Design and construction of a modular sensor fixture to monitor a laser-wire direct energy deposition system

Abstract

One of the greatest challenges of additive manufacturing processes achieving a more mainstream placement amongst manufacturing methods is their lack of consistency and quality. Having a reliable way of monitoring the processes is a crucial step towards improving the quality and repeatability – sensing different process parameters during manufacturing makes it easier to find defects and monitor various geometric properties. Tampere University laboratory has a laser-wire direct energy deposition system – a machine for manufacturing metal parts using wire as a feedstock and melting it with a laser. One of the systems current drawbacks is its lack of dedicated mounting locations for sensors to achieve useful monitoring results in a repeatable way. The use of different improvised sensor mounting solutions is time consuming and was replaced with specifically built fixtures that met the requirements either given by the team that uses the machinery for experiments or were found out by studying the manufacturing process and the hardware – the requirements include features such as adjustment possibilities of the sensor heights as well as the hardware limitations of the sensors and the current machine itself. The design process consisted of a literature review, discussions with experts of the subject, several ideation processes and evaluations of their results, as well as calculations and simulations for component sizing. The resulting prototype design manages to fulfill all the primary requirements.