CNC Machining vs 3D Printing: Which to Use

Companies need to stay ahead of the competition when it comes to manufacturing.

That doesn’t mean simply adopting the latest and greatest manufacturing methods. Instead, it’s about knowing which technology to use for their projects. Currently, two of the most popular technologies on the MakerVerse platform are CNC machining and 3D printing (also known as additive manufacturing). CNC stands for “computer numerical control” and is a subtractive method used in manufacturing to create parts with high precision and robustness.

But which one is right for your project?

Before we dive into the details, there’s an important fact to consider: CNC machining and 3D printing are not rivals. They’re complementary technologies that can work together to help you achieve your manufacturing goals.

However, each technology has its strengths and weaknesses. Knowing when to use each one can be the key to success.

CNC machining (left) and Laser Powder Bed Fusion, a 3D printing technology (right)

CNC Machining Advantages

Subtractive Manufacturing Advantages

Precision and Accuracy: CNC machines can produce parts with extremely high precision and accuracy (0.0015mm for a 6 mm diameter). These machines are programmed with specific instructions, which they follow to the letter. This means CNC machining is ideal for producing parts with tight tolerances and high accuracy. CNC milling is a key process in achieving such precision.

Materials: CNC machining is a versatile technology that can work with various materials, including metals (like aluminum, steel, and titanium) and plastics (like ABS, PVC, and polycarbonate). Cutting tools are essential in working with these materials, ensuring precision and efficiency in the production process.

Speed: CNC machines can operate at very high speeds. This means that CNC machining is ideal for producing large quantities of parts quickly and efficiently. Furthermore, CNC machining is widely used as a conventional manufacturing process, so there’s a high level of expertise surrounding the technology that helps with this speed.

3D Printing Advantages

Flexibility and Customization: 3D printing is a highly flexible manufacturing technique that allows for customization and personalization of parts. You can quickly and easily produce parts without investing time and money in tooling or molds. This makes 3D printing especially popular for prototyping, as designs can be quickly and inexpensively tested.

Complex Geometries: 3D printing can produce parts that would be difficult or impossible to make with other manufacturing techniques. This is because 3D printing builds parts layer by layer, allowing for intricate and complex designs. It is particularly advantageous for creating complex parts that would be challenging to produce with traditional methods.

Speed: While CNC machining is faster for larger production runs, 3D printing is typically quicker for small production runs since tooling isn’t required.

Wondering which 3D printing technology and material is right for you? This interactive tool gives you the best technology/material combination.

FDM is a popular, low-cost 3D printing technology for polymers.

CNC Machining vs 3D Printing: When to Use What

There needs to be more than a one-size-fits-all solution in manufacturing. Depending on your part requirements, budget, and timeline, CNC machining or 3D printing is the best choice. Here are some factors to consider: choose CNC machining for medium to high quantities of parts with simpler geometries.

CNC machining is known for its precision and accuracy, but it can take longer to produce parts, especially for complex geometries. CNC machining is a subtractive manufacturing process, which contributes to its high precision.

Cost Differences

3D printing is often more cost-effective for parts involving complex geometries. CNC machining may be the less expensive if the parts are simple enough. Traditional CNC machining can be cost-effective for simpler parts due to its established processes and efficiencies. If your part requires costly materials, then a significant advantage of 3D printing is that unused materials can often be recycled for future production, which reduces costs.

Precision

CNC machining is known for its precision and accuracy, but it can take longer to produce parts, especially for complex geometries. The use of rotating tools in CNC machining contributes to its high precision and accuracy. 3D printing, on the other hand, can make parts that may not be as precise or accurate as CNC machining. Consider your timeline and part requirements when deciding between the two.

Material Properties

CNC machining can handle various materials, including metals and plastics, making it ideal for parts that require strength and durability. CNC machines can work with a wide variety of metal alloys, showcasing their versatility. Consider the properties of your material when deciding which technology to use.

While CNC Machining is often preferred for working with metals, metal 3D printing technologies such as Laser Powder Bed Fusion and Wire Arc Additive Manufacturing are becoming increasingly popular as the technologies improve. CNC machining is particularly suitable for producing metal components due to its precision and material compatibility.

Part Size and Complexity

For large parts, CNC machining is often the best choice. CNC mills are particularly efficient for producing large parts due to their speed and material removal capabilities.

How large are we talking? With MakerVerse, it’s possible to source CNC machined parts measuring 12 meters in the longest dimension.

CNC machining can produce parts with tight tolerances and better ensure consistency across large production runs. 3D printing, on the other hand, is better suited for smaller, intricate parts with complex geometries.

Choosing the Right Technology

So, when should you use CNC machining, and when should you use 3D printing? One should choose CNC machining for medium to high quantities of parts with simpler geometries. Here are some general guidelines:

When to Use CNC Machining:

• Large production runs

• Parts with strict tolerances and high levels of precision

• Parts requiring diverse materials, including non-standard materials

When to Use 3D Printing:

• Small production runs. Industrial machines used in 3D printing are capable of producing intricate parts with good dimensional tolerances.

• Parts with complex geometries and shapes

• Prototyping and experimentation

Getting Started with 3D Printing and CNC Machining

Of course, every project is unique, and there may be situations where a hybrid approach or a different manufacturing technique is the best choice. The manufacturing industry relies on both CNC machining and 3D printing to meet diverse production needs. For example, it’s quite common for CNC machining to be used as a post-processing technique for 3D printing metal parts.

The key is to work with experts who can help guide you through the process and ensure that your parts are produced quickly, accurately, and cost-effectively. At MakerVerse, that’s precisely what we provide. Our platform offers a full range of 3D printing and CNC machining technologies with guaranteed industrial quality.