Greenfaulds High School

Higher: Graphic Communication

Sectioned Assembly

Vertical Section

Horizontal Section

Cutting Plane

Sections (Webs)

Half Section

Part Section

Revolved Section

Exceptions

• Sectioning is a process which should be used only to simplify or clarify a drawing.

•There are some engineering details that, if sectioned, lose their identity or would create a wrong impression. These items are never sectioned.

Exceptions

Exceptions

Exceptions

Engineering details that do not show hatching when sectioned• Nuts & Bolts

• Studs

• Screws

• Shafts

• Webs

• Ball Bearings & Ball Races

• Roller Bearings & Roller Races

• Keys

• Pins

• Gear Teeth

Hatching

Hatching is used in British Standards therefore it is also used throughout the Higher course.

• Hatching is drawn using type B lines.

• Equally spaced at 45 degrees

• Preferably not less than 4 mm apart

• However if hatching a small area spacing should be reduced but never less than 1mm

Hatching Single Component

When hatching separated areas of a single component the hatching lines should be in the same direction & with the same spacing.

Hatching Adjacent PartsWhere different sectioned parts meet on an assembly drawing, the direction of hatching should normally be reversed & staggered.

Hatching Adjacent PartsIn cases where hatching on adjacent parts must be at the same angle the lines should be staggered & may be more closely spaced.

Hatching Large Areas

Hatching of large areas may be limited to that part of the area which touches adjacent parts, or the outline of the large part.

Hatching Thin Material

Thin Material in section may be filled in, in preference to showing the material thickness out of scale & hatched. When adjacent parts are thus shown a clear space of not less than 1mm should be left between them.

B3 - Webbed Pulley AssemblyDimensioned orthographic views of the components and an exploded isometric view of a Webbed

Pulley arrangement are shown drawn to scale.On the worksheet provided, draw, full size;a) The elevation fully assembled. Show hidden detail.b) The section on A-A of the assembly.

Higher Graphic Communication: Technical Graphics 2 - Assembly DrawingØ

106

180

160

260

220

8 3863

130

15

22S

Q

Ø30

4 HOLES Ø14

90

78

48

8Ø

14

25

22SQ

Ø20

3590 14

Ø30

Ø88

46

Ø72

Ø46

20 (4 OFF)

R28

R65

14

22

R20

Ø20

Ø30

46

24 88

1512

Questions For B3 (TG2)

a. The elevation of the full assembly, showing all hidden detail.

b. The SECTION A-A, omitting hidden detail.

Dimensioned orthographic views together with an exploded isometric view of a webbed pulley as shown. On Worksheet B3 draw full size, using the given dimensions.