The importance of creating a viable prototype from a design schematic has been long established in manufacturing. However, options for prototyping remained largely limited until the explosion of viable 3D printing technology over the past decade. The increased use of 3D printing in manufacturing applications has led many to wonder why they should consider any other type of prototyping to demonstrate new product capabilities.
Although lacking the glamour of 3D-printing, CNC rapid prototyping is a quality, trusted option when a prototype must be created. And although 3D-printed prototypes do present design teams with a different array of benefits, there are many scenarios in which there is no substitution for quality, CNC-machined part. Not only can these be produced just as fast as 3D-printed parts, but CNC prototypes can have the same strength and quality as the anticipated full-production product.
What Is the CNC Machining Process?
CNC machining is a manufacturing process that creates parts by utilizing inputted computer parameters to control machining tools. The primary benefit of CNC machining is that materials that are harder to manipulate can be cut and crafted to create a product that falls easily within designed tolerances. This minimizes the reliance on quality control since once a CNC machine has its instructions and has been properly calibrated, it can accurately repeat the production process.
The process for CNC machining starts in the same way as other common types of prototyping, like 3D-printing. Building a product using 3D-CAD software and simulation tools is a must, requiring that the CAD-operator and the software being used are at the peak of their game. All steps must be aligned to best practice design fabrication processes and the specific instructions required by CNC machinery, such as drills or lathes.
But unlike 3D-printing, CNC machining is a subtractive process, which means that the required components are cut out of the required materials. At a glance, this may seem wasteful, but when a properly planned design is in place, the CNC operator can select a block of material that best fits the specifications in the design. The ability of a CNC machine to build components out of the same materials as your final product presents you with the capability to have a fully functional prototype.
How Do CNC Machining Strengths Align with Rapid Prototyping?
The strengths of CNC machining—high accuracy and speed, ideal material strengths, and computer-assisted controls—align with the rapid prototyping process on all levels. Like 3D-printing, CNC machining has a low-labor footprint and minimizes the effects of process variations as a result of its ability to take its guidance directly from the product’s design specifications. But the places where CNC machining stands out in rapid prototyping is something that a 3D-printing just cannot yet accomplish.
CNC machines produce prototypes at a much faster rate than other prototyping methods, often using the same materials as the final product. This allows for improved performance accuracy during testing and demonstrations, as well as the ability to utilize prototypes for post-sale support training or models for solving defects. These, and the ability to easily make size reductions in components, make CNC-built prototypes ideal candidates for generating rapid prototypes.
Although only indirectly related to rapid prototyping, the building of molds and casting models using CNC machining should be considered here as well. The ability to guide CNC machines using CAD-defined measurements to build strong and unchanging castings or molds gives CNC machining another notch in the prototyping win column. This allows material pours or base outlines for other prototyping methods to be quickly built with the same high level of accuracy as in the production of parts and components.
Where Do the Advantages of CNC Rapid Prototyping Stand Apart from the Others?
The criticisms of using CNC machining in rapid prototyping quickly fall off the tongue: it is more costly than 3D-printing and can contribute to the wasteful use of materials. Also, CNC machining cannot achieve the same highly complex internal geometric structures that additive prototyping methods can accomplish. But taking a step back to see that CNC machining is not used for prototypes in these categories and that most material scraps are recycled will make it easier for you to see the benefits.
The quality, consistency, and trueness of the final product are what make CNC machined prototypes stand out. Any prototype that needs to demonstrate a close or exact operational match to the final project is a perfect fit for CNC machining. A prototype that needs to be created quickly from a digital CAD drawing out of the same materials as will be used in its final product is a perfect fit for CNC machining.
Determining the best rapid prototyping solution for your project is a crucial step before moving to final production. Engaging a manufacturing consultant that specializes in getting manufacturing projects off the ground will allow you to see the benefits offered by CNC machining to your particular project. And, even if CNC machining turns out to not be a perfect fit for you, your manufacturing partner will help identify the best prototyping solution for you.
PRL is an end-to-end manufacturer—we pride ourselves on handling every aspect of the process for our partners. Our experts are here to guide you through each step of design, prototyping, customer analysis, development, manufacturing, and delivery.