Tolerances

Test yourself

Tolerances

Tolerance is the amount of error you will allow a part to have.

Tolerance

Tolerance is the amount of error you will allow a part to have. - It is usually measured with a + or - symbol with a specific distance or weight.
For example if your product needs to be 162mm long then a 1 mm tolerance would allow it to be 163 mm or 161 mm long.
In engineering the tolerances can be much smaller such as 0.1 mm to ensure that the part being made is 100% accurate and to the correct size.

Electronic tolerances

Electronic components such as resistors and capacitors have tolerances which need to be considered when working out how a circuit will perform.
A resistor has three bands of colour to identify which ohm the resistor has and then it has a fourth band.
This fourth band identifies how much tolerance it has.

The fourth band

Silver = 10%.
Gold = 5%.
For example a 100 ohm resistor with a gold band would have a tolerance of 95 ohms to 105 ohms.
A 100 ohm resistor with a silver band would have a tolerance of 90 ohms to 110 ohms.

A resistor diagram

Allowances

You need to consider when preparing your materials that you allow for some material to be wasted or will need to overlap.

Material allowances

You need to consider when preparing your materials that you allow for some material to be wasted or will need to overlap.
If cutting out fabric you may leave a seam allowance so there is enough material to allow a stitch to be put into it without affecting the overall size of the fabric you require.

Timber allowances

When manufacturing out of wood you may make the product slightly larger knowing that you will be sanding it which would reduce the overall size.

