PRIN. OF DRAFTING AND SHOP DRAWINGS - OD1641 - LESSON 1/TASK 2
FIGURE 19.
A PROTRACTOR WITH SOME
SAMPLE MEASUREMENTS.
f. Templates. Templates are patterns cut into shapes useful to a draftsman. They
save drawing time by enabling the draftsman to accurately trace a desired shape.
Some templates provide shapes that are difficult to draw with conventional drawing
tools (very small circles, for example). Other templates provide shapes that would
be tedious and time-consuming to layout and draw (ellipses, for example).
The most common template used in
mechanical drafting is the circle template. The
holes of a circle template are
labeled by diameter size and are generally made
slightly oversized to allow for
lead thickness.
Always check a circle template
before initial use to see if lead
allowance has been included.
To use a circle template, locate the center point of the future circle with two
lines 90, to each other. Align the template with the two 90, lines by using the
four index marks printed on the edge of the template hole.
Draw in the circle.
Keep
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