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September 29, 2021
The 3D printing business is a 10Billion USD global niche that is mainly focused on machine development (AMFG, 2020). Within this sector, there are today hundreds of companies dedicated to the manufacture of 3D printers with FDM (fused filament) technology, most of them with rectangular printing surfaces within the ranges of 200mm to 400mm.
Few companies currently offer printers with print areas larger than these, not because the market does not demand it, since many segments of the industrial sector require much larger sizes, but because there are certain technical problems that need to be solved and that some of these companies do not achieve successfully:
Filament 3D printing has a natural limit given by the amount of molten material that can be extruded through a nozzle. It is unfeasible to use desktop extrusion systems because printing times would increase drastically. Therefore, one of the most important technical aspects of a large format machine is the material flow that the machine's extruder is capable of handling. The Big-T model, for example, has an extruder system capable of consuming a standard 1 kg coil in approximately 1 hour, while a desktop model with E3D hotends would take 22 hours, which in terms of volumetric flow represents more than 20 times per unit of time. This feature, together with the possibility of reaching higher displacement speeds, makes it possible to manufacture giant parts in incredibly short times.
In 3D printing, speed is a key factor for production. With the development of advanced materials that compete with the qualities obtained by processes such as plastic injection molding, increasing the amount of printed parts per unit time is a mandatory goal if you want to take the next step and enter the final part manufacturing business. To achieve this, motion and electronic control systems that work in tandem to achieve micrometer accuracies are needed, typically in configurations widely used in the desktop machine industry that are replicated from one machine to another.
But when you want to design a giant machine, and achieve print displacements of up to 1 meter, on machines like the Big-T, you need to fine-tune the engineering. In these cases it is necessary to revise the technical definitions typically inherited from the desktop industry such as the use of Nema 17 steppers, pulleys and GT2 belts with simplified machine structures, and instead give way to robust structures engineered to absorb the problems associated with their own weight and the vibrations produced by the inertia of the movement of a heavier printhead, and to motion configurations from industrial-level machines such as CNC machining centers or SMT machines. Additionally, the power demands resulting from the use of more robust components, with characteristics superior to those of the desktop sector, require more sophisticated electronics and controllers, as well as customized firmware parts that squeeze the most out of their performance.
As with the foundation of a building, the first layer of a 3D printed object determines the success of the entire job, and achieving this is particularly difficult when the print surfaces are very large. Trideo, in its 1m3 Big-T model, manages an integral calibration formula that uses automatic digital compensation of the small curvatures of the printing surface plus an automated balancing of the structural Z-axis motion system that guarantees the equidistance of the first layer at every point of the surface. In addition, homogeneous surface heating and the use of surface adhesives complement the perfect adhesion formula.
Industry demands machines that are capable of 3D printing large parts. The time has come when the cost/benefit ratio is already similar to that of substitute technologies such as rotary or lamination, but with all the added value that additive manufacturing offers and at a small fraction of the development time.
