Hybrid Manufacturing Technique Holds Revolutionary Appeal 

Manufacturing processes fall into two major camps: the additive approach exemplified by 3D printing and the subtractive method used in machining. Product designers have up-to-now been forced to choose between one or the other, but "a best of both worlds" solution is on the horizon.

According to an article at MIT's Technology Review website, there's a new industrial revolution afoot, which could very well alter the nature and economics of manufacturing. The three main contributing factors are:

• Free 3D design software, such as Google Sketchup.
• 3D printing, which turns virtual designs into physical models.
• The falling cost of 3D printers and other rapid prototyping techniques.

For cost-conscious manufacturers atuned to the mantra of "mass production," the "make-on-demand" approach is quickly becoming a viable option. Albeit, one with size limitations.

In fact, neither manufacturing technique is perfect:

Subtractive techniques such as high speed machining are fast but cannot create certain complex shapes. Additive techniques such as laser sintering of metal powder (a type of 3D printing) cannot easily make big solid objects because internal stresses build up in the solid parts as they cool, leading to distortions.

These challenges are well-known in the industry, but now researchers from the Institut de Recherche en Communications et Cybernétique de Nantes (IRCCyN) in France are working on a solution that aims to leverage the best parts of the additive and subtractive approaches. Their "Design for Manufacturing" system sees products as 3D puzzles made up of module components. It then determines which modules will benefit from being machined and which ones are most suitable for an additive process design. The software takes into account factors such as the size of the object, its volume, the flexibility of a given cutting tool and the distance of parts of the object from the center of the manufacturing platform.

This hybrid approach combines the advantages of additive and subtractive manufacturing, and in doing so promises shorter lead times, lower costs and possibly a higher-grade end product.

The related research paper, A new DFM approach to combine machining and additive manufacturing, authored by IRCCyN's Olivier Kerbrat, Pascal Mognol and Jean-Yves Hascoët, can be found here.