Technical drawing of a certification listing for a firestop system

A drafting table with drafting machine

A drafting table

Technical pens and pencils

Another example of a drafting table with board cover and parallel rule

A bow compass

Technical drawing , also known as drafting, is the "art and practice of creating accurate representations of objects for technical, architectural and engineering needs. A Certification listing is a document against which a field installation is compared to make sure that it complies with a regulation such as a Building code. A firestop is a Passive fire protection System of various components used to seal openings and joints in fire-resistance rated wall System (from Latin systēma, in turn from Greek systēma is a set of interacting or interdependent Entities, real or abstract Industrial Arts is an umbrella term originally conceived in the early 20th century to describe educational programs which featured fabrication of objects in wood and/or metal using a variety Plans are a set of two-dimensional diagrams or drawings used to describe a place or object or to communicate building or fabrication instructions The term architecture (from Greek αρχιτεκτονικήarchitektoniki) can be used to mean a process a profession or documentation Engineering is the Discipline and Profession of applying technical and scientific Knowledge and " This definition includes the various fields and technologies underpinning electronics, which has in turn revolutionized the art with new tools in the form of Computer Aided Design. A practitioner of the craft is known as a draftsman, (or draughtsman in the UK), and recently, "drafter". In some fields, particularly electronics, draftsmen are also known by the ambiguous "designer", who's job would be distinct and separate from the engineers specifying and working out the design details. In short, draftsman are communicators that are part of an engineering team charged with producing specialty documentation packaged as a design, which following the standards of the field, can be understood by others with the same training. Most technical fields, even those not generally considered as highly techical such as plumbing have their own conventions and practices—the symbols and shorthand notations that convey a lot of information in minimal space. Plumbing, from the Latin plumbum for Lead, is the skilled trade of working with pipes, tubing and Plumbing fixtures for All of these are specialized communications. The foundation of the modern computerized world is directly founded on the accurate scale drawings on synthetic vellums that enabled the integrated circuits and printed circuit boards that underly modern electronics, as discussed in the section below Before CAD. Vellum (from the Old French Vélin for "calfskin" is mammal skin prepared for writing or printing on single pages scrolls codices or books The development and progress of the industrial revolution on the whole depends on the art, usually taught and classed as one of the Industrial arts. Industrial Arts is an umbrella term originally conceived in the early 20th century to describe educational programs which featured fabrication of objects in wood and/or metal using a variety Engineering and architectural students are introduced to the art, generally in freshman level courses.

Today the mechanics of the drafting task have been greatly accelerated through the use of CADD systems, but regardless of whether a draft is drawn by hand or with computer assistance, the field-use-drawing must be reproducible with a version control system to maintain authorized and approved changes to the master document (or computer files, the modern analog). Architectural Reprography covers a variety of technologies media and supports typically used to make multiple copies of original technical drawings and related records created

Manual drafting

The basic drafting procedure is to place a piece of paper (or other material) on a smooth surface with right-angle corners and straight sides—typically a drafting table. A drawing board (also drawing table, drafting table or architect's table) is in its antique form a kind of multipurpose Desk which can be A sliding straightedge known as a T-square is then placed on one of the sides, allowing it to be slid across the side of the table, and over the surface of the paper. A straightedge is a tool with an accurately straight edge used for drawing or cutting straight lines or checking the straightness of lines A T-square is a Technical drawing instrument primarily a guide for drawing Horizontal lines on a Drafting table.

"Parallel lines" can be drawn simply by moving the T-square and running a pencil or technical pen along the T-square's edge, but more typically the T-square is used as a tool to hold other devices such as set squares or triangles. A technical pen is a specialized instrument used by an Engineer, Architect, or draftsperson (British draughtsperson) to make lines of constant In American English, a set square is an alternative name for a T-square. In this case the draftsman places one or more triangles of known angles on the T-square—which is itself at right angles to the edge of the table—and can then draw lines at any chosen angle to others on the page. Modern drafting tables (which have by now largely been replaced by CAD stations) come equipped with a parallel rule that is supported on both sides of the table to slide over a large piece of paper. Because it is secured on both sides, lines drawn along the edge are guaranteed to be parallel.

In addition, the draftsperson uses several tools to draw curves and circles. Primary among these are the compasses, used for drawing simple arcs and circles, and the French curve, typically a piece of plastic with complex curves on it. A compass or pair of compasses is a Technical drawing instrument that can be used for inscribing Circles or arcs They can also be used as A French curve is a template made out of Plastic, Metal or Wood composed of many different Curves It is used in manual drafting to A spline is a rubber coated articulated metal that can be manually bent to most curves. A spline consists of a long strip fixed in position at a number of points that relaxes to form a smooth curve passing through those points

Drafting templates assist the draftsperson consistently recreate recurring objects in a drawing without having to reproduce the object from scratch every time. This is especially useful when using common symbols; i. e. in the context of stagecraft, a lighting designer will typically draw from the USITT standard library of lighting fixture symbols to indicate the position of a common fixture across multiple positions. Stagecraft is a generic term referring to the technical aspects of theatrical film and video production The United States Institute for Theatre Technology (USITT is a membership organization which aims to advance the skills and knowledge of Theatre, Entertainment and Templates are sold commercially by a number of vendors, usually customized to a specific task, but it is also not uncommon for a draftsperson to create their own templates.

This basic drafting system requires an accurate table and constant attention to the positioning of the tools. A common error is to allow the triangles to push the top of the T-square down slightly, thereby throwing off all angles. Even tasks as simple as drawing two angled lines meeting at a point require a number of moves of the T-square and triangles, and in general drafting can be a time consuming process.

