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Introduction to Graphic Communication KCEC 1101 CAD


The Important of Graphics in the Design Process 1. Visualization 2. Communication 3. Documentation


First phase: Visualization Visualization is the ability to mentally picture things that do not exist. “Most designers will initially capture their mental images by sketching them on paper…they sketches very roughly and quickly done…when communicating one’s sketch to other, the sketches must be refine…” Design sketch of a vehicle sunshade


Only experienced users of technical drawings can interpret the various lines, arcs, and circles sufficiently to get a clear mental picture of what this part looks like three dimensionally


Visualization phase: How the stapler object is transform to sketching the parts


Second Phase: Communication In this phase the goal is to refine your initial sketches so your design solution can be communicated to others without ambiguity You must be able to improve the clarity of your graphics to such an extent that others are able to visualize your design “…this is done by adding more detail to your sketches, then creating a 3-D model using CAD software…and then communicate with your purpose design”


Third phase: Documentation After the design solution is finalized with include an any mechanical analysis, the 3D modeling is then transfer to documentation phase. The drawings were 2D detail drawings that were copied through a process either to: 1. Blueprinting 2. CNC generic machine codes


Traditional design process “…Work in mind such as brainstorming etc…” “Collect the conceptual design, specification etc…” “…refine and solve the problem that becomes more clear…” “…such as use Finite Element Analysis…and there will repeat until final design solution is chosen” “..it must be documented and recorded in sufficient detail for the product to be manufactured..”


The design process using Concurrent Engineering (CE) Concurrent engineering gets everyone involved in the design process, including the customer. The overlapping circles indicate that designing concurrently is an integrated activity involving many people

Advantages of CE 1. Powerful process that can reduce the design time 2. Easy to identify or detect the problems 3. Reduce the design cost 4. Maximized the resourced 5. Low risk of high level impact


CAD database applications

The CAD database, which is represented as graphics, provides technical information not only to the engineers on the design team, but also to the manufacturing, marketing and sales, and training departments


Technical Drawing tools vs. CAD tools


Schematics representation of CAD software

Such as keyboard, mouse, drawing pad, etc

A CAD system consists of hardware devices used in combination with specific software, as shown in figure Such as printer, projector, CD, diskette etc

The Hardware for a CAD system consists of the physical devices used to support the CAD software


Pencils Grade


Angles combination


Drawing paper size


The grid lines

(A) Square grid (B) Isometric grid (C) Perspective grid


Technical Sketching


Methods of creating technical drawing

Freehand drawings are know as sketches and are an important communication tool that engineers use frequently when designing


Technical sketching is the process of producing a rough preliminary drawing representing the main features of a product structure

Freehand drawings are grouped by the level of detail, structure, and restrictions used to create the sketch


Example of sketching technique


Sketching is used throughout the design process to communicate information


Example of good and poor drawing techniques for lines


Line weight

Uniform lines do not vary in thickness or darkness


Sketching a circle


Poorly drawn circles


Sketching ellipses


Step in drawing an irregular curve through a series of points


Classification of sketches The sketches shown in B, C, and D is called pictorial because they represent the object as a 3-D form The multi-view sketch uses multiple flat views of the 3-D object to accurately represent its form 2-D form


Step creating a proportional sketch Step 1: Create a bounding box that represents the outer dimensional limits Step 2: Draw other boxes to represent the larger features of the object and then continue to others smallest feature‌ Step 3: Continues to draw bounding boxes until all the feature of the object have been represented Step 4: When all of the feature have been boxed, begin sketching the final line-work, which is done significantly darker than the constructions lines.


Basic steps used to create an isometric sketch of an object Step 1: Create Isometric axis Step 2: Draw 3-axis bounding box that represent the outer dimensional limits of 3-D feature Step 3 & 4: Create the blocking plane for front, top and side faces Step 5: Adding details to the isometric block by estimating the dimensions to cut out and mark these points as shown in figure Step 6: Finalize your sketches include all small features Step 7: Completed isometric sketch


Isometric representation of circles

Circular features appear as ellipses in isometric sketches. The orientation of the ellipse is set according to the face on which the circle lies. The correct orientation is shown in (A) and examples of in corrections are shown in (B)


Sketching an Isometric Ellipse


Creating an oblique sketch


Individual assignment • Procedures: – Identify any product either small or large – Make a sketch of all the parts with dimensions showing the width, height, and depth of the peaces – Label the parts and complete a parts list by listing all the parts, including the materials, basic dimensions, and the part names. – Overall length should not exceed 2 pages but not less than 1 pages. – Please staple your assignment in the upper left-hand corner. Do not otherwise bind the report or use any hard/plastic covers. – On the front page please include the title of product, your name & matrix no and date of finishing. – Please submit your assignment 24 July 2006 (before 5 pm) at my student assignment box at JKRP office.


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