Plain scale Diagonal Scale plane scale engineering graphics

1. ENGINEERING GRAPHICS
PLAIN SCALE
DIAGONAL SCALE

2. Reduced scale:
Dimensions of large
objects must be
reduced to draw on
standard size
drawing sheet.
Example:
Map Of any country

4. Enlarged scale:
Similarly in case of
tiny small objects
dimensions must be
increased to draw
on drawing sheet.
Example: Drawing
of wrist watch
parts.

5. Plain scale
A plain scale consists of a line divided into suitable number of
equal units. The first unit is subdivided into smaller parts.
The plain scales give only two dimensions, such as a unit
and it's subunit or it's fraction.

6. LENGTH OF SCALE = (R.F. ) × (MAX. LENGTH TO BE MEASURED.)

7. PROBLEM NO.1
Draw a scale 1 cm = 1 meter to read meters and decimeters,
to measure maximum distance of 6 m.
Show on it a distance of 4 m and 6 dm.

8. SOLUTION:-

9.  R.F.= 1cm/ 1meter = 1/100
We know that, 1 meter = 10 decimeter = 100 cm
 Length of scale = (R.F.) X max. distance
= 1/100 X 600 cm
= 6 cms

10. ……ANSWER
Take height of scale 5 mm to 10 mm for getting a look of
scale

11. PROBLEM NO.2
In a map a 36 km distance is shown by a line 45 cms long.
Calculate the R.F. and Construct a plain scale to read kilometers
and hectometers, for measuring maximum 12 km distance.
Show a distance of 8.3 km on it.

12. CONSTRUCTION:-
Calculate R.F.
R.F.= 45 cm/ 36 km
= 45 cm/ (36 × 1000 × 100)cm
= 1/ 80,000

13. Length of scale = (R.F.) × max. distance
= (1/ 80000) × 12 km
= (1/ 80000) × (12 × 1000 × 100)cm
= 15 cm

14. Take height of scale 5 mm to 10 mm for getting a look of scale
……ANSWER

15. Problem 3:
Construct a plain scale to show kilometers and hectometers when
25 mm is equal to 1 km and long enough to measure up to 6 km.
Find RF and show a distance of 3km and 4 hectometer on the scale.

18. Problem 4:
Construct a plain scale of R.F. = 1:50 to show meters and
decimeters and long enough up to 8 meter. Indicate 6.7 m
distance on scale

21. Problem 5:
Construct a plain scale with RF = 1/5 to show decimeters (dm) and
centimeters. The scale should be long enough to measure 1 m. Show the
length of 7.4 dm on it.

24. 6. Construct a Diagonal scale of R.F= 1/500 to read meters and decimeters. It
should be able to read maximum up to 80 meters. Measure a distance of 47.8
meters.
8
7 0 70
Length of scale = (1/500) * (80*100 cm) = 16 cm
10 20
10
decimeter
Meter
40
47.8 meter
30 50 60
meter
1
3
5
10
2
4
6
7
9
1
2
5

25. 7. Construct a Diagonal scale of R.F= 3/100 to read meters, decimeters and
cm. It should be able to read maximum up to 5 meters. Measure a distance of
3.57 meters.
Solution

26. 3 meter 5 decimeter 7 cm
3.57 meter =
cm
Meter
dm