Rulers

Architectural Ruler

• Is a specialized ruler. It is used in making or measuring from reduced scale drawings, such as blueprints and floor plans. It is marked with a range of calibrated scales (ratios).

•Architect's scale rulers used in Britain and other metric areas are marked with ratios without reference to a base unit. Therefore a drawing will indicate both its scale and the unit of measurement being used.

The paired scales are

•1:1/1:10 •1:2/1:20 •1:5/1:50 •1:100/1:200 •1:500/1:1000 •1:1250/1:2500

Architectural Scale• In the United States, and prior to metrification in Britain, Canada and Australia,

architect's scales are/were marked as a ratio of x inches-to-the-foot (typically written as x"=1'-0"). For example one inch measured from a drawing with a scale of "one-inch-to-the-foot" is equivalent to one foot in the real world (a scale of 1:12) whereas one inch measured from a drawing with a scale of "two-inches-to-the-foot" is equivalent to six inches in the real world (a scale of 1:6). It is not to be confused with a true unit less ratio (inches to inches)-- a 1:50 architectural scale would be a 1:60 unit less scale.

• Typical scales used in the United States are:• Full scale, with inches divided into sixteenths of an inch • The following scales are generally grouped in pairs using the same dual-numbered index

line:• three-inches-to-the-foot (3"=1'-0") (ratio equivalent 1:4)/one-and-one-half-inch-to-the-

foot (1-1/2"=1'-0") (1:8) • one-inch-to-the-foot (1"=1'-0") (1:12)/one-half-inch-to-the-foot (1/2"=1'-0") (1:24) • three-quarters-inch-to-the-foot (3/4"=1'-0") (1:16)/three-eighths-inch-to-the-foot

(3/8"=1'-0") (1:32) • one-quarter-inch-to-the-foot (1/4"=1'-0") (1:48)/one-eighth-inch-to-the-foot (1/8"=1'-0")

(1:96) • three-sixteenths-inch-to-the-foot (3/16"=1'-0") (1:64)/three-thirty-seconds-inch-to-the-

foot (3/32"=1'0") (1:128)

Engineers Scale Ruler• An engineer's scale is a tool for measuring

distances and transferring measurements at a fixed ratio of length. It is commonly made of plastic and is just over twelve inches (300 mm) long, so that the measuring ticks at the edges do not become unusable by wear. It is used in making engineering drawings, commonly called blueprints, in scale. For example, "one-tenth size" would appear on a drawing to indicate a part larger than the paper itself. It is not to be used to measure machined parts to see if they meet specifications.

•The engineer's scale came into existence when machining parts required a greater precision than the usual, binary fractionalization of the inch as in the architect's scale for houses and furniture. They were used, for example, in laying out printed circuit boards with the spacing of leads from integrated circuit chips as one-tenth of an inch. In the twenty-first century, those which are commonly purchased in the US are actually made in Germany.

•An engineer's scale, although identical at first glance to the architect's scale, it has a different set of measurements.

Typical engineering scales RATIO SCALE DECIMAL RECIPROCAL

1:01FULL 1 1x

1:026"=1'-0" 0.5 2x

1:043"=1'-0" 0.25 4x

1:081-1/2"=1'-0" 0.125 8x

1:163/4"=1'-0" 0.0625 16x

1:241/2"=1'-0" 0.0417 24x

1:323/8"=1'-0" 0.03125 32x

1:481/4"=1'-0" 0.0208 48x

0.086111113/16"=1'-0" 0.0156 64x

0.108333331/8"=1'-0" 0.0104 96x

0.130555563/32"=1'-0" 0.0078 128x

How to Read a Scaled Ruler?• Locate appropriate scale factor at end of scale ruler• Place line or object to be measured at zero• Read measurements from side of scale factor to end of line or object

▫ Scale factor on left = Read measurements from left to right▫ Scale factor on right = Read measurements from right to left

• Be careful to read measurements from lowest to greatest (ascending) order

• Be careful not to read measurements from scale factor from other end of scale ruler

• To measure foot increment, move scale ruler to lowest foot increment and record

• To measure inch increment, measure line or object from left of zero (scale factor on left) or right of zero (scale factor on right)

▫ Note: Measurements from zero to scale factor are 12 inches or 1 foot▫ Determine measurements by determining 3”, 6” and 9” increments first

• Record measurement in foot and inches. Do not forget symbols for foot ( ‘ ) and inches ( “ )

•Read and Work on Scale Ruler Worksheets▫These are worth 35point total

Review

•Day 2▫Quiz On Friday Over Material

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.

