Real-Life Communication
Mechanical drafters help to transform ideas into reality.
This is a complicated process that requires strong communication skills.
"The drafter needs to understand what the engineer or designer wants,
implement it, and communicate any problems or concerns if they occur," says
Charles Bales, a professor of mechanical drafting and design.
"In
many cases you will also need to communicate with production and manufacturing,"
says Bales. "The communication is technical and precise."
Often, mechanical
drafters must attach written documents with their drawings to explain what
they’re doing to non-drafters. To ensure that the idea is designed correctly,
the written communications must be accurate.
You're a mechanical drafter,
and you’ve been given an assignment to revise and edit a piece of technical
writing. As you study this document, check for spelling and punctuation errors,
mistakes in grammar and the logical presentation of information.
Sketching
Proper
sketching is very important to the communication process. Multiple sloppy
sketch marks are not proper sketching in this sense. Proper sketching is legible
freehand drawing with crisp dark lines. Guidelines for primary geometry follow:
Sketching
Straight Lines
Determine your start and end points.
Begin your stroke, but be sure to eye the end point. Start with a very faint
construction line, then go over it when you are satisfied with the direction
and smoothness of it
Keep in mind proper line types.
Sketching
Circles
1. Trammul Method
Mark off
the radius of the circle on a piece of paper. Hold one end of the paper radius
at the center of the circle mark off the other end of the radius several times
at different intervals and sketch the circle through these marks.
2. Enclosing Square Method
Lightly
sketch a square that will enclose the circle (i.e. a square with sides equal
to the diameter of the circle) Draw the center lines through the midpoints
of the sides of the square. Then draw the circle making sure that it is tangent
to the square where the centrelines intersect.
Sketching Ellipses
Ellipsis can be
sketched using a method similar to the Enclosing Square Method described above
for sketching circles. Another method of sketching ellipses is to make several
LIGHT elliptical strokes where the ellipse is desired, erase any stray strokes,
draw darkly over the desired strokes and clean up the rest.
3.
Semi-mechanical Method
Hold two pencils together
such that one pencil acts as the needle-point leg of a compass. Place this
pencil point at the center of the circle. Place the other pencilpoint at the
radius of the circle. The paper can then be rotated about the center point,
and the other pencil will describe the circle.
(This page was used with the
permission of Jon Smejkal of the department of general engineering at the
University of Illinois)