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.

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.

NC End Milling Optimization within CAD/CAM System using Particle Swarm Optimization

The authors have been set up an optimization procedure, based on Particle Swarm Optimization (PSO) evolutionary algorithm, that has been enclosed in FeatureCAM, a commercial CAD/CAM software, to automatic determine milling optimal cutting parameters. The Particle Swarm Optimization has been selected because it is very effective to solve optimization problems characterized from complex objective functions and high bonds number. This algorithm also allows to obtain a near optimal solution with a very few iterations and then a computational limited time, characteristic very important to integrate the procedure in a CAD/CAM system.

A numerical approach for the modelling of forming limits in hot incremental forming of AZ31 magnesium alloy

AbstractMagnesium alloys, because of their good specific material strength, can be considered attractive by different industry fields, as the aerospace and the automotive one. However, their use is limited by the poor formability at room temperature. In this research, a numerical approach is proposed in order to determine an analytical expression of material formability in hot incremental forming processes. The numerical model was developed using the commercial software ABAQUS/Explicit. The Johnson-Cook material model was used, and the model was validated through experimental measurements carried out using the ARAMIS system. Different geometries were considered with temperature varying in a…

A novel linear friction welding based approach for sheet-bulk joining

In the last decades, the development of new, flexible manufacturing processes caused the increase of the demands for highly customized complex functional parts in many industrial fields. The peculiar design of these components often overcome conventional sheet metal and bulk metal forming processes capabilities. In order to face this issue, new hybrid techniques, capable of exploit key advantages of different processes, have to be developed. In this paper, a novel approach based on the Linear Friction Welding process is proposed to obtain sheet-bulk joints. The feasibility of the technique on high specific strength alloys is investigated through an experimental campaign.In the last decades,…

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 …

Experimental and numerical investigation on a new FSW based metal to composite joining technique

Abstract In the last decades, different techniques were proposed to join aluminum sheets with composites materials. Each of them has advantages and weak points over the others and new techniques and patents are continuously developed to overcome these difficulties. In this paper an experimental and numerical investigation on a new Friction Stir Welding based approach to mechanically join AA6082-T6 to self-reinforced polypropylene is presented. The aluminum sheet is pre-holed along both the sides of the weld line and a pinless tool generates the heat and pressure needed to prompt back-extrusion of the composite. New experimental fixtures and hole designs were investigated in order to enhance…

An Efficient NURBS Path Generator for a Open Source CNC

In this paper a NURBS path generator (on the plane XY) is proposed to be developed for those CNC machine tools and robot which are Open Source or Opening Architecture. The goal is to use simple and efficient techniques to manufacture geometries which are very complex, whose main feature is the presence of free-form surfaces and contours. To reach this goal, the NURBS path generator has been optimized in order to enable the user to select among three different options to generate the tool path, using a specific parameter. The three options are respectively called “NURBS interpolation with constant increments of u parameter” (NICU), “NURBS interpolation with constant displacement increments b…

Simulation of Milling Machining Process within an Open Source CAD System

To verify NC programs as well to optimize the cutting conditions, it is very important to simulate machining process more precisely. The diffusion of electronic realistic representation systems of mechanical pieces suggests us to use them in order to realize a virtual simulation of the cutting tests for a milling machine Our task was to create a software which can directly read and interpret the part program and display it using a CAD solid modeler which, considering the effective geometry of the tool and of the workpiece, can simulate cutting forces behaviour during a milling process.

Meta-heuristic Algorithms for Nesting Problem of Rectangular Pieces

Abstract Nesting problems consist of placing multiple items onto larger shapes finding a good arrangement. The goal of the nesting process is to minimize the waste of material. It is common to assume, as in the present work, that the stock sheet has fixed width and infinite height, since in the real world a company may have to cut pieces from a roll of material. The complexity of such problems is often faced with a two-stage approach, so-called “hybrid algorithm”, combining a placement routine and a meta-heuristic algorithm. Starting from a given positioning sequence, the placement routine generates a non-overlapping configuration. The encoded solution is manipulated and modified by the met…

Low‐cost, High‐Capability, Embedded Systems for CNC Education and Research

Teaching of CNC and CAD/CAM technologies has recently taken a great importance, due to their development, to the great number of solutions available on the market, and to the frequent updates. Nevertheless, one of the most urgent need is to improve the quality of education coping with a rapidly growing number of students. Nowadays, in comparison to the past, many Open-Source technical solutions, both hardware and software, are available to realise easily and cheaply some scaled-down prototypes of numerical control machine tools: these are able to work perfectly and can be employed as a learning method. This paper shows some past experiences regarding the development of some degree thesis wo…

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

Machining of Steel with Advanced Ceramic Cutting-Tools

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…