scholarly journals HOMEMADE FIREARMS PRODUCED USING THE 3D PRINTING METHOD – THEIR CONSTRUCTION AND THE PECULIARITIES OF FORENSIC EXAMINATION

2020 ◽  
pp. 381-392
Author(s):  
P. Giverts
Keyword(s):  
3D Printing ◽  
New Technology ◽  
3D Printer ◽  
Wide Spread ◽  
Special Equipment ◽  
Forensic Examination ◽  
Special Knowledge ◽  
The Difference ◽  
Printing Method

The development of a new technology of material processing known as 3D printing in 2013 lead to posting on the Internet blueprints of the first pistol made with the use this technology. The pistol got the name Liberator. Within the first two days after the post, the blueprints of this pistol were downloaded more than a hundred thousand times. The difference of this construction from other constructions is that all the parts, except the firing pin, are printed on the 3D printer. For manufacturing this type of pistols special equipment (which has become easily available lately) is needed, as well as the knowledge and skill to operate it. At the same time, no special knowledge about the development and manufacturing of firearms is necessary. Availability of ready blueprints (the programs for printing the elements in 3D printer) without the need to do manual or machine treatment, lead to the wide spread of this type of homemade firearms. The law enforcements of many countries have already got cases of illegal trafficking of homemade firearms made with the use of 3D printing technology. The article discusses the construction features of Liberator pistol, as well as the peculiarities of its forensic examination. Special attention is paid to the problem of reliability and durability of this type of pistols. The possibility of damage or destruction of the pistol construction during a shot was investigated. The influence of different parameters, such as the size of the pistol, the material of its elements, the caliber of the cartridge on the possible destruction of the pistol, was also discussed. The damages in the pistols, made of different polymers, were illustrated in this article by the results of investigations taken from a few foreign professional sources. The problem of establishing the fact of a shot, which had been made from pistol printed in 3D printer, before the evidence came for forensic examination, was discussed. The article deals with the problem of the influence of this shot on the possibility of determination of the constriction durability and with the question if the evidence meets the criteria of firearms. Possible defects in the examined evidences, which should be checked be the examiners before the experimental shot, were pointed out.

Results of studying the dimensional accuracy of the bases of complete removable prostheses made using 3D printing and traditional technologies

2020 ◽  
pp. 34-39
Author(s):  
Vokulova Yu.A. Vokulova ◽  
E.N. Zhulev
Keyword(s):  
3D Printing ◽  
Traditional Method ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Digital Technologies ◽  
Dimensional Accuracy ◽  
3D Printer ◽  
Significance Level ◽  
Average Value ◽  
The Difference

This article presents the results of studying the dimensional accuracy of the bases of complete removable prostheses made using a 3D printer and the traditional method. Bases of complete removable prostheses were made using an intraoral laser scanner iTero Cadent (USA) and a 3D printer Asiga Max UV (Australia). To study the dimensional accuracy of the bases of complete removable prostheses, we used the DentalCAD 2.2 Valletta software. The Nonparametric Wilcoxon W-test was used for statistical analysis of the obtained data. We found that the average value of the difference with the standard for bases made using digital technologies is 0.08744±0.0484 mm. The average value of the difference with the standard for bases made by the traditional method is 0.5654±0.1611 mm. Based on these data, we concluded that the bases of complete removable prostheses made using modern digital technologies (intraoral laser scanning and 3D printer) have a higher dimensional accuracy compared to the bases of complete removable prostheses made using the traditional method with a significance level of p<0.05 (Wilcoxon's W-test=0, p=0.031). Keywords: digital technologies in dentistry, digital impressions, intraoral scanner, 3D printing, ExoCAD, complete removable dentures.

Investigation of the Influence of Fillers of Various Nature on the Properties of Polyether Sulfone and Determination of the Possibility of Using Composites on their Basis in 3D-Printing

2018 ◽  
Vol 935 ◽  
pp. 11-14
Author(s):  
Azamat L. Slonov ◽  
Azamat A. Zhansitov ◽  
Ismel V. Musov ◽  
Elina V. Khakyasheva ◽  
L.Kh. Kuchmenova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
3D Printing ◽  
Carbon Fibers ◽  
Polymer Matrix ◽  
Polyether Sulfone ◽  
Printing Method

The results of the studies of the effect of excipients of mineral and organic origin on the mechanical properties of polyether sulfone based on 4,4'-dihydroxydiphenyl and 4,4'-dichlordiphenylsulfone are adduced. It has been shown that the introduction of hard fillers is accompanied by the increased modulus and reduced ductility of the polymer matrix, the intensity of these effects depends on the concentration, shape and particle size additives. It was revealed that the composites with talc and discrete carbon fibers were characterized by higher mechanical properties. Their test as materials for FDM 3D printing method shows the highest suitability composites with talc for this technology.

