Which parts of humanoid robots are suitable for car milling composite processing?

A humanoid robot often has dozens of joints, and the shells, shafts, and reducer parts in each joint require extremely high machining accuracy. Therefore, the combination of turning and milling is a more suitable method.

The value of humanoid robot turning and milling composite processing lies in the fact that with one clamping, the turning, milling, drilling, and tapping are continuously completed, eliminating the accumulated errors caused by multiple clamping from the root. This article focuses on the three typical types of parts (structural support parts, transmission execution parts, and end effector parts) that are processed by robot turning milling composite machining, and analyzes their respective processing difficulties and applicable logic one by one.

1、 What is car milling composite machining?

Turning milling composite machining is a multi process machining of complex parts that can be completed on a single machine tool by integrating turning and milling functions. This technology can achieve a one-time clamping to complete all or most of the machining processes, thereby avoiding the accumulation of errors caused by the conversion of positioning benchmarks and improving machining accuracy and efficiency.

Core features:

Complete multiple processes in one clamping: all features (outer circle, hole, groove, plane) are completed in the same clamping

Unified benchmark: avoids secondary positioning errors caused by circulation between different machine tools

Suitable for complex non-standard parts: parts with strict requirements for coaxiality, positional accuracy, and symmetry

2、 What are the typical parts of humanoid robot turning milling composite machining?

The mechanical structural components of humanoid robots can be divided into three categories based on functional hierarchy: structural support components, transmission execution components, and end effector components. Among these three types of parts, there are a large number of parts that require milling and turning composite processing.

1. Structural support components

Including joint housing, sensor housing, mounting seat, flange, connecting rod, etc. The function of these parts is to carry and connect, usually requiring:

1.Precise installation hole positions and positioning features (milling/drilling)

2.Thin walled structure with strict requirements for geometric tolerances

3.Multi angle hole system and mating surface

Taking the sensor housing as an example, humanoid robots are equipped with a large number of force sensors, vision modules, IMUs, etc. The housing and mounting seat are usually compact in structure and thin in wall thickness. For every additional clamping of thin-walled components, there is an increased risk of deformation due to clamping force. The one-time molding of car milling composite can minimize the number of clamping times, reduce the risk of deformation, and ensure the positional accuracy of each installation hole.

2. Transmission actuators

The transmission components include harmonic reducer flexible/rigid wheels, planetary reducer housing, motor shaft, output shaft, cross bearing seat, etc. These types of parts directly participate in motion and torque transmission, with the highest precision requirements, usually requiring:

1.Precision outer circle (turning)

2.Axial or radial holes (drilling)

3.Keyways, splines (milling)

4.Tooth shaped features, oil passage holes

In transmission shaft components, especially those with radial cross holes, the coaxiality between the holes and the outer circle is required to be high, and traditional step-by-step machining is difficult to ensure. Car milling composite can complete all the processing of outer circles, holes, grooves, and threads in one clamping, ensuring better coaxiality and positional accuracy.

The components of the reducer require extremely high coaxiality and tooth profile accuracy. The car milling composite completes all the processing of the outer circle, inner hole, end face, and hole system in one clamping, ensuring the positional relationship between each feature - this is crucial for the transmission accuracy of the joint module.

3. End effector

The end effector includes fingers, gripper bases, tool flanges, etc., usually small in size but complex in structure:

1.Polyhedral structure

2.Multi angle hole system

3.Precision mating surface

If these parts are processed in separate processes, not only is the accuracy difficult to guarantee, but the efficiency of repeatedly clamping small parts is also extremely low. The combination of turning and milling completes all features in one clamping, with advantages in accuracy and efficiency.

3、 How to determine if a part is suitable for milling and turning composite processing?

To determine whether a part is suitable for milling and turning composite processing, the key is to check whether it has the basic characteristics of a rotating body, and whether it needs to undergo multi process composite processing in non rotating directions, while meeting the requirements of high precision or reducing clamping. Specifically judged from four dimensions:

1. Geometric feature matching

The main body of the component consists of rotating bodies such as shafts and disk sleeves, but also includes features that require milling such as eccentric holes, radial/spiral grooves, end face irregular surfaces, oblique holes, or non-circular contours. If there is only outer circle (pure turning) or only flat/cavity (pure milling), there is no need for turning milling composite.

