What is Cad-Cam?
CAD / CAM are terms that mean computer-aided design and computer-aided manufacturing. It is a technology related to the use of digital computers to perform a number of functions in design and production.

Computer aided design (CAD) can be defined as the use of computer systems to support engineering design creation, development, analysis, and modification. The CAD system consists of a trio of hardware, software and user.

CAD hardware typically includes a computer, one or more graphical terminals, keyboards, printer, plotter, and other peripheral hardware.

CAD software includes computer programs to apply computer graphics on the system and the use of the following programs to facilitate the engineering functions of the user firm. These applications;

Tensile / fatigue tests, dynamic structure analysis of mechanisms, heat transfer calculations and numerically controlled part programs.

Computer aided manufacturing (CAM) can be defined as the use of computer systems for planning, managing and controlling the activities of the facility either directly or indirectly through a computer interaction area created between the production resources of a manufacturing facility. As can be understood from the definition, the applications of CAM are divided into two broad categories:

a– Computerized Surveillance and Control: These are direct applications where computers are directly connected to the manufacturing process for the purpose of monitoring or controlling the process.

b– Manufacturing Support Applications: There is no direct interaction between the computer and the manufacturing process, the production activities of the computer in the facility.

GENERAL STRUCTURE OF CAD / CAM SYSTEMS

Although the computer event is new, the concept of "Computer Aided" or "Computer Aided" gaining effectiveness is the product of the last 15-20 years. Developments in our country are newer and, to a certain extent, at an early stage, compared to computer-aided design and production applications worldwide. Despite this, "Computer Aided Manufacturing" shows new developments all over the world and especially "Production Engineering" has reached the level of being realized in universities as a new profession.

Computer graphics have provided revolutionary developments in design through computer-aided design. Consequently, the necessity of revising the existing engineering curriculum at universities has arisen, and as a new discipline, "Production Engineering" has come to the agenda.

Computer aided production / design is a new multi-discipline technological field that uses computer techniques in general. Staff to work in this field must be highly trained. Team members who will work on a common project from different engineering levels must have a common conceptual integrity and a common technical language. In this case, we are witnessing a worldwide debate on a new education plan in universities and colleges, starting with secondary education and vocational schools.

An important element in CAD / CAM conditions is computer graphics. These have opened a new horizon, a new world for the designer. Possibilities of thinking on three-dimensional shapes with computer graphics and intervention as desired have emerged. The success of a design that can see the sections of a motor or a building from different directions from different directions can be increased, and the decision-making efficiency of those involved in production can be increased with technical drawings produced in a very short time. Along with computer graphics, "finite element methods" opened new thinking dimensions to the designer.

Especially in the last decade (CAD / CAM), important developments have occurred in applied fields such as computer aided drawing strings engineering solutions and numerical control of machine operations. When the first examples of CAD / CAM were started to be applied, they were carried out independently of each other and the data were prepared by hand as in single program applications. Consequently, the cost of processing design and production data was high. Over time, engineers and computer researchers became aware of gaps in the data flow and tried to overcome them. Today, CAD / CAM applications in design, production and management cannot be done without computer-integrated databases, although application sizes are small. In this respect, the database problem is that the compatibility between CAD / CAM strings and databases can be inefficient or rough due to the fact that they are not produced at the same time. In this respect, efforts to review these incompatibilities and develop newer facilities have gained momentum.

HISTORICAL DEVELOPMENT OF CAD / CAM SYSTEMS

Both CAD and CAM were born in the early 1950s. CAD evolution g

broadly concerned with the development of computer graphics. One of the important projects in the field of computer graphics is the APT language, which was developed in the mid and late 1950s. APT is a term formed from the initials of the English words Automatically Programmed Tools (meaning automatically programmed teams). This project was about developing an appropriate way to define geometry elements for numerically controlled part programs in computer use.

In the early 1960s, industrial organizations such as General Motors, IBM, Lockheed "Georgia McDonnell" Douglas all played an active role in computer graphics projects. Most of these projects eventually came out in the form of commercial products.

