Reverse engineering of simple surfaces of unknown shape with touch probes: Scanning and compensation issues

Author(s):  
G C Vosniakos ◽  
T Giannakakis

This work discusses issues concerning the implementation of scanning of unknown engineering objects containing just simple (i.e. no freeform) surfaces with touch probes on three-axis computer numerical control (CNC) measuring machines in order to reconstruct their shape in a computer aided design (CAD) system. Several ideas are put forward e.g. scanning along vertical slicing planes adaptive point sampling distances in-process ‘proactive’ segmentation of points into curve sections and probe radius compensation in two directions as well as limited remedy of edge scanning ambiguities. Most of the suggested algorithms are implemented as parametric numerical control (NC) programs on an OKUMA machining centre.

Author(s):  
Sim S. Simandiri ◽  
K. H. Wang

Reverse engineering proceeds in the reverse of conventional manufacturing order, based on the pull system instead of the traditional push system. This paper is concerned with applying the reverse engineering concept to the development of parts. With this procedure the development of parts involves an iterative reverse process from the scanning of a developmental prototype towards the design model. The focus is on the use of two set-ups of network in providing computerized data of the prototype that are exchangeable among Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) systems. The first set-up applies a direct approach to manipulate the scanned data in the CAM environment for generating Numerical Control (NC) programs used for machining the workpiece. The second set-up applies an indirect approach to manipulate the scanned data in a CAD environment prior to generating the NC programs. The major benefits gained from the reverse engineering application in the development of parts are also described.


Author(s):  
A Mohole ◽  
P Wright ◽  
C Séquin

A key element in the overall efficiency of a manufacturing enterprise is the compatibility between the features that have been created in a newly designed part, and the capabilities of the downstream manufacturing processes. With this in mind, a process-aware computer aided design (CAD) system called WebCAD has been developed. The system restricts the freedom of the designer in such a way that the designed parts can be manufactured on a three-axis computer numerical control milling machine. This paper discusses the vision of WebCAD and explains the rationale for its development in comparison with commercial CAD/CAM (computer aided design/manufacture) systems. The paper then goes on to describe the implementation issues that enforce the manufacturability rules. Finally, certain design tools are described that aid a user during the design process. Some examples are given of the parts designed and manufactured with WebCAD.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3819
Author(s):  
Ting-Hsun Lan ◽  
Yu-Feng Chen ◽  
Yen-Yun Wang ◽  
Mitch M. C. Chou

The computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication technique has become one of the hottest topics in the dental field. This technology can be applied to fixed partial dentures, removable dentures, and implant prostheses. This study aimed to evaluate the feasibility of NaCaPO4-blended zirconia as a new CAD/CAM material. Eleven different proportional samples of zirconia and NaCaPO4 (xZyN) were prepared and characterized by X-ray diffractometry (XRD) and Vickers microhardness, and the milling property of these new samples was tested via a digital optical microscope. After calcination at 950 °C for 4 h, XRD results showed that the intensity of tetragonal ZrO2 gradually decreased with an increase in the content of NaCaPO4. Furthermore, with the increase in NaCaPO4 content, the sintering became more obvious, which improved the densification of the sintered body and reduced its porosity. Specimens went through milling by a computer numerical control (CNC) machine, and the marginal integrity revealed that being sintered at 1350 °C was better than being sintered at 950 °C. Moreover, 7Z3N showed better marginal fit than that of 6Z4N among thirty-six samples when sintered at 1350 °C (p < 0.05). The milling test results revealed that 7Z3N could be a new CAD/CAM material for dental restoration use in the future.


