Advanced manufacturing has been identified as one of the key enabling technologies with applications in multiple industries. The growing importance of advanced manufacturing is reflected by an increased number of publications on this topic in recent years. Advanced manufacturing requires new and enhanced metrology methods to assure the quality of manufacturing processes and the resulting products. However, a high-level coordination of the metrology community is currently absent in this field and consequently this limits the impact of metrology developments on advanced manufacturing. In this article we introduce the new European Metrology Network (EMN) for Advanced Manufacturing within EURAMET, the European Association of National Metrology Institutes (NMIs). The EMN is intended to be operated sustainably by NMIs and Designated Institutes in close cooperation with stakeholders interested in advanced manufacturing. The objectives of the EMN are to set up a permanent stakeholder dialogue, to develop a Strategic Research Agenda for the metrology input required for advanced manufacturing technologies, to create and maintain a knowledge sharing programme and to implement a web-based service desk for stakeholders. The EMN development is supported by a Joint Network Project within the European Metrology Programme for Innovation and Research.

We propose a unified theory for the metrological treatment of helical machine elements such as cylindrical and conical gears, worms, and screw threads. The main idea is to introduce a universal 3D geometry model for threaded components that provides for distinct parameterization using a unique set of geometry parameters and that offers and a functional description of the transverse profile. Using modern 3D coordinate measuring technology, a holistic evaluation algorithm yields the actual geometry as the result of a high dimensional best-fit procedure and form deviations as corresponding residuals. All determinants and evaluation parameters can then be calculated from the set of actual geometry parameters. By applying certain constraints to the model to be fitted, the novel method can be reduced to the established 2D methods and hence meets demands for the comparison of the two procedures. The results of the novel approach have proven to be very stable and they enable the evaluation of areal measurements with no loss of information.

The novel approach for holistic screw thread calibrations developed by the Physikalisch-Technische Bundesanstalt was published in 2019. A significant achievement has been made in order to meet increasing demands in manufacturing processes and quality assurance, particularly when workpieces with complex geometries are under inspection. This article deals with the verification of the previously presented three-dimensional calibration procedure for screw threads. Screw thread pitch diameters, the lead and flank angles are compared to those determined by the standardized method based on line-like, rather two-dimensional measurements and evaluation. In order to provide a reliable basis for the verification, one thread gauge was calibrated under laboratory conditions for precision metrology. Additionally, calibrations were conducted by three alternating operators on three different coordinate measuring machines to investigate the influence by user and machine. The resulting normalized errors | E n | of screw thread determinants under test and reference values are significantly smaller than 0.5 which indicates a high level of agreement.

Gears are fundamental precision components that are crucial to many industries, including the wind energy sector. They are traditionally analysed using profile and helix line measurements but this does not consider the majority of the contacting surface with intricate surface variations that dictate functional performance. Practical measurement and evaluation of involute gear surfaces remain underexplored. This paper uses the Fourier and wavelet transforms to evaluate measured gear surface deviation harmonic content for a single trace, a trace set, and surface analysis and describes the utility of each. The methods are first demonstrated with synthetic data and then with measured data, then the measured data is simulated in a quasi-static FE tooth contact analysis, which yields insights not solely gleaned from harmonic analysis. The uncertainty of harmonic content analysis is to be established in future work and how that effects the uncertainty of simulated functional performance should be investigated.

Gear users desire increased performance from their products and are interested in predicting the behavior (vibration, loss, service life, etc), and gear manufacturers are interested in adjusting machining parameters to manufacture even better gears. Both require proficient metrology. The evaluation standards were originally written to classify the manufacturing capability of machine tools and as tolerances tighten they may not provide enough insight into the functional performance of the manufactured parts. Furthermore, the advantage of modern coordinate and gear measuring machines is not fully taken into account when applying standardized measurement and evaluation strategies. Improved analysis tools can increase the relevant information gained from current measurement capabilities and enable more useful functional characteristics to be specified by designers and manufacturers. A key improvement is to move from profile and helix line traces to flank surfaces and corresponding fitted form elements. This is achieved by the introduced method. We present an inversion algorithm that fits dimension, form, and pose, and is applicable with current methods through freezing of specific fitting parameters. The method fits a synthetic point cloud with output results that are accurate to the 7^th digit, or in practical terms are numerically equal. The inversion method can increase the understanding of error contributions and the functional performance of gears.

Gewinde sind Maschinenelemente mit vielseitiger Funktionalität. Sie werden zum Befestigen, Verbinden, Abdichten oder Zentrieren verwendet und in großen Stückzahlen hergestellt. Dabei steigen die Anforderungen an die Fertigung und Qualitätssicherung stetig an. Nach aktuellen Normen und Richtlinien erfolgt die Prüfung der Bestimmungsgrößen an Gewinden stichprobenartig in wenigen festgelegten Axialschnitten und Prüfebenen. Die komplex geformten und stark gekrümmten Werkstückoberflächen von Gewindeflanken werden deshalb hinsichtlich ihrer Funktionalität unzureichend bewertet. Das neuartige Messverfahren basiert auf einem dreidimensionalen mathematischen Modell zur Beschreibung der Gewindegeometrie. Die Aufnahme der Messpunkte als Ist-Punktewolke erfolgt durch eine flächenhafte Messstrategie auf konventionellen Koordinatenmessgeräten. Der anschließende ganzheitliche Auswertealgorithmus ermöglicht erstmals die Bestimmung aller relevanten Bestimmungsgrößen am Gewinde auf Basis eines einzigen Datensatzes. Des Weiteren liefert der neue Auswertealgorithmus erstmals ein Ergebnis für die lokalen Bestimmungsgrößen, welche zur Berechnung des Paarungsflankendurchmessers benötigt werden. Screw threads are important machine elements with various functions. They are used for mounting, connecting, sealing or centering of components and are produced in large quantities. At the same time the requirements for manufacturing processes and quality assurance are increasing constantly. In accordance with current standards the inspection of screw thread determinants is performed in single axial sections. Therefore, the complex geometry of the flanks is not assessed sufficiently with respect to the functionality of the flanks. The novel measurement procedure is based on a three-dimensional mathematical model which describes the screw thread geometry. The actual point cloud of the rough shape is gathered by an areal-oriented measuring strategy using a conventional coordinate measuring machine. The following holistic evaluation algorithm ensures the calculation of all relevant screw thread determinants based on a single data set. Furthermore, the novel measurement procedure provides measurement results of the local screw thread determinants, which are crucial for the calculation of the virtual pitch diameter.