Traditional computer modelling is performed using CAD systems. Everything starts with a constructor idea. They present their concept on a technical drawing and then perform it in a virtual environment of a 3D model. This model may then be manufactured with the use of available methods. The problem arises when technical documentation of an object, for example, a tooth model, is not available.2D images are the traditional way of presenting anatomical structures; unfortunately, this method is sometimes ineffective. In advanced cases of dental conditions, there are difficulties in the recognition and proper interpretation of 2D images of the affected area. This is why other ways to show the shape of the complex internal structures have been researched, such as the (3DP and FDM). They were similarly aligned in the work space of both printers to maintain similar conditions of printing, and similar layer thicknesses of 0.1 mm and 0.13 mm were used. The printed models were scanned using a focus variation (FV) microscope. The scanned geometry of the models of the two teeth was compared with the geometry of the teeth after their segmentation and filtering. A fitting process was carried out using the best fit algorithm with a fitting condition of 0.001 mm. The achieved accuracy of the FV measurements was significantly higher than the accuracy of the used printing methods. FV can be applied to performing 3D scans of complex shapes such as the crown and roots of a tooth. 3DP models have more homogenous structure, whereas layer structure is easy to recognize for FDM models. Due to that, the 3DP models have to be strengthened using infiltration, which makes it more difficult to predict the final dimensions and to achieve required accuracy. Keywords: dental model, reverse engineering, rapid prototyping, focus variation Highlights • The accuracy of FDM and 3DP techniques were examined in terms of manufacturing dental models such as tooth models.• The infiltration applied to the 3DP models reduced in accuracy compared to FDM models.• For the FDM models, the values of mean deviation were negative and met the accuracy specified by the printer's manufacturer.• Due to infiltration the values of mean deviation of 3DF models were positive.• The infiltration also caused the models manufactured with the FDM to be more accurate than the 3DP ones.• It was determined that the focus variation method can be applied to measure parts with a complex shape, such as the crown and roots of a tooth.

Purpose The purpose of this paper is to determine the influence of the shape of a cutting edge on high-performance milling high-performance cutting. The main purpose of the test was to determine the possibility of increasing the efficiency of machining AlZn5.5CuMg alloy, which is used mainly for the thin-walled structural aerospace components. Design/methodology/approach In all, eight cutters for machining aluminum alloys with different shape of the cutting edge (1 – continuous, 4 – interrupted, 3 – wavy) were tested. The influence of different shapes of a cutting edge on cutting force components and vibration amplitude was analyzed. Furthermore, the impact of a chip breaker on the form of a chip was determined. Findings The conducted test shows that using discontinuous shapes of a cutting edge has impact on the reduction of the cutting force components and, in most cases, on the increase of vibration amplitude. Moreover, using a chip breaker caused significant chip dispersion. The optimal shape of a cutting edge for cutting AlZn5.5CuMg alloy is fine wavy shape. Practical implications Potential practical application of the research is high-performance milling of AlZn5.5CuMg alloy, for example, production of thin-walled aerospace structural components. Originality/value Different shapes of a cutting edge during high-performance milling of aluminum alloy were tested. The influence of tested geometries on HPC process was determined. The most favourable shape of a cutting edge for high-performance cutting of AlZn5.5CuMg alloy was determined.

Purpose The purpose of this paper is to determine the influence of a toroidal cutter axis orientation and a variable radius of curvature of the machined contour of sculptured surface on the five-axes milling process. Simulation and experimental research performed in this work are aimed to determine the relationship between the parameters of five-axes milling process and the shape and dimensional accuracy of curved outline of Inconel 718 alloy workpiece. Design/methodology/approach A subject of research are sculptured surfaces of the turbine blade. Simulation research was performed using the method of direct mapping tools in the CAD environment. The machining research was carried out with the use of multi-axis machining center DMU 100 monoBLOCK DMG, equipped with rotating dynamometer to measure the components of the cutting force. To control the shape and dimensional accuracy, the coordinate measuring machine ZEISS ACCURA II was used. Findings In this paper, the effect of the toroidal cutter axis orientation and the variable radius of curvature of the machined contour on the parameters of five-axes milling process and the accuracy of the sculptured surfaces was determined. Practical implications Five-axes milling with the use of a toroidal cutter is found in the aviation industry, where sculptured surfaces of the turbine blades are machined. The results of the research allow more precise planning of five-axes milling and increase of the turbine blades accuracy. Originality/value This paper significantly complements the current state of knowledge in the field of five-axes milling of turbine blades in terms of their accuracy.

The article presents the results of experimental studies in high performance milling of AlZn5.5MgCu aluminum alloy. The tests were performed with the use of end mill cutters with different serrated shapes of the cutting edge. End mills with continuous, interrupted and wavy with varied profile radius were used. The tests were conducted on a DMG's DMU 100 MonoBlock machining center with cutting force components measurement in workpiece system capabilities. The experimental tests were carried out using varied radial depth of cut ae and feed per tooth fz parameters according to applied three-level full design of experiment. The relationships between ae and fz parameters and cutting force components for various cutting edge shapes were determined. A continuous cutting edge was adopted as a reference shape. Based on the results of the tests, cutting force components models for analyzed cutting edge shapes were determined. A comparative analysis between the developed models and relationships was conducted. The study proved that when adopting end mills with serrated cutting edges, lower cutting force components are obtained, in comparison with cutters with continuous cutting edges. The results also showed that for end mills with serrated cutting edges radial depth of cut ae has a negligible influence on the feed force component Ff. The results proved, that end mills with serrated cutting edges should be used in high performance machining, where high values of ae and fz parameters are adopted. Furthermore, machining of thin-walled workpieces can be a potential application of these end mills, as lower values of cutting force components reduce the risk of deformation of milled thin walls.

Servicing aircraft engines sometimes requires manufacturing only a single piece of a given part. Manufacturing a turbine disc using traditional methods is uneconomical. It is necessary to use a different machining method recommended for small lot production. One of the proposed methods is WEDM (wire electrical discharge machining). The article presents the results of the research on finishing WEDM of Inconel 718 turbine disc fir tree slots. The influence of infeed, mean gap voltage, peak current, pulse off-time, and discharge energy on the shape accuracy, surface roughness, microcracks, and the white layer thickness were determined. Mathematical models were developed based on the DoE (Design of Experiment) analysis. The statistical significance of the models was verified with the ANOVA (Analysis of Variance) test. The machining parameters control methods that allow achieving the required shape accuracy, surface roughness, and surface layer condition were presented. The obtained surface roughness was Ra = 0.84 μm, the shape accuracy of the slot in the normal-to-feed direction was Δd = 0.009 μm, the profile shape accuracy was Δr = 0.033 μm, and the thickness of recast (white) layer was approximately 5 μm.