Section 5. Graphic techniques for portfolio presentation

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1 Graphics techniques 117 Section 5 Graphic techniques for portfolio presentation A general knowledge of some basic graphic techniques is needed by all Technology students in order that the presentation and communication of their ideas can be displayed clearly. Graphics is there to help you express and communicate your ideas; it is a tool for Technology and that is how it is treated here. Graphics can be taken as a subject on its own, where instrument drawing is studied (it used to be called Technical Drawing). This section of the book is not meant to be used for pure Graphics but instead as a source of techniques for making your work look good; conveying your ideas and designs in their best form. The techniques to be covered are: crating oblique view rendering and shading isometric view orthographic (working) drawings exploded diagrams schematic diagrams. Crating Crating is an aid to sketching. As the name implies, you start off by drawing a box or crate which acts as a framework. The quickest and easiest way to draw a 3D box or crate is to draw two squares of the same size, one slightly above and to one side of the other. You then join the corners of both the squares to each other. That is, top left-hand corner of one square to top lefthand corner of the second square; then top right-hand corner of one square to top right-hand corner of the second square; and so on until all corners are connected. You will now have a crate sitting before you. These lines should be drawn freehand and not with a ruler. Look at the stages below: Practise doing longer, shorter, rectangular and square crates of all different sizes and angles to prepare you for the next stage in crating. When sketching an object such as a cylindrical pencil case or a hammer, the object can sometimes prove difficult. First of all, look at the object that you wish to draw and decide how many boxes/crates would be needed in to which to fit your object. For example, a saloon car would need 3 crates: one for the bonnet, one for the cabin and the third for the boot. A 4 4 vehicle would need 2 crates: one for the bonnet and one for the cabin. If you lightly draw a crate (or several adjoining crates) and use this as a framework into which you draw your object, then this will help you. Rub out the crating lines afterwards to leave just the object. Sketching is an important part of the design process. Crating is a technique that makes sketching much easier. 1 Find something in your schoolbag, and place it on the desk in front of you. When drawing your crate(s), use a 2H pencil as this does not show up too heavily on your drawings. For your sketch within the crating frame, use an HB or 2B pencil as this will appear darker. 2 Ask yourself these questions: Would this object fit inside a square box (cube) or a rectangular box (cuboid)? Does it have a handle or legs? If so, do I need to draw more than one crate in order to help me draw this object? 3 Think about how many crates you will need before you start filling them in. 4 Give it a go.

2 118 Section 5 Graphics techniques 119 Oblique view Oblique view is a good method to use when drawing anything. However, it is especially good for geometric drawings. Like crating, you start with your front, 2D face (whether it is a square, rectangle, circle, or whatever), and this time draw receding lines back at an angle of 45 to the horizontal. Using a basic square, look at the example below: The purpose of rendering (putting in texture) and shading is to give the object depth and to make it appear 3 dimensional (3D). This is achieved by looking at the effect that the light has on the object, particularly how it falls on each side. Compare the diagrams below. One cube has shading and the other does not. The second cube appears solid whereas the first cube does not. Each side is shaded in different tones ranging from dark to light. By observing where the light lands and shading accordingly, you can successfully achieve a realistic effect. 45º 45º 45º Draw the square Take back the receding lines at an angle of 45 to the horizontal The front face has to be drawn first. Receding lines are taken from the corners of the front face. All receding lines are at 45 to the horizontal. (This can be done by eye as 45 is half a right-angle Join the tips of the receding lines, and you have a cube in oblique form and should be easy to bisect.) This be achieved not only by using colour and shading tones, but also by using different rendering techniques. That is, by using different dots, dashes, squiggles, lines, etc., you can create the effects of different materials or mediums. In Section 5 and on the website there is a shading/colouring/rendering sheet to practise on; a completed sheet is shown here as an example. The receding lines of the actual shape are half the length of the front face line. (There are variations on oblique; the style here is called cabinet oblique. If you want more detail, look at a specialist Graphics book.) All the lines should be parallel to each other. 1 Draw a city scene of buildings in oblique form. 2 Make sure that you draw buildings that recede to the left and to the right. 3 Colour them appropriately (see Rendering and shading for tips). Remember to keep all receding lines parallel with each other. Keep all vertical lines vertical. Use a 45 set-square to help you. Rendering and shading We see objects around us because they reflect light. Therefore, the main considerations to take into account when we are observing an object are: the position of the object our viewing position in relation to the source of light.

3 1 Section 5 Graphics techniques 121 Remember, we only see the objects around us because they reflect light. Study both the light falling on your object and the material from which it is made, and colour/ shade accordingly. Observe, observe, observe. Copy what you see, not what you think should be there. 1 Print out the practice shading/colouring/rendering sheet and enlarge it to A3. Copy the completed sheets above to get your eye in. Practise doing these both in black-and-white and in colour. 2 Complete a fresh sheet in your own way using just a pencil (HB is best). 3 Complete another fresh sheet in your own way, using colour this time. Isometric view If we were to use the cube as an example again, isometric drawing takes the front edge of the cube as the front view, rather than the face. Therefore, to draw a cube in this form you need to start with a straight, vertical line. From the bottom of this line, you draw one line out to the left and one out to the right. The lines are of equal length to your vertical line, and both lines are at 30 to the horizontal. You then draw two more vertical lines starting from the ends of these two lines, again of equal length to the original line. Confused? Well, look below at the diagrams which illustrate what has just been explained. To help, there is isometric paper available with lines drawn in an isometric grid this can be placed under your paper as a guide.. Some isometric paper is provided on the website 30º

