Presentation on theme: "WHAT ARE THEY ? SEE SOME EXAMPLES HOW DO YOU DO IT ? EXERCISES."— Presentation transcript:
WHAT ARE THEY ? SEE SOME EXAMPLES HOW DO YOU DO IT ? EXERCISES
WHAT ARE THEY ? They are used on drawings to allow you to see the inside detail of an object more clearly than hidden detail can. Sectional views show the internal construction details which may not be as obvious from a normal drawing.
SOME EXAMPLES OF SECTIONAL VIEWS
HOW DO YOU DO IT ? CUTTING PLANES. The cutting plane shows where the object is sliced through. It is shown as a dashed line with thick ends. A A The cutting plane has arrows to show the direction of viewing and letters to distinguish it from other cutting planes.
The cutting plane shows where the object is sliced. The direction of the viewing is indicated by the arrows. The part of the object BEHIND the arrows is removed and the sectional view is left. A A A A
To show the surface that has been cut the section is cross hatched. This means that lines at 45º approximately 5mm apart are drawn on the cut surface. A A
Hatching rules. A web is used to strengthen or support various engineering components. Webs.
Hatching rules. Webs are never hatched when they are sectioned length ways. A A
Hatching rules. A A Sectional A-A demonstrates that you DO NOT cross hatch a web that is sectioned along its length.
Hatching rules. Sectional B-B demonstrates that you DO cross hatch a web that is sectioned across its length. B B
Hatching rules. Hidden detail is never shown on a sectional view. Note no hidden detail is shown. You do not show sectional views through nuts, bolts, washers, screws and shafts.
Ø 5 X X ELEVATION PLAN SECTIOAL END ELEVATION ON X-X Ø 10 Ø 29 Ø 39 Redraw the elevation and plan of the toggle used at the end of a pull cord switch. Draw the sectional end elevation on X-X. Leave 50mm in between views
R50 Redraw the elevation and plan of a CD spindle. Draw the sectional end elevation on X-X. Leave 50mm in between views. X X R40 R30 R10 X X
Hatching rules. Sectioned areas that are adjacent to each other should be cross hatched in different directions, still at 45 º.