology specifically designed for precision robot joint assemblies, CNC machine tool automation, and semiconductor handling equipment where backlash-free robot movement is non-negotiable.

Available models:

• PH08-51/101: Compact Ø40mm precision joints for small robot joint actuators

• PH11-51/101: Mid-range Ø52mm with 6mm through-bore for cable-routing robot joints

• PH14-51/101: Heavy-duty Ø70mm for industrial robot shoulder joints

• PH17-51/101: High-torque Ø80mm for heavy-payload robot applications

• PH20-81/121: Large-bore Ø90mm for multi-axis robot joint integration

• PH25-81/101: Maximum power Ø110mm for industrial robot base joints

Key advantages: Ultra-low backlash (15 arcsec), exceptional positioning accuracy, and superior torque density make these joints the preferred choice for high-precision robotic applications requiring zero-backlash robot performance.

Selection by Application Category

Collaborative Robot Development

For collaborative robot joint design, start with Harmonic ProServo PH11 or PH14 series. The built-in collision detection servo joints and drag-to-teach robot actuators functionality make them perfect for safe human-robot collaboration. These precision servo gearboxes offer exceptional integration capabilities for demanding applications.

Pro tip: Consider our robot joint modules with integrated encoders for simplified wiring and improved reliability.

Industrial Automation Systems

Industrial applications benefit from our larger Harmonic ProServo models (PH17-PH25) offering industrial robot joint actuators with exceptional durability. Perfect for automated manufacturing cells, pick-and-place robot gearboxes, and assembly line automation.

Medical and Precision Devices

Medical robotics demands our highest precision joints. Harmonic ProServo PH08 and PH11 provide medical robot joint actuators with smooth, quiet operation essential for surgical robot arms and rehabilitation therapy devices.

Educational and Research Platforms

Universities and research labs love our Planetary ProServo series for educational robot joint kits and research robot platforms. The modular servo joint design allows rapid prototyping and easy integration into custom robotic systems.

Key Selection Criteria

1. Torque and Speed Requirements

Match your load requirements to our specifications:

• Low torque (0.2-2N·m): PP05, PP08, PH08 series

• Medium torque (6-18N·m): PP11, PH11, PH14 series

• High torque (30-144N·m): PH17, PH20, PH25 series

  
  

2. Precision Requirements

Choose based on positioning accuracy and robot joint backlash tolerance:

• Standard precision: Planetary ProServo (12 arcmin backlash) - suitable for general automation

• Ultra-high precision: Harmonic ProServo (15 arcsec backlash) - essential for precision robot gearbox applications requiring minimal robot joint backlash

Critical consideration: For applications requiring robot joint repeatability and accurate robot positioning, the 48x improvement in backlash performance (15 arcsec vs 12 arcmin) makes Harmonic ProServo the only viable choice for high-precision robot joint assemblies.

3. Integration Complexity

All our joints feature servo joints with integrated controllers, eliminating external drives. Consider:

• CAN 2.0A communication for multi-joint coordination

• Through-bore design for cable management

• Modular mounting for easy integration

  
  

4. Software Compatibility

Our joints support multiple platforms:

• Linux (ROS) servo joint integration

• Windows automation development

• Android mobile robot control

• MATLAB/Python/C++ APIs available

Advanced Features That Matter

Built-in Intelligence

Every Costr servo joint includes intelligent servo joint controllers with:

• Collision detection and response

• Drag-to-teach programming

• Position, velocity, and torque control modes

• Safety monitoring and protection

  
  

Communication and Networking

Industrial Ethernet servo joints connectivity through:

• CAN bus robot joint networks (up to 1Mbps)

• Ethernet adapter modules for PC integration

• Daisy-chain servo joint connections for simplified wiring

  
  

Common Questions Answered

"How do I replace existing robot joints?" 

Our servo gearboxes are designed as drop-in robot joint replacements for many popular platforms. Check our compatibility guide or contact our engineers for robot joint retrofit solutions.

"Can you customize joints for specific applications?" 

Absolutely. As a custom servo gearbox manufacturer, Cosmotr regularly modifies servo reducers for unique requirements including custom robot joint assemblies and specialized robotic actuators.

"What about software integration?" 

We provide comprehensive robot joint control software including APIs for servo joint programming and motion control integration. Our open-source robot joint libraries accelerate development.

"How do they compare to imported alternatives?" 

Our servo gearboxes offer comparable performance to premium robot gearbox brands while providing better value, local support, and Chinese servo gearbox manufacturing advantages including shorter lead times and customization flexibility.

Getting Started with Your Selection

For most collaborative robots: PH11-51 or PH14-51 series For precision automation: PH08-51 with ultra-low backlash For educational projects: PP05-36 or PP08-36 for affordability For industrial heavy-duty: PH20 or PH25 series

Implementation Support

1. Technical consultation: Our engineers help optimize joint selection

2. Integration support: Complete documentation and software libraries

3. Prototyping assistance: Development units for proof-of-concept

4. Production scaling: Volume manufacturing and quality assurance

Ready to revolutionize your robotic system? Contact us at info@cosmotrglobal.com for technical discussions about your servo joint application requirements. Our team specializes in matching the perfect joint to your specific needs, ensuring optimal performance and seamless integration.

Remember: The best servo joint isn't necessarily the most powerful or most precise - it's the one that perfectly balances your performance requirements, integration constraints, and budget considerations. Let our experts help you find that perfect match.