Free Hand Drawing

8/12/2019 Free Hand Drawing

1/16

Chapter 21

FREEHAND DRAWING

Freehand drawing refers to the act of drawing the views of the object

without using a scale or instruments. Though freehand sketches are

drawn without exact dimensions, they should be proportionate. A goodfreehand drawing is one which resembles the scaled drawing. This

chapter provides important tips and tricks for freehand drawing.

Pencil Use

Freehand drawings are prepared using a pencil, a paper and an eraser.

A soft grade pencil, preferably HB grade, with rounded lead tip(Section 1.4.2) will provide good results. The pencil shall be gripped at

distance of approximately 30 mm from lead tip. The angle between

pencil and paper should be smaller (preferably 45) than that used in

instrumental drawing.


2/16

Hand Strokes

The next requirement is the practice of line strokes as explained in

Section 2.2.5. In freehand sketching, maximum hand movement must

be made about the wrist and elbow. The movement about the shoulder

should be as minimum as possible.

While practicing hand strokes for straight lines, make movements

about the elbow and shoulder keeping the wrist rigid. For circular hand

strokes, make movements about the knuckle and wrist.

Visual Judgement

Judgement about lengths and angles is very important in freehand

sketching. It helps to draw proportionate drawings. Readers are

advised to see closely the ruling edge of the scale. The spacing

between centimetre marks should be observed carefully. This willenable the readers to know what distance on a paper approximately

corresponds to 1 cm.

Judgement about angles can be practiced in a similar way by observing

the protractor scale.


3/16

SKETCHING STRAIGHT LINES

Straight lines can be drawn in three steps as follows, Fig. 21.1:

Step 1Locate the start point 1 and end point 2. Without touching the pencil to

the paper, make trial movements from left to right and right to left.

Step 2

Sketch a very light segmented line starting from 1 and going on till 2.

Step 3

Draw a continuous thick line over the segmented line. The segments not

aligned to the direction of the line should be discarded.


4/16

SKETCHING CIRCLES

Small Circles

Method I: Diagonal l ine method Adopt the following steps, Fig. 21.4.

Step 1

Draw two light centrelineshorizontal and vertical. Locate the centre at

their intersection. Draw diagonal lines in each quadrant. These lines will

approximately bisect the angle formed by the centrelines.

Step 2

Mark small perpendicular segments on each of the lines, at a distance

equal to radius by the visual judgment. First, mark the segments on the

centrelines and then on the diagonal lines.

Step 3

Draw a smooth freehand circle tangent to each segment. Follow

direction sense. Make the circle sufficiently thick and uniform.


5/16


6/16

Method II: Square method Adopt the following steps, Fig. 21.5.

Step 1Draw a square of sides equal to the diameter of the circle. Mark the

midpoint of each side.

Step 2

Draw two diagonals of the square. On each diagonal, locate points at a

distance of radius from the centre.

Step 3

Draw tangent arcs to square sides at the midpoints. Draw perpendicular

arcs at the points on diagonals. Join the arcs to complete the circle.

The construction lines may be erased after the circle is completed.Circular arcs may be drawn in a similar way.


7/16


8/16

Large Circles

Method I: Paper str ip method Adopt the following steps, Fig. 21.6.Step 1

Take a paper strip and make a hole at one end of it. The hole may be of

nailtip size or fingertip size. At the other end, make a small V-notch. The

perpendicular distance between the hole and V-notch will decide the

radius of the circle.

Step 2

Locate the centre of the circle on paper. Place the paper strip such that

the hole will match with the centre. Insert a finger of left hand (or a nail)

in the hole and hold the finger firmly at the centre. Fix the pencil tip in

the V-notch and rotate the strip clockwise with the help of the pencilabout the centre to draw the circle.


9/16


10/16

Method 2: Hand Compass Adopt the following steps, Fig. 21.7.

Step 1Form the hand compass as shown. The little finger will act as a needle

leg. The pencil is to be held between the forefinger and the middle

finger. The pencil tip should protrude the finger tips.

Step 2

Locate the centre of the circle on paper. Hold hand compass on the

paper with the little fingertip on the centre and pencil tip touching the

paper. By the other hand, rotate the paper gently in anticlockwise

direction about the fingertip pivot, holding the hand compass rigidly.


11/16


12/16

SKETCHING THE ANGLES

The angles of 90, 45, 30 and 10 can be sketched as explained in Fig.

21.9. A 5 angle can be obtained by dividing 10 angle equally.

90 angle

Draw a horizontal line and a vertical line to form a 90 angle.

45 angle

First construct a 90 angle and then draw a square as shown. Draw thediagonal of the square to form a 45 angle.

30 angle

First construct a 90 angle and draw a quadrant arc. Divide the arc by

trial and error in the three approximately equal parts. Join each division

with the centre of the arc to form 30 angles.10 angle

First construct 30 angle as explained. Divide the 30 arc into three

approximate parts. Join each division with the centre of the angle to

form 10 angles.


13/16


14/16

MULTIVIEW ORTHOGRAPHIC SKETCHING

It is easy to maintain proportions in smaller orthographic drawings.

Bigger drawings may get distorted when drawn freehand. To avoid

distortions, bigger drawings are divided into smaller blocks. Each blockis then drawn separately, considering its proportion in relation to the

adjacent block.

Example 21.1 Figure 21.10(a) shows a pictorial view of a gasket. Sketch

its FV.

Solution Refer Fig. 21.10(b). Complete the sketch stepwise as shown.


15/16

ISOMETRIC SKETCHING

The small isometric drawings, may be constructed in three steps as

shown in Fig. 21.11. In the first step, draw isometric axes. In the second

step, mark the length, width and height of the block on the

corresponding axes. In the third step, draw the edges of the block by

drawing lines parallel to the isometric axes.For bigger drawings, isometric grid may be used initially. An isometric

grid consists of a number of lines drawn parallel to three isometric

axes, Fig. 21.12(b).

Example 21.2 Figure 21.12(a) shows FV and TV of an object. Sketch its

isometric view.Solution Refer Fig. 21.12(b). Complete the sketch stepwise as shown.


16/16

Documents

Free Hand Drawing