Although many stationary suppliers will offer drafting supplies, the better option is getting them from a specialist store, because this way you are more likely to get everything you need at a better price. Technical drawing specialists, engineers and designers all use special equipment, and instruments for their trades, and the convenience of the internet allows you to find what you need with ease.
Technical buyers can keep drawing offices well supplied so that architects and engineers that draw blueprints and plans can complete their drawing products efficiently. Drawing of building and machine plans and blueprints are done using measuring instruments like protractors, triangles, compasses, and other specialized tools for the drawing trade.
The highest quality drafting supplies can be costly, making it sensible to do comparisons in prices at different stores online. If you want to upgrade your offices invest in the newest furniture like drawing boards and easels, to make the work so much easier for design engineers. With new digital technology projects can be made even simpler with CAD software, which can be used on computers for any designs.
Accurate plans are vital for any project and even the slightest errors can affect the outcomes. This is why only the best accessories are used in this profession by architects, and construction engineers, or anyone that creates blueprints for projects. It is frustrating having to buy specific items at different outlets, so once a suitable supplier is located online it is worth while book marking for future references.
After the plans have been designed on computer assisted drawing programs called CAD, they still have to be transferred onto blueprint paper to use in the field. This will either be done by special printing machines, or the engineer will draw them onto suitable drawing materials which are lastly treated with chemicals to make them tough.
Any plans for a project must be accurate to the finest decimal point otherwise there could be serious repercussions especially in buildings and electrical plant. This is why it makes perfect sense buying the best tools and instruments possible. Instead of getting it from different suppliers, find one that has everything you want for more convenience. Shopping around at different stores is best considering these products are extremely expensive.
Artists will also find superior quality tools for their work at suppliers that offer equipment and accessories for draftsmen and architects. With the correct furniture and tools any project can easily be completed successfully. Find sketchpads, quality lighting, cutters, and graph plotting paper, plus writing instruments in top well known brand names online, that can be used with complete confidence.
To make the life easier for architects and technical drawing professionals, there are ergonomically designed desks and chairs fitted with the basic instruments which can also be found at suppliers. Once you found Drafting Supplies store that has everything you need, then in future when you need to replace consumables, you will know where to shop. This will save you time and money for finding suitable equipment for all your drawing projects
Looking for Drafting Tables and Drafting Supplies? Look Canada’s online shop for top brands for your creative and workspace needs.
Tuesday, May 31, 2011
Monday, May 30, 2011
Engineering drawing
An engineering drawing, a type of technical drawing, is created within the technical drawing discipline, and used to fully and clearly define requirements for engineered items.
1 Overview
2 Engineering drawings: common features
2.1 Line styles and types
2.2 Multiple views and projections
2.2.1 Orthographic projection
2.2.2 Auxiliary projection
2.2.3 Isometric projection
2.2.4 Oblique projection
2.2.5 Perspective
2.3 Scale
2.4 Showing dimensions
2.5 Sizes of drawings
2.6 Technical lettering
3 Example of an engineering drawing
4 See also
5 References
6 Further reading
7 External links
Overview
Engineering drawings are usually created in accordance with standardized conventions for layout, nomenclature, interpretation, appearance (such as typefaces and line styles), size, etc. One such standardized convention is called GD&T.
The purpose of such a drawing is to accurately and unambiguously capture all the geometric features of a product or a component. The end goal of an engineering drawing is to convey all the required information that will allow a manufacturer to produce that component.
Engineering drawings used to be created by hand using tools such as pencils, ink, straightedges, T-squares, French curves, triangles, rulers, scales, and erasers. Today they are usually done electronically with computer-aided design (CAD).
The drawings are still often referred to as "blueprints" or "bluelines", although those terms are anachronistic from a literal perspective, since most copies of engineering drawings that were formerly made using a chemical-printing process that yielded graphics on blue-colored paper or, alternatively, of blue-lines on white paper, have been superseded by more modern reproduction processes that yield black or multicolour lines on white paper. The more generic term "print" is now in common usage in the U.S. to mean any paper copy of an engineering drawing.
The process of producing engineering drawings, and the skill of producing them, is often referred to as technical drawing or drafting, although technical drawings are also required for disciplines that would not ordinarily be thought of as parts of engineering.
[edit] Engineering drawings: common features
Drawings convey the following critical information:
Geometry – the shape of the object; represented as views; how the object will look when it is viewed from various standard directions, such as front, top, side, etc.
Dimensions – the size of the object is captured in accepted units.
tolerances – the allowable variations for each dimension.
Material – represents what the item is made of.
Finish – specifies the surface quality of the item, functional or cosmetic. For example, a mass-marketed product usually requires a much higher surface quality than, say, a component that goes inside industrial machinery.
[edit] Line styles and types
Standard engineering drawing line typesA variety of line styles graphically represent physical objects. Types of lines include the following:
visible – are continuous lines used to depict edges directly visible from a particular angle.
hidden – are short-dashed lines that may be used to represent edges that are not directly visible.
center – are alternately long- and short-dashed lines that may be used to represent the axes of circular features.
cutting plane – are thin, medium-dashed lines, or thick alternately long- and double short-dashed that may be used to define sections for section views.
section – are thin lines in a pattern (pattern determined by the material being "cut" or "sectioned") used to indicate surfaces in section views resulting from "cutting." Section lines are commonly referred to as "cross-hatching."
Lines can also be classified by a letter classification in which each line is given a letter.
Type A lines show the outline of the feature of an object. They are the thickest lines on a drawing and done with a pencil softer than HB.
Type B lines are dimension lines and are used for dimensioning, projecting, extending, or leaders. A harder pencil should be used, such as a 2H.
Type C lines are used for breaks when the whole object is not shown. They are freehand drawn and only for short breaks. 2H pencil
Type D lines are similar to Type C, except they are zigzagged and only for longer breaks. 2H pencil
Type E lines indicate hidden outlines of internal features of an object. They are dotted lines. 2H pencil
Type F lines are Type F[typo] lines, except they are used for drawings in electrotechnology. 2H pencil
Type G lines are used for centre lines. They are dotted lines, but a long line of 10–20 mm, then a gap, then a small line of 2 mm. 2H pencil
Type H lines are the same as Type G, except that every second long line is thicker. They indicate the cutting plane of an object. 2H pencil
Type K lines indicate the alternate positions of an object and the line taken by that object. They are drawn with a long line of 10–20 mm, then a small gap, then a small line of 2 mm, then a gap, then another small line. 2H pencil.
[edit] Multiple views and projections
Image of a part represented in First Angle Projection
Symbols used to define whether a projection is either Third Angle (right) or First Angle (left).
Isometric view of the object shown in the engineering drawing further down the page.Main article: Graphical projection
In most cases, a single view is not sufficient to show all necessary features, and several views are used. Types of views include the following:
[edit] Orthographic projection
The orthographic projection shows the object as it looks from the front, right, left, top, bottom, or back, and are typically positioned relative to each other according to the rules of either first-angle or third-angle projection.
First angle projection is the ISO standard and is primarily used in Europe. The 3D object is projected into 2D "paper" space as if you were looking at an X-ray of the object: the top view is under the front view, the right view is at the left of the front view.
Third angle projection is primarily used in the United States and Canada, where it is the default projection system according to BS 8888:2006, the left view is placed on the left and the top view on the top.
Not all views are necessarily used, and determination of what surface constitutes the front, back, top and bottom varies depending on the projection used.
[edit] Auxiliary projection
An auxiliary view is an orthographic view that is projected into any plane other than one of the six principal views.[1] These views are typically used when an object contains some sort of inclined plane. Using the auxiliary view allows for that inclined plane (and any other significant features) to be projected in their true size and shape. The true size and shape of any feature in an engineering drawing can only be known when the Line of Sight (LOS) is perpendicular to the plane being referenced.
[edit] Isometric projection
The isometric projection show the object from angles in which the scales along each axis of the object are equal. Isometric projection corresponds to rotation of the object by ± 45° about the vertical axis, followed by rotation of approximately ± 35.264° [= arcsin(tan(30°))] about the horizontal axis starting from an orthographic projection view. "Isometric" comes from the Greek for "same measure." One of the things that makes isometric drawings so attractive is the ease with which 60 degree angles can be constructed with only a compass and straightedge.
Isometric projection is a type of axonometric projection. The other two types of axonometric projection are:
Dimetric projection
Trimetric projection
[edit] Oblique projection
An oblique projection is a simple type of graphical projection used for producing pictorial, two-dimensional images of three-dimensional objects:
it projects an image by intersecting parallel rays (projectors)
from the three-dimensional source object with the drawing surface (projection plan).
In both oblique projection and orthographic projection, parallel lines of the source object produce parallel lines in the projected image.
[edit] Perspective
Perspective is an approximate representation on a flat surface, of an image as it is perceived by the eye. The two most characteristic features of perspective are that objects are drawn:
Smaller as their distance from the observer increases
Foreshortened: the size of an object's dimensions along the line of sight are relatively shorter than dimensions across the line of sight.
[edit] Scale
Main articles: Architect's scale, Engineer's scale, and Metric scale
Plans are usually "scale drawings", meaning that the plans are drawn at specific ratio relative to the actual size of the place or object. Various scales may be used for different drawings in a set. For example, a floor plan may be drawn at 1:50 (1:48 or 1/4"=1'-0") whereas a detailed view may be drawn at 1:25 (1:24 or 1/2"=1'-0"). Site plans are often drawn at 1:200 or 1:100.
[edit] Showing dimensions
The required sizes of features are conveyed through use of dimensions. Distances may be indicated with either of two standardized forms of dimension: linear and ordinate.
With linear dimensions, two parallel lines, called "extension lines," spaced at the distance between two features, are shown at each of the features. A line perpendicular to the extension lines, called a "dimension line," with arrows at its endpoints, is shown between, and terminating at, the extension lines. The distance is indicated numerically at the midpoint of the dimension line, either adjacent to it, or in a gap provided for it.
