Computer Aided Design Or Cad Computer Science Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

Today Computer Aided Design or CAD is the most phenomenon software used by many organisations. The usage of CAD play a vital role within the organisation to capture the completion of project. In the past almost every drawing of a project was done using paper, pencil or ink. If there is any problem or mistake within the drawing means, the draft man have to rub the contents which may create scratch to the drawing. If that slight change in the first drawing affects the next few drawings, then totally every drawing has to be edited or re-draw by the draft man. In one way it is time and energy wasting.

Due to the introduction of Auto CAD, such problems are solved very easily. Designing of parts became easy with the help of CAD. If the designer need to re-draw the sketch, within the corrupted drawing, one can edit and re-draw it effortlessly. The introduction of CAD not helped the industrial firms, but also in the private firms for making building layout and it can be also used as tool for learning design drawing. The advancements in the software guided people to view the 3D structure before the construction.

The operation of CAD boosted the scope of rapid prototyping in the engineering field. Many serious medical implants, which are manufactured using additive manufacturing technique are designed in the CAD software. The geometrical errors are negligible in the CAD software, so the output is absolutely perfect.

2.0 History of CAD,,

CAD software is a drafting software, which help engineers and designers in wide variety of industries. It is used as a base for making bridges, buildings, air-crafts, ships and so on. During 350 B.C, a great mathematician called Euclid, from Alexandria formulated mathematical postulates and assumptions as a theory which later lead for the development of CAD software.

The year 1950 is known as the implementation of computer graphics and the Numerical Control (NC). On the same year Automatically Programmed Tools(APT) explored into the industry. The first true phase of CAD was a creative system which is called as "Sketch pad". It was in 1960 Ivan Sutherland developed this pad. He tested drawings and modifications on a Cathode Ray Tube (CRT). In 1970, further experimental research based on computer graphic became bright and gradually the concept became more popular in the industries and was accepted by the government. This year is considered as the golden period of graphical environment. National Computer Graphics Association(NCGA) and Initial Graphics Exchange Specification(IGES) came into existence. The algorithm and integration of element for the manufacturing and design was introduced in the year 1980. At the same time, many important researches were held for reaching the CAD design ahead of 3D geometry in the engineering stream.

The high expense of computers and the high in need of design in the manufacturing area earliest CAD software came into the market. Today CAD concentrate on the advancement of algorithm and improvement of quick integration in the design and manufacturing side. Now it is considered as a support for design and fabrication. In early 90's the parametric operation of CAD and PRO-E attracted local customers and the company's began to sell licensed version of CAD to the clients. In the year 1996, Intergraph published a 3D CAD software comparable to solid works. At the same instant, auto desk published the latest mechanical 3D solid modelling software, which became the number one selling software at that era. Now many latest edition of CAD are in the market for designing and drafting purposes.

3.0 Requirements of CAD

In the past, in order to carry out the innovative ideas it was very tough to implement it. Now it became much easy with the help of CAD software. The Engineers or Designers can execute the data's very easily without any stoppage. Today the updated version of CAD required high compatible system for executing the software. Most designing software needs more graphics and memory space for running properly. There are few requirements of CAD for speeding the software.

The minimum requirement of the hard disk is 80G.B to operate the CAD program. Normally CAD program takes almost 1GB of the hard disk for the installation. Moreover , the data's loaded and the work done inside the CAD needs much more space for storage purposes. Extra spaces are allotted for the CAD software for avoiding the collision between the files, which may hang the P.C.

At present, polished version of processors are used. The processors that supports the CAD program are Advanced Micro Device(AMD), Athlon 64, Intel Pentium 4 and the updated version of it. Besides that, XP or advanced versions of XP are used as an operating system (OS) for running the product.

The most important factor to work the CAD perfectly is the Random Access Memory (RAM) capacity. If a one or more program operates in a less capacity RAM, the system will get crashed. So for avoiding such instance RAM with 2GB capacity or more is used.

4.0 CAD

Computer Aided Design or CAD is a software which uses computer oriented tools in wide areas for designing bridges, roads, machines and more, according to the actual dimensions that help engineers or architects to make their effort into reality.

4.1 Types of CAD

CAD is worldwide software which is commercially used by many organisations. According to the orientation of the drawing, CAD is divided into three different types. They are :-

Two Dimensional CAD Drawing (2D)

Two and a Half Dimensional CAD Drawing (2 1/2D)

Three Dimensional CAD Drawing (3D)

4.0.1 Two Dimensional CAD Drawing

2D CAD drawing can be called as the orthographic projection of views which exhibits 2D view. The layers of the 2D views are transparent and the drawing separations are supported by layers. The example of 2D drawing can be shown with the help of a diagram.

