Transcript Sketching - ETP - Engineering Technology Pathways

Sketching
By
Brian Nettleton
This material is based upon work supported by the National Science Foundation under Grant No. 0402616.
Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and
do not necessarily reflect the views of the National Science Foundation (NSF).
Oblique
In an Oblique sketch, the
front view is flat and
sketched true size. The
depth is sketched at a 45
degree angle. The lines on
the grid paper are used for
reference. Each square on
the grid is ¼” and the lines
are vertical, horizontal, and
at a 45 degree angle.
Starting at the lower right
hand corner of the sketch,
sketch the length of the front
view, the depth of the object
on the 45 degree angle line,
and the height of the front
right corner.
Oblique
Sketch the front
view of the object.
These lines should
be horizontal and
vertical.
Oblique
After the front view is
complete, begin creating the
depth by sketching the side
and top views. It is
sometimes easier to sketch
the 45 degree angle lines
first and then add the vertical
and horizontal lines to form
the back of the object.
Oblique
To make the sketch more
presentable, erase any
stray lines and clean up
the corners to make them
sharp.
Isometric
An Isometric grid has vertical lines
for height and 30 degree angle lines
for width and depth. One way to
create a sketch is to use the total
height, width, and depth, and make
a box, Start at the front corner of the
object and sketch the lines for the
height, width and length. Now
square off the front, top, and sides of
the box.
Isometric
Sketch in the lines that
define the side view. The
box helps to show where
the different views belong
in the sketch.
Isometric
Now sketch the lines that
define the front and top views.
Isometric
To finish up the sketch,
erase the construction
lines and cleanup the
corners.
Orthographic Projection
Orthographic projection is a 2dimensional representation of a
3-dimensional object. When
sketching an Orthographic
Projection drawing, the front view
needs to be sketched first. Any
side of the object can be
considered the front view. The
side that shows the most detail
and the fewest hidden lines
should be the first choice. All of
the views should be sketched
actual size or the same scale.
Orthographic Projection
The lines that define the right
side of the object need to be
projected to the right side of the
paper. The vertical lines that
define the width of the object
need to be sketched next.
Orthographic Projection
The side view is now completed.
The top view can be done
without any further measuring.
Above the side view sketch a line
at a 45 degree angle. This is
called 3rd angle projection.
Sketch construction lines from
the sides of the side view up to
the angled line.
Orthographic Projection
At the points where the vertical
construction lines intersect the
angled line, sketch horizontal
lines over the top of the front
view. Sketch vertical
construction lines from the front
view at the points that define the
top view up through the
horizontal lines.
Orthographic Projection
Darken all of the lines
that define the object in
each view and erase all
of the construction lines.
Standards and Benchmarks
Standard 11: Students will develop abilities to apply the design
process.
J. Make two-dimensional and three-dimensional representations of the
designed solution.
Standard 17: Students will develop an understanding of and be
able to select and use information and communication
technologies.
K. The use of symbols, measurements, and drawings promotes clear
communication by providing a common language to express ideas.