2. Process chain requirements

In traditional craftsmanship, these types of parts need to be circulated between lathes and milling machines, and multiple clamping processes result in accumulated benchmark conversion errors, with strict requirements for coaxiality and positional accuracy. If the requirements for coaxiality, symmetry, positional accuracy, and other indicators of the parts are strict, the advantages of one-time clamping of milling and turning composite are more obvious.

3. Batch and Cost Logic

Car milling composite is suitable for small to medium batch, multi variety customized parts or high value-added parts. If it is a pure simple rotary body (only requires turning) or a pure plate type box body (only requires milling), it can be machined with a single machine, and the combined economy of turning and milling is insufficient.

4. Material and Precision Sensitivity

Difficult to cut materials (titanium alloys, high-temperature alloys) or thin-walled parts increase the risk of deformation with each additional clamping. The car milling composite is completed in one clamping, which can avoid deformation and thermal deformation accumulation errors caused by multiple clamping.

4、 Practical suggestions

1. Prioritize trial milling and composite during the sampling stage

During the R&D iteration period, only a small number of samples are usually required. Although the cost of turning, milling, and adjusting the machine is slightly higher, for parts with high precision requirements, one-time molding to maintain accuracy is much more cost-effective than later repair and patching.

2. Communicate with the process supplier in advance about tool interference

The internal space of the milling machine is more cramped than that of a conventional machining center. If the groove of the part is particularly deep and the angle is particularly tricky, it is necessary to confirm with the supplier before processing whether the tool can reach it, in order to avoid discovering that it cannot be processed only after the design is completed.

3. Choose a manufacturer with a complete process chain

Humanoid robot parts usually involve multiple processes (such as turning, milling, grinding, wire cutting, etc.). Choosing a manufacturer with their own core processes does not require outsourcing, and the delivery time is more controllable and the quality is more stable. For example, in a humanoid robot customer project, Shenzhen Huiwen Zhizao not only completed the turning, milling, and composite processing of joint shells, transmission shafts, and other parts, but also dispatched software engineers to work with the Huiwen assembly team to complete the overall machine debugging during the assembly stage, reducing the accuracy risk of cross factory circulation.

5、 Summary

The suitable parts for robot turning milling composite machining usually have three characteristics: both rotational body characteristics and milling/drilling characteristics, strict requirements for coaxiality or positional accuracy, or thin-walled and easily deformable structures. The core value of turning milling composite machining lies in "one-time clamping and multi process completion", which fundamentally avoids the cumulative error of secondary clamping. For products such as humanoid robots that require extremely high motion accuracy, process selection directly affects the overall performance of the machine.

Shenzhen Huiwen Zhizao has long focused on precision mechanical parts processing, with a factory area of 20000 square meters and more than 370 processing equipment. It has its own full process production lines for turning, milling, composite, five axis CNC, precision grinding, and wire cutting, with the ability to design, manufacture, and assemble the entire chain of services. It can meet the different needs of mechanical dogs, flexible robotic arms, bionic robots, medical robots, etc. from single piece sampling to medium to large-scale production, and help customers achieve rapid delivery.

In terms of robots, Huiwen Intelligent Manufacturing relies on its own full industry chain service capabilities and innovatively adopts a combination of "new materials+new molds+precision machining" technology to meet the trend of mass production demand in the robot track.

At present, Huiwen Zhizao has passed ISO9001 and IATF16949 quality management system certification. It is a national high-tech enterprise and a specialized and innovative enterprise. It has served many listed companies and industry-leading companies, such as Lenovo, Xinsong, Xiaomi Ecological Chain, Beijing Institute of Technology and other customers, with reliable and guaranteed quality.

If you need to obtain a machining plan or quotation for humanoid robot parts, you can visit the official website of Huiwen Zhizao (www.hw-robots. cn) to submit drawings.