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accuracy of cad/cam-fabricated bite splints: milling vs 3d printing | springerlink

accuracy of cad/cam-fabricated bite splints: milling vs 3d printing | springerlink

The aim of this study was to investigate the accuracy of CAD/CAM-fabricated bite splints in dependence of fabrication method (milling vs 3D printing), positioning (horizontal vs vertical), selection of material, and method of deviation measurement.

Bite splints were 3D-printed in either horizontal or vertical position (n = 10) using four different resins (Dental LT, Ortho Clear, Freeprint Splint, V-Splint). As control, ten bite splints were fabricated by CNC milling (ProArt CAD Splint). The splints were scanned and deviations between the CAD-file (trueness) and between each other within one group (precision) were measured by two different software applications and methods (cloud-to-cloud vs cloud-to-mesh). Data were analyzed using univariate analysis, Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests.

The highest impact on accuracy was exerted by the selection of the material (trueness: P2 = 0.871, P < 0.001; precision: P2 = 0.715, P < 0.001). Milled splints showed the highest trueness (P < 0.01) but not the highest precision at the same time. Horizontally positioned 3D-printed bite splints showed the least deviations in terms of trueness while vertical positioning resulted in the highest precision. The cloud-to-cloud method showed higher measured deviations than the other methods (P < 0.001P = 0.002).

In dentistry, bite splints are used for a variety of treatments. They can be used for alleviating symptoms of temporomandibular disorders or for protecting teeth from excessive occlusal forces arising from certain patients habits like for example tooth grinding [1, 2]. Additionally, new occlusal situations can be tested in patients facing full mouth rehabilitation [3]. Bite splints can be manufactured by different procedures. Traditionally, vacuum thermoforming, sprinkling acrylic resin, or a combination of both is used [4,5,6]. With the introduction of computer-aided-design/computer-aided-manufacturing (CAD/CAM) in dentistry, a digital approach for manufacturing such devices is feasible [7]. The patients situation can either be digitalized with an intra-oral scanner or by means of a conventional impression which is later scanned in the dental laboratory. Based on these data, the splint is then designed digitally. This allows for a more efficient and precise workflow and enables the uncomplicated reproduction of the device if it needs replacement [8, 9].

As for the CAM process, there are two possibilities available today. The splint can either be milled out of a prefabricated blank or manufactured additively. The subtractive method entails high waste of material as well as high wear of the milling burs, especially for hard materials like ceramics. Furthermore, the production of one single splint is quite time-consuming. In the case of additively manufactured bite splints, only the support structure has to be discarded and several devices can be fabricated simultaneously [10]. Though additive manufacturing (AM) has been known since the 1980s, its application in dentistry is relatively new. The use of 3D printing for the manufacturing of bite splints was first described in 2013 [11]. Three-dimensional printing consists of different technologies and covers resin processing systems as well as ceramic or metal sintering devices [12]. For the manufacturing of bite splints, mostly stereolithography (SLA) or digital light processing (DLP) are used. They process liquid resin that is either polymerized punctually by a single-laser spot (SLA) or polymerized on a larger area with a beam (DLP) [13]. Since the object is manufactured layer by layer, it is anisotropic which means that the positioning of the object in relation to the printers platform during fabrication has an impact on its properties [14]. Aims of this study were to evaluate if the position of additively manufactured bite splints affects their accuracy and to investigate the accuracy of 3D-printed bite splints in comparison with milled ones.

Resins for 3D printing in dentistry often based on known formulas of existing products, like temporary materials for crowns and bridges. However, their chemical composition has to be adapted for the AM process. The resin must possess the right viscosity to easily flow between the printers platform and the bottom of the vat after each layer. The incorporation of fillers, pigments, and photoinitiators not only influences the materials mechanical properties but also affects its accuracy. If the refractive index between the resin and the incorporated substances is not well adapted, laser light is scattered which leads to reduced polymerization depth and consequently to inaccuracies of the final object. Consequently, another aim was to investigate if the choice of material affects the accuracy of additively manufactured bite splints.

Different software applications are available for investigating the accuracy of an object on a 3D scale [15,16,17,18]. These applications calculate deviations between two files by superimposing them. Using this method, two variables can be measured according to ISO standard no. 57251:1994: trueness and precision. In this case, trueness represents the deviation of the manufactured splint from the reference (CAD-data), while precision represents the deviation between repeatedly manufactured splints [19]. Although the different software applications work in the same manner in terms of superimposing two files and calculating the deviations between both, their results can differ. This is due to the way deviations are calculated. Hence, another aim of this study was to compare the results of two different software applications and two different measurement methods within one of these software solutions.