Untitled-1 copy.jpg

Figure 1: 2D Drawing of Gear Oil Pump

In here the 2D view is drawn and taken for retrieving detailed measurements. In 2D drawing each and every dimensions of the drawn part can be visualised clearly. Moreover, it gives the evaluation of material tolerance. The geometrical dimension is stored in the data base which includes numeric value that helps the user to find the dimensions by pointing into the drawn portion without any risk or error. The 2D CAD normally works on the x-y plane. And the drawings and done using standard subsistence such as points, lines, arcs.

4.0.2 2D CAD Elements

According to the usefulness of CAD, it has different types of elements for drawing. They are point, line, arc/circle, polygon, Ellipse, Spline, Mesh, Cross-Hatch and dimension, Delta from existing point, Circle Centre, Intersection of two curves, on a curve, on a curve normal to point and intersection of curve and surface.

4.0.3 2D CAD Facilities (Layers)

2D CAD drawing contain certain facilities they are :-

Better Handling of drawing

Good visual features

High progress in performance

Each layers can be renamed easily

Layers can be made in On or Off mode which gives clear dimension

Drawing sections are helped by layers

4.0.4 Advantage of 2D CAD Drawing

The main benefits of 2D CAD drawing are "cross-hatching of sectional views". The computer system calculates the joining section of hatch lines in the chosen area and trims the unwanted lines or parts. Multiple boundaries are drawn in the drawings. It generates complicated construction very clearly. Furthermore, construction accuracy is accurate for complex geometry. The geometry is influenced by transformation methods. At the same time, it can give a detailed dimension of interiors of the sectional part. And editing is done quite easily by showing the drawn area.

4.0.5 Types of 2D CAD software's



Aide CAD Drawer

Aide is 2D CAD software, which is used to draw and edit drawing without any other costly software's.

Auto CAD free style

It gives professionalism for the drawings. And it is mainly used to draw landscape design, garden design and so on.

Auto Sketch

It is software which is used for drafting purposes. This software can be used by the beginner, since the tools are really easy to find and use.

CAD std Pro

It is user friendly 2D CAD software, used to draw house plans, mechanical designs and blue prints.

Creo Elements or Direct Drafting

The software helps mechanical engineers to build the structures and it works beyond as a 2D CAD design structures, which may be useful for product development process.

Design CAD

Design CAD is adaptable and easy accessible software used to make hundreds of draft drawing with high precision and accuracy.

Graphite one 2D drafting

It is 2D Drawing software used to edit the drawing using magnificent 2D CAD tools.

Turbo CAD Designer

This is a user friendly 2D CAD software used to draw the plans of house, technical drawings, flow charts and beyond.

4.1.0 Two and Half Dimensional Drawing

Two and half Dimensional drawing is an isometric, planometric and oblique view which gives all three types of view on the drawing. The view can be demonstrated with the help of a diagram.


Figure 2: Two and Half Dimensional Drawing

In the above diagram, it gives the clear vision of 2D drawing view of front, top and right side view. At the same instant isometric projection of the same part is displayed in the diagram. Meanwhile, isometric drawing shows the whole three views at the same time.

4.1.1 Advantage of Two and Half Dimensional Drawing

Three views can be seen in the single instance.

An overall view of the final design can be seen.

Analyse and edit can be done in the drawing.

4.2.0 3Dimensional CAD Drawing (haris,

3D CAD Drawing is the computer propagated model is used and the object can be rotated on the screen, which can view in any angle. In the 3D CAD system right hand Cartesian rule is used, by making the axis point to (0,0) as fixed point. That point is called as Global Co-ordinate Systems (GCS). Furthermore, the axis point can put as movable, such cases are called as Works Co-ordinate Systems (WCS). The following diagram describes 3D view of a gear oil pump.

assem very impo.JPG

Figure 3: 3D view of a Gear Oil Pump

In the 3D CAD, the user can view isometric, oblique and perspective views. The angular and straight views of the drawn component are more accurate and it allots provision to edit in display. According to the users wish, the designed object can be rotated.

4.2.1 Types of 3D Modelling

Wire-Frame Modelling

Surface Modelling

Solid Modelling

4.2.2 Wire-Frame Modelling

3D wire-frame is the 3D representation of drawn models, for visualising the interior parts of the 3D Models. It is done by creating the smooth edges connected using straight lines or curves. The following diagram shows the detailed view of a wire frame model.

Figure 4: Wireframe Model

Normally wireframe has two dimensional views with one additional axis called "z". Mainly wireframe contains lines and points, whereas planes can be drawn using arc or other planar surfaces. This model is very simple and used in many complex 3D models, for viewing the interiors of the model. In some cases high graphical visualisation is needed, on that instance it automatically include the new textures, after the doing the wireframe.

