Drawing techniques

Question 1

what does free hand mean

Answer 1

drawing without using any equipment

Question 2

advantages of using freehand

Answer 2

• quick, so its easier to get initial design ideas down on paper
• you can combine 2D and 3D sketches to explain details
• you can annotate your sketches to explain details further

Question 3

what does perspective drawing do

Answer 3

shows us what something actually looks like in 3d, smaller in the distance but larger close up
- does this by using lines that appear to meet at the vanishing point

Question 4

what are isometric drawings used for

Answer 4

to show a 3D picture of an object
- doesn’t show perspective but it’s easier to get across the dimensions

Question 5

what are the three main rules when drawing isometric

Answer 5

• vertical edges are drawn as vertical lines
• horizontal edges are drawn at 30 degrees
• parallel edges appear as parallel lines

Question 6

what are system diagrams

Answer 6

flowcharts that separate a system into an input, process and output boxes

Question 7

what are annotations used for

Answer 7

to outline the concept of the system, they describe what the components and mechanisms will do

Question 8

features of schematic diagrams

Answer 8

• clearly show the layout of electrical and mechanical systems
• a circuit diagram is an example of a basic schematic diagram
• repair manuals often use schematics to show how the system should be assembled
• they should be easy to read and simple to draw

Question 9

what features make schematic diagrams easy to read and simple to draw

Answer 9

• they aren’t drawn to scale, so components can be nicely spaced out
• they often use symbols
• they can also use simplified and often unrealistic graphics

Question 10

what are scale drawings used to do

Answer 10

to draw a big object on a small piece of paper

Question 11

what does a scale of 1:2 mean

Answer 11

the drawing is half the size of the real object

Question 12

what are assembly drawings

Answer 12

drawings that show how separate parts join together
- an example would be an exploded diagram

Question 13

rules when drawing an exploded diagram

Answer 13

• theyre always in 3d
• you draw the product with each separate part or it moved out as if its been exploded
• each part of the product is drawn on line with the part it’s attached to
• dotted lines show where the path has been exploded from and therefore where it fits into the overall product

Question 14

benefits of exploded diagrams

Answer 14

• theyre designed so you can use them on their own, you don’t need many words to explain how to assemble something
• theyre often used for flat pack instructions

Question 15

what do orthographic drawings do

Answer 15

show a 3d object as a set of 2d drawings;

Question 16

features of a 3d orthographic drawing

Answer 16

• 2d view is drawn accurately to scale
• the dimensions are given in millimetres always
• lines and dimensions must follow certain conventions to avoid confusions
• theres always a gap between projection lines and the object

Question 17

what lines are used for what in 3d orthographic drawings

Answer 17

outlines - thick and continuous
construction lines - light and continuous
centre lines - alternate long and short dashes
hidden details - light dashes
dimension lines - medium and continuous

Question 18

how to draw 3rd angle orthographic drawings

Answer 18

1. draw the front view
2. add construction and centre lines to the right
3. add construction and centre lines going up from the front view
4. draw a line at 45 degrees
5. draw construction and centre lines going up from the end view. when they reach the 45 degree line, draw the going 90 degrees and to the left

5.mark the hidden details
6. add the dimensions