Chapter 5Conventional Practice

in Section View

TOPICS

Section view representationpof rib, web, spoke and lug.

Aligned sectiong

Conventional breakConventional break

Section view representation ofp

rib web spoke and lugrib, web, spoke and lug

TERMINOLOGYRib and Web are thin, flat feature of an object that acts as a str ct ral s pportacts as a structural support.

Rib RibWeb

Rib Rib

TERMINOLOGY

Spoke is the rod radiating from the hub to the rimf h lof a wheel.

HubHub

Hub

Spoke

Spoke

Rim

RimSpoke

TERMINOLOGYLug is an ear which is built as portion of an object f tt h tfor attachment.

CONVENTIONAL PRACTICE

Omit the section lines on the section view of

Rib, Web and Lug, if the cutting plane is d fl t i th hpassed flatwise through.

Spoke if the cutting plane is passed longwise Spoke, if the cutting plane is passed longwisethrough.

EXAMPLE : RIB

Normal multiview drawing

Normal section view

Section view drawing with gconvention

EXAMPLE : WEB : flatwise cut

Normal multiview drawingg

Normal section view

Section view drawing withSection view drawing with convention

EXAMPLE : WEB : crosswise cut

EXAMPLE : WEB : multiple section view

EXAMPLE : SPOKE

Misleading impression

EXAMPLE : LUG

Ali d S tiAligned Section

DEFINITIONAligned section is a section view that is drawnb i i t ti th bj t’ f tby imaginary rotating the object’s featuresappeared in a principal view about symmetryaxis

Example : HOLE

Gives the impression that this holes are at unsymmetrical position.

Example : HOLE

Example : RIB

Example

Example : Aligned section of keywayExample

Example : Aligned section of lug

C ti l B kConventional Break

CONVENTIONAL PRACTICE

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

Example

SCALE 1:1SCALE 2:1SCALE 1:1SCALE 2:1

STANDARD BREAK LINES

WoodRectangularcross section

Wood

Metal

CylindricalCylindricalcross section

Tubularcross section

TO DRAW CYLINDRICAL BREAK

R

30o

30o

R/3 R/3R/3 R/3

TO DIMENSION A BROKEN PART16

800Typical method

16

800

Use not to scale dimensions