Types of Drafting▫Engineering drawing ▫Cutaway drawings ▫Exploded view drawing ▫Patent drawing ▫Technical illustrations ▫Technical sketches ▫Working drawings

Drafter

•Drafters prepare technical drawings and plans, which are used to build everything from manufactured products such as toys, toasters, industrial machinery, and spacecraft to structures such as houses, office buildings, and oil and gas pipelines.

Drafting Specialties• Drafting work has many specialties:• Aeronautical drafters prepare engineering drawings detailing plans and

specifications used in the manufacture of aircraft, missiles, and related parts.

• Architectural drafters draw architectural and structural features of buildings and other structures. These workers may specialize in a type of structure, such as residential or commercial, or in a kind of material used, such as reinforced concrete, masonry, steel, or timber.

• Civil drafters prepare drawings and topographical and relief maps used in major construction or civil engineering projects, such as highways, bridges, pipelines, flood control projects, and water and sewage systems.

• Electrical drafters prepare wiring and layout diagrams used by workers who erect, install, and repair electrical equipment and wiring in communication centers, power plants, electrical distribution systems, and buildings.

• Electronics drafters draw wiring diagrams, circuit board assembly diagrams, schematics, and layout drawings used in the manufacture, installation, and repair of electronic devices and components.

• Mechanical drafters prepare drawings showing the detail and assembly of a wide variety of machinery and mechanical devices, indicating dimensions, fastening methods, and other requirements.

• Process piping or pipeline drafters prepare drawings used in the layout, construction, and operation of oil and gas fields, refineries, chemical plants, and process piping systems.

Manual Drafting• The basic drafting

procedure is to place a piece of paper (or other material) on a smooth surface with right-angle corners and straight sides—typically a drafting table. A sliding straightedge known as a T-square is then placed on one of the sides, allowing it to be slid across the side of the table, and over the surface of the paper.

Manual Drafting• Parallel lines" can be drawn simply by moving the T-

square and running a pencil or technical pen along the T-square's edge, but more typically the T-square is used as a tool to hold other devices such as set squares or triangles. In this case the drafter places one or more triangles of known angles on the T-square—which is itself at right angles to the edge of the table—and can then draw lines at any chosen angle to others on the page. Modern drafting tables (which have by now largely been replaced by CAD workstations) come equipped with a parallel rule that is supported on both sides of the table to slide over a large piece of paper. Because it is secured on both sides, lines drawn along the edge are guaranteed to be parallel.

• In addition, the drafter uses several tools to draw curves and circles. Primary among these are the compasses, used for drawing simple arcs and circles, and the: French curve, typically a piece of plastic with complex curves on it. A spline is a rubber coated articulated metal that can be manually bent to most curves.

Line Conventions

Lines of varying style and thickness are used in specific ways to develop and communicate graphic messages about an object’s geometry. The next few slides show some basic line conventions and their use.

Line Conventions

Line Conventions

Construction Line: Very lightly drawn lines used as guides to help draw all other lines and shapes properly.

Construction Line

Line ConventionsObject Lines: Lines are thick and dark; used to define the

object.. Object Line

Object Line

Line ConventionsHidden Line: Lines used to show interior detail that is not visible from the outside of the part.

Hidden Line

Hidden Line

Line ConventionsCenter Line: Lines that definethe center of arcs, circles, or Symmetrical parts. They are half as thick as an object line.

Center Line

Center Line

Line ConventionsSection Lines: Lines are used to define where there is material after a part of the object is cut away.

Section Line

Section Line

Line ConventionsShort-Break Line: A freehand drawn line that shows where a part is broken to reveal detail behind the part or to shorten a long continuous part.

Short-Break Line

Line Conventions

Dimension Line

Dimension Line

• Dimension Lines: Lines that are used to show distance.

