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.

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.

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.

A Laser Sensor Technique for Measuring 3D Surfaces Based on the Polarized Heterodyne Astigmatic Principle

2005 ◽  
Vol 295-296 ◽  
pp. 483-488
Author(s):  
L.R. Qiu ◽  
X.M. Ding
Keyword(s):  
Optical Sensing ◽  
Coordinate Measuring Machine ◽  
Measuring Method ◽  
Laser Source ◽  
Profile Measurement ◽  
Laser Sensor ◽  
Sensing System ◽  
3D Surface ◽  
Measuring Machine ◽  
Better Than

A laser measurement technique based on polarized heterodyne astigmatic principle is proposed for high precision three-dimensional (3D) profile measurement. In the presented system, the defocus astigmatic signal coming from the polarized reflection of the detected 3D surface is used to determine the position of the surface. The work of tracing, scanning and processing of the detected 3D surface is performed by combining the system with an ultra precision laser coordinate measuring machine (CMM). Compared with the current heterodyne astigmatic measuring technique, a polarization incidence and Glan-Thompson prism (GP) is used in the novel polarized heterodyne astigmatic measuring method. The anti-interference ability of the optical sensing system is significantly improved. The undesired influence on the measurement results, caused by fluctuation of surrounding brightness, by the intensity disturbance of the laser source, and by the multi-reflection among optical elements, is effectively restrained. Experimental results show that the stability of the optical sensing system is better than 2%. The resolution of the system is better than 0.005µm.

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.

Evaluation of Different Internal Structure and Build Orientation for Multijet Modeling Process

2013 ◽  
Vol 315 ◽  
pp. 587-591 ◽  
Author(s):  
M.N. Hafsa ◽  
M. Ibrahim ◽  
S. Sharif ◽  
M.F.M. Omar ◽  
M.A. Zainol
Keyword(s):  
Surface Roughness ◽  
Internal Structure ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Part Quality ◽  
Modeling Process ◽  
Measuring Machine ◽  
Complex Parts ◽  
Processing Steps ◽  
Better Than

Rapid Prototyping (RP) technology has proven its capability to produce complex parts with shorter lead time. This advantage could benefit tremendously in application such as the Investment Casting (IC) process. The focus of the study is the production of sacrificial IC patterns produced using Multijet Modeling (MJM) RP technology. It includes the evaluation of dimensional accuracy and the surface roughness of part with a hollow and quasi hollow inner support patterns. Different internal structure's pattern were developed using CAD software, and the part were fabricated using MJM technique in two different build orientations. Analyses were done using Coordinate Measuring Machine (CMM) and the surface roughness tester. Results show that part built with 90º orientation is better than part built with 0º orientation both in terms of accuracies and roughness. Different internal structure similarly affects the final part quality, though the post processing steps also have their influence, thus making it no clear different among the parts. However, it demonstrated parts with square structure produced the best dimensional accuracy and the part with hatch structure produced the best surface roughness.

Novel Prediction Analysis Method for Error Separation of Stylus System and CMM Machine

2014 ◽  
Vol 875-877 ◽  
pp. 671-679 ◽  
Author(s):  
Salah Hamed Ramadan Ali
Keyword(s):  
Experimental Investigation ◽  
Large Range ◽  
Coordinate Measuring Machine ◽  
Detection Accuracy ◽  
Analysis Method ◽  
Machine Accuracy ◽  
Error Separation ◽  
Dimensional Measurements ◽  
Measuring Machine ◽  
Specific Error

Coordinate Measuring Machine (CMM) is nowadays widely used for a large range of accurate and precise dimensional measurements. The strategy of µ-scale measurement is expected to carry out with ever-increasing performance in term of root error separation for stylus system and CMM machine accuracy. The experimental analysis method in this paper aims to study the effect of dynamic root errors at different undulations per revolution (UPR) response of artifact measurement using selected two types of CMM touch-triggering stylus. Direction of stylus characteristics and stylus speed parameters were adopted and emphasized upon throughout the course of experiment. The results were investigated using Fourier analysis could thus be derived to ensure foreseeable accurate and precise results of CMM machine and stylus errors. Some specific error equations for stylus system and machine responses have been postulated and analysed empirically. The results may also employ validating an experimental investigation to detection accuracy development using PRISMO-Bridge-CMM-type in NIS.