A solution to these problems was the introduction of the mechanical "drafting machine", an application of the pantograph (sometimes referred to incorrectly as a "pentagraph" in these situations) which allowed the draftsman to have an accurate right angle at any point on the page quite quickly. A pantograph (from Greek roots παντ- 'all every' and γραφ- 'to write' from their original use for copying writing is a mechanical linkage connected in a These machines often included the ability to change the angle, thereby removing the need for the triangles as well.

In addition to the mastery of the mechanics of drawing lines, arcs and circles (and text) onto a piece of paper—with respect to the detailing of physical objects—the drafting effort requires a thorough understanding of geometry, trigonometry and spatial comprehension, and in all cases demands precision and accuracy, and attention to detail of high order.

Although drafting is sometimes accomplished by a project engineer, architect—or even by shop personnel such as a machinist—skilled drafters (and/or designers) usually accomplish the task and are always in demand to some level. A machinist is a person who uses Machine tools to make or modify parts primarily Metal parts a process known as Machining.

Before CAD

Before CAD, master technical drawings were produced on a either paper or vellum within a technical field. There was great need to be able to "pick off a dimension" from a drawing accurately, requiring in turn a need for extremely accurate master drawings. While the blueprint process enabling 1:1 scaled copies dates from the 1840s, large accurate-to-scale drawings were technologically handicapped because quality natural vellums were limited in size and expensive, paper shrinks and expands drastically with humidity, and initial accuracy quickly degraded in the field situation where such documents made or broke a product.

The problem was resolved in part by the invention of a modern imitation "vellum" made from plasticized cotton. Cotton is a soft staple Fibre that grows around the seeds of the cotton plant ( Gossypium sp Like natural vellum, the synthetic is more dimensionally stable than a linen or paper sheet, which is frequently critical in the development of large scaled drawings and plans such as Blueprints. A blueprint is a type of paper-based reproduction usually of a Technical drawing, documenting an Architecture or an Engineering design It was also extremely important in that reproduction technology for dissemination of the plans as like a high quality natural vellum, it could be produced in a thin enough sheet to be virtually transparent to strong light enabling a source drawing to be used directly in the blueprint reproductions of field-used drawings. A blueprint is a type of paper-based reproduction usually of a Technical drawing, documenting an Architecture or an Engineering design

During the last century, antedating integrated CAD and modern laser printing which only came about after development of VLSI based microprocessors, synthetic vellums were at the heart of any large engineering or architectural project. A laser printer is a common type of Computer printer that rapidly produces high quality text and graphics on plain paper A microprocessor incorporates most or all of the functions of a Central processing unit (CPU on a single Integrated "Blueprints" are a copy of such master drawings, and are used as the field and day to day references originally drafted on the vellum masters. Large paper drawings require an additional step (tracing paper amenable to letting light pass through it, and hence is more error prone)

Drafting vellums eventually came to be standardized into a series of drawing sizes known as "A-size", "B-size", . . . , "G-size" drawings which doubled in sheet size area with every step. Indeed, VLSI microcircuits themselves were layed out on such vellums layer by layer, "masked" to the dimensions of the given layer (a tracing step of sorts), and those masks photographed, all to scale in very large specialty light boxes. In photography a lightbox has several applications One is a container with several Lightbulbs and a pane of Frosted glass on the top The negatives (known as photomicrographs, photo+micro+graph) thus obtained, were then step-reproduced in carefully aligned arrays and etched onto a glass plate Master of that layer.

In short huge dimensional drawings representing the guts of an integrated circuit were scaled down optically and reproduced to produce each layer of the computer chips which eventually came to be part of the systems which replaced the vellums that made the CAD technology possible. Large scale hand drafted drawings in today's world are unusual and rare, but the old technology still exists and is the foundation upon which the modern computerized world is built. It is still common for engineers and architects to work out the details of a concept, so called "Sketches" on paper drawings before going to CAD. Even in the heyday of hand drafted blueprint technology technical workers found that working with a sketch was an aid to clear thinking.

CAD

Main article: Computer-aided design

Today, the mechanics of the drafting task have largely been automated and accelerated through the use of Computer Aided Design systems (CAD).

Projections

Common views of objects include:

External links

• Trazoide. Dibujo técnico con ejercicios y teoría practica in Spanish. A floor plan ( floorplan) in Architecture and Building engineering is a Diagram, usually to scale, of the relationships between rooms A bird's-eye view is a View of an object from above as though the observer were a Bird, often used in the making of Blueprints, Floor plans Orthographic projection is a means of representing a three- Dimensional (3D object in two dimensions (2D Axonometric projection ("to measure along axes" is a technique used in orthographic pictorials Isometric projection is a form of Graphical projection —more specifically an Axonometric projection. Dimetric projection is a form of Axonometric projection, in which its direction of viewing is such that two of the three axes of space appear equally foreshortened of which Trimetric projection is a form of Axonometric projection, where the direction of viewing is such that all of the three axes of space appear unequally foreshortened This article discusses imaging of three-dimensional objects For an abstract mathematical discussion see Projection (linear algebra. Perspective (from Latin perspicere to see through in the graphic arts such as drawing is an approximate representation on a flat surface (such as paper of an image as it is perceived Perspective (from Latin perspicere to see through in the graphic arts such as drawing is an approximate representation on a flat surface (such as paper of an image as it is perceived An engineering drawing is a type of Technical drawing, used to fully and clearly define requirements for engineered items and is usually created in accordance An auxiliary view is an angle at which one can view an object that is not one of the primary views for an Orthographic projection. Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula.
• Technical drawing exercise
• Examples of cubes drawn in different projections
• Animated presentation of drawing systems used in technical drawing (Flash animation)