## 1 Introduction
In an earlier paper [1], we presented plots of the distribution of thin-wall dimensional deviations in the horizontal orientation of Ti6 Al4V titanium alloy specimens. We measured the deformations using the optical method (a 3D optical scanner--Atos ScanBox 6130--was used) and the contact method (a Zeiss Contura coordinate measuring machine). The dimension deviations with the smallest value (up to 0.09 mm) were observed for the sample made with the tool for high-performance machining by adaptive face milling. The measured maximum deviations for the individual specimens ranged from 0.09 mm to 0.89 mm--depending on the input factors used. We found up to 8 per cent differences between the results obtained from measurements by optical and contact methods. Also in earlier publications [21; 22], some of us reported thin-wall deviations in vertical orientation for samples of titanium alloy Ti6 Al4V and nickel alloy Inconel 625. We prepared the samples using a constant material removal rate of 2.03 cm\({}^{3}\)/g. We measured the dimensional and shape accuracy using the same 3D optical scanner. For both the Ti6 Al4V alloy and the Inconel 625 nickel alloy, the deviations were no larger than 0.08 mm [22]. [PERSON] et al. [6] reported the possibility of using a 3D optical scanner for products containing thin walls. They presented color maps of an aircraft frame made of 7075 aluminum alloy, for which the semifinished product had overall dimensions equal to 1012 \(\times\) 1354 \(\times\) 55.8 mm. [PERSON] [23] reported the dimensional deviations of thin-wall (2.5 mm thick) Ti6 Al4V samples in vertical orientation. The largest deviation value was 0.1 mm in the middle part of the thin wall. [PERSON] et al. [24] also reported a maximum thin-wall deviation of 0.1 mm for Ti6 Al4V titanium alloy samples machined in various combinations of assembly methods. [PERSON] et al. [25] reported for Ti6 Al4V titanium alloy the deviations of the thin wall in the vertical orientation in the range of 0.06-0.34 mm. For the same alloy, [PERSON] et al. [26] reported the highest dimensional deviation equal to 0.18 mm while [PERSON] al. [27] found a maximum deviation of 0.21 mm for a sample containing a fan blade shape made of the same alloy. [PERSON] et al. [28] compared results for an aluminum alloy cube (not containing thin-walled structures) obtained using a coordinate measuring machine, a 3D optical scanner, and a 3D computer tomograph. The maximum difference was 0.05 mm; clearly, the results coincide. The main objective of the experiment is to evaluate the dimensional and shape deviations of thin-walled specimens in horizontal orientation of nickel alloy 625 made under different variants of input factors--using a variety of cutting tools and two approaches of adaptive milling. An additional aim of the study is to correlate the dimensional values obtained by the optical method (using a 3D optical scanner) and by the contact method (using a coordinate measuring machine). Several articles have presented results for specimens containing thin-walled shapes in other orientations [23; 24; 25; 26; 27; 28]. No leading works containing studies of thin-walled components in horizontal orientation have been observed, so the advantage of the presented scope of work is the presentation of test results for thin-walled structures in horizontal orientation. Current scientific work mainly focuses on thin-walled structures in vertical orientation. Focusing on thin-walled products used in many industries, we note that they are a composite of various shapes, such as thin-walled structures with walls in vertical and horizontal orientations, cylindrical parts with thin walls, or circular parts (shafts, pins) with small diameters [6]. Depending on the shape to be performed, it is necessary to choose the suitable cutting strategy, which has a significant impact on the measured quantities. Based on this, it can be seen that tests should also be provided for other shapes or thin-wall orientations.