## 2 Methodology
### Design of Other Components of The Structure  
Based on a theoretical analysis dealing with FDM technology, we know that key components characterize each device's design. In our case, the following features are the effector with the print head, the Bowden extrusion system and the print pad. The design of the printing pad is based on knowledge from the field of FDM technology. The designed printing pad has a relatively simple manual positioning system (Figure 24). This is based on the principle of tightening the screw (5) and the \"T\" nut (8) located at the top of the printing pad (1). By turning the screw, we derive the pressing force, which moves one of the corners of the printing pad downwards or upwards when it is released. By positioning each corner of the pad in this way, we then achieve the base's correct position for the  
Figure 23: Structural design of the X, Y, Z and Z’ axis arm. (**a**) The arm of the first stage of the proposed construction; (**b**) the second stage arm; (**c**) trolley in Z and Z\({}^{\prime}\) axes. printing process. Due to the series-connected design used and the fact that our proposed solution is based on the principle of a kinematic model that has not yet been tested, it was not our intention to complicate the solution using automatic calibration tools. Their simple design and the principle of operation were based on averaging the position of the limit switch during calibration. In the case of larger deviations, it would average a value higher than the layer's height during printing. This fact could cause insufficient or no adhesion of the material to the printing substrate in this design. The conclusion of the design is conceptual solutions of the effector and the system for material extrusion. These devices form one unit and are located at the end of the X, Y, Z and Z\({}^{\prime}\) axes. The effector has six joints for the joints, which were created to verify the kinematics of the six-axis device and as support elements that would be needed when using aluminium profiles in the arms and to verify the kinematic model and possible collisions. A Bowden material extrusion system was chosen in the design to reduce the weight of the effector. It is basically a standard system with commonly available components. It is based on the Nema 17 (9) drive, which ensures the fibre's extrusion. Extruder design that provides the pressure required to extrude the material (Figure 25). The material is moved through a pneumatic coupling (10) in which a PTFE tube (11) is fixed from the extruder. Inside, the material slides toward the print head (12). There it is heated to the desired temperature and is subsequently extruded in the form of a molten fiber through a nozzle (13). An atypical nozzle was chosen for the design, which will allow the creation of non-planar surfaces on a larger scale. The effector (2), i.e., a key component of the proposed device, consists of bearings. A movable joint is formed between the effector and the end element of the arms X and Y of the second stage after the screw connection has been formed. The bearings are positioned within the effector so that their axis is always parallel to the axis of the lead screw of the respective axis. Other elements of this printing set are fans used as standard. A 20 \(\times\) 20 \(\times\) 10 mm centrifugal fan (7) for cooling the passive cooling of the print head and a 40 \(\times\) 40 \(\times\) 10 mm axial fan (3) for cooling the layer of material on the printing pad. Both of these components are fixed to the effector body through standard screws (4, 6). The last component of this assembly is the blower used to direct the airflow under the nozzle. The application of theoretical knowledge to designing a device for printing non-planar surfaces can be seen in Figure 26. The resulting device consists of two pairs of identical arms that connect the individual axes with the end effector. The base frame is made of aluminium profiles measuring 20 \(\times\) 20 and 20 \(\times\) 40 mm.