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One of the main benefits of using 3D printing in orthopedics is the ability to create custom solutions tailored to a patient's specific anatomical and functional needs. Conducting a reliable evaluation of the accuracy of the manufacture of anatomical structure models is essential. However, particular standards or procedures still need to be implemented to control the surface quality of anatomical models manufactured using additive manufacturing techniques. Models of pelvic parts made of polylactic acid (PLA) material were manufactured using the Material Extrusion (MEX) additive technique. Subsequently, guidelines were developed to reliably verify the geometric and surface roughness of the 3D printed models using Computer-Aided Inspection (CAI) systems. For this purpose, a measuring arm system (MCA-II) with a mounted laser head and Atos II Triple Scan was used. To inspect surface roughness parameters, procedures were developed for an Alicona InfiniteFocusG4 optical microscope. The results of the geometrical verification of the models are within the tolerance limits of ±0.22 mm to ±0.6 mm. In the case of surface roughness measurement, the highest values for the arithmetical mean height Sa were obtained on the side of the support material, while the smallest values were found along the applied layers. After the metrological control process, the models were used in the planning process for hip surgery. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) techniques are among the fastest-growing technologies for producing even the most geometrically complex models. Unfortunately, the lack of development of metrology guidelines for these methods, related to dimensional and geometry accuracy and surface roughness, significantly limits the commercialization of finished products manufactured using these methods. This paper aims to evaluate the macro- and micro-geometry of models manufactured using the PolyJet method from three types of photopolymer resins: Digital ABS Plus, RGD 720, and Vero Clear. For this purpose, test parts were designed and then manufactured on an Object 350 Connex3 3D printer. The Atos II Triple Scan optical system and the InfiniteFocusG4 microscope were used to evaluate macro- and micro-geometry, respectively. For both systems, measurement procedures were developed to obtain statistical results for evaluating geometric accuracy and surface roughness parameters. In the case of macro-geometry, for Digital ABS Plus and Vero Clear materials, 50% of the central deviations (between first quartile Q1 and third quartile Q3) lie within the range (−0.06, 0.03 mm) and for RGD 720 material within the range (−0.08, 0.01 mm). For micro-geometry, the arithmetic mean height (Sa) values for the Digital ABS Plus and Vero Clear samples were approximately 1.6 and 2.0 µm, respectively, while for RGD 720, it was 15.9 µm. The total roughness height expressed by reduced peak height (Spk) + core height (Sk) + reduced dale depth (Svk) for the Digital ABS Plus and Vero Clear samples was approximately 9.1 and 10.5 µm, respectively, while for the RGD 720, it was 101.9 µm. [ABSTRACT FROM AUTHOR]

The article presents the possibilities of automating production pre-processing and post-processing operations for the Material Extrusion - MEX process based on Fused Filament Fabrication technology. Automation is based on hardware and software solutions. For this purpose, a special research station was developed, equipped with a warehouse of working platforms, a 3D printer and a collaborative robot that integrates individual elements of the manufacturing process. The developed solution allows for increasing the efficiency of the manufacturing cell and reducing the operator's involvement in manual operations at the pre-processing and post-processing stages. [ABSTRACT FROM AUTHOR]

The article presents an analysis of the geometric accuracy of wax models produced using PolyJet molds. Photopolymer resin was used to make the molds, and the surface of the model was finished in a gloss mode in the 3D printing process. This allows you to obtain a smooth surface of the molded part model. The geometric accuracy of the models was determined by measurements with the GOM ATOS scanner and analysis of the measurement results in relation to the base model made in the 3D-CAD program. Accuracy analysis was the basis for determining the wear of the mold wear when making subsequent models. [ABSTRACT FROM AUTHOR]

Broadly, understood additive manufacturing techniques expand the spectrum of production of machine parts that are used in various types of devices. However, the requirements to ensure dimensional and shape accuracy require the determination of appropriate material allowances or clearances to enable correct assembly. For the above reasons, the study presents an analysis of the impact of the assumed geometry modifications on the possibility of assembling a splined connection manufactured using selected AM techniques. The work focused on the analysis of changes in geometry resulting from the technology used. Using the Atos II Triple Scan optical measurement system and Gom Inspect software, the possibility of installation was determined for four variants of the splined shaft connection geometry, resulting from the technologies used. [ABSTRACT FROM AUTHOR]

This article presents a procedure for minimizing ATOS II Triple Scan system measurement errors during the verification of geometrical accuracy of the final lateral-mandibular condyle model. The process of manufacturing a template geometrically similar to that of lateral-mandibular condyle was performed on the five-axis machining centre 100 DMU MonoBlock. The next stage of the research was related to the implementation of the measurement system procedure on the template model, and the 12 anatomical models of the mandibular body-condyle were manufactured using five different additive methods. As a result of the comparison of anatomical models of the mandibular body-condyle designed in reverse engineering/computer-aided design systems and manufactured using additive methods, the average results of histograms and parameters determining the accuracy of geometry of 12 models were obtained. In the case of models manufactured using fused deposition modelling, PolyJet and selective laser sintering techniques, a unimodal distribution was observed in the same way as in the template model. The best results were obtained in the case of models manufactured using selective laser sintering techniques (standard deviation = 0.06 mm). In the case of fused deposition modelling and PolyJet, a similar value of standard deviation (about 0.07 mm) was observed, despite the fact that the layer thickness for PolyJet technology was 0.016 mm. In the case of melted and extruded modelling and ColorJet Printing technologies, there was a bimodal distribution. Through the implementation of own template and measurement method, it will be easier to estimate errors in the manufacturing of anatomical models of lateral-mandibular condyle part. As a result, medical models, surgical templates and implants will be manufactured more accurately and precisely, which will significantly reduce intraoperative complications during the surgical procedure in this area. [ABSTRACT FROM AUTHOR]

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Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper presents a complex process calculations and design development, FDM model manufacturing and accuracy analysis of a demonstrative prototype of a dual-power path gear unit to be applied in aeronautical systems of drive transmission. The process of making a demonstrator of a dual-power path gear unit by means of 3DCAD modeling and Rapid Prototyping has been described here. The first stage of the designing process of a gear unit is always defining basic parameters of gear work (among others; power, rotational speed, transmission ratio) depending on the unit’s predestination. On the basis of the above, the calculation of main constructional parameters is carried out. Subsequently, it is possible to make 3D-CAD models of toothed wheels and the remaining parts of the gear unit. In case of designing demonstrative prototypes, it is important to take into consideration the assumptions of modeling similarity to a real gear unit. 3D-CAD systems are often equipped with modules for analyzing geometrical parameters and cooperation of individual parts of the unit for example the area of contact. A detailed analysis of cooperation of gear parts of the unit allows for detecting models’ faults early and for deleting them. After making 3D-CAD models one can approach to creating a prototype by means of Rapid Prototyping methods. It is necessary to prepare the numerical data essential as a subsequent stage of the process of making the demonstrator. On that basis the individual parts of the gear unit are made in an incremental process. The accuracy of creating a physical prototype depends mainly on the accuracy of a 3D-CAD/3D-RP model prepared in a process of processing numerical data. A demonstrator described in the paper has been made by means of FDM method. The prototype allowed for analyzing constructional solutions of gear units on a physical model and for preparing assumptions for introductory stand tests. In case of measurement of gear wheels using modern technologies based on numerical machines, measurement process is based on processing of numerical data obtained by measurement using coordinate measuring machines. In this paper is present the opportunity to automate the measurement process of gears, using coordinated optical CMM Baty Venture machine. [ABSTRACT FROM AUTHOR]