SECTION VIEWS

This is done by using the technique of drawing… Can you guess what is inside of this box? This is done by using the technique of drawing… SECTION VIEWS If you had the Invisible Women’s powers you could make the box invisible and see what is hidden from view. How can a Designer show on a drawing what is hidden from view?

A Section Drawing of a V-Type Four Stroke Diesel Engine Section Views: are used to show inside features of objects that would otherwise be unseen. A Section Drawing of a V-Type Four Stroke Diesel Engine

Hand out Unit organizers The Big Picture The Unit Organizer Techniques used on Working Detail Drawings LAST UNIT/ Experience Basic Dimensioning CURRENT UNIT PRODUCE SECTION VIEW DRAWINGS NEXT UNIT/ Experience Auxiliary Views Inside feature are not visible Principles & Exceptions Required When When omitted Section Views Have many types Are identified by Types of Section Views Are Labeled by Section Lines (X-Hatch) Hand out Unit organizers C.P.L. Elements & Placement What determines the need for a section view? What are some types of section views? How are webs, ribs and spokes represented in a section view? And why? UNIT SELF-TEST QUESTIONS UNIT RELATIONSHIPS

The Unit Organizer Section Views Basic Dimensioning The Big Picture Techniques used on Working Detail Drawings LAST UNIT/ Experience Basic Dimensioning CURRENT UNIT PRODUCE SECTION VIEW DRAWINGS NEXT UNIT/ Experience Auxiliary Views UNIT SCHEDULE 2-col note vocab Hand-outs worksheets Jeopardy Game Drawings Quizzes Unit Test Inside feature are not visible Principles & Exceptions Required When Section Views When omitted Have many types Are identified by Labeled by Are Types of Section Views Section Lines (X-Hatch) C.P.L. Elements & Placement What determines the need for a section view? What are some types of section views? How are webs, ribs and spokes represented in a section view? And why? UNIT SELF-TEST QUESTIONS UNIT RELATIONSHIPS

Objectives Explain why section views are necessary. Explain and accurately draw a cutting- plane line and X-hatch (cross-hatch) lines. Recognize and appropriately use the following section view types on a drawing: Full section, Half section and Offset section.

Why Use Section Views? Section Views: are used to show inside features of objects that would otherwise be unseen.

Why Use Section Views? How can we dimension to these interior features without using the hidden lines?

Cutting-Plane Lines (CPL) Cross-Hatch Lines (X-Hatch) and Cross-Hatch Lines (X-Hatch)

CUTTING PLANE LINESTYLES This course Thick line Viewing direction ANSI standard Thick line Viewing direction JIS & ISO standard Thin line Viewing direction

SECTION LINING Section lines or cross-hatch lines are used to indicate the surfaces that are cut by the cutting plane. Section lines Drawn with thin dark lines usually at a 45 degree angle.

SECTION LINES SYMBOLS The section lines are different for each of material types. For practical purposes, the cast iron symbol is used most often for any materials. Cast iron, Malleable iron Steel Concrete Sand Wood

SECTION LINING PRACTICE The spaces between lines may vary from .125 inches for small sections to .25 inches for large sections. COMMON MISTAKE

SECTION LINING PRACTICE Section lines should not be drawn parallel or perpendicular to contour of the view. COMMON MISTAKE

Types of Section Views

FULL SECTION VIEW The view is made by passing the straight cutting plane completely through the entire part.

HALF SECTION VIEW The view is made by passing the cutting plane halfway through an object and removing a quarter of it.

HALF SECTION VIEW A center line is used to separate the sectioned half from the unsectioned half of the view. Hidden lines are omitted in the unsectioned half of the view.

OFFSET SECTION VIEW The view is made by passing the bended cutting plane completely through the part. Do not show the edge views of the cutting plane.

The Unit Organizer Section Views Basic Dimensioning The Big Picture Techniques used on Working Detail Drawings LAST UNIT/ Experience Basic Dimensioning CURRENT UNIT PRODUCE SECTION VIEW DRAWINGS NEXT UNIT/ Experience Auxiliary Views UNIT SCHEDULE 2-col note vocab Hand-outs worksheets Jeopardy Game Drawings Quizzes Unit Test Inside feature are not visible Principles & Exceptions Required When Section Views When omitted To show the inside features of mech. parts Have many types Are identified by Labeled by Are Types of Section Views Section Lines (X-Hatch) C.P.L. Elements & Placement Full section Half section Offset section Surfaces Direction Spacing Angle Material specifications Line types Arrows Labeling What determines the need for a section view? What are some types of section views? How are webs, ribs and spokes represented in a section view? And why? UNIT SELF-TEST QUESTIONS UNIT RELATIONSHIPS

Types of Section Views (continued)

Objectives Recognize and appropriately use the following section view types on a drawing: Removed section, Revolved section and Broken-out section. Explain how hidden lines are used in section views. Accurately draw Ribs, Webs, Spokes and Lugs in section views.

REMOVED SECTION VIEW Example : Revolved vs. removed sections. Revolved section Removed section

REMOVED SECTION VIEW Example : Situation that removed section is preferred. Poor Preferred Too messy !!

