We analyze the key differences between these two processes so you can make a better decision for your next plastic project. 

Updated July 15, 2024

Controlled Fluidics is very selective about the technology, procedures, and materials we use to serve our customers. Several industries use specialized plastic components (like those in the healthcare industry, aerospace, scientific research, and more) in their regular operations. We understand fully what these components need to withstand. Many components we produce perform routinely in high heat, high pressure, and chemically aggressive environments, serving imperative purposes.

While each as their merits, 5-axis CNC machines and 3D printing meet different needs that maybe your project doesn't have. We'll go over when CNC machining would benefit over 3D printing and vice versa.

When would you choose to machine plastic components instead of 3D printing? It's important to ask these questions:

WILL I NEED ONLY A FEW PIECES (LIKE FOR A PROTOTYPE RUN), OR MUCH MORE THAT MIGHT BE CONSIDERED HIGH VOLUME?
Plastic machining can prove versatile in this regard. Whether the project calls for a few components or a few thousand, machining can meet the needed quantity without much issue, generally speaking. Additionally, plastic fabrication via machining tends to save time and money over 3D printing. 

WHAT'S THE EXPECTED SIZE OF THE ITEM I WANT TO PRODUCE?
Like 3D printing, plastic machining can produce large and small components. However, with 3D printing, there stands the chance that the finer details within a CAD file could be lost in the additive process. If your component has precise detail, thin walls, or has a feature that cannot tolerate some wide tolerances, then that needs consideration before proceeding on how to handle that challenge. 

WHAT MATERIAL WILL I NEED THIS COMPONENT TO HAVE? WHAT KIND OF RESISTANCES WILL IT NEED? DO I NEED TO THINK ABOUT ANY CERTIFICATIONS FROM REGULATORY BODIES?
3D printers can use only certain types of plastic, and that can limit the range of options for resins one can use. This also limits the types of finishes and resistances that a component can have. So here, the designer/engineer needs to consider what environment the component will regularly find use in. If a component needs to withstand exposure to harsh elements (e.g. UV exposure, radiation, and strong chemicals), then teams need to consider that factor when thinking of the component's expected material. If this is a prototype, maybe it won't need to have those qualities right away, and whatever material the printer uses will suffice for now. However, if needing to showcase the component in real-world situations, then teams need to work with an expert to find a suitable material for 3D printing that component. 3D printing often limits material options that could meet component's needs better. The same goes for regulatory bodies. Some materials are FDA approved for use while others are not. If teams 3D print a component with a material not approved, that could spell the end of that project. 

There are few disadvantages to CNC plastic machining, but they do exist. The drawbacks are that CNC produces more waste material from the subtractive process and setup costs are higher for small quantity runs.

Some circumstances apply where 3D printing will serve a customer’s needs better. Teams need to answer these questions:

WILL THE MATERIAL I NEED BE DIFFICULT TO MACHINE?
Some materials are more difficult to machine, especially if the component has complex geometries and configurations and/or have internal 3D structures. We strongly recommend consulting with a manufacturing expert to find out options if this is the case for your component. 

WHAT DO I PLAN ON DOING WITH THIS COMPONENT ONCE MADE? HOW SOON DO I NEED THIS IN MY HANDS?
For small quantities and prototype runs, 3D printing can provide a quick solution for testing design concepts while maintaining cost efficiency. Printers can also offer faster turnaround times for production, depending on several factors, including internal geometries and materials. 

While teams use 3D printing usually for making small samples of components that will be machined later, those components are not often used for final functional testing as they do not have the same properties and finish of the machined component. Designers and engineers need to consider this when thinking of their product's end purpose. Because of 3D printing's limited materials choices, this reduces design flexibility and oftentimes performance due to lower tensile strength among other setbacks. Also, components finish with a rough surface that we do not advise using for liquid flow.

We provide comprehensive support for each project from beginning to end, including help with design. Our experienced professionals inspect each prototype to see that each requirement is met. Click the button in the footer to get started!