CNC Machining vs 3D Printing

You’ve probably heard of the 3D printed car or the 3D printed gun in the news lately and while there has been plenty of talk surrounding the capabilities of 3D printing around the world, manufacturing is still dominated by CNC machining production processes. Here’s why.

Process and Quality

CNC machining is a subtractive machining process, meaning material is removed as the part is being manufactured. A piece of solid material has pieces removed based on the specifications of the design by cutters and rotating objects. Because the base material stays intact as material is being removed, the material properties will mostly not be affected. There are various kind of machines available to create your product, but this is the general idea of how they function.

3D printers, however, build the product layer by layer out of fed material. So it is actually adding material (an additive manufacturing process) to create an end product. It can print really complex designs but the structural integrity of the finished component is questionable if not completely absent.

Limitations on Materials

With CNC machining, material usage isn’t very limited at all. Most machines can not only handle variations of metals but also some woods, plastics, and other specialized materials allowing flexibility and customization. Because you’ll likely choose a CNC machine for full-scale production, you will be able to create a part or prototype out of the exact material needed.

On the other hand, 3D printing does come with its limitations. While most 3D printers commonly use plastics as a source material, many advances in technology have allowed some metals and ceramics to also be available. Depending on the project, some 3D printers can use stainless steel, gold, silver, titanium, and aluminum and cobalt derivatives, all in powder form.

Finishes and Testing

Depending on the type of part you are interested in creating, surface finish and a production-ready product may be crucial.

CNC machining provides the ability to control surface finishes on custom parts as production is occurring, whether that be for mechanical purposes or simply for look-and-feel. The result is a part that is ready for testing and later full-run production.

After an object has been 3D printed, the finish is solely based on how the machine layers material on top of material. A different finish can be applied to the part after completion, however there is no guarantee that the finishing process won’t corrupt the structure of the part causing issues with testing. On top of that, you’re adding more time and costs to be able to finish a part to your specifications.

So CNC machining and 3D printing can be used for a variety of projects but mostly for different projects altogether. If you’re looking for parts and prototypes that are ready for use and testing, you’ll need a CNC machine shop to handle your project.

Contact the CNC machining experts at Texas Metal Tech today. We’ve worked with a wide variety of industries to complete projects on time and on budget. Call (281) 893-0411 today to get started!