With ordinate dimensions, one horizontal and one vertical extension line establish an origin for the entire view. The origin is identified with zeroes placed at the ends of these extension lines. Distances along the x- and y-axes to other features are specified using other extension lines, with the distances indicated numerically at their ends.
Sizes of circular features are indicated using either diametral or radial dimensions. Radial dimensions use an "R" followed by the value for the radius; Diametral dimensions use a circle with forward-leaning diagonal line through it, called the diameter symbol, followed by the value for the diameter. A radially-aligned line with arrowhead pointing to the circular feature, called a leader, is used in conjunction with both diametral and radial dimensions. All types of dimensions are typically composed of two parts: the nominal value, which is the "ideal" size of the feature, and the tolerance, which specifies the amount that the value may vary above and below the nominal.
Geometric dimensioning and tolerancing is a method of specifying the functional geometry of an object.
[edit] Sizes of drawings
Main article: Paper size
Sizes of drawings typically comply with either of two different standards, ISO (World Standard) or U.S. customary, according to the following tables:
ISO paper sizesISO A Drawing Sizes (mm) A4 210 X 297
A3 297 X 420
A2 420 X 594
A1 594 X 841
A0 841 X 1189
U.S. Customary Drawing Sizes A 8.5" X 11"
B 11" X 17"
C 17" X 22"
D 22" X 34"
E 34" X 44"
Other U.S. Drawing Sizes D1 24" X 36"
E1 30" X 42"
The metric drawing sizes correspond to international paper sizes. These developed further refinements in the second half of the twentieth century, when photocopying became cheap. Engineering drawings could be readily doubled (or halved) in size and put on the next larger (or, respectively, smaller) size of paper with no waste of space. And the metric technical pens were chosen in sizes so that one could add detail or drafting changes with a pen width changing by approximately a factor of the square root of 2. A full set of pens would have the following nib sizes: 0.13, 0.18, 0.25, 0.35, 0.5, 0.7, 1.0, 1.5, and 2.0 mm. However, the International Organization for Standardization (ISO) called for four pen widths and set a colour code for each: 0.25 (white), 0.35 (yellow), 0.5 (brown), 0.7 (blue); these nibs produced lines that related to various text character heights and the ISO paper sizes.
All ISO paper sizes have the same aspect ratio, one to the square root of 2, meaning that a document designed for any given size can be enlarged or reduced to any other size and will fit perfectly. Given this ease of changing sizes, it is of course common to copy or print a given document on different sizes of paper, especially within a series, e.g. a drawing on A3 may be enlarged to A2 or reduced to A4.
The U.S. customary "A-size" corresponds to "letter" size, and "B-size" corresponds to "ledger" or "tabloid" size. There were also once British paper sizes, which went by names rather than alphanumeric designations.
American National Standards Institute (ANSI) Y14.2, Y14.3, and Y14.5 are standards that are commonly used in the U.S.
[edit] Technical lettering
Technical lettering is the process of forming letters, numerals, and other characters in technical drawing. It is used to describe, or provide detailed specifications for, an object. With the goals of legibility and uniformity, styles are standardized and lettering ability has little relationship to normal writing ability. Engineering drawings use a Gothic sans-serif script, formed by a series of short strokes. Lower case letters are rare in most drawings of machines.
[edit] Example of an engineering drawing
Example mechanical drawingHere is an example of an engineering drawing (an isometric view of the same object is shown above). The different line types are colored for clarity.
Black = object line and hatching
Red = hidden line
Blue = center line of piece or opening
Magenta = phantom line or cutting plane line
Sectional views are indicated by the direction of arrows, as in the example above
1 Overview
2 Engineering drawings: common features
2.1 Line styles and types
2.2 Multiple views and projections
2.2.1 Orthographic projection
2.2.2 Auxiliary projection
2.2.3 Isometric projection
2.2.4 Oblique projection
2.2.5 Perspective
2.3 Scale
2.4 Showing dimensions
2.5 Sizes of drawings
2.6 Technical lettering
3 Example of an engineering drawing
4 See also
5 References
6 Further reading
7 External links
Overview
Engineering drawings are usually created in accordance with standardized conventions for layout, nomenclature, interpretation, appearance (such as typefaces and line styles), size, etc. One such standardized convention is called GD&T.
The purpose of such a drawing is to accurately and unambiguously capture all the geometric features of a product or a component. The end goal of an engineering drawing is to convey all the required information that will allow a manufacturer to produce that component.
Engineering drawings used to be created by hand using tools such as pencils, ink, straightedges, T-squares, French curves, triangles, rulers, scales, and erasers. Today they are usually done electronically with computer-aided design (CAD).
The drawings are still often referred to as "blueprints" or "bluelines", although those terms are anachronistic from a literal perspective, since most copies of engineering drawings that were formerly made using a chemical-printing process that yielded graphics on blue-colored paper or, alternatively, of blue-lines on white paper, have been superseded by more modern reproduction processes that yield black or multicolour lines on white paper. The more generic term "print" is now in common usage in the U.S. to mean any paper copy of an engineering drawing.
The process of producing engineering drawings, and the skill of producing them, is often referred to as technical drawing or drafting, although technical drawings are also required for disciplines that would not ordinarily be thought of as parts of engineering.
[edit] Engineering drawings: common features
Drawings convey the following critical information:
Geometry – the shape of the object; represented as views; how the object will look when it is viewed from various standard directions, such as front, top, side, etc.
Dimensions – the size of the object is captured in accepted units.
tolerances – the allowable variations for each dimension.
Material – represents what the item is made of.
Finish – specifies the surface quality of the item, functional or cosmetic. For example, a mass-marketed product usually requires a much higher surface quality than, say, a component that goes inside industrial machinery.
[edit] Line styles and types
Standard engineering drawing line typesA variety of line styles graphically represent physical objects. Types of lines include the following:
visible – are continuous lines used to depict edges directly visible from a particular angle.
hidden – are short-dashed lines that may be used to represent edges that are not directly visible.
center – are alternately long- and short-dashed lines that may be used to represent the axes of circular features.
cutting plane – are thin, medium-dashed lines, or thick alternately long- and double short-dashed that may be used to define sections for section views.
section – are thin lines in a pattern (pattern determined by the material being "cut" or "sectioned") used to indicate surfaces in section views resulting from "cutting." Section lines are commonly referred to as "cross-hatching."
Lines can also be classified by a letter classification in which each line is given a letter.
Type A lines show the outline of the feature of an object. They are the thickest lines on a drawing and done with a pencil softer than HB.
Type B lines are dimension lines and are used for dimensioning, projecting, extending, or leaders. A harder pencil should be used, such as a 2H.
Type C lines are used for breaks when the whole object is not shown. They are freehand drawn and only for short breaks. 2H pencil
Type D lines are similar to Type C, except they are zigzagged and only for longer breaks. 2H pencil
Type E lines indicate hidden outlines of internal features of an object. They are dotted lines. 2H pencil
Type F lines are Type F[typo] lines, except they are used for drawings in electrotechnology. 2H pencil
Type G lines are used for centre lines. They are dotted lines, but a long line of 10–20 mm, then a gap, then a small line of 2 mm. 2H pencil
Type H lines are the same as Type G, except that every second long line is thicker. They indicate the cutting plane of an object. 2H pencil
Type K lines indicate the alternate positions of an object and the line taken by that object. They are drawn with a long line of 10–20 mm, then a small gap, then a small line of 2 mm, then a gap, then another small line. 2H pencil.
[edit] Multiple views and projections
Image of a part represented in First Angle Projection
Symbols used to define whether a projection is either Third Angle (right) or First Angle (left).
Isometric view of the object shown in the engineering drawing further down the page.Main article: Graphical projection
In most cases, a single view is not sufficient to show all necessary features, and several views are used. Types of views include the following:
[edit] Orthographic projection
The orthographic projection shows the object as it looks from the front, right, left, top, bottom, or back, and are typically positioned relative to each other according to the rules of either first-angle or third-angle projection.
First angle projection is the ISO standard and is primarily used in Europe. The 3D object is projected into 2D "paper" space as if you were looking at an X-ray of the object: the top view is under the front view, the right view is at the left of the front view.
Third angle projection is primarily used in the United States and Canada, where it is the default projection system according to BS 8888:2006, the left view is placed on the left and the top view on the top.
Not all views are necessarily used, and determination of what surface constitutes the front, back, top and bottom varies depending on the projection used.
[edit] Auxiliary projection
An auxiliary view is an orthographic view that is projected into any plane other than one of the six principal views.[1] These views are typically used when an object contains some sort of inclined plane. Using the auxiliary view allows for that inclined plane (and any other significant features) to be projected in their true size and shape. The true size and shape of any feature in an engineering drawing can only be known when the Line of Sight (LOS) is perpendicular to the plane being referenced.
[edit] Isometric projection
The isometric projection show the object from angles in which the scales along each axis of the object are equal. Isometric projection corresponds to rotation of the object by ± 45° about the vertical axis, followed by rotation of approximately ± 35.264° [= arcsin(tan(30°))] about the horizontal axis starting from an orthographic projection view. "Isometric" comes from the Greek for "same measure." One of the things that makes isometric drawings so attractive is the ease with which 60 degree angles can be constructed with only a compass and straightedge.
Isometric projection is a type of axonometric projection. The other two types of axonometric projection are:
Dimetric projection
Trimetric projection
[edit] Oblique projection
An oblique projection is a simple type of graphical projection used for producing pictorial, two-dimensional images of three-dimensional objects:
it projects an image by intersecting parallel rays (projectors)
from the three-dimensional source object with the drawing surface (projection plan).
In both oblique projection and orthographic projection, parallel lines of the source object produce parallel lines in the projected image.
