Third angle orthographic projection Sectional views Assembly drawings Isometric drawing Perspective drawing

EXPLODED or ASSEMBLY DRAWINGS Exploded views can be drawn using any drawing technique but it is more common to use isometric It shows how the separate parts of an object fit together In exploded drawings it is important that the separate parts line up You need to plan your drawing carefully leaving just the right amount of space between the parts http://www.technologystudent.com/despro2/pen2.html

Task 1. Exploded drawing exercise worksheet 2. Complete the worksheet. Draw a three dimensional view and an exploded view to show how a product fits together. 3. Check yourself exam question page 90

Tasks 1. Single point perspective lettering worksheet 2. Drawing cubes in single point perspective

Task 1. Draw cubes in two point perspective 2. Two point perspective exercise worksheet 3. Mobile question sheet 4. Check yourself exam question page 89

ORTHOGRAPHIC DRAWING Combines a number of 2D drawings to give you details about a 3D object The three most common views used in this drawing technique are the plan, front and end view Plan view is always positioned above the front view, front and end views are always viewed from ground level. End view is positioned to the right of the front view (what we see on the right we draw on the right) The drawings of all the different views must be in line with each other. Feint construction lines are projected from one view to another to ensure they are the correct size and in the correct place A special symbol is used to show an orthographic drawing It may be helpful to draw an orthographic drawing on squared paper Hidden lines are drawn as dashed lines http://www.technologystudent.com/despro_flsh/clock1.html

Tasks 1. Orthographic drawing exercise worksheet 2. Two shapes to draw in third angle orthographic 3. Draw the symbol 4. Check yourself exam question page 80

SCALE ENLARGEMENT SCALES 2:1 5:1 10:1 20:1 REDUCTION SCALES 2:1 5:1 10:1 20:1 REDUCTION SCALES 1:2 1:5 1:10 1:20 1:50 1:100

DIMENSIONS Measurements need to be added to working drawings Measurements should always be in mm Limit lines should be drawn out from the object and then the dimension written above this Measurements should be read from the bottom right hand corner of the drawing Only include the dimensions needed

What are the two missing dimensions? Do they need to be included? 20 10 20 5 10 50

CIRCLES R

DIMENSIONS There is no need to write mm on each measurement If the measurement is less than 10mm you draw the arrowheads differently

Types of lines Outline = Centre line = Construction lines = Hidden detail = Dimension lines =

TASKS Draw and dimension this orthographic drawing. Add the third angle orthographic symbol

ISOMETRIC DRAWING Side lines = 30 degrees Vertical lines stay the same Circles in isometric are drawn differently http://www.technologystudent.com/despro_flsh/isomty2.html

BASIC SHAPES

ISOMETRIC CIRCLES METHOD 1 – compass technique. (textbook page 49) METHOD 2 – segment method - worksheet

ISOMETRIC CYLINDERS

ISOMETRIC GRID PAPER

TASKS Draw an isometric cube, dimension 50mm Draw an isometric cuboid, dimensions 80mm width, 40mm depth and 125mm height On your isometric cube draw a circle using the compass method (textbook page 49) on the front 2 faces. On the worksheet use the segment method to create an isometric circle on all the faces of the cube. 5. Have a go at using the isometric grid paper 6. Complete the worksheet isometric projection 7. Check yourself exam question page 84

Sectional views and hidden detail

~ Sectional drawings show what the product would look like inside if you cut it in two ~Cross hatched lines are used to show where a product has been cut. Hatched lines are normally drawn at 45degress and are evenly spaced ~ Hidden detail lines are shown as a series of thin short dashed lines -------- They are used to show parts of an object that cannot be directly seen

Tasks 1. Draw a sectional view of a mug. Show hidden lines. 2. Draw sectional views of the three chocolate bars. Used hatching and colours/patterns to show the different parts. Include labels