Dimensional Tolerance of Casting in the Bridgman Furnace Based on 3D Printing Techniques

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 299
Author(s):  
Xintao Zhu ◽  
Fu Wang ◽  
Dexin Ma ◽  
Andreas Bührig-Polaczek
Keyword(s):  
3D Printing ◽  
Investment Casting ◽  
Systematic Approach ◽  
Low Cost ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Metal Casting ◽  
Measuring Machine ◽  
Printing Techniques ◽  
Short Times

In this article, the feasibility and the dimensional accuracy based on the 3D printing technology during investment casting of non-vacuum and Bridgman furnace are investigated based on the coordinate measuring machine to calculate the dimensional tolerances through a systematic approach. The research proved that both the investigated RC solutions are effective at obtaining cast technological prototypes in short times and at low cost, with dimensional tolerances that are completely consistent with metal casting processes.

A Study on the Shrinkage Characteristics and Dimensional Accuracy of Cast Gears

1992 ◽  
Author(s):  
Jimmy Adjunta ◽  
Donald Houser
Keyword(s):  
Investment Casting ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Machining Process ◽  
Spur Gears ◽  
Design Phase ◽  
Process Variables ◽  
Measuring Machine ◽  
Thickness Measurements

Abstract This paper is primarily concerned with the evaluation of the dimensional quality of spur gears produced by two casting processes, i. e., the investment casting and v-sand casting processes. The casting patterns used were designed by compensating for process shrinkage, and were manufactured using a flexible CNC gear machining process. A computer program, CASTGR, was written to facilitate the design phase of the patterns. The various gear configurations cast were inspected using an universal coordinate measuring machine. The geometry of the casting and pattern were correlated to verify the contraction characteristics of the gear castings. In an attempt to categorize the precision capabilities of the two casting processes, the spread of the deviations found for tooth thickness measurements and measurements along profiles and leads of the cast gears were examined. The observed effects of other process variables is also included.

Proposal of an Innovative Benchmark for the Evaluation of 3D Printing Accuracy for Photopolymers

2022 ◽  
Vol 1048 ◽  
pp. 279-290
Author(s):  
Paolo Minetola ◽  
Vinicius de Freitas Pacheco ◽  
Marcelo Massarani ◽  
Flaviana Calignano ◽  
Giovanni Marchiandi
Keyword(s):  
3D Printing ◽  
Low Cost ◽  
Coordinate Measuring Machine ◽  
Geometric Accuracy ◽  
Digital Light Processing ◽  
Dimensional Measurements ◽  
Measuring Machine ◽  
T Values ◽  
Two Machines ◽  
Better Than

In recent years, the diffusion of additive manufacturing (AM) or 3D printing (3DP) techniques for polymers have been boosted by the expiration of earlier patents from the last century and the development of low-cost machines. Since these technologies become more widespread, there is a need to assess the capability and accuracy of low-cost machines in terms of dimensional and geometric tolerance. To this aim, this work proposes an innovative reference part for benchmarking layerwise processes that involve the curing of photopolymers. The geometry of the part is conceived to include several classical shapes that are easily measurable for defining the part accuracy in terms of ISO IT grades and GD&T values. Two replicas of the reference part were fabricated by stereolithography (SLA) and digital light processing (DLP) using two machines and related proprietary materials by Sharebot Company. The replicas were printed with a layer thickness of 50 μm for the DLP process and 100 μm for the SLA one. The results of dimensional measurements of the replicas, that were carried out using a Coordinate Measuring Machine (CMM), show that the geometric accuracy of the time-consuming DLP process is slightly better than that of stereolithography.

scholarly journals Evaluation of dimensional accuracy of dental bridges manufactured with conventional casting technique and CAD/CAM system with Ceramill Sintron blocks using CMM