[edit] Perspective
Perspective is an approximate representation on a flat surface, of an image as it is perceived by the eye. The two most characteristic features of perspective are that objects are drawn:
Smaller as their distance from the observer increases
Foreshortened: the size of an object's dimensions along the line of sight are relatively shorter than dimensions across the line of sight.
[edit] Scale
Main articles: Architect's scale, Engineer's scale, and Metric scale
Plans are usually "scale drawings", meaning that the plans are drawn at specific ratio relative to the actual size of the place or object. Various scales may be used for different drawings in a set. For example, a floor plan may be drawn at 1:50 (1:48 or 1/4"=1'-0") whereas a detailed view may be drawn at 1:25 (1:24 or 1/2"=1'-0"). Site plans are often drawn at 1:200 or 1:100.
[edit] Showing dimensions
The required sizes of features are conveyed through use of dimensions. Distances may be indicated with either of two standardized forms of dimension: linear and ordinate.
With linear dimensions, two parallel lines, called "extension lines," spaced at the distance between two features, are shown at each of the features. A line perpendicular to the extension lines, called a "dimension line," with arrows at its endpoints, is shown between, and terminating at, the extension lines. The distance is indicated numerically at the midpoint of the dimension line, either adjacent to it, or in a gap provided for it.
With ordinate dimensions, one horizontal and one vertical extension line establish an origin for the entire view. The origin is identified with zeroes placed at the ends of these extension lines. Distances along the x- and y-axes to other features are specified using other extension lines, with the distances indicated numerically at their ends.
Sizes of circular features are indicated using either diametral or radial dimensions. Radial dimensions use an "R" followed by the value for the radius; Diametral dimensions use a circle with forward-leaning diagonal line through it, called the diameter symbol, followed by the value for the diameter. A radially-aligned line with arrowhead pointing to the circular feature, called a leader, is used in conjunction with both diametral and radial dimensions. All types of dimensions are typically composed of two parts: the nominal value, which is the "ideal" size of the feature, and the tolerance, which specifies the amount that the value may vary above and below the nominal.
Geometric dimensioning and tolerancing is a method of specifying the functional geometry of an object.
[edit] Sizes of drawings
Main article: Paper size
Sizes of drawings typically comply with either of two different standards, ISO (World Standard) or U.S. customary, according to the following tables:
ISO paper sizesISO A Drawing Sizes (mm) A4 210 X 297
A3 297 X 420
A2 420 X 594
A1 594 X 841
A0 841 X 1189
U.S. Customary Drawing Sizes A 8.5" X 11"
B 11" X 17"
C 17" X 22"
D 22" X 34"
E 34" X 44"
Other U.S. Drawing Sizes D1 24" X 36"
E1 30" X 42"
The metric drawing sizes correspond to international paper sizes. These developed further refinements in the second half of the twentieth century, when photocopying became cheap. Engineering drawings could be readily doubled (or halved) in size and put on the next larger (or, respectively, smaller) size of paper with no waste of space. And the metric technical pens were chosen in sizes so that one could add detail or drafting changes with a pen width changing by approximately a factor of the square root of 2. A full set of pens would have the following nib sizes: 0.13, 0.18, 0.25, 0.35, 0.5, 0.7, 1.0, 1.5, and 2.0 mm. However, the International Organization for Standardization (ISO) called for four pen widths and set a colour code for each: 0.25 (white), 0.35 (yellow), 0.5 (brown), 0.7 (blue); these nibs produced lines that related to various text character heights and the ISO paper sizes.
All ISO paper sizes have the same aspect ratio, one to the square root of 2, meaning that a document designed for any given size can be enlarged or reduced to any other size and will fit perfectly. Given this ease of changing sizes, it is of course common to copy or print a given document on different sizes of paper, especially within a series, e.g. a drawing on A3 may be enlarged to A2 or reduced to A4.
The U.S. customary "A-size" corresponds to "letter" size, and "B-size" corresponds to "ledger" or "tabloid" size. There were also once British paper sizes, which went by names rather than alphanumeric designations.
American National Standards Institute (ANSI) Y14.2, Y14.3, and Y14.5 are standards that are commonly used in the U.S.
[edit] Technical lettering
Technical lettering is the process of forming letters, numerals, and other characters in technical drawing. It is used to describe, or provide detailed specifications for, an object. With the goals of legibility and uniformity, styles are standardized and lettering ability has little relationship to normal writing ability. Engineering drawings use a Gothic sans-serif script, formed by a series of short strokes. Lower case letters are rare in most drawings of machines.
[edit] Example of an engineering drawing
Example mechanical drawingHere is an example of an engineering drawing (an isometric view of the same object is shown above). The different line types are colored for clarity.
Black = object line and hatching
Red = hidden line
Blue = center line of piece or opening
Magenta = phantom line or cutting plane line
Sectional views are indicated by the direction of arrows, as in the example above
Cad A Revolution For Engineering Drawings And Designs By: Dillip Kumar Barik
CAD is the abbreviation of "Computer Aided Design". It is a structure of design in which people work with computer tools for creating models, drawings and other prototypes. CAD was first developed in 1970s with 2D in order to assist engineers, architects, and other design professionals in their technical drawings and drafting, but now it has expanded with numerous other potential uses with 3D designs and models. Designers from various fields such as Engineering, Architecture, Fashion, Textile and Graphics are highly dependent on CAD technologies. CAD is considered as a revolutionary design tool, which provides cost-effective solutions with quick time interval.
The entire process of design using CAD involves both software and sometimes specially created hardware related to a specific industry or application. Latest systems like 2D drafting, 3D modeling and solid design modelers use CAD for their fundamental operations. Manufacturers use CAD to design virtual products, which can be tested and measured for performance. Without CAD, the entire process of manufacturing a product and then testing would be very expensive.
Computer Aided Design (CAD) is a derived technology of Co-ordinate Geometry, which is a branch of Mathematics. Due to this reason the basic entities used in any CAD environment are points, lines, polygons, texts and other geometrical figures. These entities have been further modified to create circle, ellipse, parabola, hyperbola, mesh and also three dimensional (3D) objects like spheres, cubes, cylinders and many more. Further developments have been made according to the design requirements.
CAD is a computer-assisted technology, basically used for creating graphics designs of various objects or goods considering about its consumers. It is most extensively used in the design and development of machinery. CAD is also used widely for the designing of all types of buildings. Engineering industries use CAD right from the product conceptualization stage across the entire process of manufacturing.
Now days Computer Aided Design (CAD) is used in many technical or engineering fields like architecture, civil, mechanical, aviation, ship building, construction, electronic, electrical and automotive. Architects and civil engineers use CAD to design buildings structures and interiors. In mechanical engineering, CAD is used for 2D cad drafting, legacy data conversion, data migration, platform migration, mechanical 3D modeling, solid modeling, sectional drawing preparation and isometric presentation. Electrical and electronics industries use CAD for making Printed Circuit Board (PCB) designs and wiring layout (WL) designs. CAD is also used to design the generally layout of a manufacturing unit.
3D modeling and surface construction methods are used especially in mechanical, aircraft and automotive industries to design different products and components for machinery. The entire process not only saves time and money but also guarantees optimum accuracy and correctness. After complication of CAD design the results are directly inserted into the manufacturing process using Computer Aided Manufacturing (CAM) systems in many modern sophisticated industries. Various industries use CAD for different design purposes according to their requirement. The aerospace industry was the first to use CAD commercially and popularize it as a designing tool.
Extensive use of computers in day to day life facilitates the use of Computer Aided Designs in the field of engineering and has created a revolution in industrial sectors. Due to its immense application in industries CAD has got emphasized, more and more CAD based products available in market.
CAD has revolutionized the complete engineering developments. CAD engineering enables us to see more and more new products in the market everyday. Computer Aided Design engineering is also responsible for the initiation of robotics into the manufacturing sector for enhancing industry production.
The entire process of design using CAD involves both software and sometimes specially created hardware related to a specific industry or application. Latest systems like 2D drafting, 3D modeling and solid design modelers use CAD for their fundamental operations. Manufacturers use CAD to design virtual products, which can be tested and measured for performance. Without CAD, the entire process of manufacturing a product and then testing would be very expensive.
Computer Aided Design (CAD) is a derived technology of Co-ordinate Geometry, which is a branch of Mathematics. Due to this reason the basic entities used in any CAD environment are points, lines, polygons, texts and other geometrical figures. These entities have been further modified to create circle, ellipse, parabola, hyperbola, mesh and also three dimensional (3D) objects like spheres, cubes, cylinders and many more. Further developments have been made according to the design requirements.
CAD is a computer-assisted technology, basically used for creating graphics designs of various objects or goods considering about its consumers. It is most extensively used in the design and development of machinery. CAD is also used widely for the designing of all types of buildings. Engineering industries use CAD right from the product conceptualization stage across the entire process of manufacturing.
Now days Computer Aided Design (CAD) is used in many technical or engineering fields like architecture, civil, mechanical, aviation, ship building, construction, electronic, electrical and automotive. Architects and civil engineers use CAD to design buildings structures and interiors. In mechanical engineering, CAD is used for 2D cad drafting, legacy data conversion, data migration, platform migration, mechanical 3D modeling, solid modeling, sectional drawing preparation and isometric presentation. Electrical and electronics industries use CAD for making Printed Circuit Board (PCB) designs and wiring layout (WL) designs. CAD is also used to design the generally layout of a manufacturing unit.
3D modeling and surface construction methods are used especially in mechanical, aircraft and automotive industries to design different products and components for machinery. The entire process not only saves time and money but also guarantees optimum accuracy and correctness. After complication of CAD design the results are directly inserted into the manufacturing process using Computer Aided Manufacturing (CAM) systems in many modern sophisticated industries. Various industries use CAD for different design purposes according to their requirement. The aerospace industry was the first to use CAD commercially and popularize it as a designing tool.
Extensive use of computers in day to day life facilitates the use of Computer Aided Designs in the field of engineering and has created a revolution in industrial sectors. Due to its immense application in industries CAD has got emphasized, more and more CAD based products available in market.
