Dual-Material CNC Prototype Solution for Smart Glasses Housings

Product Background

With the rapid growth of the smart wearable device industry, product innovation cycles are becoming shorter, and precision requirements are rising. Among these devices, smart glasses are emerging as a key category, demanding lighter, thinner housings with increasingly complex structures to meet performance and user experience expectations.

To ensure new smart glasses meet performance and reliability standards, the product must be prototyped and tested with different materials early in development. These prototypes help evaluate deformation behavior, assembly precision, and overall structural stability, providing data support before moving into scale production.

Magnesium Alloy vs. Aluminum Alloy: Balancing Performance and Cost

The housing serves as the core structural component of smart glasses. To meet the demands of next-generation smart wearables, the material must provide lightweight, strength, and rigidity.

Magnesium alloy, the light structural material available (density ~1.7 g/cm³), is ideal for lightweight applications. In addition to its low weight, it offers higher strength and rigidity than aluminum alloy, superior impact resistance, and less deformation.

However, magnesium alloy presents challenges: it is flammable, requires specialized equipment and expertise to process, and has lower corrosion resistance, making surface treatments more complex and costly.

Since the smart glasses are still in the prototype validation stage, the client also chose to produce samples with aluminum alloy. Aluminum offers excellent machinability, a refined appearance, and higher cost efficiency, making it well-suited for small-batch trial production.

At WayKen, we provide one-stop CNC machining services for both magnesium and aluminum alloys, enabling our clients to compare material performance and cost-effectively make a better decision for their product development.

Part Structure Analysis

The smart glasses housing features a thin-wall design to reduce weight, which increases the risk of deformation. Machining stress and clamping must be precisely controlled to maintain structural stability. It includes multiple M1.6 threaded holes for assembling internal modules and the outer casing, requiring high precision in positioning, depth, and tapping.

The part also demands excellent surface flatness and appearance to meet the aesthetic standards of smart wearables.

Key Machining Considerations of Smart Glasses Housing Prototype

To ensure the smart glasses housing met strict dimensional, structural, and appearance requirements, we addressed several key points during machining and surface finishing.

1. Thin-Wall Structure Prone to Deformation

For the smart glasses housing, the thin-wall design makes the part especially prone to deformation during machining. To minimize this risk, we used a step-by-step machining strategy.

• First, machined the external convex surfaces to stabilize the structure.
• Designed custom fixtures closely matched to the housing’s geometry for secure and stable clamping.
• Processed the reverse side once the outer profile was fixed.
• Completed thread tapping under controlled cutting forces to avoid distortion.

2. Control Thread Hole Accuracy

The housing part includes 27 M1.6 × 0.35 fine threaded holes, which must be controlled within a depth tolerance of ±0.1 mm, and the positions and depths of the holes must be highly consistent.

We used high-precision CNC machining combined with dedicated fine thread taps, strictly controlling drilling positions and tapping processes. 5-axis machining was used to enable stable processing at multiple angles and improve thread quality and consistency.

3. Magnesium Alloy is Flammable During Machining

The housing magnesium prototype cutting produces high-temperature chips and powder that can catch fire. We used special cutting fluids for cooling, controlled cutting parameters, and prepared fire-resistant sand and extinguishing equipment to ensure a safe and stable machining process.

Surface Treatment for Magnesium and Aluminum Housing Parts

Magnesium alloy uses micro-arc oxidation (MAO), forming a thick ceramic coating with high hardness and good wear and corrosion resistance. Color options are limited (natural color used here), and complex structures make uniform coating challenging. We optimized parameters and fixtures to ensure consistency and appearance.

Aluminum alloy was black anodized, forming a thinner, smoother oxide layer with a stable color. The process is mature and easy to control, but the coating is softer and more prone to scratches or edge over-etching. We controlled pretreatment and processing to ensure a uniform, high-quality finish.

Future Plan

The client praised our quick response and high-quality delivery. They highlighted the precise curvature, accurate threads, and smooth assembly. All parts met strict dimensional and performance requirements, laying a solid foundation for future production. They look forward to continued collaboration and innovation.