Many CAD / CAM system vendors emerged in the late 1960s, including Calma (1968) and Applican and Computervision (1969). These systems sell "turnkey" systems that contain all or most of the software and hardware needed by the user.

CAM subject emerged with the discovery of NC machines (1950), which was pioneered by N.I.T., working under the auspices of Air Force. These older devices proved that it is possible to control the movements of any machine tool by an electronic control mechanism attached to a perforated belt. The real development has been experienced by the perforated bands prepared depending on the physical structure and shape of the part, enabling fast and accurate work.

These developments have enabled the widespread use of NC tools. This industry developed rapidly in the 1960s and 1970s, especially in Europe and Japan. New control techniques have been developed since the early 1970s (with the advent of micro and mini computer technology). Direct numerical control (DNC) and computerized numerical control systems are being used more widely. These systems provided a direct relationship between computers and machines. Likewise, it has given the operator the chance to control the machine functions through programs. The part program is prepared based on the geometric shape of the parts to be manufactured in the designs prepared through CAD with the APT mode suitable for group processing.

Other CAM developments accelerated in the 1970s. Robot technology, which currently has 3200 applications in America, 1800 in Western Europe and 4000 applications in Japan, fulfills all functions of picking and placing operations, welding, washing, spray painting and assembly.

Nowadays, the proliferation of disk and diskette components, understanding the information link between engineering and manufacturing processes, resulting in great gains from the integration of these elements.

CAD DESIGN PROCESS

CAD is all of the working methods based on the creation of two or three-dimensional drawings and designs with computer support, using graphic features, in the solution of any research development or design problem.

Modern CAD systems (often called CAD / CAM systems) are based on Interactive Computer Graphics (ICG). ICGs are user-based systems used for computers to create, transmit and display data in shape or symbol form on the screen.

In Computer Aided Design Systems, the user is the designer who transmits data and gives commands to the computer through any of the various input tools. The computer communicates with the user through the cathode ray tube (CRT). The operator (Draftsman) creates an image (image) on the CRT screen with an input command that calls the desired software subprograms stored in the computer's memory. The operator can expand / contract in dimensions, rotate, move to another position on the screen, etc. With the help of various manipulations, he can formulate the desired details of the image with commands.

Today, screens with increasing sensitivity and high color and display abilities are produced. Even the simplest computer graphics application on these screens consists of thousands of points. As a result of the development of microchips with very large capacities, the coordinates of millions of points can be stored in the memory.

The ICG system is a component of the CAD system. The other component is the operator (user). Interactive Computer Graphics is a tool used by the operator to solve the design problem. The operator realizes the design process that best suits human mental abilities (ideation, independent thinking). The computer does its job in a way that best suits its capabilities (computational speed, display ability, memory). The result system exceeds the capabilities of these two components.
The main reasons for using the CAD system are:

1- To Increase Designer Productivity: This is achieved by helping the operator to envision the product, subassembly components and parts, and shortening the time required for synthesis, analysis and casting in the design. With the development of productivity 

Not only low design cost but also shorter project completion time is provided.

2- To Improve Design Quality: Working with a CAD system will provide the opportunity to make engineering analyzes in different situations by considering more alternatives in the design, calculating the alternatives considered. During all these studies, precision will minimize design errors. In addition, minimum drawing errors will be created in the resulting drawings, so that cleaner and standards-compliant drawings will be obtained.

3- Creating a Database for Manufacturing: During the preparation of technical documents for production, the data required for the processing of the product will also be considered. These data include the geometric dimensions of the product, what are the basic elements that make up the geometry of the product, how the details will be combined, the material information of the details, the dimensions of the raw material to be processed (rough material dimensions), etc. are information. This information can be taken from the system in different formats and used for many different purposes.

The CAD Design process can be characterized as a six-stage procedure:

1- Determination of Needs: It is the understanding by a person that some corrective actions need to be done. This could be the identification of some flaws in existing machine design by an engineer or the perception of marketing opportunities for a new product by a vendor.

2- Definition of the Problem: It contains all the specifications of the part to be designed. These include physical and functional characteristics, quality and processing performance.