CAD has revolutionized the complete engineering developments. CAD engineering enables us to see more and more new products in the market everyday. Computer Aided Design engineering is also responsible for the initiation of robotics into the manufacturing sector for enhancing industry production.
Sunday, May 29, 2011
Importance of Technical Drawing
Technical drawing allows efficient communication among engineers and can be kept as a record of the planning process. Since a picture is worth a thousand words, a technical drawing is a much more effective tool for engineers than a written plan.
1. Fields of Use
o Technical drawing is the preferred method of drafting in all engineering fields, including, but not limited to, civil engineering, electrical engineering, mechanical engineering and architecture.
Importance of Accuracy
o Precision is of the utmost importance in all technical drawing, as drafts in all fields of engineering are expected to be scaled, labeled and arranged exactly as the final product would be. For this reason, technical drawing is always performed with tools such as compasses, T-squares and shape templates.
CAD
o Because of the importance of accuracy in any technical drawing, the use of CAD, or computer-aided design programs, is becoming increasingly common. These programs increase the speed and accuracy of the drafting process, as well as making the reproduction of drafts as simple as printing text documents.
Thursday, May 26, 2011
Learn Technical Drawing: Overview of Degree and Certificate Programs
Technical drawing plays an integral role in many fields, including manufacturing, engineering, architecture and computer modeling. People who render technical drawings are usually known as drafters or drafting technicians, while those who use computer programs can also be known as CADD (computer-aided design and drafting) operators. Many drafters and CADD operators attend 2-year associate degree programs and may go on to earn certificates in specialized fields of technical drawing.
Associate Degree Programs in Drafting (Technical Drawing) Technology
From homes to highways to helicopters, almost everything that we use began as a technical drawing. Many schools offer 2-year degrees in this field; some programs offer an overall approach to technical drawing while others specialize in certain types of technical drawing, such as engineering, architectural, civil, aeronautical, manufacturing or electronics. Through these programs, students learn a combination of skills that are needed to produce precise technical drawings.Educational Prerequisites
Prerequisites vary according program, but many schools prefer students with high school courses in advanced mathematics, computer science and science. Some type of training in the graphic arts can also be helpful when applying for a drafting degree program.Program Coursework
Drafting programs focus heavily on computer, math and science classes. Coursework in communications, writing and speech are also necessary because drafters often work closely with engineers and product designers.- Computer science
- Fundamentals of drafting
- Algebra
- Computer drafting
- Communications
- Advanced science
- Geometry
Employment Outlook and Salary Information
According to U.S. Bureau of Labor Statistics (BLS) (www.bls.gov), job prospects for drafters are expected to rise slower than those for other occupations; the field is expected to only grow four percent between 2008 and 2018. However, job opportunities for certain specialties, such as civil or architectural drafting, are expected to grow much faster than the average rate.Salaries for drafters vary according to field and specialization. In 2008, the BLS reported that the median annual income for drafters in civil engineering or architecture was $44,490, electronics drafters earned $51,320 and the median income for mechanical drafters was $46,640.
Continuing Education Information
Although most 4-year colleges do not offer drafting programs, many will allow students with a 2-year degree to incorporate their credits into an engineering or architecture program. Students with an associate's degree in drafting can also continue their education with a certification program. One of the most recognized forms of drafter certification is from the American Design Drafting Association (www.adda.org), which has exams for professional and apprentice drafters.Computer-Aided Design and Drafting (CADD) Associate Degree Programs
Today, many employers are looking for technical drawing applicants with some knowledge in computer-aided drafting and design. Degree programs that specialize in CADD combine basic drafting principles with computer skills and teach students how to apply these skills when using drafting software programs. Students that specialize in CADD can apply their skills in many different fields of drafting.Educational Prerequisites
Most CAD programs require a high school diploma or GED. Many schools prefer students with solid experience in computer use and some knowledge in computer science.Program Coursework
Coursework in CADD programs cover drafting and design basics along with a special emphasis in computer-related subjects. Often the first year focuses on design basics and the final year of the program concentrates on computer drafting applications and programs.- Computer design
- 3-D modeling
- CAD applications
- Digital layout
- Dimensioning systems
Popular Career Fields
Today, almost every field of drafting uses some type of computer rendering system; some of the most popular fields for CADD operators are manufacturing and mechanical engineering.- Architecture
- Civil engineering
- Aeronautical engineering
- Computer graphics
- Digital design
- Electrical
- Surveying
- Computer animation
Continuing Education Information
Many CADD operators continue their education in specialized fields, such as MET (Mechanical Engineering Technology) and Auto CAD (engineering design software). They can also transfer their credits to 4-year programs in engineering or other fields that utilize computer-rendered drawings.Technical Drawing Certificate Programs
Many technical schools and community colleges offer certificate programs in drafting, CADD or technical drawing. Some of these programs provide an overview of drafting practices and techniques, while others specialize in certain types of technical drawing, such as mechanical, architectural or engineering. Some certificate programs are geared towards students with backgrounds in technical drawing who are looking to update their skills while others are designed for new students entering the field of technical drawing.Most technical drawing programs require a high school diploma with coursework in math, physics and graphic art. Programs designed for continuing education students may have additional educational or job-related experience prerequisites. Credits earned in certificate programs are often transferable to other institutions and may be applied towards an associate's degree in drafting.
Monday, May 23, 2011
BS 308 is the old familiar standard that many engineers grew up with. But did You know that it is no longer current?
The UK was the first country to adopt a national standard for technical drawing. Before the industrial revolution it was commonplace for workmen to work from prototypes. With the coming of the steam age it became clear that standard parts and components would be required to allow mass manufacture. Creating these standards became possible in 1840 when the blue print process was invented. For the first time many fabricators could work to identical drawings.
In 1901 the Institutions of Civil Engineers, Mechanical Engineers, Naval Architects and the Iron and Steel Institute created a committee, to standardize iron and steel sections for bridges, railways and shipping. It subsequently extended its standardization work and became the British Engineering Standards Association in 1918, adopting the name British Standards Institution in 1931 after receiving its Royal Charter in 1929.
In 1998 a revision of the Charter enabled the organization to diversify and acquire other businesses, and the trading name was changed to BSI Group. BSI was instrumental in the formation of ISO , the International Organization for Standardization, in 1947 and of its European equivalent, CEN, in 1964.
In 1998 a revision of the Charter enabled the organization to diversify and acquire other businesses, and the trading name was changed to BSI Group. BSI was instrumental in the formation of ISO , the International Organization for Standardization, in 1947 and of its European equivalent, CEN, in 1964.
The first British Standard for Engineering Drawing Office Practice ‘BS 308’ was published in September 1927 and only contained 14 clauses and five illustrations. It was printed on A5 sheets of paper and third angle projection was used.
Over the years BS 308 was updated many times. From the early 1980’s BS 308 was revised to take account of ISO standards. In 1992 it was decided that the BSI could no longer keep up with the pace of ISO output and that they would accept any new standards that the ISO adopted, rather than continue to revise BS 308.
BS 308 slowly became superseded by the new ISO standards and in the year 2000 BS 308 was withdrawn and the new BS ISO 8888 replaced it.
Sunday, May 22, 2011
How To Find Technical Drawing Supplies By Marc Alexander
A technical drawing is defined as a clear sketch which gives the dimensions, notes and specifications of a structure or object. The process of creating these drawings is known as drafting. Good technical drawings are important parts of the design and construction process, since it enables builders, architects and engineers to properly construct buildings, houses, cars and even everyday gadgets. As such, draftsmen always draw these to scale to ensure exact specifications and proportions, and even use drawing symbols to provide the correct technical information.
Essential supplies for people engaged in technical drawing would include drawing boards, a T-square, triangles, either an architect’s or engineer’s scale, and a set of quality drawing instruments. You can also include the drafting machine, a technical fountain pen, a parallel-ruling straightedge, and your ever reliable computer. It’s easy to find computers these days, but you may wonder where you can find the other stuff needed for your technical drawings.
You don’t really need to look so far with these tips:
Scour the good old Yellow Pages. Yes, they still exist and are still quite useful. You can find stores that serve companies engaged in architectural, engineering and drafting services. If you’re lucky, you might stumble upon a store near you. Once you enter a store, it might be tempting to try out everything in sight. Resist that urge and just stick to your list. Ask questions. This way, you can establish a great professional relationship with your neighborhood technical drawing supplies store.- You can also get in touch with established architectural and engineering firms and ask them for referrals on where they get supplies. At the very least, you know such supplies will have their stamp of approval. You’re not looking for just any ordinary art supplies store. Even pencils need to be classified as drawing pencils and not just any ordinary writing instrument, so referrals are key.
- Your reliable internet search engines can also help you find a drafting supplies store near you. Even if the distance is far, shipping will do the trick. To be safe, you can choose a website that offers various delivery options. Just make sure you check the shipping duration and their return policies for cases of mishandled gear. Favorable return policies also help you if you end up getting the wrong brand or ordered an incorrect item. Remember, these supplies cost money and you want to make sure you get the right ones for your needs.
- Try local search engines and listings like craigslist.org. These give you the ease of use of a search engine, and are more convenient because the listings are mostly local. Therefore you won’t have to spend too much on shipping - if anything.
- If it’s your first time placing an order, be it in person, on the phone or online, make sure you prepare for it well. Consult an experienced drafter or designer, or talk to a reliable dealer, since it may be hard to distinguish quality tools from inferior instruments. You can also ask for tips regarding the best quality tools and supplies. They may cost more now, but end up saving you more in the long run!
Whether it's for engineering drawing or architectural drawing, one thing remains clear. You need the best instruments if you want to create works of art and genius. Spending some time finding the highest quality instruments you can afford may be one of the best investments you’ll ever make in your career.