• Arrows are drawn on the ends to show where the dimension line starts and ends.

• The actual distance is usually located in the middle of this line to let you know the distance being communicated.

Line Conventions

Extension Line

Extension Line

• Extension Lines: Lines used to show where a dimension starts and stops on an object.

• Used with dimension lines to properly dimension an object.

• The line is 1/16” away from the part as to not get confused with the object lines.

Line ConventionsLong-Break

Line• Long-Break Lines:

Used to shorten very long objects that do not change in detail.

• The line is usually represented as a jagged cut or break.

Line Conventions

•Leader Lines: Leader lines are used to show dimensions of arcs, circles and to help show detail.

Leader Line

Leader Line

Though these standards relate to technical drawing, which is far more precise than freehand sketching, their conventions should be used as a guide when sketching.

Line Conventions

When sketching complex objects, different line types will often overlap each other. Therefore, line precedence must be exercised.

Precedence of Lines

The following are rules that govern line precedence in sketches and technical drawings.

• Object lines take precedence over hidden and center lines.

• Hidden lines take precedence over center lines.

• Cutting plane lines take precedence over all others.

Precedence of Lines

Precedence of LinesObject lines take precedence over

the hidden lines.

An object line here takesprecedence over the center line.

Precedence of Lines

•Object lines take precedence over the center lines you would see from the hole.

•Object lines take precedence over the hidden lines you would see from the slot cut out in top view.

An object line here takesprecedence over the center line.

An object line here takesprecedence over the hidden line.

Technical Sketch Like an artist may use sketches to develop ideas for a painting or sculpture, technical sketches are used during the development of ideas for initial or preliminary plans. The ability to make quick and accurate sketches is a valuable advantage that helps you convey design ideas to others. A sketch may be of an object, an idea of something you are thinking about, or a combination of both. Most of us think of a sketch as a freehand drawing, which is not always the case. You may sketch on graph paper to take advantage of the lined squares, or you may sketch on plain paper with or without the help of drawing instruments. Technical sketches are drawn without mechanical aid, like a t-square, compass, or straight edge, but, like other forms of architectural drafting, are drawn to scale and contain a variety of line weights and line styles (Figure 1). The pencil or pen is guided by the hand of the drafter alone and this is usually done on trace paper over a 1/4" grid paper. The grid paper becomes the guide helping to keep lines straight.

Lettering•Lettering is used on drawings to give

dimensions and other pertinent information needed to fully describe the item.

•The lettering must be neat and legible if it is to be easily read and understood.

•A drawing will be improved by good lettering.

•However, a good drawing will look sloppy and unprofessional if the lettering is poorly done.

Lettering, Continued…

•The American National Standards Institute (ANSI) recommends that the Single-Stroke Gothic Alphabet be the accepted lettering standard

  

Lettering, Continued…

•It can be drawn rapidly and is highly legible because each part of every letter is made by a single stroke.

Lettering, Continued…

•This is because there are no serifs on the letters of this alphabet. ▫A serif is like a tiny foot on a letter;

alphabets that have serifs are more difficult to letter by hand. An alphabet without serifs is always called a san serif alphabet.

Lettering, Continued…

• Today, because of computers, there are many different alphabet styles (also called fonts). ▫ When lettering a drawing,

if the single stroke Gothic alphabet is not available, choose a san serif font and use only upper case letters.   

Good Lettering, Continued…

•Use guide lines▫Guide lines should be drawn so lightly they

will not show up on a print made from the drawing

▫Vertical guide lines may be used to assure that the letters will be vertical

▫Inclined guide lines are drawn at 67 1/20 to the horizontal line when inclined lettering is to be used.

INCLINED GUIDE LINES HELP KEEP

INCLINED LETTERING UNIFORM

Good Lettering, Continued…

•Only one form of lettering should appear on a drawing.

AVOID

COMbINING

SEVERAL fORMS

Of LETTERING.

Lettering, Continued…

•Spacing:▫Proper spacing of the letters is important. ▫The letters should be placed so spaces

between the letters appear to be about the same.

SPACED VISUALLY

SPACED BY MEASURING