more about materials

• One off production

  Bespoke product to meet exact client requirements

  highly skilled workforce is expensive

  labour-intensive and time-consuming

  Prototypes produced in this way
• Batch production

  Specific quantity of product (repeated as many times as necessary)

  Can do processes on the whole batch at same time- quicker than one-off

  Lots of one product ( Sofa,Printed circuit board )

  To make the product identical, templates jigs and moulds are used

  Less detailed to make more consistent

  Flexible machinery and workforce to quickly change

  Time between batches is down time- wastes money
• Mass production

  Thousands of identical products ( newspaper, cars )

  Only used for a mass-market

  Stages broken down into small repetitive tasks along an assembly line

  Basic designs for simplicity

  Expensive specialised equipment and CAD/CAM used

  Easy recruitment - no need for highly skilled staff
• Continuous production

  Runs all the time as too expensive to stop any processes

  Entirely automated

  Equipment is built for huge amounts of one thing.

  Equipment is expensive but efficient so cost per item is low

  examples are aluminium foil and chemicals
• What is quality control?

  Ensures products are manufactured to a high enough standard by checking at stages in the manufacturing process.
• What does quality control include?

  Testing materials, products or components to check they are made to a high enough standard and meet manufacturing specifications.

  Only a sample is tested otherwise it would be too time-consuming
• What is tolerance?

  -Specifying the margin of error that is acceptable to not affect the product's functionality.

  -This is used in dimensions so parts fit together

  -Given as an upper and lower limit.

  -Included on working drawings to show limits of manufacturing

  -Components must be within the tolerance to pass size checks in quality control
• What is a Go/No go fixture?

  -Limit gauge to check if part is within tolerance

  -Double-ended ( one end is machined to lower and other to upper limit )

  -Very quick compared to ruler

  -timber-based products
• What does a registration mark do?

  -Colour registration mark is used to check the quality of colour printing on paper and board

  -appears as a cross shape

  -Check printing plates are aligned correctly

  -If it is not correct, the registration mark will be printed fuzzy
• How to check repeating prints?

  eg stripes checkers on fabric

  -Compare prints to original sample print by eye

  -Quicker and easier than to measure dimensions
• Ways to achieve consistency in manufacturing?

  -Depth stops to control drilling/cutting depth

  -Laser cutters

  -PCBs made with same exposure times
• What is a depth stop?

  Controls depth of drilling or cutting

  1. long rod clamped close to drill bit
  2. Drill a hole to an exact depth in material
  3. When this depth is reached, depth stop will come into contact with material and prevent further drilling
  4. To adjust drill depth, clamp depth stop in a different place
  5. You can carefully control the holes dimensions now
• How to correctly program a laser cutter to cut accurately?

  Program with information:

  1. Dimensions of components to be cut
  2. Correct power settings and feed rate ( dependent on material type or thickness )
• What do you have to do when laser cutting?

  Check with a sample to make sure machine is not malfunctioning or incorrectly programmed
• How are printed circuit boards manufactured?

  Photo-etching

  PCB is exposed to UV light, a developer solution and an etching solution

  This removes unwanted copper, leaving behind the copper needed to form the tracks
• Why are exposure times important?

  Too long exposed means copper tracks removed and too little exposed leaves unwanted copper remains.

  Exposure times should be kept the same for every PCB to create consistent output
• Preparation for cutting

  • wearing the correct personal protection equipment (PPE) eg goggles
  • familiar with how to isolate the equipment if powered and where the emergency stop buttons are
  • Carry cutting tools point down
• The cutting activity itself

  • Use hand cutting tools pointing away from yourself
  • All dust extraction is active when using power cutting tools
  • Power tools always select the correct speed for safe tool use
  • Hold work piece securely (hand if possible / using a vice )
  • Keep fingers away from the cutting edge when in use
  • Always focus on the cutting activity / avoid distractions