Conclusions

  1. Conventional manufacturing is mainly limited by production run size and the geometrical complexity of the component, and we are occasionally forced to use processes and tools that raise the final cost of the element. What is more, some manufacturing processes do not comply with a commitment to sustainable manufacturing (contamination, recycling, etc.).
  2. Additive manufacturing is one of the key tools for tackling the growth and the creation of added value and high quality employment.
  3. Conceptually, the term 'additive manufacturing' describes the technology in general and it is used when referring to industrial component manufacturing applications and high-performance professional and industrial equipment. Other terms exist, with the best known being "rapid prototyping and 3D printing", in accordance with the scope of the model and the type of additive machine used.
  4. Additive manufacturing techniques provide huge competitive advantages because they adapt so well to the geometrical complexity and the customisation of the design of the part to be manufactured. The following can also be achieved in accordance with the sectors of application: lighter weight products, multi-material products, ergonomic products, short production runs, fewer assembly errors resulting in lower associated costs, lower tooling investment costs, a combination of different manufacturing processes, optimum use of material, more sustainable manufacture.
  5. Even though this type of process began as a new independent technology, nowadays additive manufacturing is a manufacturing system more, comparable to others such as subtractive manufacturing or foundry. Therefore, the protocols for the classification of additive manufacturing processes do not have to be different from those applicable to other manufacturing systems.
  6. The drawbacks are: the finish of complex surfaces can be extremely rough, long production times, materials with limited mechanical and thermal properties which restrict performance under stress, higher tolerances than with other manufacturing methods such as those based on material removal.
  7. The study variables habitually taken into account when choosing the prototyping technology are: resolution-precision, the mechanical and thermal properties of the material, surface finish, production time and the cost of the prototype.
  8. The manufacturing precision is the result of superimposing different errors in the production of the model which affect the surface quality, the dimensional accuracy and the final weight of the model. The errors that occur in this process are: an error in the conversion of the 3D model into STL format (triangulation of the geometry), an error in the decomposition in layers of the 3D model (exact division of the thickness), stepping effect error (orthogonal deposition of the material by layers) and, finally, model infill error.
  9. Three-dimensional models with an aesthetic (visual) or assembly objective and functional models capable of withstanding mechanical testing can be achieved.
  10. Additive manufacturing can be applied across many sectors and it can be easily adapted to the demands of each of them.
  11. Design and printing using 3D printers is seen as being one of the major industrial revolutions of the nest few years. Proposals exist for making the manufacture of low-cost RepRap distribution units available to people all over the world via communities of users and developers who exchange 3D models, know-how and experiences for optimising the manufacturing performance of a self-replicating 3D printer.
  12. It still seems puzzling that the first scientific publications relating to the important movement that is additive manufacturing came to light several years after the development of the first inventions, the first patents and even the first commercial communications on the advance.
  13. It is also strange that the RepRap movement did not gain ground in academic environments at the beginning, and only found its niche when the movement was justified as "machines that can replicate themselves" when, as is known in technical environments, there were already milling machines available more than one hundred years earlier that were able to self-replicate.
  14. The choice of technology is directly dependent on the particular application being planned: first the application, then the technology. Laser systems are being increasingly used, especially in the field of finished part production. In the future, the use of print technology systems is going to increase by the day.