The null hypotheses were that the positioning and the choice of material for additively manufactured bite splints would not affect their accuracy. Furthermore, no differences of 3D-printed in comparison with milled bite splints in terms of accuracy were expected. Finally, it was assumed that the results of different measurement methods would not differ from each other.

The study design is presented in Fig. 1. A gypsum cast of an upper jaw was scanned (activity 885 Mark 2, Smartoptics, Bochum, Germany, working with an accuracy of 6 m according to the ISO standard no. 12836:2015-11) and a bite splint was computer-aided-designed (exocad GmbH, Darmstadt, Germany) with a material thickness of 2 mm. The corresponding STL-file (reference) was exported (Fig. 2). Subsequently, the splint was manufactured using either an additive or a subtractive method. The investigated materials and corresponding machines are listed in Table 1. For the AM method, the splint was positioned either horizontally or vertically to the printers platform. Each group consisted of ten specimens (N = 90). The additively manufactured specimens were cleaned for 5 min in an ultrasonic-activated bath (Sonorex Super RK1022, Bandelin) of 96% ethanol (Otto Fischar GmbH) and post-cured according to the manufacturers specifications (Table 1). For the subtractive method, the STL-file was imported into InLab Cam 18.0 and the splints were manufactured by the 5-axis machine MC X5 with the finest bur of 0.5 mm in diameter (both Dentsply-Sirona, Bensheim, Germany). The splints surfaces were then scanned (activity 885 Mark 2), and the resulting STL-files were exported. Solely, the intaglio surfaces of these scans were kept by cutting off the rest of the file (Meshmixer, Autodesk, USA, version 3.5). These surfaces were compared with the reference (n = 90 per measurement method), representing the trueness, respectively, to each other within one group (n = 315 per measurement method), representing the precision. For this comparison, three different measurement methods were used: I. Cloudcompare (www.cloudcompare.com, version 2.9.2 for Mac) with the parameter cloud-to-cloud [Cloud1], II. Cloudcompare with cloud-to-mesh [Cloud2], III. GOM Inspect [GOM] (GOM, Braunschweig, Germany, version 2018) operating by default with a cloud-to-mesh measurement method. For all approaches, the STL-files were superimposed at first manually and then automatically using best-fit algorithms. To this end, the distances of each superimposition were evaluated. For this purpose, the root mean-squared (RMS) value for each superimposition was calculated as follows:

where d is the distance between the compared cloud and the reference and n is the number of measurement points. The data were statistically analyzed using univariate analysis, Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests (IBM SPSS Statistics, V25, IBM Corp., Armonk, USA).

Descriptive statistics are summarized in Tables 2 and 3. According to the univariate analysis, the highest influence on measured distances for trueness was shown by material (P2 = 0.871, P < 0.001), followed by position (P2 = 0.664, P < 0.001) and measurement method (P2 = 0.601, P < 0.001). The interaction effect of the binary and trinary combinations of the three independent parameters (material, position, and measurement method) was also significant (P2 = 0.1640.411, P < 0.0001). For precision, the highest influence was shown by material (P2 = 0.715, P < 0.001), followed by measurement method (P2 = 0.709, P < 0.001) and position (P2 = 0.252, P < 0.001). The interaction effect of the binary and trinary combinations was also significant (P2 = 0.0890.735, P < 0.001). For 6 of in total 52 groups, the Kolmogorov-Smirnov indicated evidence for violation of normality assumption regarding the distribution of the data (P < 0.05). Therefore, the data was analyzed separately using non-parametric statistical tests.

Regarding trueness, within all measurement methods, the Freeprint Splint in horizontal and in vertical positions, the Dental LT in vertical position, and the V-Splint in vertical position presented the highest distances (P < 0.001). The overall lowest distances were recorded for ProArt CAD Splint (P < 0.001). Concerning the different measurement methods within one material and one position, Cloud1 presented the highest distances of all methods (P < 0.001). GOM illustrated higher distances than Cloud2 for the Dental LT in vertical position (P = 0.023), the Ortho Clear in vertical position (P = 0.011), and the Freeprint Splint in vertical position (P < 0.001). In regard to the additively manufactured specimens, horizontal positioning resulted in lower distances, regardless of the method of measurement (P < 0.001).

