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The purpose of this paper is to present a solution for the levelling plate of fused deposition modelling (FDM) additive manufacturing (AM) systems. This automatic levelling system is presented as an evolution of actual systems, which uses a new ultrasound sensing system.

After obtaining a prototype, different tests were conducted for getting a system which solves the level plate problem and can be mounted in any FDM AM machine. Several benchmark models were obtained and compared with current equipment concepts for the validity of the product.

All tests were performed with high accuracy, enabling the production of geometries that could not have been achieved without this novel system.

This development will enable experienced users to set aside the problems of calibration and focus on the purpose of this type of machines, making prototypes.

A system architecture has been developed and integrated into an open hardware AM system, allowing real-time adjustment of the plate during each layer, thus eliminating the need of levelling the plate, allowing to achieve easier printing, and without increasing the cost significantly.

The purpose of this paper is to analyze the aerodynamic improvements obtained in a wing section with a NACA 0018 airfoil manufactured using the fused deposition modeling (FDM) technique with regard to a smooth surface made by milling. The creation of micro-riblets on the surface of the airfoil, due to the deposition of the material layer by layer, improves the general aerodynamic performance of the parts, provided that the riblets are parallel to the flow line. The incidence of the thickness of the thread deposited in each layer – to be the variable on which the geometry of the riblets is based – was studied.

The wing section was designed using 3D software. Three different models were designed by rapid prototyping, using additive and subtractive manufacturing. Two of the profiles were manufactured using FDM varying the thickness of the layer to be able to compare the aerodynamic improvements. The third model was manufactured using a subtractive rapid prototyping machine generating a smooth surface profile. These three models were tested inside the wind tunnel to be able to quantify the aerodynamic efficiency according to the geometry and the riblets size.

The manufacture of an aerodynamic profile using FDM provides, in addition to the lightness and the ability to design parts with complex geometries, an improvement in the aerodynamic efficiency of 10 per cent compared with profiles with a smooth surface.

With the aerodynamic advantage gained through the use of FDM positions, the additive manufacturing serves as an excellent alternative for the manufacture of lightweight aerodynamic parts, with low structural loading and with low Reynolds number (∼5·105). This technological advantage would be applied to the UAV (unmanned aerial vehicle) industry.

The study carried out in this article demonstrates that the use of FDM as a manufacture process of end-used parts that are subject to movement generates an additional advantage that had not been considered. The additive manufacturing allows us to directly manufacture riblets by creating the necessary surface so as to reduce the aerodynamic drag.