Friday, May 20, 2011
Tuesday, May 17, 2011
Perspective - How to Draw Perspective
n understanding of perspective drawing is important no matter what subject you choose. It's easier than you think. Just start at the beginning, follow the examples, then progress to the next lesson when you are comfortable. Don't be afraid to experiment with perspective drawing. Your eyes will tell you when something looks right or wrong. Have fun!
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1. Simple Boxes in One Point Perspective
H South, licensed to About.com, Inc.
Learning to draw simple boxes in one point perspective is a great introduction to 'three d' perspective drawing. Because the shapes are simple, you can easily see if you've made a mistake. Follow along with this lesson to draw our own three-d boxes using one point linear perspective.
2.Draw Boxes in Two Point Perspective
To really have fun with perspective drawing, you need two vanishing points. Now you can draw cool 3D effects! It's a little more complex than one point perspective, because you have to make sure that you draw your vanishing lines to the right vanishing point. But once you get the idea, it's a breeze - you barely have to give it a second thought.
3. Find the Center of a Square or Rectangle in Perspective
H South, licensed to About.com, Inc.
It's a very simple process, using diagonals to locate the center of a square or rectangle in perspective. From there, you can use this point to divide the shape into half or four, or use the center points to place the vertex of a roofline or column. Works in one or two point perspective.
4. Draw a Pyramid in Perspective
H South, licensed to About.com, Inc.
Now you know how to draw boxes and find the center of their faces in perspective, you can learn to draw a pyramid. Follow the steps and learn to draw a 3D pyramid in one point and two point perspective. You could try drawing two from the same base - one pointing up, one down, to draw a crystal.
5. Draw a Brick Wall in Perspective
H South, licensed to About.com, Inc.
Use your knowledge of perspective drawing to create a complex surface. Combine the basic methods of linear perspective and dividing planes to draw a detailed brick wall with accurate perspective.
6. Draw Atmospheric or Aerial Perspective
S. Tschantz, licensed to About.com, Inc.
All of the perspective we've done so far has been Linear Perspective. However another form of perspective drawing - Atmospheric or Aerial perspective - is an important addition to your drawing skills 'toolbox'. Atmospheric perspective is most fully used by landscape artists, but the principles involved are also useful in portraiture and still life.
Monday, May 16, 2011
DRAFTING/ TECHNICAL DRAWING
Outsourcing of Detailing and Drafting Services
Assembly drawings, or mechanical
assembly drawings, are “drawings detailing an engineering perspective
view on a mechanism or physical, real-world-built object that is
comprised of more than one part.” Assembly drawings are very useful for
engineers who are dealing with complex mechanical devices. Creating
assembly drawings have become improved with the recent improvements in
2D CAD drafting and detailing software. It is very vital that designs
are visualized accurately and precisely so that the manufacturing stage
will become successful and safer and the maintenance stage will become
easier.
2D drafting and detailing is “an important aspect of any CAD tool.”
The speed of creating 2D CAD drawings is a matter of great importance
especially for projects that have 2D drawing end-results (aside from the
fact that 2D CAD drawings are far easier to handle than paper design
models). Detailing is an important part of any project, and it must be
handled by professionals. Detailing and drafting services are very
important in a potpourri of industries, and it is very important that
drawings are easily understood by people who will use them. An
improperly made drawing results to an increase in unnecessary overhead
expenses.
If you are in a company that needs 2D drawings for your projects, it
is better if you outsource your works to a company that is very
competent in the expertise that you need. In that way, you can work
harder for your specialty because other professionals are there to take
care of your other needs. The technologies that they use are frequently
being updated to improve the quality of their works. The resources it
takes to manage your employees are lessened. This shows that
outsourcing is a profitable economical solution. An outsourcing company
that has demonstrated years of experience and has produced output of
the finest quality in a timely manner is the best option for a client
that values reliability, high quality, and time. Such outsourcing
company has the capability to produce designs efficiently and without
errors. A carefully planned and analyzed design prevents unnecessary
costs to the people who will use it. As a conclusion, entrusting your
detailing and drafting projects to professionals who have the
capabilities to do them competently reduces your cost and improves your
productivity despite tough economic conditions.
Technical Drawing or Drafting
What is Technical Drawing?
Many references provide a lot of definitions for technical drawing. A
technical drawing or drafting is the “academic discipline of creating
standardized technical drawings by architects, interior designers,
drafters, design engineers, and related professionals.” It is an
“integral communication of technical or engineering drawings and is the
industrial arts sub-discipline that underlies all involved technical
endeavors.1” It is a “means of clearly and concisely
communicating all of the information necessary to transform an idea or a
concept into reality.2” It is a “drawing plan, rendered to scale, used to communicate direction and specifics to a group of people creating something.3”
It is a “formal and precise way of communicating information about the
shape, size, features and precision of physical objects,” a “universal
language of engineering used in the design process for solving
problems, quickly and accurately visualizing objects, and conducting
analysis,” and “a graphical representation of objects and structures.”
It is also the “expression of bodies by lines.4” It is a “skill, a vocation.5”
A good technical drawing is “one that properly and conveniently
communicates all of the information needed to transform a design into a
product that meets or exceeds customer expectations.2“
Technical drawings have many uses in many kinds of applications
specially where there is a need for designs and conversion processes,
such as those found in manufacturing, engineering, architecture, and
construction. Because technical drawings have many uses, there is a need
to regulate practices that are involved in creating these drawings.
Drafters use standards of practice, of which the most widely used are
practices of the US Department of Defense (DOD), the US Military (MIL),
the American National Standards Institute (ANSI), and the American
Society of Mechanical Engineers (ASME).2 Drafters use many
geometric figures and symbols to specify the scope and details of a
product because it is very important that technical drawings be
accurate.3 Drafters create technical drawings using freehand, mechanical, or computer methods.4 Processes that are involved in drafting are sometimes time-consuming.1
One thing that determines the ultimate quality of a product is the
quality of its technical drawing. We know if a technical drawing is a
good one when developers for a design should no longer need to consult
designers or drafters of the drawing because all information that these
developers need are already included in the drawing.2 In essence, technical drawing is about linear projection.5
A Quick Summary of the History of Technical Drawing
Technical drawings are things that are not new. Even during the times
of early Greek civilization, technical drawings existed. These
drawings were scratched on the floor to guide workers while they were
building. As time went on, people learned to use mechanical devices on
drafting tables to draft. Nowadays, drafters or designers use computers
to aid them in their design works.3 Computers lessened the
effort needed by designers to accomplish their tasks. Before the
widespread use of drafting software, drafters were required to have an
extensive knowledge on the principles of descriptive geometry and to
use tools such as t-square, compass, and drafting table. Now,
descriptive geometry is no longer used very often because computers do
much of the computations. With the use of computers and knowledge in
linear algebra, data, such as coordinates of points and their
projection on planes, are computed more easily, and designers can now
bypass some rules or principles on how to draw correctly.5
Methods of Technical Drawing
The three methods in technical drawing are the following:1
as a finished work.” It is a “quick way to record an idea for later
use.” Sketches serve as abstractions or summaries of complex patterns or
design solutions. Because their purpose is to summarize, sketching
results to an enhanced design process. In a way, these sketches aid in
the design collaboration.1
In manual drawing, it is very important to have an accurate drafting
table and to give much attention to the positioning of drafting tools.
Drafters use a wide array of mechanical instruments and tools, such as
compasses and French curves. Drafters of manual drawings are skilled in
geometry, trigonometry, and spatial comprehension. They have mastered
the mechanics of drawing lines, arcs, and circles, and they are
expected to be precise and accurate in giving technical details. One
procedure in manual drafting involves using a drafting table with a
paper over it, and sliding a T-square across the side of the table over
the surface of the paper. Drafters run pencils or technical pens along
the edge of the T-square to create parallel lines. Sometimes, the
T-square is used to hold other smaller drawing tools, such as squares
and triangles. With the use of these smaller drawing tools, drafters
could draw lines from different angles. When tasks become repetitive
already, drafters use templates, and these templates were made for some
specific tasks. Templates are commercially available, but sometimes,
drafters prefer to create their own.1
Manual drawings must be redrawn from scratch when there is a need to
modify them. This difficulty was removed by the use of CAD systems. A
CAD system is either 2D or 3D. A 2D CAD system is “merely an electronic
drawing board.” 2D CAD systems are capable of producing drawings of
large projects such as plans for a building or an aircraft, but they do
not have the capability to allow designers to test whether components
and parts will fit together. These kinds of projects require designers
to use 3D CAD software for the modeling, assembling, and checking of
components before the actual release of technical drawings to
manufacturers.1
CAD systems, such as AutoCAD, SolidWorks, and Pro/ENGINEER, automate
and accelerate the mechanics of drafting tasks. These systems support
symbols for common components that are found in many disciplines, such
as electrical, electronic, pneumatic, and fluidic. CAD designers follow
standards such as those provided by BS and ISO, but, sometimes, it is
up to designers to create drawings.
Assembly drawings, or mechanical
assembly drawings, are “drawings detailing an engineering perspective
view on a mechanism or physical, real-world-built object that is
comprised of more than one part.” Assembly drawings are very useful for
engineers who are dealing with complex mechanical devices. Creating
assembly drawings have become improved with the recent improvements in
2D CAD drafting and detailing software. It is very vital that designs
are visualized accurately and precisely so that the manufacturing stage
will become successful and safer and the maintenance stage will become
easier.
2D drafting and detailing is “an important aspect of any CAD tool.”
The speed of creating 2D CAD drawings is a matter of great importance
especially for projects that have 2D drawing end-results (aside from the
fact that 2D CAD drawings are far easier to handle than paper design
models). Detailing is an important part of any project, and it must be
handled by professionals. Detailing and drafting services are very
important in a potpourri of industries, and it is very important that
drawings are easily understood by people who will use them. An
improperly made drawing results to an increase in unnecessary overhead
expenses.
