IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling1 Lecture 05 Sectional Views

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling2 New Assignment: HW 05  MGC: n Reading Finish CH6 n HW 05: Sketch section for j only on p Sketch the necessary views for 6.5, p. 245 (no dimensions necessary) Sketch the necessary views for 6.19, p. 247 (no dimensions necessary); include the (1) broken-out and both (2) revolved sections n Lab: Start Solidworks Tutorial: Lesson 1 We will complete Lessons 1 – 3 next week

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling3 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

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling4  Sectional views show hidden detail clearly - a very important method!  Cutting planes are depicted in an adjacent view as lines with perpendicular arrows showing the viewing direction for the section  Cutting plane lines are patterned, thick, dark: A A Sectional Views

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling5 Types of Sections  Full Sections n fully cut with a single plane  Half Sections n cut to a center line with a single plane  Broken-out Sections n cut to a break line with a single plane  Revolved Sections n cut with a single plane, revolved in place  Removed Sections n cut with a single plane, removed from position  Offset Sections (usually prismatic parts) n cut using multiple, offset planes  Aligned Sections (usually rotational parts) n cutting plane is bent to pass through other features

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling6 Creating a Section View (Offset Section)

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling7 Partial Section Views

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling8 Revolved Sections

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling9 Keys in Drawing Sections  Visible lines behind the cutting plane are shown  Hidden lines are not typically shown  Sectioned areas are cross-hatched and always bounded by visible lines, only  Within an individual part, all cross-hatch lines are parallel  Cross-hatch lines in adjacent parts run oblique (often perpendicular) to cross- hatch lines in other parts

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling10 Cross-hatch Patterns  Differing materials may be shown with distinct cross-hatch patterns (Fig on p. 228)  Cross-hatch lines should be: n thin n dark n evenly spaced n complete* to, but not over, the visible lines  Draw at 45 o unless nearly parallel to an edge * can use outline hatching for large areas

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling11 Std Material Cross-hatch Patterns

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling12 Odd Details  Ribs (webs) and projecting lugs are not cross-hatched  Rotated / angled features that are off-plane with the cutting plane are shown sectioned as if they were aligned with the cutting plane (Fig. 2.26, p.231)  Some intersections (particularly small holes) are not shown as truly projected (Fig. 6.42, p. 238)  Isometric/Oblique cross-hatches are 60 o, typically.

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling13 Showing Ribs in Section Views

IENG 248 D. H. Jensen 5/1/2015Engineering Graphics & 3-D Modeling14 Conventional Break Lines  Short break lines are thick, dark, solid, rough  Round Solid n drawn as a gap and an ‘s-break’ on each end  Round Tube n unsectioned - hollow s-break n sectioned - similar to regular sectioning, with a regular, rough break line  Rectangular n Metal- use a regular, rough break line n Wood- exaggerate break line to look sharp, jagged, splintered