Regarding precision, within the measurement method Cloud1, the highest distances were measured for the Freeprint Splint in horizontal position and the V-Splint in horizontal position (P < 0.001). The lowest distances were recorded for the Ortho Clear in vertical position, the Freeprint Splint in vertical position, and the V-Splint in vertical position (P < 0.001). Within the measurement method Cloud2, the highest distances were measured for the Dental LT in vertical position and the V-Splint in horizontal position (P < 0.001). The lowest values were recorded for the Ortho Clear in vertical position and the Freeprint Splint in vertical position (P < 0.001). Within the measurement method GOM, the highest distances were measured for the Dental LT in vertical position (P < 0.001), followed by the Dental LT in horizontal position and the V-Splint in horizontal position. Concerning the different measurement methods within one material and one position, Cloud1 presented higher distances than the other methods for all groups (P < 0.001P = 0.002) except for the Dental LT in vertical position at which Cloud2 and GOM registered higher values (P = 0.002, P < 0.001) and the V-Splint in horizontal position for Cloud2 (P = 0.481). Between the measurement methods Cloud2 and GOM, significant differences could be stated (P < 0.001P = 0.023), except for the Dental LT in vertical position (P = 0.052), the Freeprint Splint in horizontal position (P = 0.579) or vertical position (P = 0.853), and the V-Splint in vertical position (P = 0.280). In regard to the additively manufactured specimens, vertical positioning resulted in lower distances, regardless of the method of measurement (P < 0.001).

All null hypotheses had to be rejected. The position and choice of material for additively manufactured bite splints influence their accuracy. Milled splints show a higher accuracy than 3D-printed ones. The results of different measurement methods differ from each other.

Concerning positioning, most interestingly, the results reveal a difference between trueness and precision. Horizontal positioning resulted in higher trueness but lower precision. This might be explained by the lower number of layers, which form one bite splint when it is manufactured in a horizontal position. In fact, for horizontal positioning, only about one quarter of layers is needed in comparison with a vertical position. Thus, the number of possible discrepancies between two subsequent layers is reduced and, consequently, the printed object is closer to the reference. In vertical positioning, on the contrary, more layers need to be connected to each other, and thus, the sum of repeated inaccuracies increases. On the other hand, when positioned horizontally, an over-curing effect due to a higher scattering of the laser beam seems to appear [20]. For a better connection between two layers, the polymerization extends the pre-set layer thickness. As a result, an over-curing of the previous layer occurs. This over-curing may reach an undesirable threshold on flat areas where multiple layers are polymerized successively, as in the case of the occlusal surface of bite splints when positioned horizontally. As a consequence, this inhomogeneous polymerization leads to uncalculated shrinkage behavior and to inhomogeneous polymerization of the resin. This results in deviations between each manufactured splint and thus a lower trueness. The over-curing effect may have great impact on transparent materials, as in the case of bite splints since here the light beam disperses more than in colored materials.

However, the Dental LT showed both, higher trueness as well as precision, when positioned horizontally. This material is the only one which is fabricated with a SLA printer. SLA and DLP differ in the way the resin is polymerized. For SLA, one single laser punctually polymerizes the layer, while for DLP, each layer is polymerized by a single beam. Considering the results of this study, it seems that the SLA printer has an inferior accuracy in the z-axis than the DLP printer. So, the Dental LT in vertical building direction demonstrates a greater standard deviation regarding precision than the other materials or the Dental LT in horizontal position. This result is in accordance with another study investigating the clinical fit of SLA-printed bite splints [21].

From a practical point of view, horizontal positioning results in less printing time since fewer layers are needed to manufacture the object. However, the support structure is set on the occlusal surface of the bite splint which requires more time to carefully remove it from this functionally important surface. In vertical positioning, more splints can be set on the printers platform and be manufactured simultaneously, which is highly efficient.

Regarding the Ortho Clear and Freeprint Splint, both being processed on the same printer, differences in accuracy could be stated. This may be explained on the one hand by the different pre-set layer thickness. As specified by the manufacturer, by default, the Ortho Clear is printed with 50-m thickness while the Freeprint Splint is printed with 100 m. The greater layer thickness of the Freeprint Splint leads to higher deviations from the reference, especially in the z-axis. This might explain why the Freeprint Splint in vertical position showed a higher RMS error regarding trueness than the other materials. On the other hand, differences in accuracy may be explained by the different composition of the respective materials. Its composition not only influences its mechanical parameters but also affects the accuracy with which one material can be manufactured. The accuracy depends greatly on the curing depth, which is described by the law of Beer-Lambert [22]. If there is a mismatch in the refractive index between additives and the resin matrix, the laser light is scattered significantly and accuracy declines consequently. Taking into account the results of this study, it seems that the materials composition of the Ortho Clear is better adapted than that of the Freeprint Splint.