2018 ◽  
Vol 12 (4) ◽  
pp. 264-271 ◽  
Author(s):  
Alireza Izadi ◽  
Fariborz Vafaee ◽  
Arash Shishehian ◽  
Ghodratollah Roshanaei ◽  
Behzad Fathi Afkari
Keyword(s):  
Reference Model ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Three Dimensions ◽  
Casting Technique ◽  
Dimensional Changes ◽  
Conventional Casting ◽  
Cad Cam ◽  
Milling Method ◽  
Measuring Machine

Background. Recently, non-presintered chromium-cobalt (Cr-Co) blocks with the commercial name of Ceramill Sintron were introduced to the market. However, comprehensive studies on the dimensional accuracy and fit of multi-unit frameworks made of these blocks using the coordinate measuring machine (CMM) are lacking. This study aimed to assess and compare the dimensional changes and fit of conventional casting and milled frameworks using Ceramill Sintron. Methods. A metal model was designed and scanned and 5-unit frameworks were fabricated using two techniques: (I) the conventional casting method (n=20): the wax model was designed, milled in the CAD/CAM machine, flasked and invested; (II) the milling method using Ceramill Sintron blocks (n=20): the wax patterns of group 1 were used; Ceramill Sintron blocks were milled and sintered. Measurements were made on the original reference model and the fabricated frameworks using the CMM in all the three spatial dimensions, and dimensional changes were recorded in a checklist. Data were analyzed with descriptive statistics, and the two groups were compared using one-way ANOVA and Tukey test (α=0.05). Results. The fabricated frameworks in both groups showed significant dimensional changes in all the three dimensions. Comparison of dimensional changes between the two groups revealed no significant differences (P>0.05) except for transverse changes (arch) that were significantly greater in Ceramill Sintron frameworks (P<0.05). Conclusion. The two manufacturing processes were the same regarding dimensional changes and the magnitude of marginal gaps and both processes resulted in significant dimensional changes in frameworks. Ceramill Sintron frameworks showed significantly greater transverse changes than the conventional frameworks.

scholarly journals Study of the Influence of Technological Parameters on Generating Flat Part with Cylindrical Features in 3D Printing with Resin Cured by Optical Processing

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1941
Author(s):  
Aurel Tulcan ◽  
Mircea Dorin Vasilescu ◽  
Liliana Tulcan
Keyword(s):  
3D Printing ◽  
Flat Surface ◽  
Coordinate Measuring Machine ◽  
3D Printer ◽  
Light Control ◽  
Technological Parameters ◽  
Optical Processing ◽  
Measuring Machine ◽  
The Impact

The objective of this paper is to determine how the supporting structure in the DLP 3D printing process has influences on the characteristics of the flat and cylindrical surfaces. The part is printed by using the Light Control Digital (LCD) 3D printer technology. A Coordinate Measuring Machine (CMM) with contact probes is used for measuring the physical characteristics of the printed part. Two types of experiment were chosen by the authors to be made. The first part takes into consideration the influence of the density of the generated supports, at the bottom of the printed body on the characteristics of the flat surface. In parallel, it is studying the impact of support density on the dimension and quality of the surface. In the second part of the experiment, the influence of the printed supports dimension on the flatness, straightness and roundness of the printed elements were examined. It can be observed that both the numerical and dimensional optimum zones of the support structure for a prismatic element could be determined, according to two experiments carried out and the processing of the resulting data. Based on standardized data of flatness, straightness and roundness, it is possible to put in accord the values determined by measurement within the limits of standardized values.

Experimental Investigations for Rapid Moulding Solution of Plastics Using Polyjet Printing

2011 ◽  
Vol 701 ◽  
pp. 15-20 ◽  
Author(s):  
Rupinder Singh ◽  
Varinderjit Singh
Keyword(s):  
Plastic Material ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Point Of View ◽  
Experimental Investigations ◽  
Support Material ◽  
Economic Point ◽  
Measuring Machine ◽  
Plastic Components ◽  
Polyjet Printing