If you are in a company that needs 2D drawings for your projects, it
is better if you outsource your works to a company that is very
competent in the expertise that you need. In that way, you can work
harder for your specialty because other professionals are there to take
care of your other needs. The technologies that they use are frequently
being updated to improve the quality of their works. The resources it
takes to manage your employees are lessened. This shows that
outsourcing is a profitable economical solution. An outsourcing company
that has demonstrated years of experience and has produced output of
the finest quality in a timely manner is the best option for a client
that values reliability, high quality, and time. Such outsourcing
company has the capability to produce designs efficiently and without
errors. A carefully planned and analyzed design prevents unnecessary
costs to the people who will use it. As a conclusion, entrusting your
detailing and drafting projects to professionals who have the
capabilities to do them competently reduces your cost and improves your
productivity despite tough economic conditions.
Technical Drawing or Drafting
What is Technical Drawing?
Many references provide a lot of definitions for technical drawing. A
technical drawing or drafting is the “academic discipline of creating
standardized technical drawings by architects, interior designers,
drafters, design engineers, and related professionals.” It is an
“integral communication of technical or engineering drawings and is the
industrial arts sub-discipline that underlies all involved technical
endeavors.1” It is a “means of clearly and concisely
communicating all of the information necessary to transform an idea or a
concept into reality.2” It is a “drawing plan, rendered to scale, used to communicate direction and specifics to a group of people creating something.3”
It is a “formal and precise way of communicating information about the
shape, size, features and precision of physical objects,” a “universal
language of engineering used in the design process for solving
problems, quickly and accurately visualizing objects, and conducting
analysis,” and “a graphical representation of objects and structures.”
It is also the “expression of bodies by lines.4” It is a “skill, a vocation.5”
A good technical drawing is “one that properly and conveniently
communicates all of the information needed to transform a design into a
product that meets or exceeds customer expectations.2“
Technical drawings have many uses in many kinds of applications
specially where there is a need for designs and conversion processes,
such as those found in manufacturing, engineering, architecture, and
construction. Because technical drawings have many uses, there is a need
to regulate practices that are involved in creating these drawings.
Drafters use standards of practice, of which the most widely used are
practices of the US Department of Defense (DOD), the US Military (MIL),
the American National Standards Institute (ANSI), and the American
Society of Mechanical Engineers (ASME).2 Drafters use many
geometric figures and symbols to specify the scope and details of a
product because it is very important that technical drawings be
accurate.3 Drafters create technical drawings using freehand, mechanical, or computer methods.4 Processes that are involved in drafting are sometimes time-consuming.1
One thing that determines the ultimate quality of a product is the
quality of its technical drawing. We know if a technical drawing is a
good one when developers for a design should no longer need to consult
designers or drafters of the drawing because all information that these
developers need are already included in the drawing.2 In essence, technical drawing is about linear projection.5
A Quick Summary of the History of Technical Drawing
Technical drawings are things that are not new. Even during the times
of early Greek civilization, technical drawings existed. These
drawings were scratched on the floor to guide workers while they were
building. As time went on, people learned to use mechanical devices on
drafting tables to draft. Nowadays, drafters or designers use computers
to aid them in their design works.3 Computers lessened the
effort needed by designers to accomplish their tasks. Before the
widespread use of drafting software, drafters were required to have an
extensive knowledge on the principles of descriptive geometry and to
use tools such as t-square, compass, and drafting table. Now,
descriptive geometry is no longer used very often because computers do
much of the computations. With the use of computers and knowledge in
linear algebra, data, such as coordinates of points and their
projection on planes, are computed more easily, and designers can now
bypass some rules or principles on how to draw correctly.5
Methods of Technical Drawing
The three methods in technical drawing are the following:1
- Sketching
- Manual or by instrument
- Computer-aided design (CAD)
as a finished work.” It is a “quick way to record an idea for later
use.” Sketches serve as abstractions or summaries of complex patterns or
design solutions. Because their purpose is to summarize, sketching
results to an enhanced design process. In a way, these sketches aid in
the design collaboration.1
In manual drawing, it is very important to have an accurate drafting
table and to give much attention to the positioning of drafting tools.
Drafters use a wide array of mechanical instruments and tools, such as
compasses and French curves. Drafters of manual drawings are skilled in
geometry, trigonometry, and spatial comprehension. They have mastered
the mechanics of drawing lines, arcs, and circles, and they are
expected to be precise and accurate in giving technical details. One
procedure in manual drafting involves using a drafting table with a
paper over it, and sliding a T-square across the side of the table over
the surface of the paper. Drafters run pencils or technical pens along
the edge of the T-square to create parallel lines. Sometimes, the
T-square is used to hold other smaller drawing tools, such as squares
and triangles. With the use of these smaller drawing tools, drafters
could draw lines from different angles. When tasks become repetitive
already, drafters use templates, and these templates were made for some
specific tasks. Templates are commercially available, but sometimes,
drafters prefer to create their own.1
Manual drawings must be redrawn from scratch when there is a need to
modify them. This difficulty was removed by the use of CAD systems. A
CAD system is either 2D or 3D. A 2D CAD system is “merely an electronic
drawing board.” 2D CAD systems are capable of producing drawings of
large projects such as plans for a building or an aircraft, but they do
not have the capability to allow designers to test whether components
and parts will fit together. These kinds of projects require designers
to use 3D CAD software for the modeling, assembling, and checking of
components before the actual release of technical drawings to
manufacturers.1
CAD systems, such as AutoCAD, SolidWorks, and Pro/ENGINEER, automate
and accelerate the mechanics of drafting tasks. These systems support
symbols for common components that are found in many disciplines, such
as electrical, electronic, pneumatic, and fluidic. CAD designers follow
standards such as those provided by BS and ISO, but, sometimes, it is
up to designers to create drawings.
Sunday, May 15, 2011
Definition of Technical Drawing
YourDictionary defines a technical drawing as a drawing or plan, rendered to scale, used to communicate direction and specifics to a group of people creating something. Engineers, contractors, plumbers, electricians, landscape architects, inventors and others use technical drawings to create a master plan or blueprint. The blueprint or plan communicates the necessary details among the workers to build the object detailed in the plan
Drafters are men and women trained in the art of technical drawing. Another term for a person skilled in creating technical drawings is a draftsman, although modern practitioners prefer the term drafter. Among electrical and mechanical engineers, the person on the team responsible for creating the technical drawing may also be referred to as the designer.
It is imperative that technical drawings be accurate. If the drawing is off by even centimeters, the actual work may be off quite a bit too. This leads to disastrous consequences and costly delays in construction.
A special device called the pantograph helped usher in the modern use of mechanical and computer-assisted design (CAD) While some drafters continue to use the drafting table and handheld tools, CAD helps drafters output technical drawings accurately and efficiently.
Drafters are men and women trained in the art of technical drawing. Another term for a person skilled in creating technical drawings is a draftsman, although modern practitioners prefer the term drafter. Among electrical and mechanical engineers, the person on the team responsible for creating the technical drawing may also be referred to as the designer.
What Do Technical Drawing Look Like?
Technical drawings contain geometric figures and symbols to convey the scope and details of the project. Many professions, such as plumbing, use their own suite of unique symbols. Right angles, parallel lines, curves and symbols constitute the technical drawing. To those on the team, each line or symbol conveys a specific about the project.It is imperative that technical drawings be accurate. If the drawing is off by even centimeters, the actual work may be off quite a bit too. This leads to disastrous consequences and costly delays in construction.
Tools for Technical Drawing
Technical drawings existed throughout time. Archaeological evidence included in a recent issue of Smithsonian magazine suggests that the architect of the Greek Parthenon scratched a technical drawing onto the marble floor to guide his workers! From ancient times to the present day, most drafters used a drafting table or a special table with slanted top and parallel rulers on either side. The parallel rulers on the sides of the table slide across the surface to hold the paper in place. Other tools include the T-square and compass.A special device called the pantograph helped usher in the modern use of mechanical and computer-assisted design (CAD) While some drafters continue to use the drafting table and handheld tools, CAD helps drafters output technical drawings accurately and efficiently.
Friday, May 13, 2011
Tips and Tricks - Converting paper drawings
This article describes a process that produces computer-generated isometric guides directly from a scan of an engineering drawing. The following is a step-by-step description that will produce a product illustration directly on the computer from paper engineering drawings. Compared to traditional methods, it reduces the cost of an illustration by approximately twenty-five percent and can provide a further cost advantage due to the extraordinary increase in throughput. Our volume has more than doubled since we implemented this process.
Step 1: Scanning
Scan the engineering drawing using a resolution suitable to its size and complexity. Scan into three pieces, "Front," "Side," and "Top." After scanning the engineering drawing, erase extraneous items such as call outs, title blocks, dimensions, etc.
Step 2: Auto-Trace
Auto-trace programs, which convert scanned raster images to vector graphic files, need their settings modified to produce acceptable results. To do this, open Corel Trace, select the batch tool, select your scans, select Trace - Edit Options -choose the Lines Tab and use the following settings:
* Curve precision - Very Good
* Line Precision - Very Good
* Target Curve Length - Medium
* Sample Rate - Fine
* Minimum Object Size - 5 pixels
* Outline Filter - None
* Max Line Width - 16 pixels
* Create lines of uniform width - 1 pixel
* Check - Horizontal and Vertical line recognition
* Check your File - Save Options - Save Options Directory - Change the Default Directory to the directory where you want the vector graphic (*.eps) files saved.
* Now launch the Auto-trace function by clicking on - Trace All
* Close the program when Corel Trace is finished.
Step 3: Create a Master Isometric Ellipse
To create a master ellipse, open CorelDRAW to a new drawing, select the ellipse tool (circle in the Toolbox) and while holding down the Control Key create a perfect circle. Then use the transform tool to apply a vertical scale of 57.4 percent. Using the Transform Roll-up, rotate the ellipse 120 degrees and Apply to Duplicate twice. You will now have a "top," "front," and "side" ellipse. Save the result as Ellipse.cdr and keep that as a master. Select all three ellipses and copy them to the clipboard.