Noteworthy, milled splints showed the highest trueness but not the highest precision at the same time. From that perspective, additive manufacturing seems to offer higher reproducibility than the tested milling machine, if the objects are positioning vertically. From a technical point of view, the milling procedure differs greatly from additive manufacturing. While in 3D printing, the object is built up layer by layer; the milling machine cuts out the object from a prefabricated block. By reproducing specific geometries, the milling procedure is limited by the lowest diameter of the used burs. Concave surfaces, like the intaglio ones of the specimens, require the radius of the milling tool to be smaller than the radius to be milled. Otherwise, the milling procedure can lead to oversized reproduced geometries [23]. This restriction becomes obvious on the incisal edges of the investigated bite splints (Fig. 3.) where 3D printing shows lower deviations from the designed geometry than the milling procedure.

For assessing the deviation of two STL-files, several software applications are available. The aim of this study was to compare two of these applications (Cloudcompare vs GOM) and to compare different measurement methods within one of them (Cloudcompare: cloud-to-cloud vs cloud-to-mesh). Before measuring, the two files have to be matched. For this purpose, they are at first aligned manually and then by applying a best-fit algorithm. Subsequently, the distance from one file to the other is calculated. Therefore, two strategies can be applied: either the two STL-files are each converted to point clouds or the absolute distance between two corresponding points is measured (cloud-to-cloud). Alternatively, only one STL-file is converted to a point cloud and the absolute distance is defined as the way between one point and the perpendicular from this to the mesh of the STL-file (cloud-to-mesh) (Fig. 4). Consequently, the recorded distances may vary in dependence of the measurement method. This study stated that cloud-to-cloud presented higher deviations than cloud-to-mesh. This result can be explained by a geometrical approach. The perpendicular distance between one point and one mesh is always the shortest. However, the distance between two selected points with one of them on the mesh is greater. Both distances, the perpendicular one and the one between two selected points, may become the same if the density of the point cloud increases (Fig. 4). Nevertheless, one mesh solely represents an approach to the real object; there is always a specific secant error [24]. Based on the results of this study, it seems that the calculated deviations depend more on the measurement method than on the applied software application. For studies investigating the deviation of two or more STL-files, it therefore seems to be highly recommendable to explicitly state the used measurement method in order to compare the results with further studies.

Taking into account the results of this study, milled and 3D-printed bite splints seem to be of equal quality in terms of accuracy. While the milling procedure resulted in higher trueness, AM revealed a higher reproducibility if the splints are set in vertical position. This positioning is highly efficient if multiple splints need to be manufactured and defeats the production time of the milling procedure.

A drawback of this study is the scanner used which is not industrial reference scanner. However, with an accuracy of 6 m according to the ISO standard no. 12836:2015-11, it seems suitable for the intended purpose and is in accordance with comparable studies which used a laboratory scanner as a reference as well [25,26,27]. Furthermore, valid comparisons can be drawn between specimens as they were all treated in the same way.

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Marcel, R., Reinhard, H. & Andreas, K. Accuracy of CAD/CAM-fabricated bite splints: milling vs 3D printing. Clin Oral Invest 24, 46074615 (2020). https://doi.org/10.1007/s00784-020-03329-x

thrilling milling | article | automotive manufacturing solutions

thrilling milling | article | automotive manufacturing solutions

Todays automotive manufacturing engineers appear to favour flexible manufacturing systems (FMS) or cells, as opposed to dedicated transfer lines. Typically, this is because todays vehicle models have a shorter production life than those of yesteryear as OEMs constantly evolve their designs to try and grow market share.

To ensure an FMS is as efficient and productive as possible, investment in the latest CNC machining centre technology is a prerequisite. A case in point is reported by Starrag UK, which says it has supplied another Heckert horizontal HEC 400D machining centre to the same top-tier supplier the 14th machine onsite to expand a manufacturing cell that produces a range of steel and aluminium suspension components.

According to Starrag, these four-axis machining centres are being used throughout the automotive sector by OEMs and their top-tier suppliers for the single set-up machining of workpieces such as gearboxes, coupling housings and valve bodies, and are proving effective when used in cellular or FMS configuration.

