What Role Will CNC Machining Play in the Future of 3D Printing?

The full capability of 3D printing in the manufacturing environment is just being realized. In its earliest days, 3D printing was used mainly for creation of prototypes. Today, the move is towards production with additive manufacturing processes.

What role will CNC machining, long the mainstay of manufacturing, have going forward?

Complexity vs. Precision

3D printing is an additive process and CNC is a cutting/removal process. This difference holds both the pros and the cons of either process. 3D printing is an additive process, where material is built up to specific form, based on a software program. Because the process is controlled via programming, it supports the creation of complex geometric shapes. 3D printing offers maximum flexibility of design. It is also the preferred method when fast turnaround time is important.

On the other hand, CNC is a subtractive process. It begins with a solid block of material that has material cut away to make a part. CNC offers consistent production over high volume runs and precision to tight tolerances. It can also be used for custom pieces or small runs, though these will be more costly because of the tooling needed. CNC pieces will be uniform, so it is the preferred choice where precision of multiple parts fitting together is required.

Tom Kohm, President & CEO of Premier Equipment explains further,“3D printing starts from nothing and has to build up from scratch. It's very costly and more of a process used for prototyping. When you are using a CNC, you are starting with a piece of metal that was made at a forge and it is much, much cheaper to take metal away to create a part than it is to start from nothing and continue to add.”

Looking ahead

One area that is driving the big change from straight 3D printing to additive manufacturing is materials. 3D printing is no longer plastic only. Making parts from challenging materials such as titanium, which has out-of-reach CNC production costs, becomes economically feasible with 3D printing.

There are jobs where the limitations of 3D printing can be not only overcome, but actively turned to advantage. Suppose the requirement is for an item with complex contours and tight tolerances. It can be produced by the 3D printing process since that is the best choice for parts requiring complicated geometry. The part can then be machined by CNC to the precise tolerances. 3D printing will get it close, and CNC can complete the detail work.

The use of CNC finishing methods for 3D printed parts drives the economics of the expected growth of additive manufacturing. Industry watchers predict that top performing companies will be looking to 3D printing as a key factor in staying competitive, especially with greater data integration of the CNC piece.

3D printing will gain in speed and quantity of production while reserving CNC for the areas where it performs best. The future of additive manufacturing will be a seamless software-driven union of the two technologies.

This article does not necessarily reflect the opinions of the editors or management of EconoTimes