In recent years, additive manufacturing (AM)—commonly known as 3D printing—has gained significant traction across a wide range of industries. While traditionally, CNC machining has been the go-to method for producing high-precision parts, additive manufacturing is emerging as a complementary technology that offers new possibilities and advantages. When combined with CNC machining, these two processes open up new realms of efficiency, cost-effectiveness, and design flexibility.

In this blog, we will explore the advantages of additive manufacturing in CNC machining, how the two technologies can work together, and why adopting both can benefit your manufacturing operations.

Additive manufacturing refers to a family of processes used to create objects by building them layer by layer from a 3D model. Unlike traditional subtractive manufacturing processes, like CNC machining, which remove material from a solid block, additive manufacturing adds material in a controlled manner, gradually forming the desired part.

AM includes various technologies such as:

• Fused Deposition Modeling (FDM)
• Stereolithography (SLA)
• Selective Laser Sintering (SLS)
• Metal 3D Printing (Direct Metal Laser Sintering - DMLS)

These techniques allow the creation of complex geometries that would be challenging, or even impossible, to achieve using traditional methods.

While both CNC machining and additive manufacturing have their strengths and weaknesses, combining the two can lead to a more versatile and efficient production process. Here's how:

Complex Geometries and Design Freedom

Additive Manufacturing allows you to produce parts with highly intricate and organic shapes that would be difficult to machine using traditional CNC processes. This includes internal channels, hollow structures, complex lattice frameworks, and conformal cooling channels—elements that would be either impossible or prohibitively expensive to achieve through CNC machining alone.

With additive manufacturing, you can push the boundaries of design, offering greater freedom and flexibility to your engineering team.

Rapid Prototyping and Design Iteration

CNC machining is well-suited for producing highly accurate, finished parts, but it can take time to create prototypes and iterate on designs. Additive manufacturing allows for rapid prototyping. Engineers can quickly design, print, and test multiple iterations of a part, making real-time design adjustments based on performance, fit, or aesthetic requirements. Once the design is finalized, CNC machining can be used to produce the final, high-precision part.

This reduces time to market and ensures that final products are well-optimized before the production stage.

Tooling and Fixture Manufacturing

One often-overlooked advantage of additive manufacturing in CNC operations is its ability to produce custom tooling, such as fixtures, jigs, and clamps. These tools are essential for securely holding workpieces in place during machining, and traditional manufacturing methods can take weeks to produce them.

With 3D printing, companies can rapidly create tooling that fits unique parts or provides additional flexibility. This drastically reduces the time and cost associated with producing custom CNC tooling.

Material Savings

Additive manufacturing only uses the material that is necessary to create the part, leading to significantly less waste. In contrast, CNC machining often involves cutting away large amounts of material from a solid block.

For industries that work with expensive or rare materials, like titanium or inconel, additive manufacturing can result in substantial material cost savings. When used for prototyping, it can also minimize the need for expensive material and allow for more material-efficient designs.

Let’s take a deeper look into the specific advantages that additive manufacturing brings to CNC machining operations:

Enhanced Design Flexibility

Additive manufacturing enables the creation of parts that were previously impossible to machine or too costly to produce using traditional methods. CNC machining relies on specific tool geometries and limited cutting paths, but 3D printing offers unlimited design freedom. For example:

Complex internal geometries:

Additive manufacturing allows for the creation of parts with internal structures like cooling channels, cavities, or internal supports that would be difficult or time-consuming to produce with CNC machining.

Organic shapes: 

With additive manufacturing, it’s easier to produce organic, curvaceous designs that are not feasible with traditional subtractive processes.

Faster Lead Times and Prototyping

One of the greatest advantages of 3D printing is its speed, especially in prototyping. CNC machining can be time-intensive, especially when creating multiple design iterations or preparing tooling. In contrast, additive manufacturing allows for quick turnaround times:

Iterate faster:

Engineers and designers can print a prototype overnight and test it the next day, drastically reducing lead times compared to traditional manufacturing methods.

Rapid tooling: 

Custom tooling can be printed and tested quickly before moving to CNC machining for mass production. This iterative process speeds up the design phase and helps catch design flaws earlier.

Reduced Manufacturing Costs for Low-Volume Production

For low-volume or small-batch production runs, additive manufacturing can be more cost-effective than CNC machining. Traditional machining often requires expensive molds, tooling, and setup times, which can be prohibitively expensive for low-run production. In contrast, 3D printing:

No tooling required: 

There are no expensive molds or fixtures needed for additive manufacturing, making it ideal for low-volume production or custom parts.

Reduced labor costs: 

With 3D printing, the need for manual labor to set up and operate machines is often less intensive than CNC machining. This can result in significant labor cost savings.

Weight Reduction through Innovative Geometries

In industries like aerospace, automotive, and medical, reducing the weight of parts is often a priority for improving performance and efficiency. Additive manufacturing can be used to create lightweight structures without sacrificing strength or durability:

Topology optimization allows designers to remove unnecessary material from parts while maintaining their strength and integrity. This results in lighter components that still meet engineering requirements.

With lattice structures and other complex geometries, 3D printing can optimize material usage and reduce weight in a way that CNC machining cannot achieve.

On-Demand Production

Additive manufacturing also offers the ability to produce parts on demand. Instead of relying on a large-scale, traditional supply chain and waiting for tooling or custom parts to arrive, 3D printing enables on-site, on-demand production. This is particularly useful for:

Low-volume production runs: 

Businesses can produce small batches or even individual parts as needed without the need for tooling or long lead times.

Spare parts: 

Manufacturing companies can produce spare parts on-demand for maintenance, reducing downtime in operations where a quick replacement is required.

Customization and Personalization

In industries like medical devices, consumer products, and fashion, there is increasing demand for customized parts or products tailored to specific user needs. Additive manufacturing enables easy customization, allowing for:

Unique geometries and sizes: 

Custom parts can be made to exact specifications, whether it’s a personalized implant for a patient or a tailored component for a machine.

Mass customization:

Businesses can use additive manufacturing to provide customers with highly personalized products or services without significantly increasing costs.

Integrating additive manufacturing and CNC machining into a single workflow can create a highly efficient and effective manufacturing process. Here’s how to successfully combine the two:

Prototyping: 

Use 3D printing for rapid prototyping and testing before final production. Once the design is verified, CNC machining can be used to produce the final part with high precision.

Hybrid Production: 

Some machines offer hybrid manufacturing, which combines CNC machining and 3D printing capabilities. This can be especially useful for creating parts with complex geometries that require high-precision finishing or surface quality.

Tooling: 

Utilize additive manufacturing to create custom fixtures, tooling, or support structures that assist with CNC machining, optimizing the setup time and cost.

Post-Processing: 

After 3D printing a part, CNC machining can be used to perform fine-tuning, such as adding precise holes, fine surface finishes, or achieving tighter tolerances.

The synergy between additive manufacturing and CNC machining offers a wealth of opportunities to manufacturers looking to stay ahead in a competitive landscape. By combining the flexibility, speed, and material efficiency of 3D printing with the high precision and capability of CNC machining, manufacturers can produce innovative, cost-effective, and high-quality parts faster than ever before.

Incorporating both technologies into your manufacturing process allows for greater design freedom, reduced lead times, and the ability to create complex parts that would be difficult or expensive to produce using traditional methods alone.

Whether you’re prototyping, producing low-volume custom parts, or creating intricate designs for high-performance applications, the combined power of additive manufacturing and CNC machining is the future of modern manufacturing.