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Lecture 05

Sectional Views

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New Assignment: HW 05

MGC: Reading

Finish CH6

HW 05:Sketch section for 6.4 - j only on p. 244.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

Lab: Start Solidworks Tutorial: Lesson 1We will complete Lessons 1 – 3 next week

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Lab & Homework Grading

Each print / sketch / set of questions is graded on a 10 point basis 10 points – Near perfect 9 points – Better than average 8 points – Average 7 points – Needs much improvement 6 points – Great improvement required,

credible attempt 2 points – Something submitted

Additional penalties for late/incomplete work

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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

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Types of Sections

Full Sections fully cut with a single plane

Half Sections cut to a center line with a single plane

Broken-out Sections cut to a break line with a single plane

Revolved Sections cut with a single plane, revolved in place

Removed Sections cut with a single plane, removed from position

Offset Sections (usually prismatic parts) cut using multiple, offset planes

Aligned Sections (usually rotational parts) cutting plane is bent to pass through other features

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Creating a Section View (Offset Section)

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Partial Section Views

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Revolved Sections

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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

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Cross-hatch Patterns

Differing materials may be shown with distinct cross-hatch patterns (Fig. 6.18 on p. 228)

Cross-hatch lines should be: thin dark evenly spaced complete* to, but not over, the visible lines

Draw at 45o unless nearly parallel to an edge

* can use outline hatching for large areas

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Std Material Cross-hatch Patterns

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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 60o, typically.

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Showing Ribs in Section Views

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Conventional Break Lines

Short break lines are thick, dark, solid, rough Round Solid

drawn as a gap and an ‘s-break’ on each end

Round Tube unsectioned - hollow s-break sectioned - similar to regular sectioning,

with a regular, rough break line

Rectangular Metal - use a regular, rough break line Wood - exaggerate break line to look

sharp, jagged, splintered