Points to be borne in mind while drawing orthographic projections from pictorial views:
1.
Since the pictorial view shows the object as it appears to the observer
from one direction only, it may not clearly show the hidden parts,
constructional details and the real shapes of its structures. All these
have to be imagined before making the orthographic views
2.
If a portion of a symmetrical object shown in the pictorial view is
hidden, the same should be assumed to be similar to the corresponding
visible part.
3. All holes, slots, grooves etc. should be assumed to run right through the object unless mentioned otherwise
4. If the radius of any curved portion is not specified, the same should be assumed suitably.
5.
While making the views, the longest face of the object or the most
informative contour may in general be treated as the front. The other
views are placed depending on the orientation of the front view
6.
It is not necessary that one view must be completed before proceeding
to the other. The views are to be carried along together
7. Unless otherwise specified; front, top, and right side views should be selected for the description of models and pictures
8.
An intersection of two surfaces, edges of surfaces and the surface
limits should be shown by using full lines while the hidden features are
to be shown by dashed lines
9.
Each view must contain all the lines of the object, both visible and
hidden. The centre lines of holes, cylindrical parts of objects must be
clearly indicated. The centre of a circle is shown as the intersection
of two mutually perpendicular centre lines. For parts with an axis, such
as a cylinder or a cone, the axis is drawn as the centre line.
10.
If a hidden edge coincides with a visible edge, draw the full line.
When a centre line coincides with a hidden edge, draw a dashed line.
Thus, give consideration to the precedence of lines
11. In orthographic views, a surface may appear as an area or as a line. An edge may appear as a line or as a point.
Orthographic Drawing Practice Problems 1:
Orthographic Drawing Practice Problem Solution 1:
Orthographic Drawing Practice Problems 2:
Orthographic Drawing Practice Problem Solution 2:
Orthographic Drawing Practice Problems 3:
Orthographic Drawing Practice Problem Solution 1:
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