Optimal positioning of irregular shapes in stamping die strip

The nesting of two-dimensional shapes is a common problem, where raw material has to be economically cut. As for the single-pass single-row strip layout, several algorithms, based on established methods, have been proposed. Moreover, it should be noticed that the optimum layout should also consider a few constraints, like grain orientation for subsequent forming operation, correct bridge width, and the commercial roll of metal width in order to make solutions applicable in real industrial environments. Most of the procedures until now shown in literature are quite complex and often ignore these real constraints. They usually make use of sliding techniques and are not able to effectively wor…

INTERNET BASED DEVELOPMENT OF AN OPEN SOURCE LOW-COST CNC

In this paper we show how to realize a low-cost numerical system, based on an “open source” software called EMC (Enhanced Machine Control). First, we assembled a low cost CNC workstation with a remote control by means of an online computer with a webcam, as an example of the software's potentiality. Moreover, we translated a graphical user interface (AXIS), in co-operation with the international development community, in order to improve its userfriendliness.

Simulation of a Milling Process with Virtual Reality

A more efficient method for clustering sheet metal shapes

The nesting of two-dimensional irregular shapes is a common problem which is frequently encountered by a number of industries where raw material has to be, as economically as possible, cut from a given stock sheet. A frequently recurring problem as far as cutting stock is concerned, is how to obtain the best nesting of some pieces of flat patterns which occupy minimalarea convex enclosure. The area of convex enclosure is related to the convex hull of the union of patterns which can be imagined as a large rubber band surrounding the set of all polygons. Our goal is to automatically obtain the smallest area convex shape containing all the patterns. As a matter of fact, Cheng and Rao have prop…

CAD/CAM Integration for NURBS Path Interpolation on PC Based Real-Time Numerical Control

As anybody knows, there is a fundamental difference between the newest CAD system and the conventional Numerical Control. As a matter of fact, almost every CAD Software allows programmers to use parametric 2D or 3D curves, whereas standard Numerical Control cannot perform anything more than linear or circular interpolations. NURBS are the most successful among all the proposed parametric curves, since they allow us to give an exact uniform expression to both the analytical and the free form curves. Nevertheless, this typical characteristic nowadays entails that in CAM systems a tool path is rounded down using a small movements and imposing a maximum acceptable gap. This approach leads up to…

An E-learning Experience in Technical Education

E-Learning is relatively new emerging technology that spans the universities and other institutions. It concentrates on utilizing Knowledge of teachers in a way that academic courses can be delivered anywhere and anytime.

Algoritmo per la rasterizzazione di curve di grado superiore al secondo.

A CAD/CAM oriented Learning Management System

Part program automatic check for three axis CNC machines

Abstract The simulation and verification of NC codes for CNC machining is a very important task. The aim of this work is to limit the number of cutting tests needed to verify the right writing of the part program for a CN milling machine in the intent of saving time, human resources and money. This is obtained through the Boolean operation among solids, in AutoCAD environment, of the volume covered by the tool during the operations ruled by the part program.

A Web based remote control of CNC machines

Due to the large variety of products in small batch sizes, a modern machining shop floor requires an advanced real-time control system able to both monitor all the features and adapt the manufacturing system to the rapid changes of production capability and functionality. This is especially true when the shop floors are combined with the e-Manufacturing concept. e-Manufacturing is a transformation system which enables the manufacturing operations to achieve a predictive near-zero-downtime performance as well as to synchronize with the management systems through the use of infotronics technologies (i.e., wireless connections, web applications, networking systems, etc.). In recent years, the …

Developing Tele-Operated Laboratories for Manufacturing Engineering Education

The aim of the PeTEX-project is to establish an e-Learning platform for the development, implementation, and delivery of educational training programs in the field of manufacturing engineering. The PeTEX team designs both: a technical platform for eLearning based on “Moodle” including distributed tele-operated experimentation facilities, and didactic and socio-technical requirements for a successful online learning community. User interfaces are deployed for remote access to instruments, data analysis and multiplexed data access via network protocols. Hence, the platform provides complex tools in order to perform various activities to support the educational process, from telemetric experim…

An XML interface to Step-NC Systems For Remote Collaborative Concurrent Engineering

A More Simple G-Code Programming within an Open Source CNC System

In this paper we introduce the utilization of a new CNC programming language, named O-Word, a way to implement several branching routines into the EMC interpreter. It opens new interesting possibilities to programmers who can build subroutines, loops, and conditionals while taking advantage of the interpreter's use of variables and computation. Therefore, it allows us to make pieces describing theirs features instead of tool's movements. We will demonstrate a new complex routine in order to show both the language syntax and its potential for advanced applications.

CNC Milling Machine Simulation in Engineering Education

In this work an effective simulator for a CNC milling machine is presented. It has been developed in EMC2, a free Opens Source NC software running in Linux environment, developed by an international community. It can be installed on a common PC and is able to: control a CNC machine; read part programs; display the tool path; send instructions to the CNC machine for the cutting process. In this work a new feature has been implemented, which can both display a 3D model of the machine and simulate all the motions of the movable parts of a real 3 axis end milling machine. This simulator lets the users not only verify the toolpath but also detect any possible collision by using the very computer…