**5. Conclusion**

This chapter demonstrates the application of three different AM technologies for the development of customised parts for the specialised multirotor UAVs—fused deposition modelling (FDM), selective laser sintering (SLS), and stereolithography (SLA). Special purpose multirotor UAVs are often produced in small series, with the option of personalization and modular design. In the case of prototyping or individual production, conventional manufacturing technologies are too expensive and not flexible enough to be able to make parts quickly and put them into exploitation. AM offers new possibilities for rapid development of UAV multirotor reducing costs and time of research, development, and production. To take full advantage of AM, a new design approach for AM is needed to achieve lightweight and durable structures of UAV parts. Preliminary tests have shown that the use of the proposed AM technologies is very promising in terms of designing parts of specialised aircraft, as many factors (i.e., geometry, strength, firmness, and weight) often have to be changed and adjusted during the design process. In future work, it is planned to use AM technologies to make parts of other aircraft subsystems and to integrate them in the overall multirotor UAV system. Furthermore, the oncoming tests of mechanical properties are expected to have a great significance for frame structure optimisation.