Author(s):  
L Q Tang ◽  
D N Moreton

The timing scroll is an important feeding mechanism on packaging lines. As packaging line speeds have increased and the shape of containers has become more diverse, the techniques used for the design and manufacture of such timing scrolls have become critical for successful packaging line performance. Since 1980, various techniques have evolved to improve scroll design, manufacture and the associated line performance. In recent years, as CAD (computer aided design), CAM (computer aided manufacture) and CNC (computer numerical control) techniques have evolved, scroll design and manufacturing techniques began to be linked with computer techniques. In this paper, a scroll design and manufacturing package is presented which can be run on a minicomputer, such as a μ-VAX on an IBM PC clone. This scroll package can produce a timing scroll for any type of container with a correct pocket shape and good dynamic characteristic. Tests using carefully chosen containers have been made using this package and the results indicate that the scrolls obtained by this package have the correct pocket shape and good line performance. However, the design of a good pick-up geometry for some container shapes remains a problem.


2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771038 ◽  
Author(s):  
Isad Saric ◽  
Adil Muminovic ◽  
Mirsad Colic ◽  
Senad Rahimic

This article presents architecture of integrated intelligent computer-aided design system for designing mechanical power-transmitting mechanisms (IICADkmps). The system has been developed in C# program environment with the aim of automatising the design process. This article presents a modern, automated approach to design. Developed kmps modules for calculation of geometrical and design characteristics of mechanical power-transmitting mechanisms are described. Three-dimensional geometrical parameter modelling of mechanical power-transmitting mechanisms was performed in the computer-aided design/computer-aided manufacturing/computer-aided engineering system CATIA V5. The connection between kmps calculation modules and CATIA V5 modelling system was established through initial three-dimensional models – templates. The outputs from the developed IICADkmps system generated final three-dimensional virtual models of mechanical power-transmitting mechanisms. Testing of the developed IICADkmps system was performed on friction, belt, cogged (spur and bevel gears) and chain transmitting mechanisms. Also, connection of the developed IICADkmps system with a device for rapid prototyping and computer numerical control machines was made for the purpose of additional testing and verification of practical use. Physical prototypes of designed characteristic elements of mechanical power-transmitting mechanisms were manufactured. The selected test three-dimensional virtual prototypes, obtained as an output from the developed IICADkmps system, were manufactured on the device for rapid prototyping (three-dimensional colour printer Spectrum Z510) and computer numerical control machines. Finally, at the end of the article, conclusions and suggested possible directions of further research, based on theoretical and practical research results, are presented.


Author(s):  
Fernando Rangel ◽  
Jami J. Shah

This paper discusses the issues of integrating the Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) programs in commercial software. Integration was achieved through implementation of a computer-aided process planning (CAPP) system within the commercial software. The part model was imported into, or designed in, the commercial CAD system. Manufacturing information was then extracted from the part model by the CAPP system using commercial Application Programming Interfacing (API) methods. The CAPP system then uses the extracted information to produce a process plan consistent with the requirements of the commercial CAM module to produce Numerical Control (NC) code. The internal integration was accomplished using commercial API methods that dynamically bind the CAD, CAPP, and CAM into a single continuous application. These APIs are implemented using the Orbix middleware following the CORBA standard. A case study demonstrating the integration is presented. Strengths and weaknesses of integrating the CAD and CAM domains using APIs and middleware are discussed.


Author(s):  
Antor Mahamudul Hashan ◽  
Abdullah Haidari ◽  
Srishti Saha ◽  
Titas Paul

Due to the rapid development of technology, the use of numerically controlled machines in the industry is increasing. The main idea behind this paper is computer-aided design (CAD) based low-cost computer numerical control 2D drawing robot that can accurately draw complex circuits, diagrams, logos, etc. The system is created using open-source hardware and software, which makes it available at a low cost. The open-source LibreCAD application has been used for computer-aided design. Geometric data of a CAD model is converted to coordinate points using the python-based F-Engrave application. This system uses the Arduino UNO board as a signal generator of the universal g-code sender without compromising the performance. The proposed drawing robot is designed as a low-cost robot for educational purposes and aims to increase the student's interest in robotics and computer-aided design (CAD) skills to the next level. The drawing robot structure has been developed, and it meets the requirements of low cost with satisfactory experimental results.


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