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Mechanical part prototyping: choosing between 3D printing and CNC machining


The latest technologies have effectively taken mechanical machining to a whole new level compared to what was possible just a few years ago. The manufacturing processes have become extremely sophisticated and now make it possible to produce impressive parts. Two processes that are often considered for this task are CNC machining and 3D printing.

In this article, find out what the main differences between these processes are in order to help you choose the one best suited to your machining needs such as mechanical part prototyping.

What are the differences between CNC machining and 3D printing?

First, it is important to understand the differences between CNC machining and 3D printing processes.

3D printing is an additive manufacturing process that creates a physical object from a digital design. This object is then manufactured by gradually laying thin layers of materials (metals, plastic or cement, liquids or powders) that are then fused together.

Unlike the additive manufacturing process, CNC (Computer Numerical Control) machining is more of a subtractive manufacturing process. CNC boring machine tools are controlled using software integrated in a microcomputer that is linked to them. These machines can be used for machining metal, plastic or wooden parts.

Determine the most appropriate type of machining for your prototyping needs

Naturally, both CNC machining and 3D printing have several advantages. However, there are instances where one of these processes is preferable, such as in prototyping. In order to determine which one best suits your machining needs, you will need to consider the following factors.

CNC machining: an economic advantage and great versatility

There is a popular belief that CNC machining is an expensive process, since it would inevitably require hiring a specialized technician to operate this sophisticated machine. While this may have been true in the past, the automation of today’s CNC boring machines renders the task much less complex.

In fact, these machines employ user-friendly interfaces that virtually any machinist can learn to operate with a few days of training. There is therefore no need to rely on expensive expertise to manufacture parts in large quantities or produce a unique prototype.

In addition, CNC machining makes it possible to work with all kinds of materials that still cannot be printed, such as wood. CNC boring machines are also known for their high cutting accuracy, making them ideal for manufacturing fairly complex parts, such as custom gears or parts.

Special features of 3D printing

3D printing is often less expensive when it comes to making a single prototype. However, the price can vary depending on the material used in manufacturing the prototype, its volume and its complexity, all of which influence printing time. In addition, there are several post-printing steps required for the finishing of mechanical parts created by additive manufacturing, which are important to consider in your budget. For these reasons, this process may be less cost-effective when it comes to producing 50 or 100 prototypes.

The greatest advantage of 3D printing is its ability to produce parts with high geometric complexity. In fact, additive manufacturing makes it possible to create unique shapes that are impossible to make by subtractive manufacturing, such as openings at particular angles. If your industry has similar needs, 3D printing prototyping could be particularly attractive.

Contact Braidwood Industries Ltd. for the prototyping of custom mechanical parts

In conclusion, 3D printing and CNC machining each have their own particular uses. In the end, your choice will depend mainly on your budget, the type of material to be machined, the quantity of parts to be produced and their geometric complexity.

At Braidwood Industries Ltd., our team of machinists works with CNC boring machines, among others, to manufacture all kinds of custom mechanical prototypes. Contact us if you would like to do business with a Quebec machine shop.

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