Rapid prototyping (RP) has been in evidence for the past twenty years and is being widely used in diverse areas, from the building of aesthetic and functional prototypes to the production of tools and moulds for technological prototypes. The purpose of the present study is to experimentally investigate the rapid moulding (RM) solutions for plastic components using polyjet printing (PP) technique. Starting from the identification of component/benchmark, prototypes with three different type of plastic material were produced, at different orientation and support material. Measurements on the coordinate measuring machine helped in calculating the dimensional tolerances of the plastic components produced. Some important mechanical properties were also compared to verify the suitability of the components. The study highlighted the best orientation, support material quantity and type of plastic material for the selected component from dimensional accuracy and economic point of view as RM solution for plastic components. This process ensures rapid production of pre-series technological prototypes and proof of concept at less production cost and time.

scholarly journals Evaluation of a Desktop 3D Printed Rigid Refractive-Indexed-Matched Flow Phantom for PIV Measurements on Cerebral Aneurysms

2019 ◽  
Vol 11 (1) ◽  
pp. 14-23 ◽  
Author(s):  
W. H. Ho ◽  
I. J. Tshimanga ◽  
M. N. Ngoepe ◽  
M. C. Jermy ◽  
P. H. Geoghegan
Keyword(s):  
3D Printing ◽  
Flow Visualization ◽  
Investment Casting ◽  
Flow Model ◽  
Low Cost ◽  
Ammonium Thiocyanate ◽  
Cerebral Aneurysms ◽  
Model Material ◽  
Flow Phantom ◽  
3D Printed

Abstract Purpose Fabrication of a suitable flow model or phantom is critical to the study of biomedical fluid dynamics using optical flow visualization and measurement methods. The main difficulties arise from the optical properties of the model material, accuracy of the geometry and ease of fabrication. Methods Conventionally an investment casting method has been used, but recently advancements in additive manufacturing techniques such as 3D printing have allowed the flow model to be printed directly with minimal post-processing steps. This study presents results of an investigation into the feasibility of fabrication of such models suitable for particle image velocimetry (PIV) using a common 3D printing Stereolithography process and photopolymer resin. Results An idealised geometry of a cerebral aneurysm was printed to demonstrate its applicability for PIV experimentation. The material was shown to have a refractive index of 1.51, which can be refractive matched with a mixture of de-ionised water with ammonium thiocyanate (NH4SCN). The images were of a quality that after applying common PIV pre-processing techniques and a PIV cross-correlation algorithm, the results produced were consistent within the aneurysm when compared to previous studies. Conclusions This study presents an alternative low-cost option for 3D printing of a flow phantom suitable for flow visualization simulations. The use of 3D printed flow phantoms reduces the complexity, time and effort required compared to conventional investment casting methods by removing the necessity of a multi-part process required with investment casting techniques.

scholarly journals Characterization of machining quality attributes based on spindle probe, coordinate measuring machine, and surface roughness data

2014 ◽  
Vol 1 (2) ◽  
pp. 128-139 ◽  
Author(s):  
Tzu-Liang Bill Tseng ◽  
Yongjin James Kwon
Keyword(s):  
Surface Roughness ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Quality Characteristics ◽  
Machining Parameters ◽  
Production Environment ◽  
Significant Interaction Effect ◽  
Machining Quality ◽  
Measuring Machine ◽  
Touch Probe

Abstract This study investigates the effects of machining parameters as they relate to the quality characteristics of machined features. Two most important quality characteristics are set as the dimensional accuracy and the surface roughness. Before any newly acquired machine tool is put to use for production, it is important to test the machine in a systematic way to find out how different parameter settings affect machining quality. The empirical verification was made by conducting a Design of Experiment (DOE) with 3 levels and 3 factors on a state-of-the-art Cincinnati Hawk Arrow 750 Vertical Machining Center (VMC). Data analysis revealed that the significant factor was the Hardness of the material and the significant interaction effect was the Hardness + Feed for dimensional accuracy, while the significant factor was Speed for surface roughness. Since the equally important thing is the capability of the instruments from which the quality characteristics are being measured, a comparison was made between the VMC touch probe readings and the measurements from a Mitutoyo coordinate measuring machine (CMM) on bore diameters. A machine mounted touch probe has gained a wide acceptance in recent years, as it is more suitable for the modern manufacturing environment. The data vindicated that the VMC touch probe has the capability that is suitable for the production environment. The test results can be incorporated in the process plan to help maintain the machining quality in the subsequent runs.