3- Synthesis (Engineering Design): As it is known, traditional engineering design starts on the drawing table and a detailed document turns into a technical drawing there. Design in mechanical engineering; It contains all the technical drawings of a product, its sub-parts and even the tools and assemblies required to manufacture this product. Design in electrical and electronics engineering includes processes such as the preparation of electrical circuits and schemes. Similarly, designs made in other branches of engineering are subject to manual documentation.

Engineering design traditionally consists of documenting the design on drawing tables in the form of detailed engineering drawings. In computer-aided design, all processes foreseen to be done in a design process now consist of a CAD system instead of a drawing table. A CAD system consists of the following parts:

a- Designer
b- Hardware: Computer and peripherals (printer, plotter, etc.)
c- Software: General system software and CAD software.
d- Problem; the design problem to be solved.

The designer solves the problem in his hand using the CAD program in the computer available in front of him. The computer used in the CAD system has a CAD software that allows the necessary design to be made. With this software, the designer is in constant interaction with the peripheral units of the computer (screen, keyboard, etc.). Drawings are carried out on the screen by using various geometric drawing elements according to the type of design to be made. In other words, drawings and designs traditionally made on paper on the drawing table are now made on screen in CAD systems. In the meantime, if there are operations such as corrections, changes, enlargement, reduction, copying and so on on the designed geometry, these can be easily done on the screen. Thus, tiring and time-consuming processes in other design methods can be easily done on computers.

With CAD, the designer can visualize his design much more easily; After analyzing a few alternative designs in a short time, they can be easily assembled on the screen together with their related sub-parts and many different analyzes can be made on them. In addition, if the new design will be obtained by changing some parts of the old designs, this is achieved by calling the old design to the screen and making the necessary changes very quickly. In summary, the productivity of the designer increases with the use of CAD systems.

4- Analysis and Optimization: Synthesis and analysis are closely related to the design process. The idea of ​​a certain component or a subsystem of a whole system is created, analyzed, developed and redesigned with the analysis procedure by an operator.

5- Evaluation: It is to measure the design according to the specifications determined in the problem definition phase. This evaluation is the testing and manufacturing of the prototype model to evaluate operational performance, quality, reliability and other criteria.

6- Presentation (Preparation of Engineering Drawings): It is the last stage in the design process, it is necessary to document the engineering designs made. These can usually be in the form of drawings and reports. Their preparation is essential for manufacturing. A CAD 

Documentation of the designs made in the system is done by using plotters and printers. This process is carried out directly by transferring the drawings on the computer to the paper with the help of printers and plotters, and the drawings obtained are much more precise and of higher quality compared to the technical drawings made by the traditional method.

The reason for these studies is that the designs made allow them to create a database that can be used later in manufacturing. After the designs made with traditional methods, two separate procedures are applied by manufacturing engineers in two separate sections. Thus, some processes that are the same are repeated by the design and manufacturing units, so a certain amount of time is lost. On the other hand, in a CAD / CAM system, a database is created during the design phase and the same database is used for manufacturing. Previous transactions are not repeated. In other words, the part, mold, etc. designed in front of the screen. The product is still processed on the screen. During this process, the machine tool and the existing cutter pen etc. of this machine. The properties of the computer can be simulated. In this way, NC part programming is done and NC coding is obtained for that part. This NC data is then transferred to the machine tool by either tape, magnetic tape or direct connection. Thus, the part that is planned to be manufactured is realized by using the CAD system from design to production.

USE OF THE COMPUTER IN THE DESIGN

Design-related works performed by computer-aided modern systems can be grouped into four functional areas.

Geometric Modeling,
Engineering Analysis,
Design Review and Evaluation,
Automatic Drawing.
Geometric Modeling:

CAD starts with drawing the picture of the part at the lowest level. In addition to the shape, part dimensions can also be entered. However, the important point is that the geometry of the designed object must be mathematically definable. Three main methods draw attention in geometric modeling.

These:

2D Design: Two-dimensional design method is used for plane objects (such as point, line and circle).
3D Design: This method is used in design for the design of very complex 3D profiles.