Bend Testing of Parts Made by Rapid Prototyping with Respect to Possible Use in Robotics

2015 ◽  
Vol 760 ◽  
pp. 141-146 ◽  
Author(s):  
Jan Lipina ◽  
Václav Krys ◽  
Jiří Marek
Keyword(s):  
3D Printing ◽  
Rapid Prototyping ◽  
Experimental Determination ◽  
Internal Structure ◽  
Detailed Knowledge ◽  
3D Printer ◽  
Bend Strength ◽  
Bend Testing ◽  
Material Parameters

Recently, the Rapid Prototyping technology (RP hereafter) has been increasingly used for a final product, which requires detailed knowledge of designing parts made by the RP technology. In order to apply parts made by the RP technology in robotics, and design in general, in a wider range, one of the most important material parameters is their bend strength. The paper describes an experimental determination of bend strength in parts printed on a 3D printer. The parts were made of polycarbonate. The tests were carried out in parts with various types of internal structure. The achieved results can be implemented when designing parts made by 3D printing provided that professional printers are used.

scholarly journals Possibilities for obtaining the length-measured images of skeleton using modern X-rays equipment

2018 ◽  
Vol 25 (3-4) ◽  
pp. 89-94
Author(s):  
A. A Artemiev ◽  
A. Yu Silin ◽  
A. N Ivashkin ◽  
B. I Maximov ◽  
A. A Shipulin ◽  
...  
Keyword(s):  
X Rays ◽  
Special Equipment ◽  
High Quality ◽  
Teaching Activities ◽  
Medical Expertise ◽  
Special Knowledge ◽  
Data Documentation ◽  
Examination Process ◽  
Different Parts

Modern traumatology and orthopaedics is inconceivable without high-quality X-rays diagnostics. In the recent years special equipment that enables to obtain the length-measured images of different parts of a human body was introduced into clinical practice. The details of examination process, i.e. the position of a patient, position of an extremity and many others require special knowledge and experience. The aim of the study is to optimize the possibilities for obtaining the length-measured images of the different parts of a skeleton using modern X-rays equipment. The peculiarities of the determination of segments’ axes and length in patients with lower extremity deformities and shortening are presented; the most typical mistakes are analyzed. The results of the study are of great importance for medical expertise as well as for data documentation in practical, scientific and teaching activities.

scholarly journals Tribological Behaviour Comparison of ABS Polymer Manufactured Using Turning and 3D Printing

2019 ◽  
Vol 4 (1) ◽  
pp. 46-57
Author(s):  
Sharba Muammel M Hanon ◽  
M. Kovács ◽  
László Zsidai
Keyword(s):  
3D Printing ◽  
Acrylonitrile Butadiene Styrene ◽  
3D Printer ◽  
Dynamic Friction ◽  
Tribological Behaviour ◽  
Friction Factors ◽  
Subtractive Manufacturing ◽  
3D Printed ◽  
The Difference ◽  
Butadiene Styrene

Additive and subtractive manufacturing of Acrylonitrile Butadiene Styrene (ABS) were employed for fabricating samples. The Additive manufacturing was represented through 3D printing, whereas subtractive manufacturing carried out by Turning. Some developments have been applied for enhancing the performance of the 3D printer. Tribological measurements of the turned and 3D printed specimens have been achieved. Studying the difference between static and dynamic friction factors and the examination of wear values were included. A comparison of the tribological behaviour of the turned and 3D printed ABS polymer has been investigated.

scholarly journals Development and investigation of device for processing polymer materials by 3D-printing method

2019 ◽  
Vol 5 (3-4) ◽  
pp. 25-32
Author(s):  
Petro Zozulia ◽  
◽  
Oleg Polishchuk ◽  
Nazar Kostyuk ◽  
Andriy Polishchuk ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
3D Printing ◽  
Polymer Materials ◽  
New Method ◽  
3D Printer ◽  
Current State ◽  
Main Components ◽  
Processing Polymer ◽  
Printing Method

The analysis of the current state of 3d industry and prospects for its future. In the work, calculations were made and graphs of dependence were obtained, which influence the work of the auger and the installation itself. A new method of printing parts with polymer granules is described and the principle of operation of the equipment used is described. The picture of the working installation with the main components and the method of its attachment on a 3D printer is presented. The heating modes of the extruder itself are simulated and a thermal diagram of the device is shown, which accurately displays the temperature distribution across the sections.

Research on the Influence of the Orientation of Deposited Material on the Mechanical Properties of Samples Made from ABS M30 Material Using the 3D Printing Method

2015 ◽  
Vol 809-810 ◽  
pp. 429-434
Author(s):  
Răzvan Păcurar ◽  
Ancuţa Păcurar ◽  
Adrian Radu Sever
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
3D Printing ◽  
Mechanical Strength ◽  
3D Printer ◽  
The Finite Element Method ◽  
Building Orientation ◽  
3D Printers ◽  
Polymer Deposition ◽  
Printing Method

The majority of commercially available 3D printers utilize an additive manufacturing (AM) technique known as molten polymer deposition, whereby a solid thermoplastic filament is forced through a computer-driven extrusion nozzle. Even if it sounds simple at a first look, there are a series of factors that significantly influence the mechanical strength of parts manufactured by using the 3D printing method. The present work tries to investigate by using the finite element method and experimental research how the building orientation is influencing the mechanical strength of samples made from ABS M30 material using a Desktop 3D Printer machine that has been originally designed and produced at the Technical University of Cluj-Napoca (TUC-N).

