Drawing techniques/sustainability/manufacture

Question 1

describe how cams work

Answer 1

• the follower rests on the cam as it rotates and follows its shape
• cams change rotary motion to reciprocating motion: the cam rotates so the follower moves up and down
• changing the size or shape of a cam will change the magnitude of the reciprocating motion of the follower

Question 2

name the different cams (4)

Answer 2

• circular (offset/eccentric) - produces a uniform reciprocating motion, the pivot is placed off-centred to cause the follower to move up and down
• snail - the follower will gently rise and the suddenly drop, only works in one direction
• pear - will not move for half a turn then will gently rise and fall
• four-lobed - has four lobes that stick out, each turn the follower will rise and fall suddenly 4 times, only works in one direction

Question 3

describe the adv of renewable energy

Answer 3

• have a smaller environmental impact as they produce clean energy
• after initial set-up costs, energy provided is usually free
• the sources won’t run out and is renewed as it is used

Question 4

describe the disadv of renewable energy

Answer 4

• initial set-up costs are high
• don’t produce as much energy as finite resources
• rely on external factors wind/sunlight) so are less reliable
• resources may look ugly/spoil the landscape or be noisy - affects local residents
• can impact the environment - valleys/habitats are flooded to make dams/hydroelectric power, birds can be injured by wind turbines

Question 5

describe the properties and use of foil-lined board/ tetrapak

Answer 5

• board with an aluminium foil lining
• used for food packaging - foil keeps flavours in and air+moisture out

Question 6

describe the properties and use of foam core board

Answer 6

• expanded polystyrene foam is sandwiched between two thin layers of card
• stiff+ lightweight, outer card layers can be scored
• used for making models, mounting posters

Question 7

describe the properties and use of duplex board

Answer 7

• one side is solid white board - visible side, smooth for printing, high quality
• one side is cardboard
• used for food packaging

Question 8

describe the properties and use of corrugated card

Answer 8

• made of a fluted inner core sandwiched between two outer layers/liners
• the flutes add strength+ rigidity - used for secondary packaging to protect products during transit
• outer liners can be printed on
• is flexible/can be bent without breaking but is rigid enough to keep its shape
• negative - stronger materials are bulkier so could increase transport costs

Question 9

describe the properties and use of ink jet card

Answer 9

• used for ink jet printing - ink does not bleed so the printed image is sharply defined+ high quality

Question 10

describe the properties and use of solid white board

Answer 10

• high quality, bleached surface ideal for printing
• used for luxury primary packaging (packaging for individual items)

Question 11

describe the sizes of paper and how they relate to each other

Answer 11

• sizes start of A0 and half in size/area each time
• e.g. A4 is half the size of A3

Question 12

describe the process of offset lithography

Answer 12

• UV light is used to transfer the image onto a smooth aluminium printing plate
• the image area is coated with a chemical that attracts the oily ink but repels the water (so non-image area holds water)
• the image is printed onto a rubber blanket cylinder which squeezes away the water+leaves the ink/image behind
• the ink is transferred onto the paper between the blanket cylinder and an impression cylinder

Question 13

describe the uses & benefits of offset lithography

Answer 13

• fast and high-quality finish
• good for print runs of 1000+ copies
• books, newspapers, magazines, packaging

Question 14

describe the process of flexography

Answer 14

• a flexible rubber/plastic printing plate holding the image (sticks out a bit on the plate) is applied to the surface with an impression cylinder underneath

Question 15

describe the uses & benefits of flexography

Answer 15

• can be used to print onto surfaces that aren’t completely smooth
• quicker than lithography and the printing plates last longer
• used for large print runs 5000+
• cardboard, plastic bottles, packaging, wallpaper, carrier bags

Question 16

describe the process of screen printing

Answer 16

• a stencil is put under a fine mesh screen
• ink is spread over the top of the mesh screen
• ink goes through the stencil and is printed onto the material below

Question 17

describe the uses & benefits of screen printing

Answer 17

• low cost - ideal for short print runs 100-300 where detail isn’t needed
• can be used to print on various surfaces
• posters, estate agents signs, textiles, t-shirts

Question 18

describe the process of dry/digital printing

Answer 18

• a design is sent from a computer
• the printer recognises required colours and adds layers of cyan, magenta, yellow, and black (CMYK) to make the final colour

Question 19

describe the uses & benefits of dry/digital printing

Answer 19

• less fiddly than printing plates, no set-up costs apart from buying the printer + ink
• is expensive per sheet but is cheaper for short print runs around 100 copies
• posters, flyers, digital photos

Question 20

describe the process of die cutting

Answer 20

• a CAD design is sent from a computer to the machine
• the die has sharp blades for cutting and round-edged blades for creasing which are formed into the right shape
• the blades are mounted on a strong plywood base and pressed down onto the card

Question 21

describe the uses & benefits of die cutting

Answer 21

• efficient - can cut through many layers of material at a time
• expensive but is good for large quantities of nets with complicated designs
• used for packaging nets, stencils, shapes

Question 22

describe the 6 Rs

Answer 22

• repair - fixing things instead of throwing them away
• re-use - extend a product’s life by using again/passing it on, reuse products for other purposes
• recycle - uses less energy than obtaining new materials, products with multiple materials should be easy to separate, use recyclable/mobius loop logo
• rethink - think about your design carefully to make it more sustainable
• reduce - making long-lasting/durable products to reduce the number of products customers have to buy
• refuse - refusing to buy a product if you think it is wasteful (unnecessary packaging, big carbon footprint)

Question 23

describe one-point perspective

Answer 23

• uses lines that are vertical, horizontal, or to the vanishing point
• first the front view of the object is drawn, then draw lines to the vanishing point

Question 24

describe two-point perspective

Answer 24

• two points are marked at either end of the horizon line
• uses lines that are vertical or to the vanishing point
• start with the front vertical edge then draw lines to the vanishing point
• provides a realistic drawing that gives an idea of width/height/depth

Question 25

describe orthographic projection

Answer 25

• show a 3d object from three angles: front view, plan view, side/end view
• dimensions always given in mm
• process:
  -front view is drawn in bottom left corner
  -use dotted lines to create the outline of the side view and complete the shape in line with the front view
  -draw a line at 45 degrees in the top right corner of the front view
  -draw dotted lines going up from the end view, when they reach the 45 degree line begin the dotted lines to the left; this creates the outline for the plan view
  -mark the hidden details on

Question 26

describe the types of linkages (2)

Answer 26

• push/pull linkage: uses two fixed pivots, input+output motions act in the same direction whereas the motion of link is in the opposite
• bell crank: changes the direction of a force through 90 degrees
• changing the position of the fixed pivots changes the magnitude of the output force
• moving pivots connect the linkage and allow movement