4.2.3 Surface Modelling

Surface modelling is the "skinning or surfacing" of the wireframe part inorder to create a finished part. This process is used in the CAD software to illustrate the skin of 3D model. It does not have inflexible dimensions. Therefore, this surface modelling is used to explain turbine blade, car bodies and so on. The following diagram gives a clear view about surface modelling.


Figure 5: Surface Modelling Figure 6: Surface Modelling(single Surface)

In Surface Modelling, unwanted drawings are ignored during visuals. For drawing complex geometrical structures this method is more appropriate. Moreover, it has a good background for analysing and manufacturing models.

4.2.4 Solid Modelling

Solid modelling is the three dimensional modelling which gives precise accuracy in the geometrical modelling. The combination of geometric and solid modelling gives CAD. The operation of Solid Modelling paves the way to solve several critical engineering calculation smoothly. The diagram shows the solid modelling part of CAD.


Figure 7: Solid Modelling of Mine Detection Vehicle

Solid Modelling methods are of two types, they are Constructive Solid Geometry (CSG) and Boundary representation (B-Rep). CSG Modelling is the basic modelling, which is used in making complex parts of aircrafts, cars and more. Whereas, boundary representation shows the connectivity of the surface. Today progressed users prefer the combination of both during the surface modelling. Such modellers are called as Hybrid Modellers.

5.0 Application of CAD

Computer Aided Design is designing software for developing real time appliances. The CAD has many applications in many areas. The few applications listed below are :-

CAD in Medical Sector (Rapid Prototyping)

CAD in Industries

Application of CAD in Mechanical Stream (automobile)

Application of CAD in Aircraft Designing

Application of CAD in Architectural Field

Application of CAD in Textile Industry

CAD in Entertainment Area

5.1 CAD in Medical Sector (Rapid Prototyping)

In the medical industry the CAD plays a key role in the surgical procedures. For the Preoperating planning for Cranio-Maxilofacial Surgery, doctors prefer CAD software for the creation of implants. The 3D images from the Digital Imaging and Communication In Medicine (DICOM) in the form of Standard Triangulation Language (STL) engineered using CAD software. The following diagram shows the surgery for the implantation of skull.

Figure 8 : Mirror Image of Skull using CAD Software

3D models of the parts can visualise clearly using advanced versions of CAD software such as SolidWorks, Magics etc. The system will scan the STL models and it will make the missing part of the skull. CAD modelling of the implant is done and send it for further inspection.

Figure 9: Final Inspection for Making Skull Implant

Using Rapid Prototyping technique (Laser Sintering) outlayer of the skull is manufactured. This outlayer helps doctors to make the implant properly. The following two diagrams show how the implant is made and fixed in the skull.

Figure 10: Implant using Jetting (R.P) Figure 11: Skull and Implant

The implant is manufactured using Rapid prototyping Jetting technique. And by the combination of laser sintering and jetting technique, preoperating planning for cranio-Maxilofacial Surgery can be done. Now a days the use of CAD really boosted the Rapid Prototyping methods to enhance its products in different levels of market sector.

5.2 CAD in Industries

The Industrial application of CAD has elevated to a great extent, for the production of outputs. The industrial fields include mechanical, civil, Aircraft and more. The inclusion of CAD in these sectors boomed market strategy in the Global Market. The CAD software accelerates the 2-D Drawing and 3-D Drawing, which helps the organisation to complete the projects fastly. Apart from that, CAD software helps the technicians to make the parts of vehicles, this method can be called as Computer Aided Manufacturing (CAM), which is a part of CAD. Recently CAD provides different type of tools to exhibit engineering, architectural and constructional fields.

5.2.1 Application of CAD in Mechanical Industry (Automobile)

CAD is the most popular software in the mechanical field. The utilization of CAD is very deep, for designing mechanical components. Today many fundamental parts in a machine are designed using CAD. The surface finish and accuracy make the people to use the CAD as the basic tool for designing purposes. The following diagrams show the operation of Cad in designing the engine of a motor bike.

Drawing1.jpg engine.jpg

Figure 12: Design Drawing of Engine Figure 13: 3D CAD Model of an Engine

The above mentioned figures are the engine designed by a company called Fuji Tech for motor bikes. This is drawn using 2D CAD and 3D CAD. For modelling progressive version of CAD software's are used. Besides that, engine is designed in such a way that, it gives enough space for installing the engine parts. Earlier engine designing dedicated only to bog firms, with large number of talented engineers, but now 3D CAD, pave way for a single user to make a perfect engine part. Moreover, CAD is used in analysing the current engine parts such as engine blocks, crank shafts, pistons, cam shaft and cylinder heads.

5.2.2 Application of CAD in Aircraft

In the recent days, the usage of CAD in the Aerospace industry increased rapidly. The combination of reverse engineering along with the CAD software's such as Rhinoceros and Rapid form, helps the engineers to construct the features of wings and fuselage in appropriate way. The figure given below gives the picture of 3D CAD model of an Aircraft.

