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This lecture covers the basics of freehand sketching and introduces solid modeling in engineering graphics. Topics include sketch construction, lettering, geometric construction, key features of solids, and boolean operations.
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Lecture 02 IENG 248: Free Hand Sketching & Intro to Solid Modeling Engineering Graphics & 3-D Modeling
Texts & Materials • Suggested: • Modern Graphics Communication, 4th ed. • Giesecke, Mitchell, Spencer, Hill, Dygdon, Novak, Lockhart & Goodman • Available for rent via Amazon • Make sure all appendix pages are intact • Will get one per lab team*– stored in the lab for access • Required: • Engineering Notebook • 7-1/2" x 9-3/4", quad ruled, 80 – 100 pp • Available at the Bookstore, Staples, etc • Anything that fits in this notebook is available for exams Engineering Graphics & 3-D Modeling
Materials • Required: • Engineering Problems Paper/Pad • five squares/division, 8-1/2 x 11, three hole drilled • Mechanical Pencil, 0.5 mm • good grip • Lead • HB, B • ‘Clickable’ Eraser Pencil • Plastic rather than rubber • Recommended: • Small, wireless mouse • Two buttons, with scroll-wheel • Small Engineering Triangles • 30-60-90 and 45-45-90 Engineering Graphics & 3-D Modeling
Example HW Assignment Layout • No cover sheet req’d if heading blocks filled out • Use front side, never use back (grid is on the back side) IENG 248 CH X: 2.1, 2.2 IENG 248 CH X:. 2.3, 2.4 1 2 9/2/14 A. STUDENT 2 9/2/14 A. STUDENT 2 PROB. 2.1 PROB. 2.3 FULL-SECTION VIEW: ISOMETRIC VIEW: A A D Ø l H D PROB. 2.2 H ORTHOGRAPHIC MULTI-VIEW: SECT A-A PROB. 2.4 Ø l BROKEN-SECTION VIEW: D Ø l H D H Engineering Graphics & 3-D Modeling
Example Lab Cover Page Layout • A cover sheet is always required for labs • Can be either handwritten or word-processed 0 9/2/14 A. STUDENT 3 ENGR 248 ENGR 248 LAB 1: LESSONS 1 - 3 LAB 1: TUTORIAL LESSONS 1-3 A. STUDENT CONTENTS CONTENTS 1: BLOCK SECTION 2: BLOCK ASSEMBLY 3: BLOCK DIMENSIONED 4: BLOCK ASSEMBLY 1: BLOCK SECTION 2: BLOCK ASSEMBLY 3: BLOCK DIMENSIONED 4: BLOCK ASSEMBLY 9/2/14 PAGE 0 OF 3 Engineering Graphics & 3-D Modeling
Some Common Lines • Visible Lines • Construction Lines* • Hidden Lines • Center Lines • Dimension Lines • Extension Lines or Section Lines • Cutting Plane Lines** • Phantom Lines • Break Lines** Engineering Graphics & 3-D Modeling
Sketch Construction • Block in ending, transition, and mid-points with light construction lines • Lines: • Horizontal strokes left to right (right handed) • Vertical strokes downward • Curves: • Draw with a downward motion • Use enclosing rectangles, centerlines, cards/trammels • Proportions (scaling, too): • Divide and conquer with enclosing rectangles • Use exit and entry points of background grid Engineering Graphics & 3-D Modeling
Sketch Construction Engineering Graphics & 3-D Modeling
Lettering • Upper case, no serifs, even width line strokes • Widths of letters: • 1, I are one unit wide • W is eight units wide • TOM Q VAXY set is six units wide • Remaining letter set is five units wide • Last two letters are almost as wide as they are tall • Top portions of a letter are usually NOT as wide/tall as bottom portions • Space between adjacent letter strokes is even, not the space between adjacent letter ‘envelopes’ Engineering Graphics & 3-D Modeling
Purpose of Geo Construction • Geometric construction techniques are used for: • CAD feature creation • Layout of prototype parts for manufacture • CAD drawing creation using 2-D software or manual drafting equipment* • Compass, dividers, triangles, and T-square or drafting arm Engineering Graphics & 3-D Modeling
Geometric Construction/Modeling • Terminology: • Points • Lines • Angles • Triangles • Quadrilaterals • Polygons • Circles • Arcs • Ellipses • Ogee Curve Engineering Graphics & 3-D Modeling
Constructs • Tangency • Bisection • Perpendicular / Right • Orthogonal • Oblique • Radius • Diameter • Circumference Engineering Graphics & 3-D Modeling
Key features: Pyramid Axis Cylinder Cone Sphere Torus Know how to generate solids – you’ll do it with SolidWorks Solid Types • Polyhedra • X - agon is a 2-D figure • X - ahedron is 3-D • Prisms • Faces • Parallelepiped • Truncated Engineering Graphics & 3-D Modeling
Boolean Operations • Union • addition of material using primitives • Difference • subtraction of material using complete primitives • Intersection • salvage of material common to two primitives • Primitives are the basic solids (features) • SolidWorks primitives are related to manufacturing operations • ACIS primitives are related to geometric shape Engineering Graphics & 3-D Modeling
Example Engineering Graphics & 3-D Modeling
Assignment • HW02: • See links on Schedule page: • Complete “Hands On 2.2”on photocopy • Sketch Top and Front views of the “Boiler Stay” on EP paper • Complete, staple, and turn in with a cover page • Load SolidWorks & MakerBot Desktop • http://www.makerbot.com/desktop -> 64 bit version! • SolidWorks takes about 2 hours -> start & return • May only be used from SDSM&T network addresses* • Labs: • Tu, W: 3:00 – 3:50 PM MFG E lab (Rm 130) • W: 4:00 – 4:50 PM MFG E lab (Rm 130) • also Collaboration Space, Design Studios (basement) Engineering Graphics & 3-D Modeling