4 122 Section 5 Graphics techniques 123 Your drawing starts with the leading edge rather than a face. All receding lines are at an angle of 30 to the horizontal. All sides are of equal length. All lines pointing in the same direction should be parallel. 1 Draw an object in the classroom in isometric projection. Start with something simple. 2 When you feel comfortable with this style, attempt something more complex. Although you can draw isometric view using instruments, isometric paper is available for you to place underneath your paper as a guide. It is acceptable to do this. Use the sheet provided on the website. Orthographic (working) drawings Orthographic is just Greek for flat presentation. Again we will keep it simple and use a cube to demonstrate. This is a way of presenting a 3D object in 2D form, and is used for planning the making of your article in the workshop. It should have the actual measurements placed on it, though don t draw it actual size. It is a good idea to label the scale, e.g. 1 : 3 or whatever it may be. Orthographic drawings show all the sides needed in construction, so it is a plan of what you are going to need in the workshop. The usual way is to show a bird s eye view (plan view), a front view and a side view. If your object is a little complicated, split it up into the different segments you need and draw these separately in orthographic view. 45º line drawn top right corner of front face These drawings really should be used as working drawings and be taken into the workshop with you. Do not be afraid to write notes on them to help you with the making of your article. Orthographic drawing is just a 2D version of a 3D object. It is a very good method to use for working drawings, as measurements can be placed on them easily. Always make sure that each elevation, bird s eye, side and front, are in the correct position in relation to each other. This is very important, especially when you are using your orthographic presentation as your working drawings. 1 Place an object on a stool at the front of the class, making sure that it is not sitting at an angle. Look at it from above and draw what you see (bird s eye view). 2 Next, move around so that you are looking at the object from the side at eye level. Draw what you see (side view). 3 Finally, move again so that you are looking at the object from the front. Draw what you see (front view). 4 Copy all the drawings onto an A3 sheet in their correct position in relation to each other. Schematic diagrams Schematic diagrams are used extensively in Electronics, where they are used to draw up circuits, called circuit diagrams. They consist of lines representing wires or conducting strips, and components represented by symbols. Bird s eye plan Key: 9 V battery 330 resistor Switch Front view Side view Light-emitting diode (LED) The key is not normally placed on a schematic diagram, but is given here for your understanding

5 124 Section 5 Graphics techniques 125 There are many components, and therefore many symbols to represent them. When you draw your circuit diagrams, you would not normally write a key as these are standard symbols that you would learn. However, in your Codes of Practice sheet, you would: draw the symbol draw or have a photograph of the actual component that the symbol represents explain its function explain its relevance to your circuit why you need it. The circuit that has been drawn above is very simple, but however complicated your circuit gets, the same basic presentation principles apply (see Key points). <a/w 5-13 to come; allow 1/2 page> Keep your lines straight (use a ruler). Use symbols for your components (you will find these in any Electronics textbook). All lines must be parallel. The only exception to straight lines is that you put a curve in the line when it represents a wire crossing over another. For this, you draw a semi-circular bridge over the line you are 1 Draw the following circuit: 1 9 V battery Ω resistor 1 LED 1 switch 3 Draw the same circuit as in 2, but in parallel. Exploded diagrams This type of diagram is very useful for illustrating all the elements of a design and where they fit. A good starting point for the diagram is to begin with the middle of the inside of whatever you are making, and draw all the bits attached to it on their own, with space between but in close proximity to where they would normally be attached. This is a useful tool especially for Electronics and Hard Materials, although I have seen it used in Textiles as well. It is useful for both you and your assessor to see where things are to fit, especially as this drawing needs to be done before you make your final product. It is a good aid to planning, and if your project is planned well you will have fewer problems when you come to make it. 2 Draw the following circuit in series: 1 9 V battery Ω resistor 4 LEDs 1 push switch Keep things simple! Do not squash these schematics into small areas of your presentation sheets. The circuits may be small, but this does not mean that your diagrams should also be small. Always give yourself plenty of space; these drawings are not meant to be cramped. Always label the parts in detail and give their function. Place the exploded parts close to where they actually sit, but with enough space around to enable you to write about them comfortably. Draw the parts in all directions. That is, if a part sits on the right-hand side of the article, explode it to the right-hand side. And a lefthand part on the left, etc. An example of an exploded diagram is shown in Exemplar 12. Do not expect to be able to do a complicated exploded drawing straightaway. Practise with something simple, such as a book. Keep the presentation of the parts all in the same style. That is, if you are choosing the oblique presentation, keep it all in oblique view. Having said that, isometric presentation is the most commonly used presentation for exploded diagrams. If you can manage to do this presentation well then I recommend that you use it as it does look the best. This is a very good technique to use for doing visual disassembly in Product Analysis as part of your research. 1 Look in your schoolbag. Pick an object that you feel comfortable drawing, and roughly sketch on a piece of paper all the parts that you can see. Make sure that they are positioned close to where they actually sit in the object you are observing. 2 Decide on the style of presentation you want to use:: oblique, isometric, exploded, etc. 3 Draw it all out neatly on an A3 sheet of paper. 4 Colour, render and label with explanatory notes.