74 What does the word simulation make you think of? Give examples. Computer numerical control (CNC) is a manufacturing method that automates the control, movement, and precision of machine tools through the use of pre-programmed computer software, which is placed inside the tools. COMPUTER-ASSISTED DRAWING Computer-Aided Design (CAD) Computer-Aided Design (CAD) is software used by designers for precision technical drawings. It is threedimensional and can test the model of an object through simulations of real-world conditions. It provides a digital workspace where drafters can create and manipulate virtual objects. It typically offers tools for drawing, modelling, and modifying designs. Designs can be viewed from different angles, it is possible to add dimensions, apply materials, simulate motion, and more. Besides this, it improves the quality of the design by reducing mistakes, and the drawings can be automatically converted into manufacturing instructions. It can also create a database for manufacturing, which means that all the changes and implementations occurred during the design stage of the object is recorded for further uses. Another efficient feature of CAD is that it can zoom on certain elements of the model to facilitate inspection. CAD modelling CAD modelling can be: constrain: vincolo to deal with: occuparsi di issue: problema, questione workflow: flusso 176 MeCHAniCs Solid, when it creates solid 3D models as actual parts, with a logical workflow that is similar to the processes which would be used to manufacture the part. Some of these operations include extruding, drilling, and threading. Solid models can intersect, join, and subtract objects from one another to create the desired part (assembly modelling); Surface, when it deals with the surfaces of a part, with no solid interior. Surface modelling is generally used for more aesthetic features of a product; it is in fact easier to create more organic and freeform geometry using this type of CAD software. Once the part has enough surfaces to close the part, it can be filled and then used for 3D printing. In this way many of the constraints found in solid modelling are not an issue; however, this comes at a cost of sometimes being less accurate. Computer-Aided Manufacturing (CAM) Computer-Aided Manufacturing (CAM) software deals with the automated production process and is the evolution of numerically controlled machines . Starting from a CAD drawing, CAM is the following step that tells the operators how to manufacture the item; in other words, CAM works by translating data from a CAD drawing into procedures and instructions, making it possible for a machine to build the object. CAM is used to program and control machine tools and all the stages of manufacturing, and it can also be used to assist operators in every function carried out in a manufacturing plant such as planning, transportation, and storage.