Prototypes: CNC or 3D Print?

3D printing is becoming a considerable player in the manufacturing industry. We know there are advantages of 3D printing over traditional manufacturing methods, but we also know 3D printing does not offer competitive mass production capabilities and can be limited in speed and accessibility. Similar things could be said about CNC machining. Let’s compare the two: CNC or 3D print prototypes?

Subtractive vs Additive Manufacturing

An obvious difference is that CNC minimizes the material being worked on while 3D printing creates more material. CNC advantages are its accuracy with compatible materials including wood, metals and plastic. 3D printing advantages are its freedom of shape, applications in many sectors, accuracy, speed and ability to cut costs and weight in parts.

Things get interesting when you discuss combining these capabilities into a single machine. There are some machines that have pursued this, for example a CNC mill of sorts with 3 axes, and a print head.

3D Printing vs CNC Machining: Materials

Both operations can use a wide variety of materials. However, 3D printing focuses more on plastic but you can expect to see a transition into more 3D printed metal sooner than later.

Ease of Use

Communities would agree that 3D printing is easier than CNC machining. Unlike machining, 3D printing can operate unsupervised. CNC requires more attention, there must be a skilled operator to make decisions about tools, speeds, cutting paths and any repositioning needs.

Accuracy, Size limitations & Geometric Complexity

SLS, FDM, DMLS metal printing vs CNC. Throw metal in the equation and CNC takes the lead. Different aspects of 3D processes compare differently to CNC functions. Though this may be true, 3D printing can achieve geometries that no traditional manufacturing method could achieve.


Machine vs machine, the 3D printer would be cheaper, but this is without considering the cost of the parts required for a given project. To produce in large volume, CNC would be more economical and for low volume projects 3D printing would achieve lower cost. Comparing these technologies, in terms of cost, it can be difficult for many reasons.

Environmentally Friendly

Excess material from machining is waste. It is important that this material be disposed of appropriately. This is not required for 3D printing.


These comparisons do not make one technique better than the other. They are both useful technologies and appropriateness should be determined on a case by case basis. Determine whether CNC or 3D print prototypes is right for you, by reading the full article here.

Categories: Prototyping