Economic efficiency analysis of complex CAD/CAM systems demonstrated by an integrated design/SFM system

1995 ◽  
Vol 28 (1) ◽  
pp. 47-56
Author(s):  
Raoul G. Wild
Author(s):  
A. V. Petukhov

The modern stage of development of CAD-systems is characterized by a significant expansion of the scope of their use. An interesting direction for improving CAD systems is their integration with CAM systems. One of the main tasks solved by CAM systems is the development of control programs for CNC machines. Many software developers for automation of design and technological preparation of production have already equipped their systems with appropriate modules. These circumstances pose an urgent task for higher educational institutions to introduce the study of integrated CAD/CAM systems into the educational process of training design engineers. In this case, the emphasis should be placed on the practical mastery of the skills of developing control programs using a 3D-model of the manufactured part. The stages of preparation for the implementation of the system are described, starting with the analysis of the market of necessary software products and ending with the adaptation of the licensed system to the conditions of use in the educational process of the university. A link is given to the description of the methodology used in the assessment of automated systems at the stage preceding the tender for their purchase. It is emphasized that the study of the possibility of using a CAD/CAM system in the preparation of design engineers was carried out by students during the course and diploma projects in the discipline “Automated systems for technological preparation of production”. The methodology for designing control programs used by students is given, and the results obtained are assessed.


Author(s):  
Yuh-Min Chen ◽  
R. Allen Miller ◽  
K. Rao Vemuri

Abstract Due to the incomplete representation schemes and the lack of high-level reasoning capability of current CAD/CAM systems, manufacturability assessment is performed by experienced designers and manufacturing engineers. The problems associated with automating manufacturing assessment include (1) the integration of a knowledge based environment within a design environment to provide reasoning capability, and (2) the development of flexible, modularized and responsive part models with levels of abstraction to support high-level reasoning which is required. Since modification of part geometries are frequently made during manufacturability assessment, the capability for part geometry modification is required at the level of interacting procedures. Consistency problems therefore occur between the geometric database in design environment and the part model in knowledge based environment. This paper presents a framework for an integrated design and manufacturability assessment environment which address these concerns.


Author(s):  
ERIC RAMALHO FERREIRA DE CARVALHO ◽  
MARCOS VINICYUS OLIVEIRA ◽  
erijanio Silva ◽  
Gutembergy Diniz ◽  
João Dehon Rocha Junior ◽  
...  
Keyword(s):  
Cad Cam ◽  

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.


2014 ◽  
Vol 598 ◽  
pp. 591-594 ◽  
Author(s):  
Li Yan Zhang

ISO 14649, known as STEP-NC, is new model of data transfer between CAD/CAM systems and CNC machines. In this paper, the modeling based on machining feature is proposed. The machining feature comes from the manufacturing process considering the restriction of machining technology and machining resource. Then the framework for computer aided process planning is presented, where the algorithms of operation planning is studied. The practical example has been provided and results indicate that machining feature based model can integrate with CAPP and STEP-NC seamlessly.


2014 ◽  
Vol 87 ◽  
pp. 162-168
Author(s):  
Paula Cipriano da Silva ◽  
Roberto de Oliveira Magnago ◽  
Camila Aparecida Araujo da Silva ◽  
Bianca de Almeida Fortes ◽  
Claudinei dos Santos

ZrO2(Y2O3)-based ceramics with coloring gradient can facilitate the development of dental prosthesis by the improvement of esthetic properties. In this work, ZrO2 powders with different particle sizes were investigated. White and yellow zirconia powders (TOSOH Corporation-Japan) were characterized by particles size distribution using nanoSight-LM20 analyzer. Furthermore, samples were characterized by X-Ray diffraction, Scanning Electron Microscopy and relative density. Compacts with two layers, one white and one yellow were uniaxially pressed at 80MPa and sintered at 1530°C-120min. The yellow-powder presented average particles size of 180±66nm, while the white-powder presented particles size of 198±73nm. After sintering, full dense ceramics with tetragonal phase were obtained. The linear shrinkage of the yellow and white-layer was 22.75% and 22.05% respectively. This difference in shrinkage is important in the machining of prostheses in ceramic CAD/CAM systems, because they lead to difficulties in adapting this customized prosthesis in patients.


Author(s):  
B. T. Cheok ◽  
A. Y. C. Nee

Abstract This paper discusses the development of a set of algorithms for the automatic nesting of ship/offshore structural plates. The algorithms are developed to take advantage of the peculiarity of most ship/offshore structural plates with the aims of optimising material usage and minimising computer search time. The parts to be nested are first processed by a shape processing routine which employs a simple feature extraction approach to classify the plates according to predefined rules specially adopted for ship/offshore structural shapes. The most appropriate search path for each class of plates is used to obtain the best enclosing rectangle for similar shapes. The search paths are based on heuristics developed to simulate the manual method used by the human operator. Finally, all the plates are laid out on the stock sheet using a “rectangle packing” approach. A computer package, Patnest-Ship was developed to demonstrate the efficiency of the algorithms and very encouraging results are achieved. The input and output files to and from Patnest-Ship are described in DXF format so that it can be integrated with existing CAD/CAM systems. Pre- and post-processors for this package have been implemented on AutoCAD to permit the user to define the plates and interactively improve on the solutions provided by Patnest-Ship, if necessary.


Author(s):  
D. Kiritsis ◽  
Michel Porchet ◽  
L. Boutzev ◽  
I. Zic ◽  
P. Sourdin

Abstract In this paper we present our experience from the use of two different expert system development environments to Wire-EDM CAD/CAM knowledge based application. The two systems used follow two different AI approaches: the one is based on the constraint propagation theory and provides a natural language oriented programming environment, while the other is a production rule system with backward-forward chaining mechanisms and a conventional-like programming style. Our experience showed that the natural language programming style offers an easier and more productive environment for knowledge based CAD/CAM systems development.


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