Taking a modular approachOver at German machine tool builder Heller, the school of thought extends to machine tool modularity, particularly for systems producing parts such as cylinder blocks and heads, crankshafts and camshafts, transmission and chassis components. To be able to cover such a broad range of vehicle applications, from a small two-cylinder motorcycle engine to a V12 construction machine engine, Heller opts for scalable production systems.

According to the German Automotive Association (VDA), some 78.7m passenger cars were produced worldwide in 2015, 1.7% more than the year before. In Germany alone, 5.7m vehicles rolled off the production line an increase of almost 2%. The countrys car makers are being driven by increasingly shorter innovation cycles and growing model and variant diversity.

Manfred Maier, managing director and COO of the Heller Group explains what this means for machine tool manufacturers as suppliers to car builders: For many companies in the automotive industry today, maximum flexibility comes before maximum productivity with the smallest possible investment. The implementation time between the investment decision and start of production is also becoming increasingly important.

This concept is realised with four- and five-axis modules featuring direct loading, as well as custom-made and process machines that can be interlinked at any point in time to create a fully automated manufacturing platform.

Greater complexity, less volumeThe challenges for machining are increasingly smaller batch sizes, more complex components and the integration of innovative technologies to achieve complete machining operations.

During the course of the collaboration, we not only focus on designing the machine technology and machining processes, but we also provide assistance and support for optimising the part for production, specifically with regard to material flow, workpiece clamping design, optimum handling between the machining steps and the selection of process-optimised tools. Depending on requirements, we also deliver various automation solutions.

A specific project example is a production system for the Fiat plant in the Polish city of Bielsko-Biala. Over 1,000 two-cylinder engines roll off the production line here every day. The solution comprises three Heller MCi 25.1 machining centres, 40 MC10 machining modules with direct loading, six MCH 250 machining centres, one automated loader, statistical process control, a NOK conveyor for loading and unloading defective parts, as well as an automated parts handling facility between the individual stations.

As Fiat prefers cast iron rather than the current standard light alloy engines for its engine block (for reasons of strength), the intricate structure of the component presents a challenge. In addition to the prominent cylinder bores, the part is littered with flange surfaces, cooling channels and holes all in the smallest spaces. However, some 450,000 two-cylinder engine housings are milled from G25 GH190B cast iron every year at Bielsko-Biala with a cycle time of under 40 seconds each.

We were Fiat's key development partner for designing the production of its TwinAir engine, emphasises Roth. And when truck manufacturer MAN was looking for a partner with adequate experience in the development of diesel engines and the machining of GGV compacted graphite iron for the housing, Heller responded in the same way (despite the difference in scale): four- and five-axis machining modules with direct loading, as well as special-purpose and process machines.

Right-sizing machining solutionsWe will not develop a proprietary machine for every task. Instead, we will make use of a modular system, explains Roth. Such a machine must be designed for series production, and must be adaptable to customer requirements. In a nutshell, we talk about right-sizing. This means that the customer gets a production solution that matches their specific application.

So, what happens when series production is not quite the volume normally associated with automotive contracts? Well, it appears the solution is rather similar, as highlighted at UK-based Grainger & Worrall (GW), a provider of machined engine castings to high-performance manufacturers including Porsche, Aston Martin, Bugatti and McLaren.

Designed specifically for high-end automotive components, such as body-in-white structures and powertrain parts, the FMS houses three Mazak Variaxis i-600 five-axis machining centres. GW says that this enhanced manufacturing capability enables shorter turnaround times and lower inventories, which are required by low-volume vehicle manufacturers.

The Variaxis i-600 is a fully simultaneous five-axis vertical machining centre that performs multiple and complex curved surface machining on small and medium-sized workpieces in single set-ups. The machine falls within Mazak's Done in One concept by incorporating all processes from raw material input through to final machining on a single machine platform.

The machine also offers high levels of productivity via 12,000 rpm, high-rigidity spindles that are said to handle applications from heavy-duty cutting to high-speed machining of aluminium and other non-ferrous materials. An optional two-pallet changer provides continuous machine operation and integration within a Palletech manufacturing system for automated manufacturing, as is the case at GW.

The 20-pallet system allows fixtures to remain set, so that feeding the three i-600 five-axis machining centres is both efficient and repeatable, says Edward Grainger, director at GW. This solution offers good flexibility to cater for changing demands while giving total process control, good levels of reliability and high part accuracy.

