2. OBJECTIVES
1. Identify different working drawings
according to technical drawing.
2. Draw and sketch objects according to
job requirements.
3. Value the importance of working
drawing in a project proposal.
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3. WORKING DRAWING
A working drawing is a part of production information provided by
the designers to the construction team to help construct a project.
Production information is of two types:
working drawing and construction drawing. Working
drawings provide graphical, and dimensioned information.
4.
5. PICTORIAL
DRAWING
○ A view of an object (actual or imagined) as it would be seen by an observer
who looks at the object either in a chosen direction or from a selected point of
view. It shows the three dimensions of the object, height, width, and depth.
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8. 8
OBLIQU
E
- a pictorial drawing that one surface is
parallel to plane of projection
- An oblique sketch has a more focus on the
front side of an object or the face.
9. 9
ISOMETRI
C
- a pictorial drawing that is
drawn in equal
measurement
- (3D) 3 dimensional
drawing ( width, height
and depth)
12. STEPS IN
SKETCHING AN
ISOMETRIC
BOX
○ 3. Determine the width and length of the box
and then draw a vertical line
○ 4. Draw a left and right axis to the
determined height of the box.
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13. STEPS IN
SKETCHING AN
ISOMETRIC
BOX
○ 5. Project a line parallel to the left and right
axis
○ 6. Label the box to determine the top, front
and the right-side view
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14. 14
ASSEMBLY DRAWING
Drawings that give a big picture view of the completed project and
show: a list of all the parts or components, the general arrangement of these
components, how they fit together, and. the overall dimensions – but not the
specifics.
15. 15
DETAILED DRAWING
Provide a detailed description of the
geometric form of a part of an object
such as a building, bridge, tunnel,
machine, plant, and so on. They tend to
be large-scale drawings that show
in detail parts that may be included in
less detail on general
arrangement drawings
16. 16
ORTHOGRAPHIC PROJECTION
Orthographic projection is a means of
representing three-dimensional
objects in two dimensions. It is a
form of parallel projection, in which
all the projection lines are orthogonal
to the projection plane, resulting in
every plane of the scene appearing in
affine transformation on the viewing
surface
17. Comparing Projections
• Perspective drawings look nicer when
used by an artist, but…
• Isometric, oblique and multi-view
drawings give more accurate information
when used in technical drawing.
• Isometric drawings show accurate
dimensions, but distorted angles.
• Oblique drawings give accurate
dimensions for one side only.
• Orthographic (multi-view) are the best
choice for most technical drawing.
Oblique
Orthographic
(multi-view)
34. 34
11. The overall dimension should
always be given. It should be placed
outside of smaller dimensions and
be the farthest from the part.
12. Do not duplicate dimensions
and avoid using unnecessary
dimensions.