Imaging Device Housing Case: How WayKen Handle Deformation and Dual Surface Treatments?

This project includes 29 items, a total of 186 components. Here we will share a typical component – the housing part of the image device.

1. Determine the Process for Machining Housing

Let’s take a closer look at the imaging device housing’s features. There are many blind holes at the top and bottom, and it is notably multifaceted eight sides with different machining directions.

In addition, from the top and bottom sides of the housing, you can observe that there are undercuts below some blind holes.

So after being assessed by our engineers, WayKen chose the 5-axis CNC machining to process this housing part and we also used custom tools to machine the undercuts.

2. Consider Deformation and its Strategies

Upon process selection, WayKen carefully evaluated the machining potential issues and developed an appropriate plan. Within machining this housing part, the following deformation causes require special attention.

2.1 Deformation Causes

As a whole, the housing part size is large at 253*160*115mm, while the thickness is only 3.5mm. As a result, it is prone to deformation during processing.

The imaging housing has a hollow structure, which lacks internal supports, and an unconventional eight-sided shape. Mechanically, this unconventional shape makes it inherently less stable than structures with cylindrical, triangular, or quadrilateral sides. This instability often leads to warping or deformation during the CNC machining.

What’s more, when removing material from an unsupported structure, the external force upsets the stress balance of the material, resulting in deformation.

2.2 Machining Strategies

To mitigate deformation risk, we have implemented the following strategies:

Choose Heat-treated Materials

In common, heat treatment materials have enhanced hardness and strength, which typically allows them to retain their shape more reliably during machining, lowering the chances of deformation. In this housing part, considering the client’s specifications for surface quality, WayKen suggested the Aluminum 6061-T6.

Control Machining Parameters and Maintain Consistent

Heat build-up during processing increases the risk of distortion. Therefore, WayKen needed to pay special attention to changes in machining parameters and manage coolant control to avoid excessive localized heat build-up.

We also avoided intermittent stops and starts, which is one of the reasons for choosing 5-axis machining. In this way, it could diminish the influence of thermal fluctuations on the aluminum material to avoid deformation.

Utilize Optimized Fixtures

WayKen carefully designed and selected fixtures that securely hold the workpiece in place during machining, reducing the risk of vibration and subsequent deformation. We use jigs to provide support for the cavity and the underside of blind holes to minimize the deformation effects of external forces.

Through the above methods, WayKen controlled the housing part deformation to be well for applications. After machining, there’s one more challenge for this imaging housing part.

3. Two Surface Treatments on One Part

To cope with complex outdoor environments, the surface of this imaging device needs to be chemically treated, yet some areas will retain electrical conductivity. As a result, this housing required two surface treatments, the inside using chromate and the outside receiving black anodization.

Performing two surface treatments on one part is challenging. Anodizing is a multi-step process that includes cleaning, pickling, anodizing, and neutralizing, which can easily affect inside areas while anodizing the outside of the housing.

So, we decided to begin the process with the chromate conversion coating first. To shield the sections designated for black anodization, we employed suitable masking materials such as tapes, glues, and waxes to prevent the treatment solution from affecting those anodizing areas.

Once the initial treatment was completed, we meticulously removed the masking materials. The sections intended for black anodization are then processed according to the established protocol.

It’s worth noting that all metal debris is completely cleared from the blind holes throughout this procedure. If not, it will form a hard-to-remove block at the bottom of the blind or threaded holes, which affect the product’s assembly.

4. Ensure the Assembly

For each machined part, WayKen will perform a trial assembly. As you can see from the picture below, the through holes of the upper and lower image device covers and the threaded holes of the housing are assembled together well by screws. Not only control the deformation, WayKen also ensures the hole’s position for the use of the product.