scholarly journals Universal CubeSat Platform Design Technique

2018 ◽  
Vol 179 ◽  
pp. 01002
Author(s):  
Zhiyong Chen
Keyword(s):  
3D Printing ◽  
System Development ◽  
Low Cost ◽  
Fem Simulation ◽  
Frame Structure ◽  
Scientific Impact ◽  
Advantages And Disadvantages ◽  
Small Parts ◽  
3D Printing Technique ◽  
Printing Techniques

This article summarizes cubesat technology, provides examples of their scientific impact, and describes the design and the manufacturing of a Cubesat platform. As for the design of the overall frame structure of the CubeSat, we have searched a lot of literature and consulted many predecessors' designs, and collected many satellite structure images. After analyzing the data, we aimed at all kinds of different structures’ advantages and disadvantages, finally we got a best design. It is a satellite of cubic shape (10 cm per side), weighing approximately 1kg, based on the creation of a central body made of different material using the 3D-Printing techniques. The 3D-Printing technique has several advantages including fast implementation, accuracy in manufacturing small parts and low cost. Moreover, concerning the construction of a small satellite, this technique is very useful thanks to the accuracy achievable in details, which are sometimes difficult and expensive to realize with the use of tools machine. The structure must be able to withstand the launch loads. For this reason, several simulations using an FEM simulation and an intensive vibration test campaign will be performed in the system development and test phase.

Experimental Investigations for Statistically Controlled Rapid Moulding Solution of Plastics Using Polyjet Printing

2010 ◽  
Author(s):  
Rupinder Singh ◽  
Varinderjit Singh ◽  
Manohar Singh Saini
Keyword(s):  
Plastic Material ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Point Of View ◽  
Experimental Investigations ◽  
Economic Point ◽  
The Past ◽  
Measuring Machine ◽  
Plastic Components ◽  
Polyjet Printing

Rapid prototyping (RP) has been in evidence for the past twenty years and is being widely used in diverse areas, from the building of aesthetic and functional prototypes to the production of tools and moulds for technological prototypes. The purpose of the present study is to experimentally investigate statistically controlled rapid moulding (RM) solutions for plastic components using polyjet printing (PP). Starting from the identification of component/benchmark, prototypes with three different type of plastic material were prepared, at different orientations. Measurements on the coordinate measuring machine helped in calculating the dimensional tolerances of the components prepared. Some important mechanical properties were also compared to verify the suitability of the components. The study highlighted the best orientation, support material quantity and type of plastic material for the selected component from dimensional accuracy and economic point of view as RM solution for plastic components. Final components prepared are acceptable as per ISO standard UNI EN 20286-I (1995). This process ensures rapid production of statistically controlled pre-series technological prototypes and proof of concept at less production cost and time.

scholarly journals Research of three dimensional laser scanning coordinate measuring machine

2018 ◽  
Vol 232 ◽  
pp. 02015
Author(s):  
Zhihua Jiang ◽  
Wenjian Zhang ◽  
Lizhen Cui
Keyword(s):  
3D Printing ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Coordinate Measuring Machine ◽  
Coordinate Measuring Machines ◽  
Measuring Instrument ◽  
Calibration System ◽  
Measuring Range ◽  
Measuring Machine

Three dimensional laser scanning coordinate measuring machine is suitable for the measurement of 3D printing products, and its measuring range depends on the three coordinate measuring machine. It is the main 3D printing product measuring instrument [1]. In this paper, the principle of laser scanning three coordinate measuring machine is analyzed. The accuracy and reliability of the calibration system for 3D printing products are verified. According to the newly revised JJF 1064 Calibration specification for coordinate measuring machines [3], it is calibrated.

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