Properly Create Section - Engineering Design Graphics - Lecture Slides, Slides of Engineering Drawing and Graphics

Download Properly Create Section - Engineering Design Graphics - Lecture Slides and more Slides Engineering Drawing and Graphics in PDF only on Docsity!

Learning Goals

• Properly Create Section (Cut-Away)

Views to Show Internal Features Of

Objects That Are Not Easily

Understood In Standard

Orthographic Projection View

Drawings

Learning Goals cont

• Use and/or Apply

• How & Where to Construct the Cutting Plane Line
• Section Lines (a.k.a. “Hatch Lines”)
• Several Types of Section Drawings

Full Section

• The cutting plane passes completely

through the part as a single flat plane

Half Section

• The cutting plane only passes half way through the part
• The other half is drawn as usual
• Hidden lines are not shown on either half of the part
• A center line is used to separate the two halves
• Mostly used on cylindrical parts

Offset Section cont

• The actual part would show a new visible line (at

the edge) at the bend in the cutting plane

• Since the cutting plane bend is arbitrary, do not show the line representing this bend in the sectioned drawing
• Hidden lines

are NOT

shown

• Be sure to

include object

lines BEHIND

the cutting plane

Broken Out Section

• Only a portion of the view is sectioned
• A jagged break line is used to divide the

sectioned and unsectioned portion of the drawing

Revolved Section Caveats

 Superimposition of Rev-Sec

requires Removal of All

ORIGINAL Lines

Underneath the Section

 Retain the TRUE-

SHAPE of the Rev-Sec

Regardless of the Line-

Direction in the Visible-

View

Removed Section

• Similar to the revolved section except that the sectioned drawing is not superimposed on the drawing but placed adjacent to it
• The view and the cutting plane are labeled (Sec. A-A)
• The removed section may be drawn at a different scale - Very Useful for Detailing Small Parts or Features

Intersections - PortHoles

c) The Offset of the intersection

from the Visible Lines is

SMALL or Negligible

• Can DisRegard the True Projection and Align to Vis-Lines

d) Larger Intersections

• For the Smaller Hole Use Tube OD (R 1 ) and ID (r 1 ) Arc at Depth Found by True Projection
• For Hole K, r (^) k = r 1 , SemiEllipses of Intersection appear as Straight-Lines

Special Sections

• There are special rules (conventions) that are followed to make some parts more understandable
• Some features are rotated to their TRUE RADIAL position in sectioned views
• The object is difficult to understand using standard multiview drawings where hidden lines are used to represent internal features

Special Sections cont

• Ribs/Webs are not

sectioned when the

cutting plane

passes through them

lengthwise

• Ribs are sectioned

if the cutting plane

passes through them

at other orientations

Special

Sections

cont

• The side view is replaced by a full section view
• The cutting plane shown in the Front view shows the direction of the line of sight
• The holes and ribs have been revolved to their true radial position
• The ribs are not sectioned in this orientation
• The section lines are all drawn at the same angle since the object is one solid part

Demo – Pipe Intersection

• Let’s make a Cross

Section for a Drilled,

Thick-Walled Pipe

Final Result