Step 4: Create Layers
Start a new drawing and paste the ellipses you just created onto the drawing. Reduce them to 25% of their original size and place them outside the paper border. In order to differentiate between the auto traces when they are imported into CorelDraw, they need to be color-coded. Open the Layers Roll-up and create the following three new layers with the stated names and settings:
* Front - Select Visible, Deselect Printable, Deselect Locked, Select Color Override and choose Red.
* Side - Select Visible, Deselect Printable, Deselect Locked, Select Color Override and choose Blue.
* Top - Select Visible, Deselect Printable, Deselect Locked, Select Color Override and choose Green.
Printable was deselected so that when Print Preview is invoked the Auto Traces will be invisible. Locked was deselected so that the auto traces can be moved.
Step 5: Import
Import the Auto-Traces onto their respective layers correcting any orientation and rotation as necessary. Save the drawing.
Step 6: Create the Front
From the Layers Roll-up, deselect MultiLayer and select the "Front" layer. Select the trace and from the Transform Roll-up, choose a 86.6 horizontal scale and apply, then a -30.0 degree vertical skew and apply. The result will be the guide for the left face of the illustration.
Step 7: Create the Side
From the Layers Roll-up, select the "Side" layer. Select the trace and from the Transform Roll-up, choose a 86.6 horizontal scale and apply, then a 30.0 degree vertical skew and apply. The right side guide is now complete.
Step 8: Create the Top
From the Layers Roll-up, select the "Top" layer. Select the trace and from the Transform Roll-up, perform a vertical scale of 86.6% to your trace and apply. Choose a -30.0 degree horizontal skew and apply, then choose rotate -30.0 degrees and apply. You now have a "plan view" guide in isometric. Next, choose each layer and position them so that everything lines up at the front, right, top corner.
Step 9: Setting Preferences
In order to control how the software produces vector objects, some of CorelDRAW’s default settings need to be changed. Choose Preferences (Ctrl + J) and set the following:
* Place Duplicates and Clones - Horizontal = 0.000, Vertical = 0.000. These settings will ensure that duplicated objects are not offset.
* Nudge = 0.010. The default nudge is too large for technical work. Using this setting gives you more control of your work. A thin sheet metal thickness can be shown with two or three nudges.
* Constrain angle = 15.0 degrees. This is the Corel default and is perfect for an isometric projection.
* Miter limit = 45.0 degrees. This is the Corel default.
* Undo levels = 4. Limiting undo levels will conserve system resources.
Step 10: Constraining lines on an isometric axis
Make Layer 1 active. Choose your pencil tool (straight line) and while holding down the control key on the keyboard draw a line. While still holding down the key, watch the status line while moving the end point in a good sized circle you will note that the line jumps in 15 degree increments. Since the normal axis in isometric is 30 degrees, this will provide all "On Axis" and most of the "Off Axis" conditions you will encounter. Releasing the control key permits drawing on any angle.
Now the magic can happen. If you combine the ellipses, constrain the angles, and use the Auto-Traces you have everything you need to complete an illustration. I usually require approximately ten minutes to complete the above and begin drawing. In this time conventional methods would be less than twenty percent complete.
In a time of restricted budgets and impossible deadlines a process like this can be an invaluable tool. Our per-person output is a multiple of the organizations we compete with who use "high tech" methods to produce their isometrics. In the technical illustrating field this may be as close to "good, fast, and cheap" as we are likely to get.
Step 1: Scanning
Scan the engineering drawing using a resolution suitable to its size and complexity. Scan into three pieces, "Front," "Side," and "Top." After scanning the engineering drawing, erase extraneous items such as call outs, title blocks, dimensions, etc.
Step 2: Auto-Trace
Auto-trace programs, which convert scanned raster images to vector graphic files, need their settings modified to produce acceptable results. To do this, open Corel Trace, select the batch tool, select your scans, select Trace - Edit Options -choose the Lines Tab and use the following settings:
* Curve precision - Very Good
* Line Precision - Very Good
* Target Curve Length - Medium
* Sample Rate - Fine
* Minimum Object Size - 5 pixels
* Outline Filter - None
* Max Line Width - 16 pixels
* Create lines of uniform width - 1 pixel
* Check - Horizontal and Vertical line recognition
* Check your File - Save Options - Save Options Directory - Change the Default Directory to the directory where you want the vector graphic (*.eps) files saved.
* Now launch the Auto-trace function by clicking on - Trace All
* Close the program when Corel Trace is finished.
Step 3: Create a Master Isometric Ellipse
To create a master ellipse, open CorelDRAW to a new drawing, select the ellipse tool (circle in the Toolbox) and while holding down the Control Key create a perfect circle. Then use the transform tool to apply a vertical scale of 57.4 percent. Using the Transform Roll-up, rotate the ellipse 120 degrees and Apply to Duplicate twice. You will now have a "top," "front," and "side" ellipse. Save the result as Ellipse.cdr and keep that as a master. Select all three ellipses and copy them to the clipboard.
Step 4: Create Layers
Start a new drawing and paste the ellipses you just created onto the drawing. Reduce them to 25% of their original size and place them outside the paper border. In order to differentiate between the auto traces when they are imported into CorelDraw, they need to be color-coded. Open the Layers Roll-up and create the following three new layers with the stated names and settings:
* Front - Select Visible, Deselect Printable, Deselect Locked, Select Color Override and choose Red.
* Side - Select Visible, Deselect Printable, Deselect Locked, Select Color Override and choose Blue.
* Top - Select Visible, Deselect Printable, Deselect Locked, Select Color Override and choose Green.
Printable was deselected so that when Print Preview is invoked the Auto Traces will be invisible. Locked was deselected so that the auto traces can be moved.
Step 5: Import
Import the Auto-Traces onto their respective layers correcting any orientation and rotation as necessary. Save the drawing.
Step 6: Create the Front
From the Layers Roll-up, deselect MultiLayer and select the "Front" layer. Select the trace and from the Transform Roll-up, choose a 86.6 horizontal scale and apply, then a -30.0 degree vertical skew and apply. The result will be the guide for the left face of the illustration.
Step 7: Create the Side
From the Layers Roll-up, select the "Side" layer. Select the trace and from the Transform Roll-up, choose a 86.6 horizontal scale and apply, then a 30.0 degree vertical skew and apply. The right side guide is now complete.
Step 8: Create the Top
From the Layers Roll-up, select the "Top" layer. Select the trace and from the Transform Roll-up, perform a vertical scale of 86.6% to your trace and apply. Choose a -30.0 degree horizontal skew and apply, then choose rotate -30.0 degrees and apply. You now have a "plan view" guide in isometric. Next, choose each layer and position them so that everything lines up at the front, right, top corner.
Step 9: Setting Preferences
In order to control how the software produces vector objects, some of CorelDRAW’s default settings need to be changed. Choose Preferences (Ctrl + J) and set the following:
* Place Duplicates and Clones - Horizontal = 0.000, Vertical = 0.000. These settings will ensure that duplicated objects are not offset.
* Nudge = 0.010. The default nudge is too large for technical work. Using this setting gives you more control of your work. A thin sheet metal thickness can be shown with two or three nudges.
* Constrain angle = 15.0 degrees. This is the Corel default and is perfect for an isometric projection.
* Miter limit = 45.0 degrees. This is the Corel default.
* Undo levels = 4. Limiting undo levels will conserve system resources.
Step 10: Constraining lines on an isometric axis
Make Layer 1 active. Choose your pencil tool (straight line) and while holding down the control key on the keyboard draw a line. While still holding down the key, watch the status line while moving the end point in a good sized circle you will note that the line jumps in 15 degree increments. Since the normal axis in isometric is 30 degrees, this will provide all "On Axis" and most of the "Off Axis" conditions you will encounter. Releasing the control key permits drawing on any angle.
Now the magic can happen. If you combine the ellipses, constrain the angles, and use the Auto-Traces you have everything you need to complete an illustration. I usually require approximately ten minutes to complete the above and begin drawing. In this time conventional methods would be less than twenty percent complete.
In a time of restricted budgets and impossible deadlines a process like this can be an invaluable tool. Our per-person output is a multiple of the organizations we compete with who use "high tech" methods to produce their isometrics. In the technical illustrating field this may be as close to "good, fast, and cheap" as we are likely to get.
Monday, May 9, 2011
GLOBAL STANDART
1 SCOPE:
This standard establishes uniform drafting practices for preparation of engineering drawings.
2 APPLICATION:
This standard applies to all new Sauer-Danfoss (SD) Engineering drawings.
3 GENERAL:
To ensure that drawings are unambiguous, international standards (ISO and IEC) are used for general principles of presentation, definitions, scales, dimensioning, symbols, tolerances, thread designations etc.
If no international standards are available, European standards (EN), national standards or Sauer-Danfoss Standards and Guidelines are used.
The reference to GS-0074 is as shown in figure 1.
If there is a reference to GS-0074, one or more of the Sauer-Danfoss documents listed in this Guideline are used.
If other standards are used, they must be the subject of special reference.
If a drawing refers to a standard that conflicts with a standard in the body of GS-0074, then the standard noted on the drawing shall have priority.
The English language version is the original and the reference in case of dispute.
This standard establishes uniform drafting practices for preparation of engineering drawings.
2 APPLICATION:
This standard applies to all new Sauer-Danfoss (SD) Engineering drawings.
3 GENERAL:
To ensure that drawings are unambiguous, international standards (ISO and IEC) are used for general principles of presentation, definitions, scales, dimensioning, symbols, tolerances, thread designations etc.
If no international standards are available, European standards (EN), national standards or Sauer-Danfoss Standards and Guidelines are used.
The reference to GS-0074 is as shown in figure 1.
If there is a reference to GS-0074, one or more of the Sauer-Danfoss documents listed in this Guideline are used.
