Robot milling processing: Interpretation of high-precision mass production process plan for lightweight core structural components of humanoid robots

This year, a certain household service robot enterprise placed an order for leg supports, requiring the overall weight of the parts to be ≤ 120g, the positional accuracy of the installation holes to be ≤ 0.01mm, and to meet the load strength requirement of 15kg. In the early stage, the parts produced by die-casting technology had batch fracture problems due to multiple internal air holes and insufficient strength. Through the optimization scheme of robot milling processing and the lightweight design of hollow topology, we finally achieved the goal of batch part strength compliance and weight control within 115g.

Milling Processing Application of Lightweight Humanoid Robots

To achieve longer endurance and more flexible movement of humanoid robots, lightweighting of core structural components is the key technical direction - for every 10% reduction in weight, endurance can be increased by about 12%, while joint load pressure is reduced, resulting in corresponding improvement in motion accuracy.

Robot milling is the process of forming various lightweight structural and transmission components of robots through CNC milling technology. It can adapt to various lightweight design schemes such as topology hollowing and thin-walled forming. It is currently the mainstream technology for mass production of core structural components of humanoid robots, and the three most widely used scenarios are as follows:

1. Processing of core moving parts of robots, such as joint shells, motor end caps, and reducer mounting seats, requires extremely high requirements for form and position tolerances and surface roughness. Robot milling can achieve high-precision processing of multi-faceted features through one clamping, while reducing weight through internal cutting to ensure that parameters such as coaxiality and end face runout meet assembly requirements, avoiding problems such as jamming and rapid wear during motion.

2. Processing of robot body structural components such as humanoid robot arms, leg supports, and torso connectors, which are mostly complex curved surfaces and thin-walled structures that require a balance between lightweight and strength requirements. Robot milling can be combined with topology optimization design to achieve precise weight reduction through cutting, hollowing, and other processes, while ensuring that the mechanical properties of the parts meet load requirements. This is currently the core application direction of aluminum alloy milling in the field of robot lightweight.

3. The robot end effector is capable of processing dexterous hand fingers, gripper components, sensor mounting brackets, and other end effector parts with small size, dense features, and high precision requirements. The robot milling process can achieve micrometer level feature processing, while reducing the end effector weight and joint load through thin-walled hollow design, ensuring that the fitting clearance of the parts is controlled within the standard and meeting the high-precision motion requirements of the end effector.

Comparison of different process advantages for lightweight structural components

For lightweight structural components of humanoid robots, there are significant differences in the advantages and disadvantages of robot milling and other forming processes under different batch sizes and precision requirements. The specific comparison is as follows:

It can be seen that robot milling has comprehensive advantages in precision, strength, and lightweight design adaptability, which perfectly matches the needs of the humanoid robot industry for fast new product iteration, frequent small-scale trial production, and high weight reduction requirements. It can achieve a weight reduction of 28% while maintaining structural strength, and is currently the preferred process for customizing small batch robot parts.

Key technical points for milling lightweight structural components

The lightweight structural components of humanoid robots are mostly aluminum alloy thin-walled and hollow topology structures, and three core technical points need to be controlled during the processing:

Thin walled components enable deformation control of the blade

Lightweight parts such as robot leg supports and arms have a wall thickness of only 1.5-2mm, which can easily cause tool deformation during cutting due to stress, resulting in dimensional deviations.

The process team of Shenzhen robot milling service provider Huiwen Zhizao will control the deformation of the tool within the standard range through layered cutting, forward milling optimization, tool path compensation, and customized fixtures to disperse cutting force, without the need for subsequent calibration processes.

Precision Control of Complex Hollow Surface

There are a large number of free-form surfaces and hollow cavities in the biomimetic lightweight structural components of humanoid robots. Conventional three-axis machining requires multiple clamping, which can easily lead to form and position errors and disrupt the force distribution of topological design.

We adopt a five axis linkage robot milling processing technology, which can complete the processing of all curved surfaces and hollow features in one clamping. The contour of the curved surface can be controlled within ± 0.008mm, fully retaining the strength design optimized by topology, and meeting the assembly requirements of robot joint structure processing.

Batch processing consistency control

Batch orders for processing robot joint structural components are usually between 100-1000 pieces, and lightweight design has lower tolerance for dimensional deviations. It is necessary to ensure the dimensional consistency of all parts to avoid assembly defects or insufficient strength.

We have established a standardized process parameter library to preset optimal cutting parameters for commonly used lightweight scenarios in aluminum alloy milling. At the same time, key dimensions are measured every 20 pieces to ensure that the size deviation of batch parts is controlled within the standard range, and the pass rate is stable at over 98%.

Huiwen Intelligent Manufacturing's Lightweight Milling Processing Service Capability

As a high-end robot full industry chain service provider specializing in the field of robotics in Shenzhen, Huiwen Zhizao was registered and established in 2018. It is a national high-tech enterprise and a specialized and new enterprise recognized in 2024. Currently, we are equipped with 10000 square meters of standardized factory buildings and 150+precision machining equipment (including 16 five axis linkage machining centers), with a machining accuracy of ± 0.005mm.

Huiwen Zhizao provides hardware design and manufacturing services for robot bodies, operating in a modular ODM mode, covering the entire process of design (mechanical structure/electrical scheme design/process optimization), manufacturing (CNC machining/mold/surface treatment), assembly (component trial assembly/product assembly and debugging), and supporting customers to choose single or multiple service modules as needed. The core service advantages are as follows:

1、Design+Manufacturing Integration: Can cooperate with customers to complete lightweight structural optimization, adjust design schemes for manufacturability, and avoid processing failures;

2、Accuracy control: equipped with 20+testing equipment such as German Zeiss CMM and roughness meter, all parts can issue full-size testing reports;

3、Material adaptation: Cutting parameters can be optimized for different lightweight materials, with mature processing experience for 6 series, 7 series aluminum alloys, magnesium alloys, titanium alloys, and carbon fiber composite materials;

4、Delivery capability: Supports small batch customization of robot parts, with samples of up to 10 pieces delivered within 3 days and bulk orders of up to 1000 pieces delivered within 15 days;

5、Qualification certification: We have passed ISO9001 and IATF16949 quality management system certification, and have more than 20 related patents. Currently, we have provided lightweight services for robot joint structure processing and aluminum alloy milling for customers such as Huawei, Xinsong, Xiaomi ecological chain enterprises, and the Chinese Academy of Sciences.

If you have a need for lightweight structural component robot milling or small batch customization with humanoid robots, you can directly send drawings to obtain process plans and quotations. Our engineers will provide targeted responses within 24 hours.