Computer Aided Geometric Design of Line Constructs

1991 ◽  
Vol 113 (4) ◽  
pp. 363-371 ◽  
Author(s):  
B. Ravani ◽  
J. W. Wang

This paper develops a mathematical foundation for Computer Aided Design (CAD) of sculptured shapes based on line geometry. First, a new representation is presented for a line based on Plu¨cker coordinates that would allow specification of a line segment (rather than an infinite line) in an elegant manner and suitable for computational purposes. Then, methods are presented for geometric design of shape patches (here referred to as line constructs) by interpolating or approximating a set of control lines (rather than control points) using ruled surfaces, line congruences, and line complexes. The methods presented are general and allow utilization of different basis functions such as Be´zier, Cardinal, and B-spline bases. As Computer Aided Manufacturing (CAM) application of the theory, methods are developed for generation of offsets of ruled surfaces useful in Numerical Control (NC) milling and tool motion generation in the Wire Cut Electric Discharge Machining (EDM) operation.

Author(s):  
B. Ravani ◽  
J. W. Wang

Abstract This paper develops a mathematical foundation for Computer Aided Design (CAD) of sculptured shapes based on line geometry. First, a new representation is presented for a line based on Plücker coordinates that would allow specification of a line segment (rather than an infinite line) in an elegant manner and suitable for computational purposes. Then, methods are presented for geometric design of shape patches (here referred to as line constructs) by interpolating or approximating a set of control lines (rather than control points) using ruled surfaces, line congruences and line complexes. The methods presented are general and allow utilization of different basis functions such as Bézier, Cardinal and B-spline bases. As Computer Aided Manufacturing (CAM) application of the theory, methods are developed for generation of offsets of ruled surfaces useful in Numerical Control (NC) milling and tool motion generation in the Wire Cut Electric Discharge Machining (EDM) operation.


2015 ◽  
Vol 76 (6) ◽  
Author(s):  
Dzullijah Ibrahim ◽  
Zahurin Samad ◽  
Yusli Yaakob ◽  
Norasikin Hussin ◽  
Siti Mardini Binti Hashim

Standard for Exchange of Product Model Data (STEP) is a Standard associated with representation of product data model to enable data communication between different Computer-aided Design (CAD), Computer-aided Manufacturing (CAM) and other engineering systems without any ambiguities and any possible data losses. The development of Open Architecture (PC-based) Numerical Control (OAPC-NC) Interpolator has enhanced the possibilities of data communication between the systems. A tool path data interface to OAPC-NC interpolator is proposed and developed; and a hierarchical-based algorithm is used to extract the tool path data from STEP-NC tool path file of a product model. The generated output of the interpolated data is computer simulated for 3D straight-line path to verify the validity of the interpolator input generated by the proposed interface.


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.


1999 ◽  
Vol 121 (4) ◽  
pp. 502-506 ◽  
Author(s):  
Q. J. Ge ◽  
M. Sirchia

This paper brings together the notion of analytically defined two-parameter motion in Theoretical Kinematics and the notion of freeform surfaces in Computer Aided Geometric Design (CAGD) to develop methods for computer aided design of two-parameter freeform motions. In particular, a rational Be´zier representation for two-parameter freeform motions is developed. It has been shown that the trajectory surface of such a motion is a tensor-product rational Be´zier surface and that such a kinematically generated surface has a geometric as well as a kinematic control structure. The results have not only theoretical interest in CAGD and kinematics but also applications in CAD/CAM and Robotics.


2020 ◽  
Vol 18 (01) ◽  
pp. 2150015
Author(s):  
Fatma Güler

Developable surfaces are defined to be locally isometric to a plane. These surfaces can be formed by bending thin flat sheets of material, which makes them an active research topic in computer graphics, computer aided design, computational origami and manufacturing architecture. We obtain condition for developable and minimal ruled surfaces using rotation frame. Also, the validity of the theorems is illustrated with examples.


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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