If other standards are used, they must be the subject of special reference.
If a drawing refers to a standard that conflicts with a standard in the body of GS-0074, then the standard noted on the drawing shall have priority.
The English language version is the original and the reference in case of dispute.
Sunday, May 8, 2011
Thursday, May 5, 2011
If its technology don't fear CAD Drawing India is near
When it comes to technicalities or operations, management guys show the white flag. The moment someone utters in the organization “Let us move into some technology jargons say 2D, 3D, vectors or similar stuff, its the top management which raises its hands in tremor. CAD short of computer aided design is one such scary technical monster which as usual turns the highly trained and qualified professionals in the organisation, apprehensive. But anyway that monster has been taken care of by CAD Drawing India. Here stands the company as a pillar guarding the diverse industrial sector from technological pitfalls. Good news for the construction and manufacturing industries, “No more drafting of technical and engineering drawings of products and buildings manually”. CAD Drawing India with its CAD Drawing Services has elevated the whole platform of engineering and technical drawings of product designs, building layouts and blueprints etc. to a new era of augmentation. Now strictly taking a step to purely mechanical details, CAD Drawing Services is used to generate design and documentation through computer technology. The CAD environments of CAD Drawing India aids the construction and manufacturing giants in aligning the design processes, drafting documentation and manufacturing processes. Its this technological potential gifted by CAD Drawing India which has empowered the construction companies to design curves and figures of their building layouts in two dimensional space, or curves, surfaces and solids in three dimensional objects. Carrying the presence of firms into a raised pedestal or epoch of advancement, CAD Drawing India has spread its ambit into a list of industries including automotive, ship building, aerospace, architecture, prosthetics etc. The list does not end here. CAD Drawing Services has managed to penetrate into a fissure of the entertainment industry. These services are also used to generate computer animations for special effects in movies and advertising. One profitable ramification of the of the ingression of CAD Drawing India is that there would be a reduction in the salary costs of the construction firms as there is no more requisite for hiring drafts-men for any manual work. No intricacies, no hyperbolic comments, no irony. Lets just keep it simple “ Why to fear, if CAD is near”. CAD Drawing India is benignly trying to offer its technology rich services to organisations with an intention to share the anguish produced from the cumbersome load of work faced by organisations. They understand the work culture complexities prevailing in the organisations. Their message is straightforward and clear, “If you have to many functions, outsource some loads to us”.
Monday, May 2, 2011
Engineering drawing McGraw-Hill Science & Technology Encyclopedia
A graphical language used by engineers and other technical personnel associated with the engineering profession. The purpose of engineering drawing is to convey graphically the ideas and information necessary for the construction or analysis of machines, structures, or systems. See also Computer graphics; Drafting; Graphic methods; Schematic drawing.
The basis for much engineering drawing is orthographic representation (projection). Objects are depicted by front, top, side, auxiliary, or oblique views, or combinations of these. The complexity of an object determines the number of views shown. At times, pictorial views are shown. See also Descriptive geometry; Pictorial drawing.
Engineering drawings often include such features as various types of lines, dimensions, lettered notes, sectional views, and symbols. They may be in the form of carefully planned and checked mechanical drawings, or they may be freehand sketches. Usually a sketch precedes the mechanical drawing.
Many objects have complicated interior details which cannot be clearly shown by means of front, top, side, or pictorial views. Section views enable the engineer or detailer to show the interior detail in such cases. Features of section drawings are cutting-plane symbols, which show where imaginary cutting planes are passed to produce the sections, and section-lining (sometimes called cross-hatching), which appears in the section view on all portions that have been in contact with the cutting plane.
In addition to describing the shape of objects, many drawings must show dimensions, so that workers can build the structure or fabricate parts that will fit together. This is accomplished by placing the required values (measurements) along dimension lines (usually outside the outlines of the object) and by giving additional information in the form of notes which are referenced to the parts in question by angled lines called leaders.
Layout drawings of different types are used in different manufacturing fields for various purposes. One is the plant layout drawing, in which the outline of the building, work areas, aisles, and individual items of equipment are all drawn to scale. Another type of layout, or preliminary assembly, drawing is the design layout, which establishes the position and clearance of parts of an assembly.
A set of working drawings usually includes detail drawings of all parts and an assembly drawing of the complete unit. Assembly drawings vary somewhat in character according to their use, as design assemblies or layouts; working drawing assemblies; general assemblies; installation assemblies; and check assemblies.
Schematic or diagrammatic drawings make use of standard symbols which indicate the direction of flow. In piping and electrical schematic diagrams, symbols are used. The fixtures or components are not labeled in most schematics because the readers usually know what the symbols represent. See also Schematic drawing; Wiring diagram.
Structural drawings include design and working drawings for structures such as building, bridges, dams, tanks, and highways. Such drawings form the basis of legal contracts. Structural drawings embody the same principles as do other engineering drawings, but use terminology and dimensioning techiques different from thoses shown in previous illustrations. See also Nomograph.
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The basis for much engineering drawing is orthographic representation (projection). Objects are depicted by front, top, side, auxiliary, or oblique views, or combinations of these. The complexity of an object determines the number of views shown. At times, pictorial views are shown. See also Descriptive geometry; Pictorial drawing.
Engineering drawings often include such features as various types of lines, dimensions, lettered notes, sectional views, and symbols. They may be in the form of carefully planned and checked mechanical drawings, or they may be freehand sketches. Usually a sketch precedes the mechanical drawing.
Many objects have complicated interior details which cannot be clearly shown by means of front, top, side, or pictorial views. Section views enable the engineer or detailer to show the interior detail in such cases. Features of section drawings are cutting-plane symbols, which show where imaginary cutting planes are passed to produce the sections, and section-lining (sometimes called cross-hatching), which appears in the section view on all portions that have been in contact with the cutting plane.
In addition to describing the shape of objects, many drawings must show dimensions, so that workers can build the structure or fabricate parts that will fit together. This is accomplished by placing the required values (measurements) along dimension lines (usually outside the outlines of the object) and by giving additional information in the form of notes which are referenced to the parts in question by angled lines called leaders.
Layout drawings of different types are used in different manufacturing fields for various purposes. One is the plant layout drawing, in which the outline of the building, work areas, aisles, and individual items of equipment are all drawn to scale. Another type of layout, or preliminary assembly, drawing is the design layout, which establishes the position and clearance of parts of an assembly.
A set of working drawings usually includes detail drawings of all parts and an assembly drawing of the complete unit. Assembly drawings vary somewhat in character according to their use, as design assemblies or layouts; working drawing assemblies; general assemblies; installation assemblies; and check assemblies.
Schematic or diagrammatic drawings make use of standard symbols which indicate the direction of flow. In piping and electrical schematic diagrams, symbols are used. The fixtures or components are not labeled in most schematics because the readers usually know what the symbols represent. See also Schematic drawing; Wiring diagram.
Structural drawings include design and working drawings for structures such as building, bridges, dams, tanks, and highways. Such drawings form the basis of legal contracts. Structural drawings embody the same principles as do other engineering drawings, but use terminology and dimensioning techiques different from thoses shown in previous illustrations. See also Nomograph.
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Sunday, May 1, 2011
Engineering drawing
Overview
Technical drawing of a certification listing for a firestop system
Engineering drawings are usually created in accordance with standardized conventions for layout, nomenclature, interpretation, appearance (such as typefaces and line styles), size, etc. One such standardized convention is called GD&T.
Each field in the Fields of engineering will have its own set of requirements for the producing drawings in terms line weight, symbols, and technical jargon. Some fields of engineering have no GD&T requirements.
The purpose of such a drawing is to accurately and unambiguously capture all the geometric features of a product or a component. The end goal of an engineering drawing is to convey all the required information that will allow a manufacturer to produce that component.
Engineering drawings used to be created by hand using tools such as pencils, ink, straightedges, T-squares, French curves, triangles, rulers, scales, and erasers. Today they are usually done electronically with computer-aided design (CAD).
The drawings are still often referred to as "blueprints" or "bluelines", although those terms are anachronistic from a literal perspective, since most copies of engineering drawings that were formerly made using a chemical-printing process that yielded graphics on blue-colored paper or, alternatively, of blue-lines on white paper, have been superseded by more modern reproduction processes that yield black or multicolour lines on white paper. The more generic term "print" is now in common usage in the U.S. to mean any paper copy of an engineering drawing.
The process of producing engineering drawings, and the skill of producing them, is often referred to as technical drawing or drafting, although technical drawings are also required for disciplines that would not ordinarily be thought of as parts of engineering.
Technical drawing of a certification listing for a firestop system
Engineering drawings are usually created in accordance with standardized conventions for layout, nomenclature, interpretation, appearance (such as typefaces and line styles), size, etc. One such standardized convention is called GD&T.
Each field in the Fields of engineering will have its own set of requirements for the producing drawings in terms line weight, symbols, and technical jargon. Some fields of engineering have no GD&T requirements.
The purpose of such a drawing is to accurately and unambiguously capture all the geometric features of a product or a component. The end goal of an engineering drawing is to convey all the required information that will allow a manufacturer to produce that component.
Engineering drawings used to be created by hand using tools such as pencils, ink, straightedges, T-squares, French curves, triangles, rulers, scales, and erasers. Today they are usually done electronically with computer-aided design (CAD).
The drawings are still often referred to as "blueprints" or "bluelines", although those terms are anachronistic from a literal perspective, since most copies of engineering drawings that were formerly made using a chemical-printing process that yielded graphics on blue-colored paper or, alternatively, of blue-lines on white paper, have been superseded by more modern reproduction processes that yield black or multicolour lines on white paper. The more generic term "print" is now in common usage in the U.S. to mean any paper copy of an engineering drawing.
The process of producing engineering drawings, and the skill of producing them, is often referred to as technical drawing or drafting, although technical drawings are also required for disciplines that would not ordinarily be thought of as parts of engineering.
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