Three examples of diagonal scales follow.
This scale would be used where the drawing is twice the m* of the natural object and the draughtsman has to be able to measure on a scale accurate to 01 mm
The longest natural dimension is 60 mm. This length is first divided into six 10 mm intervals. The first 10 mm is then divided into 10 pans, each 1 mm wide (scaled) Each of these 1 mm intervals is divided with a diagonal into 10 more equal parts
echtlich geschütztes Material
To construct a diagonal seal«, 30 mm = 1 mm, 4 m long to read to 10mm Fig 1/5 Length of scale is 4 * 30 mm - 120 mm First division into 4 30 mm lengths Second division into 10 100 mm lengths. Diagonal divoion into 10 10 mm lengths
Urheberrechtlich geschütztes Ma
To construct • diagonal seal*. 60 mm =1 mm. 3 mm long to re»d 0.01 mm Fig. 1/6
Length ol scale is 3 * 50 mm - 150 mm. First division is 3 50 mm lengths. Second division is 10 0.1 mm lengths. Diagonal division «10 0.01 mm lengths.
It is possible to construct one plain scale directly from another, so that the new scale is proportional to the original one. An example of this is given in Fig. 111. The new scale is a copy of the original one but is J times larger. The proportions of the scales can be varied by changing the ratios of the lines AB to BC
2. Construct a plain scale of 50 mm - 300 mm to read to 10 mm up to 1200 mm. Using this scale, draw to scale a triangle having a perimeter of 1200 mm and having sides in the ratio 3:4:Q. Print neatly along each side the length to the nearest 10 mm.
Oxford Local Examinations (Question originally set in Imperial units; see Chapter 2 for information not in Chapter 1).
3. Construct the plain figure shown in Fig. 2 and then, by means of a proportional scale, draw a similar figure standing on the base AG. All angles must be constructed geometrically in the first figure. Measure and state the length of the side corresponding with CO. Oxford Local Examinations (Question originally set in Impenal units; see Chaptar 2 for information not in Chapter 1).
1. (a) Draw the simple key shown m Fig. 1 full size
(b) Construct a plain scale with a representative fraction of suitable for use in the making of an enlarged drawing of this key. Do not draw this key again. Southern Region»/ Exemptions Board (Question originally set in Imperial units).
Was this article helpful?