CNC Prototyping Machining in Biomedical Optical Instrument Enclosures

Project Background

Precision optical instruments play a key role in the biomedical field, enabling cell observation and tissue imaging. Scientists use them to study cell structures, diagnose diseases, and analyze molecular interactions. For these devices, even minor errors can affect results, so these optical enclosures must protect components, maintain accurate light transmission, and prevent distortion or contamination.

Recently, a global optical equipment manufacturer approached us with an invitation. While developing an enclosure for a biological optical instrument, they struggled to find a manufacturer that could meet both their high-precision requirements and small-batch production needs.

The enclosure required micron-level accuracy, flawless surfaces, and contamination-free machining to ensure optical performance. Many traditional manufacturers either lacked the necessary precision and quality control or could not accommodate small-batch production.

Finding the Right Manufacturer is Key to Success

Faced with strict precision and small-batch production requirements, a reliable manufacturing partner is the key to make success. With years of CNC machining experience, WayKen is the ideal partner. We specialize in high-precision small-batch production, ensuring each part meets quality standards without defects . Our machining expertise can help to achieve the accuracy and reliability of the biological optical instrument enclosures.

Part Structure Analysis

The optical enclosure consists of eight main shell parts and eight smaller components. The main shell parts are made from AL6061-T6, each with a unique shape and a precise assembly relationship. Proper function is only achieved when all parts are correctly assembled.

The main shell parts have complex, irregular designs, with each requiring a different machining direction. This placed high demands on equipment selection. Additionally, each part contains multiple holes and threaded holes with tight dimensional tolerances to ensure accurate assembly and maintain optical performance.

Therefore, this project required careful attention to machining accuracy, equipment selection, and quality control to meet the assembly and performance requirements.

Precision Requirement in Optical Enclosure Part Manufacturing

Manufacturing the optical enclosure required precise control over complex geometries, tight tolerances, and accurate assembly. The client’s 2D drawings specified strict requirements, including a perpendicularity tolerance of 0.03mm, flatness of 0.02mm, surface profile of 0.05mm, and dimensional tolerances of 0.03mm for certain holes. Maintaining these tolerances was essential to ensuring the stability and performance of the optical system.

Challenges in Machining Complex Components

The irregular shapes and multi-axis features of the parts required machining from multiple directions. Traditional three-axis machining risked error accumulation, making it difficult to achieve the required precision. Controlling each surface’s position and dimensions while preventing error buildup was a key challenge.

Additionally, the enclosure parts required black anodizing with a layer thickness between 0.003 and 0.012mm. Certain areas needed a high surface finish of Ra1.6, requiring both precision machining and careful surface treatment to maintain optical performance.

Advanced Machining and Inspection Solutions

In this project, WayKen utilizes advanced 5-axis CNC machining technology combined with in-machine automated inspection functions to ensure high precision and consistency in part manufacturing. 5-axis machining allows simultaneous control of multiple machining surfaces, making it particularly suitable for complex geometries while effectively avoiding the tolerance accumulation issues common in traditional 3-axis machining.

By integrating high-precision sensors and laser measurement systems, the in-line inspection system collects machining data in real-time and compares it with design specifications. Any deviations are promptly detected, and machining parameters are automatically adjusted to ensure that the part’s dimensions, shape, and accuracy consistently meet strict tolerance requirements.

In addition, for high-precision complex optical components, traditional machining methods often struggle to achieve precise fits, especially in controlling multiple machined surfaces and critical dimensions. With the introduction of the in-line inspection system, we can monitor the machining process in real-time and automatically correct deviations, eliminating the need for manual adjustments and rework. This enhances machining accuracy and consistency while improving production efficiency, reducing human intervention, and ensuring high-quality, reliable parts that fully meet the machining requirements.

Surface Treatment and Final Inspection

To meet the stringent requirements of MIL-A-8625 Type II Class 2 black anodizing and Ra 1.6 surface finish, WayKen employs precise machining processes and strict quality control measures.

First, in tool selection, we use carbide cutting tools and high-speed machining to ensure the best possible surface finish.

Before anodizing, we carefully manage the machining allowance to ensure that the anodized layer thickness is controlled between 0.003 and 0.012 mm after processing. Throughout the anodizing process, WayKen continuously monitors and adjusts process parameters to ensure that the oxide layer is uniform and meets customer specifications.

Finally, we also uses a coating thickness gauge and surface roughness tester to inspect the parts, ensuring that all surface roughness and anodized layer thickness meet design requirements.

After all machining processes are completed, WayKen’s inspection department utilizes a Zeiss coordinate measuring machine (CMM) to measure key dimensions such as hole position accuracy and perpendicularity. By probing points around the hole, the center is accurately located, enabling precise hole position measurements. This ensures all tolerances meet design specifications, guaranteeing product accuracy and consistency.

Feedback

All parts successfully passed inspection, meeting the required tolerances and quality standards. The client recognized the precision and reliability of the components, which ensured seamless assembly and optimal optical performance in their biomedical imaging equipment. They expressed confidence in WayKen’s technical expertise and quality management system and look forward to further collaboration to enhance future developments in optical instrumentation.