Technical Drawing: Types, Importance, Lines, Format, and Scales
Concept of Drawing
Drawing is the art of representing natural and artificial forms, as well as forms designed by the human mind, on a surface.
- Artistic Drawing: Executed freely and with aesthetic purposes.
- Technical Drawing: Performed with various aids, according to conventional standards for practical purposes. Precision instruments are used.
Types of Technical Drawing
- Architectural Drawing: Includes all graphic representations through which the construction of buildings, houses, villas, churches, etc., can be carried out.
- Mechanical Drawing: Used for the representation of parts or machine parts, machinery, vehicles, machinery, and industrial plants.
- Electrical Drawing: Represents everything that relates to electrical connections, distribution switchboards, connections, etc.
- Electronic Drawing: Represents the constitution, components, and operation of appliances or electronic equipment.
- Geological Drawing: Represents the external profile or inner layers of the Earth or a particular area or mineral materials that compose it and their respective situations.
- Topographical Drawing: Shows the forms of a given piece of land through a series of signs set conventionally.
- Urban Drawing: Deals with matters relating to the organization and development of cities.
Importance of Technical Drawing
Technical drawing is a language, a form of communication. It is a universal language with which we can communicate with others, regardless of their spoken language. The graphic signs used are governed by international rules that make it more understandable.
For a technical drawing to represent an element of complete and effective communication, it must be clear, accurate, and contain all necessary data. All this depends on the experience of the artist in graphic expression, whether performing a sketch, a perspective, or a plane.
Lines in Technical Drawing
In drawing, lines have to be clear and defined in order to get a job with good presentation and a perfect disposition. The lines, as well as their thickness, will be a direct function of what the picture represents.
Depending on Their Shape
- Straight Line: All points are in the same direction.
- Ray: The part of the line limited at one end.
- Curve Line: Formed in a curve, but their points go in different directions.
- Broken Line: Consists of different straight lines that intersect each other and have different directions.
- Joint Line: Formed by straight lines and curves which, in turn, have different directions.
According to Their Position in Space
- Vertical Line: Perpendicular to the horizon line.
- Horizontal Line: Corresponds to the level when water is at rest.
- Inclined Line: Gives up its vertical and horizontal position and has a sloped end to one side.
According to the Relationship to Each Other
- Parallel Lines: Two or more lines in one plane that never intersect, even when extended.
- Oblique Line: Intersects a horizontal line at an angle that is not a right angle.
- Convergent Lines: Start from different points and join at another point when extended.
- Divergent Lines: Start from the same point and separate in different directions when extended.
- Perpendicular Line: Intersects a horizontal line at a right angle.
Format
The box within which all technical drawings are performed.
These boxes or formats are standardized, i.e., subject to certain standards or rules to be followed for processing.
For the preparation of the format, measure the raw format, the final format, and margins, using the standard series DIN or DIN A.
Scales
The scale is the relationship between an object drawn and the object in reality.
Scale is usually expressed as a fractional number whose numerator is unity, for example, 1:50. In this example, the real object is 50 times larger than the object drawn.
It is necessary to know the scale on which the drawings are done to establish their dimensions and calculate the area represented or the exact size of the object.
- Actual Value: How the object appears in reality.
- Chart Value: The value given to represent it in a flat format.
Types of Scales
- Enlargement: Used when representing small parts or details of a plan using an enlarged scale.
- Reduction: Used when the physical size of the plane is less than reality.
- Natural: 1:1