## 3 Results and Discussion  
### Description of the Collected Data  
Mechanical properties depend on the part orientation, and this phenomenon is already presented in [12]. Therefore, the description of the mechanical properties should be done separately for each orientation. Four orientations were used in the current analysis, which are XYZ, XZY, ZYX, and Angle (45\({}^{\circ}\) between the X and Z axes) orientations. Tables 2-4 describe the data based on the Tukey range test (looking at percentiles), including standard deviation values. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Statistical Characteristics** & **XYZ** & **XZY** & **ZYX** & **Angle** \\ \hline std & 31.912 & 35.776 & **95.763** & 46.63 \\ mean & 1066.308 & 1051.951 & 958.25 & 1013.545 \\
25\% & 1046.308 & 1035.374 & 908.038 & 983.455 \\
50\% & 1067.77 & 1055.196 & 980.038 & 1010.291 \\
75\% & 1088.461 & 1074.403 & 1032.381 & 1043.599 \\ max & 1148.078 & 1112.222 & 1090.35 & 1118.547 \\ min & 968.483 & 933.376 & **648.079** & 907.983 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Statistical data evaluation for Tensile modulus for each orientation separately. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Statistical Characteristics** & **XYZ** & **XYZ** & **ZYX** & **Angle** \\ \hline std & 0.665 & 0.604 & **5.101** & 3.334 \\ mean & 37.341 & 35.429 & 22.031 & 30.773 \\
25\% & 36.918 & 35.019 & 18.303 & 28.478 \\
50\% & 37.476 & 35.491 & 22.19 & 29.91 \\
75\% & 37.832 & 35.809 & 25.826 & 31.383 \\ max & 39.186 & 36.576 & 32.241 & 37.744 \\ min & 35.519 & 34.132 & **10.09** & 26.219 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Statistical data evaluation for Nominal Stress for each orientation separately. The results illustrated in Figure 4 support the anisotropic behaviour of PA 12 reported earlier [13; 23]. While the Tensile moduli for the XYZ and XZY orientations have similar distributions, the tensile modulus for the ZYX orientation has the widest variance and the lowest value. Tensile modulus for Angle orientation has a narrow distribution, while the maximum value of Tensile modulus is 1065 MPa. In addition to variation between orientation, variation between the nominal value (provided by EOS for balanced machine settings for PA2200 material) and obtained results is also observed for Tensile modulus. Similarly to the Tensile modulus, the distribution of nominal stress for different orientations is presented in Figure 5. The results of the XYZ and XZY orientations are similar to the Tensile modulus, although distribution for the ZYX orientation is much wider and the average value of nominal stress differs from the average value of the XYZ and XZY orientations. Additionally, if we compare the maximal value for the ZYX orientation with the value provided by EOS, one can observe that nominal stress is almost two times lower (from Table 3 it is ca. 22 MPa, while 42 MPa is expected) than that provided by EOS (dashed line in Figure 5). However, the value of nominal stress for Angle orientation is better than for ZYX. It is still relatively low compared with the results for the XYZ and XZY orientations. Elongation at break compared with two other mechanical properties has more similar results to the ones provided by EOS, and is illustrated in Figure 6. According to the EOS datasheet, elongation at break is expected to be 4% for the ZYX orientation and 18% for the XYZ orientation. The average value of elongation at break for the ZYX and XYZ orientations are ca. 3.5% and 13.4%, respectively (taken from Table 4). Since there is no information from the EOS for other orientations, the observed values for the XZY and Angle orientations cannot be compared with nominal ones. However, it is expected the XZY orientation should have similar results to the XYZ orientation due to the dominating X-axis, and thus slicing of the specimens is performed perpendicularly to the direction of force load in a tensile test.