## 3 Results and Discussion
### Summary of Research Results  
The conducted tests of surface roughness, as well as dimensional and shape accuracy, allowed for the elaboration of samples classification according to the adopted criteria for technological quality assessment. The prepared ranking was presented in Table 3.  
Based on the data in Table 3, it is possible to select FFF process parameters to achieve the most favorable results for the various technological quality indicators considered in the  
Figure 15: Average values of length and width deviation of perpendicular niches for the nine samples measured. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & & & \multicolumn{6}{c}{**Sample Designation**} \\  & **S1** & **S2** & **S3** & **S4** & **S5** & **S6** & **S7** & **S8** & **S9** \\ \cline{2-10}  & **Rating Indicator** & \multicolumn{6}{c}{**Ranking (1 Best, 9 Worst)**} \\ \hline  & Model manufacturing time & 6 & 8 & 9 & 3 & 5 & 7 & 1 & 2 & 4 \\ \hline \multirow{3}{*}{Surface roughness} & _Rq_ parameter & 1 & 3 & 2 & 5 & 6 & 4 & 7 & 9 & 8 \\  & _Rq_ parameter & 1 & 3 & 2 & 6 & 7 & 5 & 7 & 9 & 8 \\  & _Rz_ parameter & 1 & 3 & 2 & 5 & 6 & 4 & 7 & 9 & 8 \\ \hline \multirow{3}{*}{Dimensional accuracy} & Average deviation of cylindrical protrusion diameters & 5 & 3 & 4 & 7 & 1 & 6 & 9 & 2 & 8 \\  & Average deviation of cylindrical opening diameters & 2 & 6 & 1 & 5 & 8 & 3 & 9 & 7 & 4 \\  & Average length deviation for protrusions & 1 & 2 & 4 & 5 & 3 & 6 & 8 & 7 & 9 \\  & Average width deviation for protrusions & 4 & 2 & 7 & 5 & 1 & 8 & 6 & 3 & 9 \\  & Average length deviation for niches & 1 & 3 & 2 & 6 & 4 & 5 & 7 & 8 & 9 \\  & Average width deviation for niches & 9 & 6 & 8 & 3 & 2 & 1 & 7 & 4 & 5 \\ \hline \multirow{3}{*}{Shape accuracy} & Average angular deviation of cylindrical protrusions & \multirow{3}{*}{2} & \multirow{3}{*}{1} & \multirow{3}{*}{9} & \multirow{3}{*}{8} & \multirow{3}{*}{7} & \multirow{3}{*}{3} & \multirow{3}{*}{4} & \multirow{3}{*}{6} & \multirow{3}{*}{5} \\  & relative to the reference plane & & & & & & & & & \\ \cline{1-1}  & Average angular deviation of cylindrical openings & \multirow{3}{*}{8} & \multirow{3}{*}{6} & \multirow{3}{*}{9} & \multirow{3}{*}{3} & \multirow{3}{*}{2} & \multirow{3}{*}{7} & \multirow{3}{*}{5} & \multirow{3}{*}{1} & \multirow{3}{*}{4} \\  & relative to the reference plane & & & & & & & & & \\ \hline \multicolumn{11}{c}{**Summary assessment of technological quality (the less, the better)**} \\ \hline  & Total number of ranking points & 41 & 46 & 59 & 61 & 52 & 59 & 77 & 67 & 81 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Classification of individual samples with respect to the assessed indicators of technological quality. described studies. In the case of process time, samples with higher layers and lower fill rates are produced faster due to the lower number of working passes of the printing device. Samples with lower layers of material lining were characterized by the best technological quality according to the tested parameters. Sample S1 was characterized by the most favorable quality parameters, while sample S9 meets them to the least extent. However, it should be emphasized that the selection of FFF process parameters each time depends on the characteristics of the geometry of the manufactured product, the required surface roughness, the available process time, or (not tested in this case) the mechanical strength of the model. Summarizing the conducted research, the following can be stated:  
* The lower layer height of 0.12 mm has a direct, beneficial effect on the obtained roughness of the product's lateral surfaces relative to samples with layer heights of 0.16 mm or 0.2 mm. * For models with the same layer height, samples with a 50% fill rate have slightly worse surface roughness parameters, probably due to the fill pattern used or the deformation occurring in the material during the process.