REMOVED SECTION VIEW Example : Multiple removed section views B A SECTION B – B SECTION A – A

REVOLVED SECTION VIEW Basic concept

REVOLVED SECTION VIEW Steps in construction Step 1 Given Edge view of cross-section Step 1 a. Assign position of cutting plane. b. Draw axis of rotation in front view.

REVOLVED SECTION VIEW Steps in construction Step 2 Given a. Transfer the depth dimension to the front view.

REVOLVED SECTION VIEW Steps in construction Step 3 Given a. Draw the revolved section. b. Add section lines.

REVOLVED SECTION VIEW Steps in construction Given FINAL PICTURE

REVOLVED SECTION VIEW Placement of revolved section 1. Superimposed to orthographic view. 2. Break from orthographic view. Break Superimposed

BROKEN-OUT SECTION VIEW The view is made by passing the cutting plane normal to the viewing direction and removing the portion of an object in front of it.

EXAMPLE : Comparison among several section techniques

The Unit Organizer Section Views Basic Dimensioning The Big Picture Techniques used on Working Detail Drawings LAST UNIT/ Experience Basic Dimensioning CURRENT UNIT PRODUCE SECTION VIEW DRAWINGS NEXT UNIT/ Experience Auxiliary Views UNIT SCHEDULE 2-col note vocab Hand-outs worksheets Jeopardy Game Drawings Quizzes Unit Test Inside feature are not visible Principles & Exceptions Required When Section Views When omitted To show the inside features of mech. parts Have many types Are identified by Labeled by Are Types of Section Views Section Lines (X-Hatch) C.P.L. Elements & Placement Full section Half section Offset section Surfaces Direction Spacing Angle Material specifications Line types Arrows Labeling Removed section Revolved section Broken-out section Aligned section What determines the need for a section view? What are some types of section views? How are webs, ribs and spokes represented in a section view? And why? UNIT SELF-TEST QUESTIONS UNIT RELATIONSHIPS

TREATMENT OF HIDDEN LINES Hidden lines are normally omitted from section views.

The Unit Organizer Section Views Basic Dimensioning The Big Picture Techniques used on Working Detail Drawings LAST UNIT/ Experience Basic Dimensioning CURRENT UNIT PRODUCE SECTION VIEW DRAWINGS NEXT UNIT/ Experience Auxiliary Views UNIT SCHEDULE 2-col note vocab Hand-outs worksheets Jeopardy Game Drawings Quizzes Unit Test Inside feature are not visible Principles & Exceptions Required When Section Views When omitted To show the inside features of mech. parts Ribs, Webs , Spokes, hidden lines & dimensions Have many types Are identified by Labeled by Are Types of Section Views Section Lines (X-Hatch) C.P.L. Elements & Placement Full section Half section Offset section Surfaces Direction Spacing Angle Material specifications Line types Arrows Labeling Removed section Revolved section Broken-out section Aligned section What determines the need for a section view? What are some types of section views? How are webs, ribs and spokes represented in a section view? And why? UNIT SELF-TEST QUESTIONS UNIT RELATIONSHIPS

Sectioning Principles

RIBS AND WEBS Ribs and Webs are thin, flat features of an object used for bracing or adding strength. Web Rib Rib

EXAMPLE : RIB Normal multiview drawing Normal section view Section view drawing with convention

EXAMPLE : WEB : flatwise cut Normal multiview drawing Normal section view Section view drawing with convention

EXAMPLE : WEB : crosswise cut

EXAMPLE : WEB : multiple section view

SPOKES Spoke: One of several bars attaching a hub to the rim of a wheel Hub Hub Spoke Rim Spoke Rim

Misleading impression EXAMPLE : SPOKE Misleading impression

LUGS Lug: An ear-like projection used for attachment.

LUGS Lug: An ear-like projection used for attachment.

EXAMPLE : LUG

CONVENTIONAL PRACTICE Omit the section lines on the section view of Rib, Web and Lug, if the cutting plane is passed flatwise through. Spoke, if the cutting plane is passed longwise through.

Aligned Section

Objectives RXxxXXx XxxxxxxxxxxxxxxxXxxx X xxx xxxxxxxxxxxx

DEFINITION Aligned section is a section view that is drawn by imaginary rotating the object’s features appeared in a principal view about symmetry axis

Gives the impression that this holes are at unsymmetrical position. Example : Hole Gives the impression that this holes are at unsymmetrical position.

Example : Hole

Example : Rib

Example : Ribs & Holes

Example : Spoke & Keyway Example : Aligned section of keyway

Example : Lug

Conventional Break

CONVENTIONAL PRACTICE For long objects that have to draw in a small scale to fit them on the paper, it is recommended to remove its long portion (which contains no important information) and draw the break lines at the broken ends.

Example SCALE 1:1

Example SCALE 2:1

STANDARD BREAK LINES Rectangular cross section Cylindrical Wood Rectangular cross section Metal Cylindrical cross section Tubular cross section

TO DRAW CYLINDRICAL BREAK

not to scale dimensions TO DIMENSION A BROKEN PART f16 Typical dimensioning method 800 f16 800 not to scale dimensions