You might not have thought about it this way before, but the way your shop makes parts probably has always been subtractive. A block or bar gets milled or turned, for example, or a casting or forging gets milled and drilled. Material removal produces the form.
Starting in February, a new addition to Modern Machine Shop and Moldmaking Technology magazines will cover an approach to production that is the conceptual opposite of this. Additive Manufacturing, a quarterly supplement, will focus on the CNC technologies that add material in order to build parts layer by layer. “Digital manufacturing” and “3D printing” are other terms associated with this technology. The new supplement will look at the practical, industrial applications of this method of making parts—particularly the ways it is being used to make mold tooling, functional prototypes and end-use components.
Why devote a supplement to this topic? Because in the coming years, additive manufacturing is set to expand out of its current niche, growing to account for a noticeable and noteworthy portion of how discrete parts are made. Various factors argue for this prediction. They include:
1. Design possibilities. Additive processes make forms that are impractical to achieve any other way. Examples include lattice structures combining high strength and light weight, plus molds and airfoils with snaking internal channels for heat transfer. Certain engineering requirements are best met with an additively formed part.
2. Material efficiency. Manufacturers confronting higher material costs increasingly will see material removal as expensive waste. Additive processes increase material efficiency.
3. Complexity without cost. A form with intricate details or even customized details no longer needs the costs and steps associated with an intricate cutting cycle. Instead, the complexity can be built up within an additive cycle.
To be sure, comparing additive and subtractive today is not a case of comparing yin and yang. CNC machining is a proven, precise and well-understood means of making parts. Additive manufacturing faces hurdles related to tolerance, finish and process control. But innovation in this area is advancing rapidly. As hurdles are cleared, this decade will be the one in which the applications of additive start to add up.
Our new supplement will go to subscribers of Modern Machine Shop and Moldmaking Technology who are likely to have a serious interest in additive manufacturing technology soon. If that describes you, and you want to be sure to receive Additive Manufacturing, you can request it online. Click the checkbox for this supplement within the subscription renewal form available at mmsonline.com/subscribe or moldmakingtechnology.com/subscribe.
The inaugural edition of Additive Manufacturing features this article on 3D printing of functional parts as a complement to injection molding, as well as this article on using additive manufacturing to engineer conformal cooling channels into molds.