1. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling1 Lecture 04 Interpreting and Depicting Geometry in Orthogonal Projections

2. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling2 Lab & Homework Grading  Each print / sketch / set of questions is graded on a 10 point basis n 10 points – Near perfect n 9 points – Better than average n 8 points – Average n 7 points – Needs much improvement n 6 points – Great improvement required, credible attempt n 2 points – Something submitted n Additional penalties for late/incomplete work

3. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling3 HW Assignment 03  MGC: n Reading: Finish CH 5 Start CH 6 n HW 03MGC CH5: Exercises p. 207 :  5.7, # 4 (note: numbers are above object) Exercises p.210:  5.19 (note: numbers are below object) Exercises p.211:  5.28 (note: numbers are below object)  Note: n NO borders & title blocks required on HW n No more than two sets of part views per page.

4. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling4 Line Interpretations  Construction Line n Purpose: Locate intermediate / transition points and extent of features n Weight: light, thick* n Style: semi-solid, and do not reproduce  Visible (Object) Line n Purpose: show extent of features visible in the current view n Weight: dark, thick n Style: solid, crisp ends

5. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling5 Line Interpretations  Center Line n Purpose: show axis and extent of symmetry n Weight: dark, thin n Style: long dash, short dash at center, long dash  Hidden Line n Purpose: show extent of features hidden by other features n Weight: dark, thin n Style: short, even dashes

6. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling6 Line Interpretations  (Short) Break Line n Purpose: show hidden features in detail for clarity n Weight: dark, thick n Style: solid, semi-rough  Section Line n Purpose: show cross-section of material n Weight: dark, thin n Style: solid, angled to adjacent visible lines Note: For demonstration only. Prefer the use of conventional breaks in practice (see CH 6).

7. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling7 Views of Surfaces & Edges  Normal Surfaces n Parallel to one plane of projection and perpendicular to adjacent projections (appearing as a true sized line)  Inclined Surfaces n Perpendicular to one plane (appearing as a line of true size) and are inclined to adjacent projection planes  Oblique Surfaces n Inclined to all planes of projection and cannot appear as a true size edge in any standard view  Normal Edges n Perpendicular to one plane of projection, and appears there as a point n Are parallel to adjacent projection planes and appear in true length  Inclined Edges n Parallel to one plane of projection, where they appear in true size, but are inclined to adjacent projection planes  Oblique Edges n Inclined to all planes of projection, and cannot be shown in true length since they are never parallel to a standard projection

8. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling8 Types of Surfaces Normal Surfaces Inclined Surfaces Oblique Surfaces

9. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling9 Types of Edges Normal Edges Inclined Edges Oblique Edges

10. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling10 True Length & True Angle True Length Edges Foreshortened Edges True Angles

11. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling11 Planar Geometry  Points n Could represent a vertex of three or more surfaces n Could represent the point view of an orthogonal edge  Lines n Could represent the intersection of two surfaces n Could represent the edge view of an orthogonal surface n Could represent the extent of a curved surface  Angles n Appear in true size only if the angle (intersection of two edges) lies in a normal plane (in a plane parallel to a projection)

12. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling12 Intersections & Tangencies  Intersections n Are sharp transitions where adjacent or machined surfaces meet n Are shown as lines in profile and other views  Tangencies n Are smooth transitions from a surface to an adjacent curve n Are shown as lines in profile n Are not shown as lines in other views, unless: They transition to a normal surface They are runouts They are conventional edges

13. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling13 Runouts & Conventional Edges  Rounds n Are exterior rounded intersections  Fillets n Are interior rounded intersections  Runouts n Are small curves used to represent the connection of a planar to a curved surface (See Fig. 5.14 – 5.16, p.190 – 191)  Conventional Edges n For certain types of rolled / cast forms, the smooth transitions are eliminated to clarify the shape (See Fig. 5.17 p.191)

14. IENG 248 D. H. Jensen 10/13/2015Engineering Graphics & 3-D Modeling14 Scales  Revolution Conventions n Odd, rotational symmetry is depicted, not projected (See Figs. 5.34, and 5.35, pp. 198)  Drawing Scale n Specify drawing scale in the title block, i.e.: Scale 1 : 5 Left side of colon are local drawing units Right side of colon are real life units n Never measure a drawing to obtain a dimension n Never omit a required dimension from a drawing  Measuring Scales n Types of Measuring Scales Metric Scales Inch-Foot Scales Engineer’s Scales Architect’s Scales Mechanical Engineer’s Scales Patternmaker’s Scales n Measuring Scales are only used for taking measurements Never use a scale as a straight edge for drawing