PRIN.
OF DRAFTING AND SHOP DRAWINGS - OD1641 - LESSON 1/TASK 3
To transfer an angular dimensional view from an orthographic view to an isometric
drawing, convert the angular dimensional value to its component linear value and
transfer the component values directly to the axis of the isometric drawing.
Figure 41 (on the previous page) illustrates this procedure by showing two angular
dimensions that have, been converted to their respective linear values, then
showing how these values are transferred to the isometric axis.
Normally, a
draftsman simply measures his full-sized orthographic views and then transfers the
information. If the information is not available, they make a supplementary layout
from which the necessary values may be measured. Supplementary layouts may be made
on any extra available piece of paper and should be saved for reference during the
checking of the drawing.
Figure 42 (on the following page) is the solution to the problem in figure 40 and
was derived by the following procedures:
Step 1.
To the best of your ability, make a freehand sketch of the solution (view
A).
Step 2. Using very light lines, lay out a rectangular box whose height, width, and
length correspond to the height, width, and length given in the orthographic view
(view B).
Step 3. Using very light lines, lay out the specific details of the object. Where
necessary, make supplementary layouts that furnish the linear component values
which can transfer to the isometric axis. In this case, the 30, component layout
is shown in figure 41 (on the previous page).
Step 4.
Erase all excess lines and smudges, check your work, then draw in all
lines to their proper color and pattern.
c. Holes in Isometric Drawings. There are two basic methods for drawing holes in
isometric drawings. One method is to use instruments and draw the holes by using
the four-center ellipse
52
Previous Page
