1. Unit 1 Drafting Standards & Techniques -Sketching

2. Permission granted to reproduce for educational use only. 2 © Goodheart-Willcox Co., Inc. Objectives Understand the use of skills and techniques used in the technical sketching process.

3. Permission granted to reproduce for educational use only. 3 © Goodheart-Willcox Co., Inc. Freehand Sketching Done without instruments. Used to evaluate concepts before starting drawing. Used to share ideas with others.

4. Permission granted to reproduce for educational use only. 4 © Goodheart-Willcox Co., Inc. Types of Paper for Sketching Plain paper Graph paper Isometric grid paper Drafting paper Tracing paper

5. Permission granted to reproduce for educational use only. 5 © Goodheart-Willcox Co., Inc. Sketching Techniques Hold pencil firmly but loose enough for easy movement. Hold pencil farther back than in normal drawing. Keep eye focused on point where line will end. Darken finished lines.

6. Permission granted to reproduce for educational use only. 6 © Goodheart-Willcox Co., Inc. Sketching Horizontal Lines Keep your arm perpendicular to line being sketched.

7. Permission granted to reproduce for educational use only. 7 © Goodheart-Willcox Co., Inc. Procedure for Sketching Horizontal Lines

8. Permission granted to reproduce for educational use only. 8 © Goodheart-Willcox Co., Inc. Sketching Vertical Lines Work from top to bottom. Place your arm approximately 15  to line.

9. Permission granted to reproduce for educational use only. 9 © Goodheart-Willcox Co., Inc. Procedure for Sketching Vertical Lines

10. Permission granted to reproduce for educational use only. 10 © Goodheart-Willcox Co., Inc. Estimating Angles First, sketch right angle (90  angle). Subdivide to obtain desired angle.

11. Permission granted to reproduce for educational use only. 11 © Goodheart-Willcox Co., Inc. Sketching Methods for Circles and Arcs Centerline method Enclosing square method Free-circle method

12. Permission granted to reproduce for educational use only. 12 © Goodheart-Willcox Co., Inc. Centerline Method

13. Permission granted to reproduce for educational use only. 13 © Goodheart-Willcox Co., Inc. Enclosing Square Method

14. Permission granted to reproduce for educational use only. 14 © Goodheart-Willcox Co., Inc. Free-Circle Method

15. Permission granted to reproduce for educational use only. 15 © Goodheart-Willcox Co., Inc. Sketching Methods for Ellipses Rectangular method Free-ellipse method

16. Permission granted to reproduce for educational use only. 16 © Goodheart-Willcox Co., Inc. Rectangular Method

17. Permission granted to reproduce for educational use only. 17 © Goodheart-Willcox Co., Inc. Free-Ellipse Method

18. Permission granted to reproduce for educational use only. 18 © Goodheart-Willcox Co., Inc. Sketching Irregular Curves Mark points along curve spaced at 1/4  or 1/2 . Sketch through marks.

19. Permission granted to reproduce for educational use only. 19 © Goodheart-Willcox Co., Inc. Sketching Hexagons Sketch centerlines and inclined lines at 30° and 60° Construct circle with diameter equal to distance across flats of required hexagon Sketch horizontal parallel lines at right angles to vertical centerline

20. Permission granted to reproduce for educational use only. 20 © Goodheart-Willcox Co., Inc. Sketching Hexagons (Cont.) Sketch inclined parallel lines at 60° to circle Sketch lines tangent to circle at points where 30° lines intersect circle Complete hexagon with lines of desired weight

21. Permission granted to reproduce for educational use only. 21 © Goodheart-Willcox Co., Inc. Sketching Octagons Sketch centerlines and inclined lines at 45° Construct circle with diameter equal to distance across flats of required octagon Sketch parallel lines tangent to circle where centerlines intersect circle

22. Permission granted to reproduce for educational use only. 22 © Goodheart-Willcox Co., Inc. Sketching Octagons (Cont.) Sketch inclined parallel lines at 45° and tangent to circle at points where inclined lines intersect circle Complete octagon with lines of desired weight

23. Permission granted to reproduce for educational use only. 23 © Goodheart-Willcox Co., Inc.

24. Permission granted to reproduce for educational use only. 24 © Goodheart-Willcox Co., Inc. Methods Used to Keep Sketches in Proportion Proportion Unit method Enclosing rectangle method

25. Permission granted to reproduce for educational use only. 25 © Goodheart-Willcox Co., Inc. Unit Method Divide distances into units. Select appropriate unit measurement. Lay off distances on sketch in same proportion. Useful when working from picture.

26. Permission granted to reproduce for educational use only. 26 © Goodheart-Willcox Co., Inc. Enclosing Rectangle Method

27. Permission granted to reproduce for educational use only. 27 © Goodheart-Willcox Co., Inc. Lettering Used to clarify drawing information. Must be done accurately for manufacturing purposes. Manual skill comes with practice.

28. Permission granted to reproduce for educational use only. 28 © Goodheart-Willcox Co., Inc. Lettering Quality Letters are formed, not “written.” Style, height, spacing, and stroke kept uniform.

29. Permission granted to reproduce for educational use only. 29 Isometric Sketching Used to portray a 3-D object on a 2-D sheet of paper. The relationship between the 3-D axes appears differently when projected onto a 2-D surface, i.e., perpendicular angles no longer appear perpendicular.

30. Permission granted to reproduce for educational use only. 30 Isometric Axes

31. Permission granted to reproduce for educational use only. 31 Isometric Axes Note that all surfaces of an object sketched in isometric will appear distorted. The surfaces of the cube appear to be rhomboidal Isometric sketches are made as if you were looking down a diagonal of a cube

32. Permission granted to reproduce for educational use only. 32 Isometric Axes Isometric grid paper or dot paper is a useful tool for constructing isometric drawings.

33. Permission granted to reproduce for educational use only. 33 Coded Plans Pictorial sketches can be made from coded plans. Coded plans define the shape of a building made of blocks. BuildingCoded Plan

34. Permission granted to reproduce for educational use only. 34 Coded Plans Isometric sketch from corner C.

35. Permission granted to reproduce for educational use only. 35 C Step 1 & 2 Step 3 Step 4... Isometric Sketching Guidelines for constructing isometric drawings: 1. Draw edge "C". 2. Sketch surface to the right or left of edge “C”. 3. Draw a surface that shares an edge with the surface just drawn. 4. Continue drawing one surface at a time until the object is complete. NOTE: Do not show the individual blocks in the building. Just show edges where surfaces intersect. 3 1 1 2 C

36. Permission granted to reproduce for educational use only. 36 Demonstration Sketch the X-corner view of the object shown below 23 11 X