What Is CNC Prototype Machining and When To Use It?

When you need to order detailed and functional prototypes for a product or part, CNC prototype machining is a tried-and-true process that may suit your project perfectly. In this article, we will take a deeper look into the CNC prototype machining process, its advantages and applications, how it compares to other rapid prototyping technologies, and how to progress from CNC prototypes to full-fledged CNC production.

What is CNC Prototype Machining

CNC prototype machining is a subtractive manufacturing process whereby physical prototypes or products models are made using computer numerical control (CNC) machines. These machines are programmed to precisely and automatically shape and cut materials, such as metal and plastics based on digital design specifications. This is known as a subtractive process, meaning the prototype is made by cutting material away.

CNC machines work based on a pre-uploaded file called a CAD file, which only the computer can read. In other words, there is close to no human involvement in the production process. This makes CNC prototype machining one of the most reliable ways to make prototypes due to its speed and incomparable accuracy that allows engineers and designers to test and validate their designs before moving on to full-scale production.

Advantages of CNC Prototype Machining

As you may or may not already know, you have many options when it comes to manufacturing prototypes. Why use CNC for prototypes? In answer, here are 5 advantages that make CNC prototype machining so attractive among product engineers and designers.

1. Yields Fast Turnaround Time

CNC machining offers rapid prototyping, which means that prototypes can be created relatively quickly compared to traditional machining methods. This allows for faster design iterations and a shorter time to market.

2. Highly Repeatable

Since CNC machines are operated by a computer, it produce prototypes with a high degree of consistency. This repeatability ensures that multiple prototypes will be virtually identical, making it easier to evaluate and refine the design.

3. Very Precise

Another reason that CNC is so popular for prototypes is how it produces precise prototypes with high tolerance specifications. This means that the prototype can be extremely detailed – almost to the point that it is just as (or nearly) detailed as the final end use part.

4. Available in a Wide Range of Materials

With CNC prototype machining, you’re not limited to certain types of material. Your parts can be machined from a wide range of plastics as well as metals, including copper, aluminium, and stainless steel. This flexibility in material choice allows designers to experiment with different materials to find the most suitable one for their final product.

5. Suitable for Complex Geometry

CNC machines excel at creating prototypes with intricate and complex designs. They can handle three-dimensional shapes and intricate details with ease, which is especially valuable for industries like aerospace, automotive, and medical devices.

When To Use CNC Prototype Machining (+ Applications)

CNC prototype machining is a versatile and valuable tool in various industries for creating prototypes and models. It is typically used when:

1. Testing New Product Designs: CNC prototype machining is ideal for testing and validating new product designs. It allows designers and engineers to create physical models quickly and accurately to assess not just the appearance but also form, fit and function.
2. Iterative Development: When a design needs multiple iterations and refinements, CNC machining can produce prototypes rapidly, facilitating the testing and refinement process.
3. Material Evaluation: It is used to test and evaluate different materials to determine their suitability for a particular application. This is valuable for selecting the best materials for the final product.
4. Low-Volume Production: For low-volume production runs, CNC prototype machining is cost-effective and efficient, offering a viable alternative to traditional manufacturing methods.

Applications of CNC prototype machining are widespread and include:

• Medical: It goes without saying that the medical industry needs tools and equipment that are as precise and flawless as possible. Lives literally depend on their proper function. CNC machining offers the accuracy needed to properly demonstrate how new innovations will work in this field via prototypes.
• Automotive: CNC prototype machining can help automotive companies test parts that will contribute to the functionality (and more importantly, the safety) of new vehicles.
• Aerospace: Just as in automotive, precision is key in the aerospace industry. One small deviation or flaw could cause ripple effects that compromise entire aircraft, making it dangerous for them to be used. CNC machining is accurate enough that aerospace engineers rely on it to make manifolds, parts for landing gear, and other essential aircraft components.
• Consumer Electronics: Prototyping for gadgets, mobile devices, and other consumer electronics to test their functionality and aesthetics.
• Oil & Gas: CNC machines are often responsible for producing parts for the oil and gas industry, including drill bits, spacers, hydraulics, and more. You’ll also find CNC prototype machining used in the military industry, and to produce electronics.

CNC Prototype Machining Vs 3D Printing

When thinking of prototyping technologies, you will often across different methods CNC machining and 3D printing. CNC prototype machining and 3D printing are two distinct but complementary technologies in the realm of rapid prototyping and product development.

3D printing is additive, meaning it produces prototypes or parts by printing them layer by layer. Meanwhile, CNC machining is subtractive. Essentially, it carves the prototype out of raw material by removing sections of the material that don’t fit with the desired design.

Because 3D printing is an additive process, it allows for the creation of more intricate and complex geometries that would otherwise be challenging or impossible to achieve through traditional subtractive methods. For this reason, it also allows for minimal material waste, as it only uses the exact amount of material required for the model.

In contrast, due to its subtractive nature, CNC prototype machining is ideal for achieving extremely precise and accurate prototypes that often cannot be achieved with 3D printing technologies.

From CNC Prototypes To CNC Production

One of the biggest benefit of using CNC prototype machining is the pipeline to production. In most cases, prototypes are produced close to the end of the ideation phase, right before mass production of the final product begins. CNC machining can produce highly accurate prototypes that are just as functional as the end use part. They can even be made of the same materials.

This means that once the prototype has been approved, it is a simple matter to go straight into production of the end use part. Thus, the pipeline from CNC prototype to CNC production is natural and quick.

Now that you’re confident in the knowledge of how CNC prototype machining works and when it’s best used, we encourage you to contact an expert at HLH Rapid and get a quote on your next prototyping project.