Robert Jankovych

Articulated arm coordinate measuring machines are designed for in situ use directly in manufacturing environments, enabling efficient dimensional control outside of climate-controlled laboratories. This study investigates the influence of ambient temperature variation on the accuracy of length measurements performed with the Hexagon Absolute Arm 8312. The experiment was carried out in a laboratory setting simulating typical shop floor conditions through controlled temperature changes in the range of approximately 20–31 °C. A calibrated steel gauge block was used as a reference standard, allowing separation of the influence of the measuring system from that of the measured object. The results showed that the gauge block length changed in line with the expected thermal expansion, while the articulated arm coordinate measuring machine exhibited only a minor residual thermal drift and stable performance. The experiment also revealed a constant measurement offset of approximately 22 µm, likely due to calibration deviation. As part of the study, an uncertainty budget was developed, taking into account all relevant sources of influence and enabling a more realistic estimation of accuracy under operational conditions. The study confirms that modern carbon composite articulated arm coordinate measuring machines with integrated compensation can maintain stable measurement behavior even under fluctuating temperatures in controlled environments.

The possibility of using CNC machine tools as measuring systems brings several advantages. The main advantage is to increase the productivity of the production process through in-process intermittent measurement, which allows to save working time by eliminating intermittent operations. However, such measurement systems must meet the metrological requirements of the measurement task to ensure the credibility of the measured data. The assessment of the applicability of a CNC machine tool as a measurement system can be done by verifying conformity with specifications according to the ISO GPS, or by demonstrating the capability of the measurement system by methods that use specifical statistical approaches (e.g. ISO 22514–7:2021, MSA:2010, VDA 5:2011). Based on the result of the specification assessment, it is then possible to approve or reject the deployment of the relevant CNC machine in the measurement process. This paper critically analyzes the current state of the art in this field and presents a new approach to assessing the applicability and capability of CNC machine tools as length measurement systems. The analysis compares the measurement process on a three-axis vertical CNC machining center with the measurement process on a coordinate measuring machine. Based on the critical analysis, an original approach to properly understand and apply the concept of combined measurement uncertainty in assessing the applicability and capability of a CNC machine as a measurement system (MS) in the on-machine measurement process has been developed and presented in the paper.

In modern manufacturing, there is an increasing demand for reliable in-process measurement methods directly on large CNC machine tools, eliminating the need to transport workpieces to metrological laboratories. This study assesses the capability and applicability of an articulated arm coordinate measuring machine and a machine tool touch-trigger probe when measuring to a specified tolerance of 0.05 mm in a production environment. Experiments were conducted using the KOBA calibration standard and included measurements with and without applying the articulated arm coordinate measuring machine leapfrog method. The results were evaluated according to ISO 22514-7:2021 and ISO 14253-1:2017, which establish criteria for measurement system capability. The findings revealed that neither measurement system met the capability requirements of ISO 22514-7:2021, particularly due to unsatisfactory Q_MS and C_MS values. However, under ISO 14253-1:2017, both systems were deemed conditionally suitable for verifying conformity to the specifications, with the articulated arm coordinate measuring machine showing lower applicability when using the leapfrog method. This research supports the idea that unreasonable demands for compliance with current standards may lead to questioning of the systems that previously met older standards. The study contributes to the ongoing discussion on integrating advanced metrological tools into the manufacturing process and underscores the need for careful evaluation to ensure the capability and reliability of measurement systems in industrial practice.

This article deals with the design of a technical diagnostics system for hydraulic rotators and the successful implementation of a unique hydraulic test bench. Based on an analysis of the design and function of all types of hydraulic rotators available on the world market, a system of requirements for the test bench and its place in the test centre was formulated. Furthermore, four diagnostic parameters from the group of deformation diagnostics and hydraulic systems diagnostics are proposed and used to evaluate the technical condition of the Indexator IR25 hydraulic rotator. For the evaluation of individual parameter values, a modified Shewhart control chart method is proposed for individual values and moving ranges of each parameter. Based on the measurements of 30 rotators, control limits were designed for statistical evaluation of the technical condition of the mentioned hydraulic rotator.

Currently, various types of software compensations are applied to machine tools. Their aim is to increase the working accuracy of the tools. The improvement in working accuracy is then further assessed according to the increase in the dimensional and shape accuracy or the surface quality of the workpiece. This publication describes the effects of the volumetric accuracy of a machine tool on the working accuracy of a workpiece, where total roundness (RONt) is evaluated in multiple cuts. In the experiment, two test workpieces are manufactured on a three-axis milling machining centre. The first is made using a standard machine setup while the second with activated volumetric compensation. The LaserTRACER self-tracking laser interferometer is used to compensate for volumetric accuracy. In the second part, verification measurements are performed with a Ballbar, where roundness error is evaluated according to ISO 230-4. Then two test workpieces are machined, and, in the last part, measurement is performed on Talyrond 595S roundness measuring equipment. Finally, the results are analysed and the dependence between the volumetric accuracy, the circularity error of the machine and the working accuracy of the CNC machine tool is established, represented by the RONt of the workpiece. This paper presents new and unpublished relations between the volumetric accuracy of the machine tool and the RONt of the workpiece.

The unconventional technology of wire electrical discharge machining is widely used in all areas of industry. For this reason, there is always an effort for efficient machining at the lowest possible cost. For this purpose, the following comprehensive study has been carried out to optimize the machining of the copper alloy Ampcoloy 35, which is particularly useful in plastic injection moulds. Within the study, a half-factor experiment of 2^5-1 with 10 axial points and seven central points of a total of 33 rounds was carried out, which was focused on the response monitoring of the input factors in the form of the machine parameters setup: gap voltage, pulse on time, pulse off time, discharge current, and wire speed. Based on the study of the response in the form of cutting speed and surface topography, their statistical models were created, while the optimal setting of machine parameters was determined to maximize the cutting speed and minimize the topography parameters. Further, a detailed cross-sectional analysis of surface and subsurface layer morphology was performed using electron microscopy including chemical composition analysis. In order to study microstructural changes in the material at the atomic level, a lamella was created, which was then studied using a transmission electron microscope.

This paper deals with the determination of uncertainty and individual contributions to the measurement uncertainty on the CMM SIOS NNM-1 instrument fitted with the touch-probe scanning system Gannen XP. Manufacturer SIOS designates this machine as nano-CMM. Two non-simulation methods to determine...