Engineering H191 Engineering Fundamentals and Laboratory I

1. Engineering H191Engineering Fundamentals and Laboratory I Week 01 Day 01 Graphics: The Language of Design

2. Objectives • Understanding graphics as a communication tool • Technical sketching • Projections • Orthographic • Pictorial • Sketching hints • Lettering AU 2005

3. How Would You Describe This? • In teams of two, describe using only words • How effective is this approach? AU 2005

4. Three Basic Types of Technical Drawings • Freehand sketches • Instrument drawings • Computer drawings and models AU 2005

5. Introduction to Projections • Present 3-D objects with 2-D media • Two Basic Categories OrthographicPictorial AU 2005

6. Orthographic Projections Projections: Four Basic Types Axonometric Pictorials Oblique Perspective AU 2005

7. Orthographic Projections • Collection of 2D drawings • Accurately represent object • Technical Graphics - Chapter 3 AU 2005

8. Orthographic Projection AU 2005

9. Defining the SixPrincipal ViewsorOrthographic Views AU 2005

10. Which Views to Present? • General Guidelines • Pick a Front View that is most descriptive of object • Normally the longest dimension is chosen as the width (or depth) • Most common combination of views is to use: Front, Top, and Side View • Views other than the Principal Views are called Auxiliary Views (see 3.15 in the Technical Graphics text) AU 2005

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12. Width Top View Depth Right Side View Front View Height Conventional Orthographic Views AU 2005

13. Hidden Lines – represent features that cannot be seen in the current view • Centerlines – represent symmetry and mark the center of circles, the axes of cylinders, and the axes of symmetrical parts, such as bolts Hidden and Center Lines in Orthographic Projections AU 2005

14. For Example: 1. Visible 2. Hidden 3. Center AU 2005

15. Creating the Orthographic Projection Sketch • Front View • Right Side View • Top View AU 2005

16. Use very light lines for drawing in the construction lines Step 1 – Lightly Block Three Views AU 2005

17. Step 2 – Lightly Block Major Features • Holes • Arcs • Cutouts Use very light lines for drawing in the construction lines AU 2005

18. Step 3 – Refine and Locate Features in All Views Use very light lines for drawing in the construction lines AU 2005

19. Step 4 – Add Final Lines Use very light lines for drawing in the construction lines AU 2005

20. Completed Sketch AU 2005

21. Add Another View • Sketch the left side view of the object • Compare your view with the others at your table AU 2005

22. Add Another View • Does yours look something like this? AU 2005

23. Lettering Notes • Lettering Guidelines – Technical Graphics: Chapter 1 • Lettering Styles • Shape of Letters • Order of drawing lines • Character Uniformity • Spacing AU 2005

24. Lettering AU 2005

25. Sketching Tips: General • Relax and draw in a direction comfortable to you • Mark end points of the lines to be sketched and draw between them • Draw long lines as a series of short ones • Use grid paper when available • Follow sketching and text conventions • Do NOT use a straight edge to draw lines! AU 2005

26. Sketching Tips: Construction Lines • Use construction lines • Begin by drawing bounding boxes with construction lines • Make construction lines much lighter and thinner than finished lines • Identify the major features and overall dimensions • Leave construction lines on the sketch AU 2005

27. Sketching Tips: Miscellaneous • Do not shade the drawing – this is not pencil sketching • Title information is required • Keep views aligned (very important) • Include centerlines on isometrics • Avoid labels on the sketch • Draw neat circles – change page orientation if needed AU 2005

28. Today's Assignment • Drawing 1: • Blocks of each kind will be handed out at each table to sketch from. • Drawing 2: • Lettering assignment handed out in class. • An additional copy will be in your course packet from CopEZ AU 2005