# The Influence of Automated Machining Strategy on Geometric Deviations of Machined Surfaces
## 4 Evaluations of Geometrical Characteristics  
The deviation results obtained by CMM for individual test samples are shown in Table 3. All data are given as deviations from the nominal value. The nominal values for dimension and geometrical tolerances are shown in Figure 1.  
According to the same cutting parameters for the parts produced in the CAM system and in the control system Heidenhain TNC 426, the evaluation was divided into six groups:  
* Flatness--horizontal planes;
* Flatness--vertical planes;
* Perpendicularity--planes;
* Perpendicularity--cylinders; \begin{table}
\begin{tabular}{c c c} \hline \hline
**Name** & **Deviation SolidCam [mm]** & **Deviation Heidenhain [mm]** \\ \hline FLT\_Plane\_A & 0.0079 & 0.0085 \\ FLT\_Plane\_C & 0.0406 & 0.0139 \\ PAR\_C\_pd\_A & 0.0389 & 0.0379 \\ FLT\_Plane\_B1 & 0.0210 & 0.0093 \\ FLT\_Plane\_B2 & 0.0233 & 0.0106 \\ FLT\_A\_PER & 0.0056 & 0.0107 \\ PER\_A\_per & 0.0092 & 0.0159 \\ Distance\_ISO\_1X\_Y & \(-\)0.2299 & \(-\)0.2056 \\ Distance\_LSQ\_4X\_Y & \(-\)0.2179 & \(-\)0.2486 \\ Distance\_ISQ\_1Z\_Y & \(-\)0.2400 & \(-\)0.2471 \\ Distance\_ISQ\_10Z\_Y & \(-\)0.2455 & \(-\)0.2477 \\ FLT\_B1-PER\_long & 0.0315 & 0.0156 \\ FLT\_B2-PER\_long & 0.0167 & 0.0256 \\ PAR\_B1\_per\_long\_1 & 0.0063 & 0.0045 \\ PAR\_B1\_per\_long\_2 & 0.0081 & 0.0141 \\ PAR\_B1\_per-long\_3 & 0.0152 & 0.0127 \\ PAR\_B1\_per-long\_4 & 0.0054 & 0.0126 \\ PER\_Plane\_B1\_PER\_long\_pd\_PER & 0.0355 & 0.0266 \\ PER\_B1\_short\_pd\_B1 & 0.0362 & 0.0431 \\ PER\_B2\_short\_pd\_B2 & 0.0395 & 0.0463 \\ PER\_Cyll\_Par to\_Plane\_A\_PER & 0.0167 & 0.0054 \\ PER\_Cyll\_Per\_to\_Plane\_A\_PER & 0.0131 & 0.0146 \\ PER\_Cyll\_2\_Par\_to\_Plane\_A\_PER & 0.0116 & 0.0154 \\ PER\_Cyll\_2\_Per\_to\_Plane\_A\_PER & 0.0012 & 0.0035 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Coordinate measuring machine (CMM) results. Parallelism;
* Distance. For the comparison of production, graphs were created in accordance with separate groups, which include the comparison characteristics for both systems. The green color represents SolidCAM, and blue represents the control system Heidenhain TNC 426. The results of flatness measured on the horizontal planes are shown in Figure 4.  
Results of the deviations in three characteristics are higher for SolidCAM than for Heidenhain TNC 426. The smaller deviation is only by 0.6 \(\upmu\)m of Plane_A. The surface flatness is marked as Plane_C for both systems, SolidCAM and Heidenhain TNC 426 (Figure 5). The flatness was measured at a speed of 8 mm/s along a defined path (polyline) without data filtration and outlier elimination. In both cases, the scale was over 1000: 1. The maximum and minimum values of the flatness deviation are marked with red marks. In the case of the Heidenhain system, the process of deviations had no significant differences compared to the SolidCAM system. In both cases, the trajectory of the cutting tool was clearly visible (decrease in the values of deviations in one line). When comparing the two systems, the difference in the deviations of the flatness can be observed. In both systems, the trajectory of the cutting tool was visible (see Figure 5). In the CAM system, SolidCAM, where the tool overlap was 50%, the trajectory of the cutting tool was clearly visible, marked with lines, but in the Heidenhain control system, where a tool overlap of 70% was used, the height difference was slight. The Heidenhain control system showed a more even distribution of flatness deviations, which can be explained by the overlapping of the tool during the milling process. The denser overlap of the toolpaths during machining increased the number of passes to machine the surface, which increased the milling time, but the surface showed better results in terms of flatness. The comparison  
Figure 4: Deviation for flatness—horizontal. Figure 5: Flatness for Plane_C.