During the computer geometric modeling process, it converts the commands into a mathematical model, stores them in data logs and displays them as an image on the CRT screen. The model can ultimately be called from data logs for review, analysis, or modification.

Engineering Analysis:

Higher level CAD programs have the ability to calculate. In order to solve any engineering problem, it is necessary to formulate the problem. Some analysis methods can be applied on this formulation. These analyzes are various calculations such as tensile fatigue tests, heat transfer calculations, or the use of differential equations to describe the dynamic behavior of the designed system. The computer can be used to support these analysis studies.

Two important analysis methods used in CAD / CAM systems are:

Mass Properties Analysis: It is a CAD system feature with the widest application. This analysis provides the opportunity to analyze the properties of solid bodies such as surface area, weight, volume, center of gravity and internal moment.

Finite Element Analysis: One of the most effective features of the CAD system is the finite element method. In this technique, the object is divided into a plurality of finite elements (usually rectangular or triangular) that gather in nodes and form an interconnected network. With a highly computational computer, the whole object can be analyzed by calculating tensile-fatigue heat transfer and other characteristics at each node. By determining the behaviors of all nodes in the system with respect to each other, the behavior of the whole object can be reached.

Control and Evaluation of the Design:

The process of checking the correctness of the design is carried out comfortably on the computer terminal. Semi-automatic sizing and tolerancing methods that assign dimension specifications to user-displayed surfaces help reduce dimensioning errors. With their help, the operator approaches the part design details (700 m) and enlarges the view on the graphic display for closer inspection.

A procedure often called "registration" is helpful in reviewing the design. A good example for registration would be to enclose the geometrical image of the final shape of a machine part onto the image of a rough casting mold. This analysis ensures that there is sufficient material in the casting to accommodate the resulting dimensions of the machine.

One of the most interesting evaluation methods in computer aided design systems is "kinematics". Convenient kinematics packages provide the ability to simulate the movements of simple design mechanisms such as hinges and joints. This ability means that the operator's mechanism 

It increases the ability to monitor the process and makes sure that the mechanism is not an obstacle to other components.

Auto Drafting:

It is a direct copy of the engineering drawings from the database of CAD. CAD systems have increased the productivity of the drawing function by roughly 5 times that of hand drawing.

Some graphic features of CAD are very suitable for the drawing process. These features include automatic sizing, creating shaded areas, scaled drawing, enlarging the images of the details of the parts and developing some parts of them. Significant support is provided for drafting with CAD, rotation of the part and other transformations of the image (curvature, isomorphic and perspective). Many CAD systems today are capable of creating six different images of a part.

In addition to the 4 CAD functions described above, another feature of the CAD database is that it can be used in the development of part classification and coding systems. Part classification and coding is the grouping of similar part designs and establishing a relationship between these similarities with a coding scheme. CAD is a very useful aid to the operator in this regard.

COMPUTER AIDED DESIGN METHODS

The basis of CAD is based on drawing pictures traditionally drawn by technical painters by technical painters but using computers. The computer aided drawing of the two-dimensional technical drawings in question here can only be an initial level for CAD. CAD today includes a wide range of possibilities from drawing and dimensioning the most basic technical drawings to the realistic design and display of the most complex shapes. Along with CAD, user software, expert systems, analysis software, numerical control, robots, production planning software, computer integrated production are all parts of the target. In the most general approach, four basic methods are used to design a shape with CAD.

Drawing:

Two and three dimensional drawing software are used to draw technical drawings using computers instead of traditional drawing tools. All kinds of products, molds, parts, plans, projects, etc. that a draftsman can draw. his picture is drawn on the computer screen as much as possible, using the methods used by the draftsman during the drawing process. Drawing is made using basic elements such as point, line, arc, curve, and polygon. Enlarge, reduce, delete, duplicate, scan, etc. desired changes are made with the possibilities. The desired texts are written on the picture, automatic measurement is made in the desired measurement system. An archive will be created for the most used drawing parts and can be easily used in drawing. With the drawing module, isometric drawing can be made as well as two-dimensional drawing.

