Manufacturing A High-Precision Aluminum Humanoid Robot Joint Housing

Notes：

We have signed confidentiality agreements with all of our customers. The product cases you see on our website are either displayed with customer authorization or created using AI technology to simulate the manufacturing process for demonstration purposes, while ensuring that our customers’ core data and confidential information remain fully protected.

Customer Requirement & Engineering Challenges

Developing a Lightweight Structure Without Compromising Strength

Humanoid robot components require strict control over weight, strength, and dimensional accuracy.

The customer needed a compact joint housing that could:

• Reduce overall robot weight

• Maintain sufficient structural rigidity

• Provide accurate bearing and mounting interfaces

• Support reliable assembly performance

However, several manufacturing challenges needed to be solved before production.

Complex Internal Geometry and Lightweight Design

The original CAD model contained complex internal structures designed to reduce weight while maintaining mechanical strength.

These internal cavities created difficulties for traditional CNC machining because many areas were difficult or impossible to access with standard cutting tools.

Manufacturing Challenge:

• Limited tool accessibility

• Complex internal surfaces

• Reduced machining rigidity

• Higher risk of material waste

Engineering Solution:

Dawang Precision evaluated the design and recommended a hybrid manufacturing process.

The complex lightweight structure was produced through SLM metal additive manufacturing, while critical precision areas were finished through CNC machining.

Achieving Precision Assembly Interfaces

Although additive manufacturing provides excellent geometric flexibility, robotic components still require extremely accurate functional surfaces.

Critical areas included:

• Bearing mounting seats

• Connection interfaces

• Precision locating holes

• Assembly reference surfaces

These features directly affect:

• Joint movement accuracy

• Mechanical stability

• Long-term reliability

Engineering Solution:

5-axis CNC machining was applied to finish all functional surfaces.

This allowed precise control of:

• Position accuracy

• Surface finish

• Dimensional consistency

Final machining accuracy reached:

±0.01mm

Balancing Manufacturing Efficiency and Performance

A fully CNC-machined solution would require significant material removal and complex multi-angle setups.

A fully 3D-printed solution could achieve complex geometry but could not meet all precision requirements.

After engineering evaluation, the hybrid approach provided the best balance:

Final Solution:

SLM Printing + 5-Axis CNC Machining

Design Analysis & Manufacturing Strategy

From CAD Model to Final Manufacturing Process

Before production, the engineering team reviewed the 3D CAD model and developed a complete manufacturing strategy.

The analysis focused on:

• Machining accessibility

• Critical tolerance requirements

• Fixture design

• Tool path planning

• Inspection requirements

Step 1 CAD Review and DFM Analysis

The engineering team analyzed the original CAD design to identify potential manufacturing risks.

Key evaluation points included:

Wall Thickness

Ensuring the lightweight structure maintained sufficient strength.

Machining Accessibility

Checking whether cutting tools could reach critical areas.

Critical Dimensions

Identifying surfaces requiring precision machining and inspection.

Suggested Image:

CAD model screenshot with annotations:

• Internal cavity

• Bearing seat

• Mounting interface

• Machining area

Step 2 Hybrid Manufacturing Planning

Based on the design requirements, the component was divided into two manufacturing stages.

Additive Manufacturing Stage

Used for:

• Complex internal structures

• Lightweight geometry

• Near-net-shape production

CNC Machining Stage

Used for:

• Precision mounting surfaces

• Bearing seats

• Threaded holes

• Assembly interfaces

This approach reduced machining difficulty while maintaining high accuracy.

Manufacturing Process

Step-by-Step Production Workflow

1. SLM Metal Additive Manufacturing

The initial component structure was produced using Selective Laser Melting (SLM) technology.

This process allowed the creation of complex lightweight geometries that would be difficult to manufacture using conventional machining methods.

Key benefits:

• Reduced material waste

• Improved design flexibility

• Suitable for complex robotic structures

Image Required:

Metal powder bed fusion printing process.

2. CNC Machining of Precision Features

After additive manufacturing, the component underwent precision CNC machining.

A 5-axis machining center was used to complete critical functional surfaces.

Machined features included:

• Bearing mounting areas

• Precision holes

• Connection surfaces

• Alignment features

Advantages of 5-axis machining:

• Reduced setups

• Better surface consistency

• Improved positional accuracy

Image Required:

5-axis CNC machine machining the aluminum robot housing.

3. Surface Finishing

After machining, the component received surface treatment according to the customer's requirements.

Process:

• Deburring

• Surface preparation

• Bead blasting

• Anodizing

The final finish improved:

• Surface appearance

• Corrosion resistance

• Product durability

Image Required:

Finished aluminum robotic component.

4. Precision Inspection

Before delivery, every critical dimension was verified using professional inspection equipment.

Inspection methods included:

Manufacturing Results

Delivering a Reliable Robotic Component Solution

Through the combination of additive manufacturing and precision CNC machining, the final humanoid robot joint housing achieved:

Lightweight Structure

Optimized geometry reduced unnecessary material while maintaining mechanical performance.

Precision Assembly Performance

Critical interfaces achieved ±0.01mm accuracy for reliable robotic assembly.

Manufacturing Flexibility

The hybrid process enabled rapid development of complex robotic prototypes without sacrificing precision.

Why Hybrid SLM and CNC Machining Was the Right Choice

Can Metal 3D Printing Replace CNC Machining for Robot Parts?

For complex robotic components, additive manufacturing and CNC machining are complementary technologies rather than alternatives.

Metal 3D printing is ideal for:

• Complex geometry

• Lightweight structures

• Prototype development

CNC machining remains essential for:

• Precision interfaces

• Tight tolerances

• Functional assembly surfaces

The combination provides engineers with greater design freedom while maintaining manufacturing accuracy.

Quality Control for Robotic Components

Precision robotic parts require strict quality control throughout the manufacturing process.

Dawang Precision applies inspection methods including:

• CAD drawing review

• In-process measurement

• CMM inspection

• Final dimensional verification

This ensures every component meets the required specifications before delivery.

Frequently Asked Questions

Why was SLM combined with CNC machining for this robot housing?

SLM manufacturing enables complex lightweight structures, while CNC machining provides the precision required for assembly interfaces. Combining both technologies delivers better performance than either process alone.

What tolerance can be achieved for humanoid robot parts?

Precision CNC machining can achieve tight tolerances depending on material, geometry, and design requirements. For this project, critical dimensions reached ±0.01mm.

Can you manufacture custom humanoid robot components from CAD files?

Yes. Engineering teams can evaluate CAD models, optimize manufacturing processes, and produce prototypes or low-volume robotic components based on customer requirements.

What materials are suitable for robotic structural components?

Common materials include aluminum alloys, titanium alloys, and stainless steels. Aluminum is often selected for robotic housings because of its lightweight characteristics and good machinability.

Final Summary

This humanoid robot joint housing project demonstrates how advanced manufacturing technologies can work together to solve complex engineering challenges.

By combining SLM additive manufacturing, 5-axis CNC machining, and precision inspection, Dawang Precision provided a reliable manufacturing solution for next-generation robotic components.