Traditional CNC Machining is being rapidly replaced by 3D Printing for metal parts. Many companies are completely switching over to the new technology. However, there are some benefits to using both, as each has its own advantages and pitfalls to consider.
What is the difference between CNC Machining and 3D Printing for Metal Parts?
Both CNC Machining and 3D Printing start with a material and a design. It’s there, though, that the process converges. Essentially, CNC Machining uses a machine to get rid of excess metal around a programmed shape, such as a gear. This leads to excess metal waste that must be used someplace else or disposed of. 3D printing, on the other hand, uses a laser and metal powder to build a part one thin layer at a time until it is done. This results in less waste, provided the design for the part was programmed correctly.
Why Use Both CNC Machining and 3D Printing Together?
The descriptions above suggest that 3D Printing of metal parts would be the way to go. However, there are some downsides to this technology which can force a manufacturer to still use CNC Machining. For instance, the heating of the metal powder by a laser during the 3D Printing process can result in some loss of accuracy. Another downside of 3D Printing is the finishing process. Any part that needs a smooth finish may need to be blasted, sanded, or machined. Also, in some complicated designs, you will need to build in “support structures” which will keep the semi-molten metal from drooping or curling. These support structures may be small enough to removed with a Dremel, but some larger pieces may need to be drilling or milled out.
By utilizing 3D Printing and CNC Machining together, you can reduce waste, and improve metal part accuracy to achieve a great product.