Editing Technical drawing (section)

==Technical drawings==

===Types===
The two types of technical drawings are based on [[graphical projection]].<ref name="g2000p3"/>  This is used to create an image of a three-dimensional object onto a two-dimensional surface.

====Two-dimensional representation====
Two-dimensional representation uses [[orthographic projection]] to create an image where only two of the three dimensions of the object are seen.

====Three-dimensional representation====
In a three-dimensional representation, also referred to as a pictorial, all three dimensions of an object are visible.

===Views===

====Multiview====
{{Main article|Multiview orthographic projection}}
Multiview is a type of [[orthographic projection]]. There are two conventions for using multiview, first-angle and third-angle. In both cases, the front or main side of the object is the same. First-angle is drawing the object sides based on where they land. Example, looking at the front side, rotate the object 90&nbsp;degrees to the right. What is seen will be drawn to the right of the front side. Third-angle is drawing the object sides based on where they are. Example, looking at the front side, rotate the object 90&nbsp;degrees to the right. What is seen is actually the left side of the object and will be drawn to the left of the front side.

====Section====
While multiview relates to external surfaces of an object, [[Cross section (geometry)|section]] views show an imaginary plane cut through an object. This is often useful to show voids in an object.

====Auxiliary====
Auxiliary views utilize an additional projection plane other than the common planes in a multiview. Since the features of an object need to show the true shape and size of the object, the projection plane must be parallel to the object surface. Therefore, any surface that is not in line with the three major axis needs its own projection plane to show the features correctly.

====Pattern====
{{also|Rabattement (drafting)}}
Patterns, sometimes called '''developments''', show the size and shape of a flat piece of material needed for later bending or folding into a three-dimensional shape.<ref>Goetsch et al. (2000), p. 341</ref>

====Exploded====
{{Main article|Exploded-view drawing}}
[[Image:Gear pump exploded.svg|thumb|[[Exploded-view drawing]] of a [[gear pump]]]]

An ''exploded-view drawing'' is a technical drawing of an object that shows the relationship or order of [[manufacturing|assembly]] of the various parts.<ref name="US PTO05">{{cite web|url=http://www.uspto.gov/web/offices/pac/doc/general/#drawing |title=General Information Concerning Patents § 1.84 Standards for drawings |date=January 2005 |access-date=13 February 2009 |website=[[United States Patent and Trademark Office|USPTO.gov]] |archive-url=https://web.archive.org/web/20090130105045/http://www.uspto.gov/web/offices/pac/doc/general/#drawing |archive-date=30 January 2009 |url-status=dead}}</ref> It shows the components of an object slightly separated by distance or suspended in surrounding space in the case of a three-[[dimension]]al exploded diagram. An object is represented as if there had been a small controlled [[explosion]] emanating from the middle of the object, causing the object's parts to be separated relative distances away from their original locations.

An [[Exploded-view drawing|exploded view drawing]] (EVD) can show the intended assembly of mechanical or other parts. In mechanical systems, the component closest to the center is usually assembled first or is the main part inside which the other parts are assembled. The EVD can also help to represent the disassembly of parts, where those on the outside are normally removed first.<ref>Michael E. Brumbach, Jeffrey A. Clade (2003). ''Industrial Maintenance''. Cengage Learning, 2003 {{ISBN|0-7668-2695-3}}, p.65</ref>

===Standards and conventions===

====Basic drafting paper sizes====
{{Main article|Paper size}}

There have been many standard sizes of [[paper]] at different times and in different countries, but today most of the world uses the international standard (A4 and its siblings). North America uses its own sizes.

<gallery>
Image:A size illustration2 with letter and legal.svg|ISO A-series paper sizes, used in most countries of the world
Image:ANSI size illustration.svg|ANSI paper sizes, used in North America
</gallery>

===Patent drawing===
[[File:Wright brothers patent plans 1908.jpg|thumb|The [[Wright brothers]]' [[patent drawing]]s for their aeroplane (1908)]]
{{Main article|Patent drawing}}

The applicant for a [[patent]] will be required by [[law]] to furnish a [[drawing]] of the [[invention]] if or when the nature of the case requires a drawing to understand the invention with the job. This drawing must be filed with the application. This includes practically all inventions except [[wikt:composition|composition]]s of matter or [[Industrial process|process]]es, but a drawing may also be useful in the case of many processes.<ref name="US PTO05"/>

The drawing must show every feature of the invention [[specification|specified]] in the claims and is required by the [[patent office]] rules to be in a particular form. The Office specifies the size of the sheet on which the drawing is made, the type of paper, the margins, and other details relating to the making of the drawing. The reason for specifying the standards in detail is that the drawings are printed and published in a uniform style when the patent issues and the drawings must also be such that they can be readily understood by people using the patent descriptions.<ref name="US PTO05"/>

===Sets of technical drawings===

====Working drawings for production====
[[Working drawing]]s are the set of technical drawings used during the manufacturing phase of a product.<ref>Ralph W. Liebing (1999). ''Architectural working drawings''. John Wiley and Sons, 1999. {{ISBN|0-471-34876-7}}.</ref> In architecture, these include [[civil drawing]]s, [[architectural drawing]]s, [[structural drawing]]s, [[mechanical systems drawing]]s, [[electrical drawing]]s, and [[plumbing drawing]]s.

====Assembly drawings====
Assembly drawings show how different parts go together, identify those parts by number, and have a parts list, often referred to as a bill of materials.<ref>Goetsch et al. (2000), p. 613</ref>  In a technical service manual, this type of drawing may be referred to as an [[exploded view drawing]] or diagram.
These parts may be used in engineering.

====As-fitted drawings====
Also called ''as-built'' and ''as-made'', an ''as-fitted'' drawing represents a record of a completed work, literally as fitted. An as-fitted drawing is based upon working drawings and updated to reflect any changes during construction or manufacture.<ref name="BusinessDictionary.com 2017">{{cite web|title=as-built drawings| website=BusinessDictionary.com | date=2017-12-26 | url=http://www.businessdictionary.com/definition/as-built-drawings.html | access-date=2018-01-01 |archive-url=https://web.archive.org/web/20171203090423/http://www.businessdictionary.com/definition/as-built-drawings.html |archive-date=3 December 2017 |url-status=dead}}</ref>