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Scales. Introduction to Drafting and Design. What is a scale?. Scale. There are two different meanings for the word scale The size to which an object is drawn An instrument with a system of ordered marks at fixed intervals used as reference standards in measurements.
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Scales Introduction to Drafting and Design
Scale • There are two different meanings for the word scale • The size to which an object is drawn • An instrument with a system of ordered marks at fixed intervals used as reference standards in measurements. • A scale establishes a proportion used in determining the dimensional relationship of an actual object to the representation of the same object on a drawing.
Types of Scales • There are four different shapes of scales: • Two Bevel • Four Bevel • Opposite Bevel • Triangular • Triangular shaped scales are the most common scale used.
Types of Scales • There are three major scales are used in today’s industries • Architect Scale • Engineer Scale • Metric Scale
Architect Scale • Used to make drawings of buildings and building detail • Six sided with 11 different scales • Common scales on an architect scale other than the “full” scale of 16 • The 16 or full scale is a standard ruler with each mark representing 1/16” of an inch • The scales are usually grouped together when one factor is twice the other • When scales are grouped together, one of the scales is read from one end of the instrument and the other scale is read from the opposite end.
Engineer Scale • Also known as a civil scale • Is used for measuring length and transferring length of larger scale plans such as site plans • An Engineer Scale is divided into 6 scales
Engineer Scale • The engineer scale and the architect scale are similar in appearance • The engineer scale is designed to be more precise by using a decimal scaling scheme • Whereas an architect’s scale uses fractional scaling. • Engineer scales are only read from left to right where architect scales can be read from left to right and right to left.
Metric Scale • Used for drawings made in metric units or meters • The metric scale uses ratios
How do we use all of the scales? • To make a measurement, observe the scale from directly above. • Mark the desired measurement on the paper by using a light perpendicular line made with a sharp pencil • Keep you scale clean • DO NOT mark on the scale itself • DO NOT use the scale to draw straight lines
Architect Scale • To take a measurement with an architect’s scale follow these steps: • Find the scale that matches the scale of the drawing • Align the zero mark of the scale with one side of the object • Read the foot measurement by finding the closest tick mark on the scale that is to the end of the object without going past the end of the object. • Then read the inch measurement by counting the number of small tick marks that are located past the large tick mark.
Examples Answer: 1 - 5/16 Answer: 2 – 1/16 Answer: 2 – 3/4
Engineer Scale • To take a measurement with an engineer’s scale, first obtain the scale on the drawing. • The scale will either be in an inch to feet equality (1” = 20’) or a ratio (1:20) • Locate the matching scale on the engineer’s scale and line up the zero on the left side with the object being measured. • Find the tick mark that lines up with the other end. • Read the major marks and add the minor marks as the tenths and hundredths.
Examples Use the ratio 1” = 10’ Answer: 15.5’ Use the ratio 1” = 30’ Answer: 56’ Use the ratio 1” = 600’ Answer: 1150’
Metric Scale • Metric scales can be used to reduce or enlarge a drawing • Most metric drawings are drawn with a 1:1 metric scale. • To use a metric scale, find the correct ratio that matches the drawing ratio • Place the end of the object on the zero line • Find the large tick mark to indicate the tens, then use the little tick marks to find the ones and decimal numbers.
Examples Answer: 75’ Answer: 92’ Answer: 460’
Scale of a Drawing • Scales are in constant use on the drawing board because accurate drawings are a must • To select a scale for a drawing you must consider the following about the drawing: • The actual size of the objects drawn • The amount of detail to show • The media size (size of paper used for drawing) • The amount of dimension and notes required • The scale of a drawing is listed in the title block of the drawing
In summary … • There are three scales that we can use: architecture, engineering and metric scales • These scales can be either two bevel, four bevel, opposite bevel and triangular shaped • The triangular shape is the one that is used the most • Make sure to view the scale from above when making measurements and place the end of the line on the zero marker • Now take what you have learned in this presentation and complete Activity 8.1 – What’s the Scale?