Makers in the library: case studies of 3D printers and maker spaces in library settings

2014 ◽  
Vol 32 (4) ◽  
pp. 583-593 ◽  
Author(s):  
Heather Michele Moorefield-Lang
Keyword(s):  
Higher Education ◽  
3D Printing ◽  
Case Studies ◽  
Design Methodology ◽  
New Technology ◽  
Library Services ◽  
3D Printer ◽  
Content Type ◽  
3D Printers ◽  
Different Levels

Purpose – The purpose of this paper is to describe the implementation of 3D printing and maker spaces in various library settings. Insights, challenges, successes, projects as well as recommendations will be shared. Commonalities across libraries 3D printing technologies and maker space learning areas will also explored. Design/methodology/approach – This paper delves into six case studies of librarians that have implemented 3D printers and/or maker spaces in their libraries. The case studies focus on libraries at three different levels: school, public, and higher education with two case studies from each type. The author of this paper will describe the cases, projects, challenges, successes, along with other aspects of 3D printer, and maker space integration. Findings – 3D printing and maker spaces, while very popular in the field of librarianship can be incredibly exciting to implement but they come with challenges and successes just like any type of new technology. Librarians have to be fearless in implementing this technology, willing to learn on their feet, and be excited to explore. Originality/value – At this time most publications on 3D printing are held in the realm of popular publications (blogs, magazines, zines, etc.). Very little has been written on a wider range of case studies where 3D printers and maker spaces have been integrated into libraries of various types. This paper sets the foundation for further exploration in how 3D printing and maker spaces could be a part of library services.

scholarly journals Developing and Testing of Strain-Hardening Cement-Based Composites (SHCC) in the Context of 3D-Printing

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1375 ◽  
Author(s):  
Hiroki Ogura ◽  
Venkatesh Nerella ◽  
Viktor Mechtcherine
Keyword(s):  
3D Printing ◽  
Strain Hardening ◽  
New Technology ◽  
Tensile Loading ◽  
The Other ◽  
Uniaxial Tensile ◽  
3D Printer ◽  
Fiber Volume ◽  
Structural Applications ◽  
Uniaxial Tensile Loading

Incorporating reinforcement into the practice of digital concrete construction, often called 3D-concrete-printing, is a prerequisite for wide-ranging, structural applications of this new technology. Strain-Hardening Cement-based Composites (SHCC) offer one possible solution to this challenge. In this work, printable SHCC were developed and tested. The composites could be extruded through a nozzle of a 3D-printer so that continuous filaments could be deposited, one upon the other, to build lab-scaled wall specimens without noticeable deformation of the bottom layers. The specimens extracted from the printed walls exhibited multiple fine cracks and pronounced strain-hardening characteristics under uniaxial tensile loading, even for fiber volume fractions as low as 1.0%. In fact, the strain-hardening characteristics of printed specimens were superior to those of mold-cast SHCC specimens.

Kinematic Analysis of 3D Printing Mechanisms

2015 ◽  
Author(s):  
Ilie Talpasanu ◽  
Stephen Chomyszak
Keyword(s):  
3D Printing ◽  
Kinematic Analysis ◽  
Input Output ◽  
Gear Teeth ◽  
The Matrix ◽  
Angular Velocities ◽  
Gear Box ◽  
The Difference ◽  
Student Projects

The paper presents a novel technique for the kinematic analysis of a geared mechanism manufactured through 3D printing technology. In the syllabus of the undergraduate 3D Printing course, one of the student projects is to manufacture a spur Norton type gear box which includes a planetary mechanism for engaging its three planets, thus three output velocities for the gear box are obtained. The connected elements (carriers, gears, planets) are fabricated without any involvement of assembly operation. At the prototype stage, a CAD model of the mechanism is created and a search for abilities and limitations of the mechanism are required. The analysis of abilities of motion includes determination of mechanism mobility (DOF). A step by step simple technique is presented for determination of the rank for the matrix of coefficients from the kinematic equations. Thus, the DOF is the difference between the number columns and the rank previously determined. The steps required in the analysis are: numbering of links and joints, graph attached to mechanism, matrix of incidence cycles-nodes in graph, and determination of its rank by using Mathematica commands. For the set of base cycles are automatically generated independent scalar equations. The matrix, denoted velocity matroidal, has the coefficients for the mechanism’s unknown absolute angular velocities-determined based on an analogy to a system of parallel forces from static equilibrium, angular velocities being considered analog to the “forces“. The relations between the input-output links’ absolute angular velocities are determined. The coefficients in the kinematic equations for velocities are written as function of gear ratios. The number of gear teeth can be selected also for the desired input-output speed ratios.

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