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CNC vs 3D Printing: A Comprehensive Comparison

Introduction

Computer Numerical Control (CNC) and 3D printing are two widely used technologies in the manufacturing industry, each with its own benefits. CNC is an older technology that has been around since the 1950s. Meanwhile, 3D printing is a relatively new technique that has grown in popularity immensely in recent years. Both methods may be used to create three-dimensional objects from digital models, but the approaches used and the capabilities of each are quite different. In this post, we are going to explore the differences between CNC machining and 3D printing, as well as highlight their respective advantages and disadvantages.

What is CNC?

CNC is a manufacturing process that involves the use of computer-controlled machines to remove material from a workpiece. These machines are programmed to follow a set of instructions that guide the cutting tool as it removes unwanted material to leave behind the desired pattern. CNC machines are used to create complex shapes and designs and can work with a wide variety of materials, including wood, plastic, and metal.

What is 3D Printing?

It is a type of manufacturing that is known as additive manufacturing. This process is essentially the opposite of what CNC machining does. Rather than cutting material away from a workpiece, 3D printers are adding material layer-by-layer to build up the finished component. The printer reads a digital model and deposits the materials in accordance with the geometry of the model. This technology is still quite new but has gained immense popularity over recent years due to its ability to quickly produce complex objects.

cnc drilling

Comparing CNC Machining and 3D Printing

CNC machining and 3D printing offer distinctive approaches in manufacturing, each with its own set of advantages and considerations. CNC machining, characterized by its subtractive nature, excels in producing high-quality prototypes and final parts with minimal post-processing requirements. On the other hand, 3D printing, with its additive process, shines in rapid prototyping and custom designs, particularly in-house, where it eliminates the need for different tools. Its ability to work with a variety of materials, including ceramics and thermoplastics, grants engineers the flexibility to create custom parts efficiently and is adapted for low volume production. While CNC routers boast speed and precision, 3D printers excel in handling intricate geometries and layer-by-layer fabrication, making them indispensable in certain volume production scenarios. Ultimately, the choice between CNC machining and 3D printing hinges on factors like volume, post-processing requirements, material suitability, and the engineer’s specific needs and preferences.

Both CNC machining and printing have their advantages and disadvantages. As with many tools and techniques, there often isn’t a single “better” system. Rather, the best tool for the job will depend on what the job is and what qualities the tool has to offer.

Here are some of the key differences between the two technologies:

1. Accuracy and Precision

CNC machines are known for their accuracy and precision. They can produce parts with extremely tight tolerance and repeatable results. CNC machines are often used in industries where precision is critical, such as aerospace and medical manufacturing.

While modern 3D printers are capable of producing objects with high levels of detail, they might not always be as accurate as CNC machines. This is why it is important to understand when to use CNC Machining, and when to use 3D Printing, with CNC Machining providing an overall greater accuracy.

2. Lead Time

CNC machines are faster than 3D printers when it comes to producing parts; they can produce parts in a matter of hours, whereas 3D printers can take days or even weeks to produce the same parts.

However, additive manufacturing has an advantage when it comes to lead time for prototyping. CNC machining requires a lot of setups, which makes switching between different products costly. Printing does not require much setup, making it much faster to go from one product to another. Because 3D printers can create objects quickly and inexpensively, designers can rapidly prototype multiple iterations of a design before finalising it for production. This ability to quickly iterate and refine designs can significantly reduce development time.

3. Cost

The cost of CNC machining depends on a variety of factors, including the complexity of the part, the type of material used, and the amount of time required to produce the part. CNC machining can be expensive, especially for small runs of parts, though it can be very cost effective for large runs.

3D printing, on the other hand, is relatively inexpensive when considering the cost of an individual part or workpiece. This is because 3D printers build parts layer by layer, and the cost is largely dependent on the amount of material used, not the setup. This makes 3D printing an attractive option for prototyping and small production runs.

4. Materials

CNC machines can work with a wide variety of materials, including metal, wood, and plastic. They can produce parts that are strong and durable, making them ideal for applications where strength and durability are critical. However, they produce a lot of waste, since the manufacturing process is, by nature, subtractive.

3D printing, on the other hand, with its additive nature, is allowing for precise control over the amount of material used. This means there is less material waste than with CNC Machining. 3D printing can also work with a variety of materials, but the range of materials is more limited than with CNC machines. 3D printers are typically used with plastics, resins, and a few metals. 

5. Applications

CNC machines are used in a wide variety of industries, including aerospace, automotive, and medical manufacturing. They are often used to produce high-precision end-objects, with complex geometries that would be difficult or impossible to create with current printing technologies.

Conversely, additive manufacturing is undoubtedly optimal to create unique and complex shapes that would be difficult or impossible to achieve with more traditional manufacturing processes. 3D Printing is ideal for prototyping and small production runs, and is also allowing for the production of quality end-objects, in industries such as architecture, fashion, and product design.

Different 3D Printing Materials

3D printers can work with a wide range of materials, including plastics, metals, and ceramics. Here are some of the most common materials used in 3D printing:

PLA (Polylactic Acid)

PLA is one of the most commonly used 3D printing materials. It is a biodegradable and renewable thermoplastic made from cornstarch or sugarcane. PLA is easy to print with and produces objects with a smooth surface finish. It is commonly used for prototyping, toys, and household items.