Articulated Arm Length Calibration for Cantilever Coordinate Measuring Machine

2013 ◽  
Vol 333-335 ◽  
pp. 77-80 ◽  
Author(s):  
Hong Lei Ran ◽  
Shu Gui Liu ◽  
Hai Tao Zhang
Keyword(s):  
Measurement Accuracy ◽  
Small Volume ◽  
Low Cost ◽  
Coordinate Measuring Machine ◽  
Calibration Method ◽  
Measurement Range ◽  
Precision Error ◽  
Large Measurement ◽  
Measuring Machine ◽  
Error Calibration

Cantilever CMM(short for coordinate measuring machine) is non-orthogonal type one with large measurement range, small volume, light weight, low cost, but lower precision. Error calibration and compensation is an important way to improve the measurement accuracy. This paper presents a new calibration method for the length of articulated arm just using the square. Facility requirement is relatively low and it is easy to operate. Comparing with that measured by laser interferometer, this method has a relatively high accuracy, having a certain value in practical measurement.

scholarly journals Printability Study of a Conductive Polyaniline/Acrylic Formulation for 3D Printing

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2068
Author(s):  
Goretti Arias-Ferreiro ◽  
Ana Ares-Pernas ◽  
Aurora Lasagabáster-Latorre ◽  
Nora Aranburu ◽  
Gonzalo Guerrica-Echevarria ◽  
...  
Keyword(s):  
3D Printing ◽  
Low Cost ◽  
Electronic Devices ◽  
Maximum Amount ◽  
Gel Point ◽  
Digital Light Processing ◽  
Conductive Composites ◽  
Printing Quality ◽  
Conductive Polyaniline ◽  
Pure Resin

There is need for developing novel conductive polymers for Digital Light Processing (DLP) 3D printing. In this work, photorheology, in combination with Jacobs working curves, efficaciously predict the printability of polyaniline (PANI)/acrylate formulations with different contents of PANI and photoinitiator. The adjustment of the layer thickness according to cure depth values (Cd) allows printing of most formulations, except those with the highest gel point times determined by photorheology. In the working conditions, the maximum amount of PANI embedded within the resin was ≃3 wt% with a conductivity of 10−5 S cm−1, three orders of magnitude higher than the pure resin. Higher PANI loadings hinder printing quality without improving electrical conductivity. The optimal photoinitiator concentration was found between 6 and 7 wt%. The mechanical properties of the acrylic matrix are maintained in the composites, confirming the viability of these simple, low-cost, conductive composites for applications in flexible electronic devices.

scholarly journals Testing the Sandblasting Process in the Manufacturing of Reference Spheres for Non-Contact Metrology Applications

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5187
Author(s):  
Víctor Meana ◽  
Eduardo Cuesta ◽  
Braulio J. Álvarez
Keyword(s):  
Laser Scanning ◽  
Low Cost ◽  
Coordinate Measuring Machine ◽  
Point Clouds ◽  
Laser Triangulation ◽  
Laser Sensor ◽  
Measuring Machine ◽  
Laser Triangulation Sensor ◽  
Triangulation Sensor

To ensure that measurements can be made with non-contact metrology technologies, it is necessary to use verification and calibration procedures using precision artefacts as reference elements. In this environment, the need for increasingly accurate but also more cost-effective calibration artefacts is a clear demand in industry. The aim of this work is to demonstrate the feasibility of using low-cost precision spheres as reference artefacts in calibration and verification procedures of non-contact metrological equipment. Specifically, low-cost precision stainless steel spheres are used as reference artefacts. Obviously, for such spheres to be used as standard artefacts, it is necessary to change their optical behavior by removing their high brightness. For this purpose, the spheres are subjected to a manual sandblasting process, which is also a very low-cost process. The equipment used to validate the experiment is a laser triangulation sensor mounted on a Coordinate Measuring Machine (CMM). The CMM touch probe, which is much more accurate, will be used as a device for measuring the influence of sandblasting on the spheres. Subsequently, the influence of this post-processing is also checked with the laser triangulation sensor. Ultimately, the improvement in the quality of the point clouds captured by the laser sensor will be tested after removing the brightness, which distorts and reduces the quantity of points as well as the quality of the point clouds. In addition to the number of points obtained, the parameters used to study the effect of sandblasting on each sphere, both in contact probing and laser scanning, are the measured diameter, the form error, as well as the standard deviation of the point cloud regarding the best-fit sphere.

Development of Dimensional X-Ray Computed Tomography

2015 ◽  
Vol 9 (5) ◽  
pp. 567-571 ◽  
Author(s):  
Hiroyuki Fujimoto ◽  
◽  
Makoto Abe ◽  
Sonko Osawa ◽  
Osamu Sato ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coordinate Measuring Machine ◽  
National Metrology Institute ◽  
Maximum Deviation ◽  
Dimensional Metrology ◽  
X Ray ◽  
Tomography System ◽  
Dimensional Measurements ◽  
X Ray Computed ◽  
Measuring Machine

Recently, a strong need has arisen for a dimensional X-ray computed tomography system that is capable of dimensional measurements. This is because the speedy realization of dimensional measurements for outward forms and inward forms on dense spatial points remarkably simplifies and accelerates production loop. However, although the image obtained via XCT describes the structure clearly and in great detail, dimensional metrology by means of XCT is not simple. The National Metrology Institute of Japan has been carrying out performance tests using gauges that include the gauges proposed in ISO10360. In this work, the magnification variation correction is carefully presented, and a maximum deviation of less than 5 μm is shown to be possible by means of the measurement of the forest phantom of 27 ruby spheres, the locations of which are calibrated by the coordinate measuring machine.

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