Tutorial A1 q21-38

Question 1

How can the productivity of CMMs be improved? (7 points)

Answer 1

1. Machine design promotes damping
2. thermal stability of operating environment
3. calibration to compensate for systematic error
4. Revo heads for probe system (optimised movement)
5. move continuously in 1 direction to minimise vibrations
6. small distances between measuring points
7. machine controller to calculate optimised routes

Question 2

What is additive manufacturing (AM)?

Answer 2

AM is a family of automated technologies used to create physical parts, normally layer by layer, from 3D CAD files

Question 3

What is additive manufacturing also known as? (6 given)

Answer 3

• Rapid prototyping
• Rapid tooling
• Rapid manufacturing
• 3D printing
• Solid freeform fabrication
• direct digital manufacturing

Question 4

What is the fundamental concept of AM?

Answer 4

Creating a physical artefact layer by layer using one of a number of different processes

Question 5

What types of materials can be used in AM?

Answer 5

• polymers
• metals
• ceramics
• composites,
• biocompatible / active materials
• food

Question 6

What is stereolithography?

Answer 6

A process where a UV light source is used to solidify/cure layers of light-sensitive liquid polymer

Question 7

What is (selective/direct) laser sintering?

Answer 7

A process where a laser is used to selectively sinter beds of powdered metal, polymer, ceramic or glass into a solid object

Question 8

What is fused deposition modelling?

Answer 8

A process where semi-molten polymer or metallic material is extruded layer by layer to form an object

Question 9

What is 3D Printing (specifically)?

Answer 9

A process where a binding agent is distributed through a print head to fuse granules of material together

Question 10

What is laminate object manufacturing?

Answer 10

A process where a solid object is successively built up by cutting and layering thin, flat, adhesive backed paper, polymer or metal laminate materials.

Question 11

What is rapid prototyping?

Answer 11

Using additive manufacturing techniques to quickly build solid representations of designs cheaper than one-off manufacturing using traditional processes.

Question 12

What can rapid prototyping be used for?

Answer 12

• Visualisation in design process
• Presentation models
• Fit & assembly models
• Functional models

Question 13

What can rapid prototyping be used for depending on the process used?

Answer 13

The mechanical performance and the suitability of a material can be assessed

Question 14

What is rapid tooling?

Answer 14

A process used to create a moulding/casting tool which uses layer manufacturing at some point in its production

Question 15

What is indirect tooling?

Answer 15

Using additive manufacturing techniques to make the initial moulds that the final tooling (e.g. injection moulding tools) is made from

Question 16

What is direct tooling?

Answer 16

Using additive manufacturing to make the final mould tool (e.g. injection moulding)

Question 17

What are the benefits of indirect/direct tooling when compared to traditional techniques?

Answer 17

• Quicker/cheaper to make one-off moulds (e.g. for prototypes or personalised products in healthcare)
• Complex (or impossible with traditional processes) mould geometries can be made

Question 18

What types of final products benefit from being made using additive manufacturing techniques?

Answer 18

General: high value, low volume products

• Complex plastic components
• Complex metal parts that benefit from minimal interfaces/joints through production/function
• Personalised healthcare (dental implants)
• Leisure equipment (footwear)
• Jewellery

Question 19

What challenges lay ahead for AM processes before they become more accepted and used?

Answer 19

• Process speed and cost
• Quality of surface finish
• Mechanical properties (high porosity causes cracks)
• Lack of data about mechanical performance
• Process repeatability