3D Printing vs. CNC Machining for Automotive Light Components

3D printing is being used for more and more automotive applications, lending itself to everything from internal components to the entire chassis. Even tires can be 3D printed. The technology offers numerous benefits, including more lightweight components, less waste material, quicker fabrication time, less cost, and more. But there are parts of a car for which 3D printing isn’t exactly ideal – the lights. Because 3D printing is a layer-by-layer process, the final product tends to show those layer lines, which isn’t what you want when you’re aiming for an entirely clear component.

There are exceptions, of course. Certain materials and post-processing techniques essentially do away with any evidence of layer lines, for both glass and plastic parts. But overall, 3D printing isn’t the go-to technique when it comes to obtaining perfectly clear surfaces. For that, most manufacturers turn to CNC machining. CNC machining carves an object out of a solid block, so there are no layer lines, resulting in a clear component that can be used for headlights, taillights or interior lights in a car.

Automotive lights are typically CNC machined out of poly(methyl methacrylcate), or PMMA, which is also known as acrylic glass. It’s lightweight and shatter-resistant, making it ideal for automotive applications. It’s also perfectly clear, and machining it does not affect that quality.

Chinese company 3ERP knows both 3D printing and CNC machining well, and offers a wide range of CNC machining services including milling, turning, EDM (electrical discharge machining) and wire EDM, as well as surface grinding. The company has precision 3-, 4, and 5-axis CNC machining centers where it takes care of customers’ needs, including automotive applications.

“Carburetor housings, suspension components, axles, bearing caps as well as engine housings are all manufactured using CNC machines,” the company states in a recent blog post. “Acrylic/PMMA machining for headlights, exterior lights as well as interior lights are another paradigm on how numerical control machining are being utilized when components are being made in the automotive sector.”

Advantages of CNC machining in automotive manufacturing, as 3ERP points out, include multi-axis linkage, to obtain tortuous processing of prototype machining; high precision for good product consistency; a high level of automation, resulting in low labor intensity; and error-free productivity. Numerical control also ensures simplicity and efficiency.

In addition to 3ERP’s selection of advanced equipment, the company also has experienced engineers capable of handling complex and precision parts in a variety of industries, including automotive. It also offers a fast turnaround time – on average, it returns quotes within 24 hours, and parts ship within seven days or less, with a 99% on time delivery and quality rate.

So while 3D printing may be taking over more and more of the automotive industry, it’s unlikely that it will take over completely. CNC machining has a place in automotive manufacturing, one that it is not likely to give up anytime soon. Automotive lights are just one example of where CNC machining has a clear (no pun intended) advantage, but as we’ve seen in many cases, 3D printing and CNC machining continue to complement each other well, working better together than apart.

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