Wireframe Geometry:

Wireframe geometry is the simplest way to show a shape in three dimensions. Only borders and edges of the shape are shown with lines and curves. Curves are made by combining a large number of arcs. A curve can be freely defined in space or drawn on a surface. Curves are described mathematically by polynomials. There are three methods for creating curves in CAD software:

Common, mathematically easy to express curves such as circle, arc, ellipse, parabola, hyperbola.
The intersection of two complex surfaces, the projection of a curve onto a surface, etc. Computed curves determined by interactive methods.
Curves determined by joining a set of points by observing the rules of tangent and perpendicularity.

Surface Geometry:
Wireframe is formed by scanning three-dimensional shapes defined by geometry with tighter lines. Real-like surfaces are displayed by surfacing between the lines. To create a surface, equations defined by polynomials of two variables are used. There are five surfacing methods commonly used in CAD software:
Basic geometric surfaces such as cone, sphere, cylinder, spiral, plane surface.
Surfaces created by filling the curves in space in accordance with the tangent and perpendicularity rules.
-Surfaces formed by softening the edges formed in cases where the surfaces interlock with each other by providing a transition.
Surfaces formed by lines that meet the tangent and perpendicularity conditions passing through the points determined in space.
On a surface, parts of the surface can be separated by closed curves. Lines can also be used if part of the surface is to be split on a plane. Surfaces can be formed by combining the surface parts created in this way.

Solid Geometry:
Designing complex shapes based on basic geometric volumes is done with solid geometry software. The software can define basic geometric shapes such as cylinder, sphere, cone spiral, pyramid, cube curve based prism, polygon based prism, volumes formed by rotating a section (plane) around an axis. These basic shapes are combined, pulled apart, deformed, cut with surfaces to create complex shapes. More of your images 

In order to be realistic, the remaining lines are made invisible, shapes are surfaced.
Shapes created in advanced CAD software can be defined as up to 16.7 million colors and (semi) translucent. Shading of shapes is achieved by describing light sources at various points. The shapes can be rotated continuously and sectioned at the desired location. The 2D and 3D drawing module is the basis for creating other model geometries or transferring information from one module to another. The pictures drawn with the 2D and 3D drawing module can be recalled and studied in the wireframe, surface and solid model geometry modules. The shapes created in these modules can be transferred to the 2 and 3 dimensional drawing module.
In many software, all modules use a common knowledge base.

BENEFITS OF COMPUTER AIDED DESIGN
CAD has many benefits. However, only some of these can be measured easily. For example, there are intangible benefits that are difficult to determine with a certain amount, such as improved job quality, more useful information, improved control. Some of the benefits are tangible, but it is difficult to find the benefits gained from them from the production process and therefore to express them in terms of money during the design phase. Some of the benefits from implementing CAD systems can be measured directly. The benefits of integrated CAD / CAM systems can be listed as follows:

Provides shorter lead times.
The needs of engineering staff are reduced.
Easy fulfillment of customer requests that arise on the designs made.
The needs of the market are responded more quickly. After the necessary database is created, it will minimize the project time required to produce similar new products and will provide an advantage in market competition.
Copying (scratching) errors are minimized.
The accuracy of the design increases.
Designs would be more standard.
During the analysis, the interactions of the components with each other are more easily determined.
By providing a better functional analysis, the number of prototype tests is reduced.
It provides support to prepare to provide documentation.
Increases productivity in tool design.
Provides better information about costs.
Provides a better design.
Reduces training time required for NC part programs and routine drawing tasks.
Fewer errors occur in NC part programs.
It provides a potential for further processing and utilization of existing parts.
It ensures that the design is compatible with existing manufacturing techniques.
It saves materials and machine time by optimizing algorithms.
It enables the design personnel working on the projects to be managed more effectively.
It helps to examine complex parts.
It provides a better environment of collaboration and communication between engineers, designers, management and different project groups.

cnc router mold design pantograph wood processing 3d machining solid modeling mini cnc router machine design lead mold solidworks solidcam machining strategist training consulting cnc training mini cnc lathe izmir