The FMS at GW forms part of a recently opened 5m machining facility. The 33,000 sq.ft, temperature-controlled machining facility includes seven vertical, two five-axis and six horizontal machining centres. Shortly before its official opening, Aston Martin confirmed GW as its preferred partner to produce aluminium engine blocks and heads for the DB11.

Based near Turin, Italy, privately owned specialist-engineering company, Chiaro Macchine Speciali, is well located to serve established automotive tier suppliers such as Magneti Marelli and Webasto. In fact, 80% of the companys engineered products, test systems, and tooling used in manufacturing processes and on production lines are supplied to the European and global automotive sector. Andrea Beltramo and his colleague, Khalid Mahmood, are the Chiaro engineers responsible for the companys Haas CNC machine tools, among which is a recently installed VM-6. We bought the machine because we wanted a large, solid machine for milling operations, says Mahmood.

Furthermore, its precise and versatile. We dont make parts in large numbers; most of the test systems and machines we build are one-offs, but we do need versatility. The machines table, with its X and Y T-slots, gives us the ability to quickly and easily mount parts of different sizes and shapes. We do all our planning and design in-house, adds Beltramo, so its important for speed and quality control that we can make our own parts, test them, and make changes as quickly and efficiently as possible.

A typical Chiaro test system could be, for example, one designed to check fabricated automotive exhausts before they are fitted to vehicles on the production line. Weve just designed and built a fully automated machine that allows our customer to check the silencer of an exhaust system for leaks, says Beltramo. It will be located beside a production line, so it has to be designed to minimise the possibility of set-up errors and, importantly, has to accommodate a variety of different model variations without any trouble or delays. Before the Haas VM-6 arrived, we already had a Haas TM-2 milling machine, which we use for small, one-off parts, he continues.

So, we already knew the Haas control, which meant we were able to start working the new machine without the need for much additional instruction. We did a very short course, and that was it! Were happy with the VM-6, concludes Mahmood, and I know the company owner is, too. We got the machine we needed to be able to improve the way we make parts in-house. It has made a significant difference.

CAM software developer Open Mind Technologies says it worked with Volkswagens Braunschweig plant in Germany to develop a new milling cycle for the programming of rib geometries. One of the plants functions is the manufacture of moulds for cylinder heads and chassis, die cast moulds for gearboxes, coupling housings and steering boxes, as well as injection moulds for bumpers and instrument panels. The cooling ribs of gearboxes have very deep cavities that entail major risk and are extremely time consuming in terms of programming and milling.

With this in mind, a specialist in-house knowledge management group made up of planning engineers, programmers and machine operators was put together to optimise the machining of ribs from die cast components. Rib types were classified and corresponding programming processes developed. On this basis, the programming approach could be standardised and the tool database adjusted accordingly. The rib milling knowledge management group developed a test part that featured all of the known degrees of difficulty, such as nesting, deep cavities, rib intersections, radial ribs and interference contours.

Based on this specification, Open Mind has subsequently developed a rib milling cycle that introduces a lot of innovations to the machining sequence, such as: an integrated roughing/ finishing function; integrated pocket machining of wide ribs; automatic collision detection of the toolholder (taking conical milling tools into account); and integrated bottom machining. The fact that the infeed parameters always come directly from the tool database, even in the case of automatically separated areas, is said to be a particular highlight. In the case of components with a very high degree of ribbing, the new approach has made it possible to significantly reduce processing times at the machine. In fact, the new rib milling cycle cut pure programming time in half.

Further to the reductions in programming and machining times, we are also achieving greater process reliability and considerably reduced tool wear, says Wolfgang Sofftner, contact partner for 3D machining in component tool engineering at Volkswagens Braunschweig plant. The approach involves the inspection of components by knowledge management and the subsequent development of standardised machining options, and is pioneering for future projects.

The QT-PRIMOS 50 SG is a compact, CNC turning centre, designed for mass production environments, says Mazak. It features a rigid integral spindle motor and intelligent thermal shield that its claimed provides accuracy and high-speed cutting, with the main spindle capable of 5,000rpm. Other compact models include the QT-PRIMOS ...

Steed Webzell looks at edge computing and the hardware requirements for those looking to digitally monitor, measure or control their machining operations Certain terms surrounding digitisation have become pretty familiar over the past 5-10 years: Internet of Things, Industry 4.0 (I4.0), edge computing, big data, smart factory, artificial intelligence ...

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