Classwork Series and Exercises { Basic Technology- JSS1}: Board Practices

Board Practices

In order to display good board practice, it is necessary to use the appropriate drawing instruments. This chapter treats the correct procedures for setting the drawing paper, correct use of each drawing instrument, how to sharpen pencils, borderlines, title block, good freehand lettering and types and use of lines in technical drawing habits.

Setting up the Board

Drawing instruments and materials required for good board practice are listed below:

Drawing board, Tee-square, Set-square (30⁰, 60⁰, 45⁰ angles), Compass, Dividers, Protractor, French curves, Drawing pencils (HB and 2H), Eraser and Drawing paper.

Procedures for Setting Drawing Paper on the Board

Step 1: Place the drawing board conveniently on the table with the square edge to the left-hand side.

Step 2: Place the drawing paper on the board, leaving equal space all round

Step 3: Place the tee-square on the paper, and gently move or slide the tee-square to the top edge of the paper. Set the top edge of the paper parallel to the edge of the tee-square with the stock of the tee-square firmly against the edge of the drawing board on the left-hand side.

Step 4: Gently slide the tee-square down without the paper.

Step 5: Cut four pieces of adhesive tape to hold the paper in position and place them over the four corners of the paper or use two metal clips to hold the paper to the board on the top right and top left corners.

Sharpening of Drawing Pencils

A well sharpened pencil is very essential to technical drawing in that it improves the quality of line work and enhances good draftsmanship. It makes the drawing lines thin and neat. Materials for sharpening pencils are razor blade and sharpener. Pencils for lettering and free hand sketching should be sharpened to a ‘conical point’ while those for geometrical or engineering drawing should be sharpened to a ‘chisel point’.

Drawing Horizontal Lines with Tee-square

All horizontal lines are drawn with the aid of tee-square, usually from left to right, and rotating the pencil as the line is drawn. This ensures uniform thickness of the line.

Drawing Lines with a Set-square

The set-square is used sitting squarely on the tee-square to draw vertical lines. Angle lines (inclined lines) are also drawn with the set-squares turned in different directions depending on the desired angle.

The vertical strokes are made by finger movements and the horizontal strokes are made by pivoting the whole hand at the risk, while the fingers move slightly to keep the strokes perfectly horizontal.

Drawing a Circle with Compass

Mark the centre of the circle and guide the needle point of the compass to the centre of the circle with the small finger. The compass is then turned slightly in the direction of the strokes. Complete the circle with the compass, the stroke is completed to form the circle.

Types and Uses of Lines in Technical Drawing

The different lines used to make a drawing are shown below through practice, you will be able to draw them and identify where to use each of them. The different lines can be called ‘an alphabet lines.’

Drawing Borderlines

Borderlines are also called margins. A space of about 10-15mm is left all around the drawing paper and is demarcated with straight lines. These lines are called borderlines. They beautify the drawing paper and protect the drawing inside.

Title Block

After has been laid out on the paper, it is necessary to give some information to enable others understand what the drawing is about. Such information relating to name of designer, school, class, date, scale, etc, is put in what is known as the title block. The title block is usually at the bottom right-hand corner of the drawing paper.

Lettering

Lettering is the art of writing letters (alphabets) and numbers (figures) in bold form or lower-case form on drawings.

Good lettering and neat line work are very pleasing to look at on a standard. Lettering therefore, complements the overall appearance of the drawing i.e. good lettering adds more to the beauty of the work which is a source of joy and pride. So also, the appearance of a drawing can be marked by bad lettering.

However, the most important is that the characters of the lettering must be uniform, legible, equally spaced and well proportioned. Lettering can be in capital or small letters. There are various types of lettering, but the standard lettering for engineering and technical drawing is known as ‘commercial gothic’ in either vertical or inclined styles. Lettering can be done either by free hand or with an instrument (lettering sets and templates), but technical drawing students are encouraged to use freehand method. Always write your lettering between two construction lines.