Companies that design and manufacture plastic or metal parts often require rapid machining services at some stage.

This article explores the ins and outs of the manufacturing process and why it is important.

1. What is rapid machining?

Rapid machining is the machining of parts and prototypes with a focus on reducing the time it takes to make a part. It typically involves CNC machining (including milling, turning, etc.), but may also include manual machining of simple parts.

Machining can be accelerated in a variety of ways. Depending on the customer's requirements, rapid machining may involve the increased use of high-torque machines and roughing techniques to speed up material removal.

It may also involve materials that are easy to machine (such as aluminum alloys) rather than materials that take more time to machine.

While rapid machining is not mutually exclusive with precision machining, rapid machining can be seen as the opposite of precision machining, which prioritizes accuracy and detail over speed.

2. Advantages and Disadvantages of Rapid Machining

Rapid machining is an essential tool for rapid prototyping, product development, low-volume production, and custom parts. But it is not suitable for all manufacturing work.

Here are some of the advantages and disadvantages of rapid machining:

Advantages:

Fastest way to produce parts using CNC machining equipment

Quickly iterate prototypes to speed product development

Easy to make multiple versions of a part for mechanical testing, etc.

Fast time to market

Can make stronger parts than other high-speed processes such as 3D printing

No minimum order quantity

No tooling or startup costs

Compatible with a wide range of metals and plastics

Multiple surface finish options

Scalable, as CNC machining is suitable for post-production

Disadvantages:

Lower quality than precision machining

Lower geometric freedom than 3D printing

Slower than molding for large batch orders (100+)

Rapid machining

3. How does rapid machining accelerate product development and reduce time to market?

For decades, rapid machining has been the process of choice for product designers to advance products from one development stage to the next.

Rapid machining prototypes can be used for testing and evaluation, and multiple design iterations can be easily manufactured for comparative analysis. Some rapid machining parts are even suitable for end use.

It's easy to understand why designers and engineers turn to rapid machining for instant parts. In this day and age, most parts are designed using CAD software, and the exported design files can be processed by CNC machines with minimal preparation. This reduces the time gap between completing a prototype and receiving a finished part.

And this process often has to be repeated several times. If a product designer orders a rapidly machined prototype for testing, they may need to tweak the design and go through multiple iterations before the part can go into production.

Rapid machining also provides prototypes that are similar to the end-use part in terms of quality, mechanical properties, and appearance. Other prototyping processes, such as 3D printing and manual assembly, have their own unique advantages, but if the part is ultimately manufactured using a CNC machine, the machined prototype is obviously more representative of the final part after machining.

Sticking to a consistent manufacturing process can provide significant time advantages. If a 3D printed prototype must be redesigned into a machineable end-use part, a whole new design phase is added to the overall process. Rapid machining prototypes eliminate this need.

Therefore, a product development workflow using rapid machining might follow this line of thought:

Concept

CAD part design

Early concept prototype via rapid machining

Testing and evaluation

Working prototype via rapid machining

Mechanical testing and evaluation

Pre-production prototype via precision machining

Demonstration, marketing, etc.

Production

Distribution

Ultimately, faster product development and shorter time to market provide companies with a competitive advantage and a greater chance of market success.

4. What level of quality should I expect from rapid machining?

Rapid machining is most often used for prototyping. Therefore, customers should keep in mind that there are other options, such as precision machining, that may be better suited for highly detailed parts that require tight tolerances. As the name implies, rapid machining prioritizes speed over other factors.

That being said, rapid machining can produce professional-grade parts and prototypes to a very high standard.

Ordering parts from a rapid machining specialist ultimately allows customers to decide the level of quality they require by specifying tolerances and selecting materials that are of the right quality and price.

Loose tolerances, simple designs, and the use of highly machinable materials allow machinists to manufacture parts more quickly, with part quality taking a lower priority.

This is often a smart approach during prototyping and product development, as professional machinists can still produce high-quality parts while working quickly.

5. Time is of the essence: rapid machining or 3D printing?

3D printing has transformed the world of prototyping, enabling users to create one-off parts in a matter of hours. 3D printers can even be operated from an office, reducing the need for traditional factories and machine shops.

Due to the speed and ease of 3D printing, some product developers automatically turn to additive manufacturing when time is of the essence, rather than subtractive processes like rapid CNC machining.

But is 3D printing always the best option for fast turnaround parts? For in-house prototyping, there may be no better rapid solution than 3D printing, as 3D printers require little to no expertise to operate and can print parts in a matter of hours.

However, professional rapid machining services may be faster and produce better results than comparable 3D printing services.

There are some clear similarities between rapid machining and 3D printing. Both take a digital design and convert it into G-code, and both are all-in-one solutions that don’t require tooling or separate machines.

When choosing between rapid machining and 3D printing, keep the following factors in mind:

Some parts print faster; others machine faster

Although 3D printing is faster, it can take a long time to re-machine a 3D printed prototype into a final machined part

Both metals and plastics can be machined using the same machining equipment; 3D printers can only print one or the other

Machinery prototypes are often closer to the final part than printed prototypes