ABS (Acrylonitrile Butadiene Styrene)

ABS is a strong and durable thermoplastic that is commonly used in 3D printing. It is more difficult to print with than PLA and requires a heated bed to prevent warping. ABS produces objects with a glossy finish and is commonly used for automotive parts, toys, and household items.

PETG (Polyethylene Terephthalate Glycol)

PETG is a strong and flexible thermoplastic that is resistant to impact and heat. It is easy to print with and produces objects with a smooth surface finish. PETG is commonly used for mechanical parts, food containers, and medical applications.

Nylon

Nylon, such as Nylon PA12 and Nylon PA11, is a strong and durable thermoplastic that is commonly used in 3D printing. It is difficult to print with and requires a heated chamber to prevent warping. Nylon produces objects with a strong and flexible finish and is commonly used for mechanical parts, gears, and tools.

Metal

Metal 3D printing uses a variety of metals, including titanium, stainless steel, and aluminum. Metal 3D printing produces objects with a high strength-to-weight ratio and is commonly used in aerospace and medical industries.

Ceramics

Ceramic 3D printing uses materials such as porcelain, earthenware, and stoneware. Ceramic 3D printing produces objects with a high level of detail and is commonly used in art and design.

These are just a few of the most common materials used in 3D printing. The choice of material depends on the specific application and requirements of the part being produced. 3D printing technology is constantly evolving, and new materials are being developed all the time.

3d printed part being cleaned

Types of CNC Machines

There are several different types of CNC machines, each with their own unique capabilities and applications. Here are some of the most common types of CNC machines:

CNC Milling Machines

CNC milling machines are some of the most commonly used CNC machines. They use rotary cutting tools to remove material from a workpiece, producing a finished part with precise dimensions and smooth surfaces. CNC milling machines are used in a variety of industries, including aerospace, automotive, and medical manufacturing. 3D Printing is a great complement to CNC Milling.

CNC Lathes

CNC lathes are used to produce cylindrical parts such as shafts and rods. They work by rotating the workpiece while a cutting tool removes material from the surface. CNC lathes are commonly used in the production of automotive and aerospace components.

CNC Plasma Cutters

CNC plasma cutters use a high-temperature plasma arc to cut through metal. The machine is programmed to cut the desired shape, and the plasma arc melts the metal, producing a clean and precise cut. CNC plasma cutters are commonly used in metal fabrication and the production of custom metal parts.

CNC Routers

CNC routers are used to cut and shape a variety of materials, including wood, plastic, and foam. They work by using a high-speed rotating spindle and a series of cutting tools to remove material from the workpiece. CNC routers are commonly used in the production of furniture, signage, and cabinetry.

CNC Lasers

CNC lasers use a high-energy laser beam to cut through a variety of materials, including metal, plastic, and wood. They are commonly used in the production of custom metal parts, signage, and decorative items.

Each type of CNC machine has its own unique capabilities and applications. When choosing a CNC machine, it is important to consider the specific requirements of the application and the materials being used.

3D Printing vs Milling in Dentistry

In dentistry, both 3D printing and milling are used to create dental restorations such as crowns, bridges, and implants. Both techniques have their advantages and disadvantages.

Printing is ideal for creating dental models and for producing temporary restorations. The technology is fast and accurate, allowing dentists to quickly produce a model of a patient’s teeth or create a temporary crown while a permanent crown is being produced.

Milling, on the other hand, is ideal for producing permanent restorations such as crowns and bridges. Milling machines can produce restorations that are more accurate and durable than those produced by 3D printing. Milling is also faster than 3D printing when it comes to producing permanent restorations.

Cnc machining

Cost and Lead times

These two aspects depend on many different factors; that is why we encourage you to make the test using our online 3D printing platform. You can upload a 3D file of your choice and compare these two technologies’ costs and lead times. A quote will be generated automatically, as well as the lead times, depending on the production mode and materials you choose.

The price of your order is calculated thanks to four factors, the dimensions, the volume, the number of parts, and the production mode selected. 

Make the test: Upload your 3D design! If you have any questions, feel free to contact our team of 3D printing experts.

Are you looking for a manufacturing partner?

CNC machining and 3D printing are two widely used manufacturing technologies that have their respective advantages and disadvantages. CNC machines are known for their accuracy and precision, making them ideal for high-precision applications. 3D printing, on the other hand, is ideal for prototyping and for creating complex shapes and geometries quickly and inexpensively. The choice between CNC and 3D printing depends on the specific application and requirements, and both technologies have a place in modern manufacturing.

Using an online service bureau such as Sculpteo, there is no minimum order quantity, from a single object to 10 000+ parts, you can 3D print the exact amount of parts you need.  With 10+ years of expertise in additive manufacturing for production and prototyping, Sculpteo is also offering rigorous quality control. 

Sculpteo offers a wide selection of high-performance materials developed by BASF and dedicated to demanding applications. From automotive to consumer goods, including robotics or medical. Sculpteo provides adapted manufacturing tools and support to all businesses, helping them to reach the next level.  We’ll take care of your orders in our industrial ISO 9001 factory!

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