When choosing to design a prototype or functional part, the first step is to decide which technology is right for your product. 3D printing and CNC (computer numerical control) machining are two of the best ways to arrive at exactly what you want.
While they use different technology and techniques to arrive at the desired finished product, they each have their positives and negatives depending on the job.
The following article will help you to understand which technology to use in different situations.
CNC machining or 3D printing?
The main difference between CNC machining and 3D printing is that CNC is a form of subtractive manufacturing while 3D printing is a form of additive manufacturing.
This simply means that CNC machining starts with a “chunk of material” and then cuts material away until the desired outcome is reached. 3D printing, on the other hand, involves a product being made layer-by-layer until the finished product is created.
What type of material?
While both forms of production can use many types of plastic and metal, they do have their own specialties. In general, a 3D printing service is usually very “plastics heavy” while a CNC machining service usually does its best work with aluminum.
The key is to decide which material your project will use and then decide whether a 3D printing service or CNC machining is a better match.
Ease of Use
3D printing is considerably easier to use. As a customer, this probably does not affect you a great deal, but it is still worth considering. With 3D printing, once the front end work is completed, the machine runs on its own power.
CNC machining, however, remains labor-intensive throughout the process which can lead to more mistakes.
In general, the most complex projects in terms of geometric angles will be better suited for 3D printing. On the other hand, larger-scale projects in terms of the thickness or overall size will be handled better by CNC machining.
In general 3D printing is less expensive than CNC machining. With high volume projects, this can change as you will see later in the article. The cost of 3D printers is mostly in the initial investment while CNC machining has higher costs per job with less upfront investment.
Do higher quantities matter?
In a word, yes. Higher quantities greatly affect the efficiency of 3D printing because it is not set up to produce high quantity orders. 3D printing is best known for producing great prototypes while CNC machining is better to set up for medium to large size orders.
Any order of over 500 parts and you should consider a different forming technology.