Carlo Gorla –
Additive Manufacturing, or 3D printing, as you prefer: the ideal technology for Industry 4.0, but also the antithesis, if compared to the processes currently used to produce gears!
The direct shift, or almost, from a digital model to the product with production means of general use and independent from the specificity of the object to be implemented on one hand, opposed to machines, tools and processes conceived only to manufacture toothed wheels, of a well-defined geometric typology and concerning a precisely identified phase of the construction process, on the other hand.
If we think of the history of gears, in which the evolution of the products and of the machines to produce them are intertwined and connected in a way that only the advent of CNC machines has tarnished, even if only partially, some questions about the effective role of 3D printing in the manufacturing of toothed wheels seem more than licit.
To treat the theme, various distinctions would be necessary to identify correctly the reference context: gears for what applications, motion or power transmission? Of what material typology, polymeric or metallic? And many others. This is not anyway the place for a thorough and comprehensive discussion even if, in the light of the great topicality and relevance of the issue, I will risk expressing some remarks.
Referring to the high-performance gears of power transmissions, even if today industrial machines are available for the production of steel components, the idea that in short times the additive manufacturing can represent, in general, an alternative to other manufacturing technologies can just make us smile but, on the other hand, also for these applications, the 3D printing paves ways that would be otherwise hardly, or not at all, viable.
In the ambit of the prototyping or of the manufacturing of small batches for tests, the immediacy of the 3D printing annuls the biblical expectations for the construction of raw parts or the provisioning of specific dedicated tools, with relative costs, as we often hear whenever we conceive something innovative.
From the point of view of functional performances, the additive manufacturing allows unfeasible geometries with other processes: wheels with internal cavities, or with reticular structures, for instance, to implement lightweight transmissions or to achieve potential benefits of vibro-acoustic and NVH nature, eventually combining the geometrical cavities with opportune fillers.
Moreover, what is it worth saying about the product customization, where the possibility of producing small variants with almost null additional costs represents a peculiarity of the 3D printing?
Obviously, there are also some criticalities, such as the tolerances and finishes actually achievable, just to mention some of them, but I am optimist and I believe in the future of 3D-printed gears!