8662.jpg 8662 (1).jpg

Figure14: 3D Model of the Aircraft Figure 15: Wireframe Model of Aircraft

Different types of CAD software's are available for designing purposes. The main parts of aircraft are designed using software called "Radio Control-CAD" (R.C CAD). It gives the real time visualisation of model. R.C CAD is very easy to use since it workout data properly. Moreover, it is very fast in process. The features can be edited effortlessly and at the same time, the edited features are updated without any delay. Besides that, the R.C version of CAD is very cheap compare to others. In R.C CAD layout tool is very strong to check out the entire equipments for inspection (whether the tool is fit or not).

5.2.3 Application of CAD in Architectural Design

At present the CAD software became most convenient and effective mode for Architectural Design. In many cases the designers makes one or more sketches for the customer to fulfil their goals. Cad program helps architects and the owners to view the interior parts and exterior parts very clearly without any interference. The following figure describes the view of a two story building.

36070 (1).jpg 36070.jpg Figure 17: Wireframe Model of a building Figure 18: 3D model of a building

Manual drawing gives unnecessary errors and it will be very tough to edit or redraw the sketch. Furthermore, this method takes a lot of time for completing the drawing. 3D cad tools make the drawing more effective by filling the colours in the building parts such as doors, windows and roofs. This facility makes the 3D view more natural. The 3D sketch with accurate calculations help the structural engineers to complete the project perfectly. Totally almost all the structural challenges are solved by Auto CAD.

5.2.4 Application of CAD in Textile industry

The introduction of CAD has made a massive effect in the textile industry. The textile industries prefer CAD as basic tool for designing fashionable goods. The given figure gives a detailed explanation of the textile production.

1780 (1).jpg 1780.jpg

Figure 18 : wireframe of suit coat Figure 19: 3D model of suit coat

Normally textile firms works with only designers. But the CAD software serves as a tool for the designer to visualise the imaginary outcome of a design. The CAD software open way to fulfil customer satisfaction. Some of the ideas may be in the form of paint or negative image, the Cad software covert this into functionally design. The usage of CAD opened a path for the industrial goods such as Foot wears, caps, suits and beyond.

5.3 CAD in Entertainment Area

In the entertainment industry the role of CAD is vast. The Autodesk software develops digital prototyping software, which is a part of CAD software helps the digital media for visual effects, colour edition, edition of animation and more. The work done through this , will be properly trimmed and meshed for the final outcome.

6.0 Industrial Case Study

Sirkel and Mall is an astonishing company run is Estonia. The business of this company has grown remarkably high in the year 2005. During the year 2009, the company has approved ISO certification. According to the strategy, in 1913, it is going to be the most spectacular designing company in Estonia. In the middle part of the years company faced many marketing challenges. When the company rise, the workload also gets increased. So the company was forced to maintain the work speed. The engineers, designers and architects have to work together and must interchange the building information among themselves. At this instance, it was congested to notify the major works. These problems arise due to the utilization of traditional methods of designing technique. Due to this, all the information's and drawings were made individually. As a result, more time and money were lost. And in the year 2007, the company took a decision to choose the advance version of CAD technique, so they purchased Building Information Modelling (BIM) for designing and modelling the sketches. It helps them, retrieve the building information's without any further delay. The Autodesk helped the organisation to work their needs in a single atmosphere to design the parts and model. The virtual information serves the design team to supply data's whenever they needed. In this way CAD solved big problem of a well known firm.

7.0 Benefits of CAD

CAD has many benefits in different fields. They are:-

Reduce the product development expense

Provides maximum accuracy in the design

It is a well-known software to store or edit drawing

Animated models and solid model can be created easily using 3D CAD

Productivity can be increased using CAD

Drawing errors are comparatively less

Designing and documentation making is possible by the latest version of CAD software

It creates database for the further manufacture of products

For the further reference, it saves design data's and drawing.

It is base to create a good business environment for the development of products

Flexibility and reliability is another major factor in CAD software

8.0 CAD in the product development process

The cad plays a vital role in the product development process. Today CAD drawing increased the flow of drawing, and the 3D CAD takes different methods which supply's benefits in civil, structural and mechanical engineering fields.

The 3D CAD provides strong support to the product development process by increasing the quality of design by reducing unwanted errors. Product development can be done by basic few steps. They are Design, 3D modelling, Analysis, planning, manufacturing.(journal)


3D Modelling




Product Development Process(journal)

Design of the Cad can be drawn using 2D cad drawing and modelling can be done by 3D CAD software. During the process maximum errors are omitted. After the process analysis of the model can be made possible by using ANSYS software. Then proper planning can be done. Final step is the manufacturing process, thus product development in completed.

9.0 Conclusion

In conclusion it is clear that, the