Sewing pattern

1Core Technical Principles

1.1New & Emerging Technologies

1.1.1Industry

1.1.2Enterprise

1.1.3Sustainability

1.1.4People

1.1.5Culture & Society

1.1.6Environment

1.1.7Production Techniques & Systems

1.1.8Emerging Technologies & Design

1.1.9End of Topic Test - New & Emerging Technologies

1.1.10Exam-Style Questions - Emerging Technologies

1.2Energy Generation & Storage

1.2.1Fossil Fuels & Nuclear

1.2.2Renewable Energy

1.2.3Energy Storage Systems

1.3Developments in New Materials

1.3.1Modern Materials

1.3.2Smart Materials

1.3.3Exam-Style Questions - Smart Materials

1.3.4Composite Materials

1.3.5Technical Textiles

1.4Systems Approach to Designing

1.4.1Inputs

1.4.2Processes

1.4.3Outputs

1.4.4Looped Systems

1.5Mechanical Devices

1.5.1Types of Movement

1.5.2Levers

1.5.3Linkages

1.5.4Rotary Systems

1.5.5End of Topic Test - Designing & Mechanical Devices

1.6Materials Categories

1.6.1Timbers

1.6.2Metals & Alloys

1.6.3Metals & Alloys 2

1.6.4Polymers

1.6.5Polymer Types

1.6.6Textiles

1.6.7Textile Types: Fibres

1.6.8Textile Types: Weave

1.6.9Paper & Boards

1.7Material Properties

1.7.1Physical & Working Properties

1.7.2End of Topic Test - Materials

1.7.3Exam-Style Questions - Materials

2Paper & Board: Specialist Technical Principles

2.1Selection of Materials

2.1.1Paper & Boards

2.1.2Working with Paper & Boards

2.2Paper & Board: Forces & Stresses

2.2.1Paper & Board: Forces & Stresses

2.2.2Cardboard & Paper

2.3Paper & Board: Ecological & Social Footprint

2.3.1Paper & Board: Ecological & Social Footprint

2.3.2Paper & Board: The Six Rs

2.3.3Social Issues

2.4Paper & Board: Sources & Origins

2.4.1Paper & Board

2.4.2End of Topic Test - Paper & Board

2.5Paper & Board: Using Materials

2.5.1Paper & Board: Properties of Materials

2.5.2Paper & Board: Modification of Materials

2.5.3Paper & Board: Shape & Form

2.6Paper & Board: Stock Forms, Types & Sizes

2.6.1Paper & Board: Forms

2.6.2Paper & Board: Types

2.6.3Paper & Board: Sizes

2.6.4Paper & Board: Standards Components

2.7Paper & Board: Scales of Production

2.7.1Paper & Board: Scales of Production

2.7.2Exam-Style Questions - Scales of Production

2.8Paper & Board: Specialist Techniques & Processes

2.8.1Paper & Board: Techniques & Processes

2.8.2Paper & Board: Quality Control

2.9Paper & Board: Surface Treatments & Finishes

2.9.1Paper & Board: Surface Treatments & Finishes

2.9.2End of Topic Test - Specialist Techniques

3Timber: Specialist Technical Principles

3.1Timber: Selection of Materials

3.1.1Timber Based Materials

3.1.2Timber: Environment & Ethics

3.2Timber: Forces & Stresses

3.2.1Timber: Forces & Stresses

3.2.2Timber

3.3Timber: Ecological & Social Footprint

3.3.1Timber: Ecological & Social Footprint

3.3.2Timber: The Six Rs

3.3.3Timber: Social Issues

3.3.4Exam-Style Questions - Timber

3.4Timber: Sources & Origins

3.4.1Timber

3.4.2Timber: Processing & Seasoning

3.4.3Manufactured Board

3.4.4End of Topic Test - Timber

3.5Timber: Using Materials

3.5.1Timber: Properties of Materials

3.5.2Timber: Modification of Materials

3.5.3Timber: Shape & Form

3.5.4Timber: Shape & Form 2

3.6Timber: Stock Forms, Types & Sizes

3.6.1Timber: Stock Forms, Types & Sizes

3.7Timber: Scales of Production

3.7.1Timber: Scales of Production

3.8Timber: Specialist Techniques & Processes

3.8.1Timber: Tools, Equipment & Processes

3.8.2Timber: Tools, Equipment & Processes 2

3.8.3Timber: Quality Control

3.9Timber: Surface Treatments & Finishes

3.9.1Timber: Surface Treatments

3.9.2Timber: Finishes

3.9.3End of Topic Test - Specialist Techniques

4Metal: Specialist Technical Principles

4.1Metals: Selection of Materials

4.1.1Metal-Based Materials

4.1.2Ferrous Metals

4.1.3Non-Ferrous Metals

4.1.4Alloys

4.1.5Metals: Environment & Ethics

4.2Metals: Forces & Stresses

4.2.1Metals: Forces & Stresses

4.3Metals: Ecological & Social Footprint

4.3.1Metals: Ecological Footprint

4.3.2Metals: Social Footprint

4.3.3Metals: The Six R's

4.3.4Metals: Social Issues

4.4Metals: Sources & Origins

4.4.1Origins of Metal

4.4.2Processing Metals

4.5Metals: Alloy-Based Materials

4.5.1Types of Metal Alloys

4.5.2Alloying Elements

4.5.3Properties & Benefits

4.5.4Processing & Fabrication

4.5.5Applications of Alloys

4.5.6Metal Alloys in Industry

4.5.7Applications of Metal Alloys

4.6Metals: Using Materials

4.6.1Properties of Metals

4.6.2Modification of Metals

4.6.3Metals: Shape & Form

4.7Metals: Scales of Production

4.7.1Metals: Scales of Production

4.8Metals: Specialist Techniques & Processes

4.8.1Metals: Tools

4.8.2Metals: Tools & Equipment

4.8.3Metals: Cutting, Forming & Machining Processes

4.8.4Metals: Joining, Casting & Heat Treatment Process

4.9Metals: Quality Control

4.9.1Metals: Quality Control

4.9.2Metals: Quality Control Processes

4.10Metals: Surface Treatments & Finishes

4.10.1Metals: Surface Treatments

4.10.2Metals: Surface Treatments for Metals

4.10.3Metals: Finishes

4.10.4Metals: Finishing Techniques for Metals

5Polymers: Specialist Technical Principles

5.1Polymers

5.1.1Polymers: Functionality & Aesthetics

5.1.2Polymers: Environment & Ethics

5.1.3Polymers: Sources, Origins & Properties

5.1.4Polymers: Forces & Stresses

5.1.5Polymers: Ecological & Social Footprint

5.1.6Polymers: The Six R's

5.2Polymer Categories

5.2.1Categories of Polymers

5.2.2Thermoforming Polymers

5.2.3Thermosetting Polymers

5.3Polymer Forms

5.3.1Polymers: Stock Forms

5.3.2Polymers: Shape & Form

5.4Polymer Production, Techniques & Quality Control

5.4.1Polymers: Scales of Production

5.4.2Polymers: Specialist Techniques & Processes

5.4.3Polymers: Quality Control Systems: Tolerance

5.4.4Polymers: Finishes

6Textiles: Specialist Technical Principles

6.1Textile Materials

6.1.1Origin of Textiles

6.1.2Textile Industry

6.2Selection of Materials

6.2.1Natural Fibres

6.2.2Synthetic Fibres

6.2.3Environmental Concerns

6.2.4Environmental Impact

6.2.5Ethical Challenges

6.3Forces & Stresses

6.3.1Forces & Stresses

6.4Ecological & Social Footprint

6.4.1Ecological Footprint

6.4.2Social Footprint

6.4.3Addressing Ecological & Social Footprints

6.4.4The Six R's

6.4.5Labour Conditions

6.4.6Social Issues

6.4.7Addressing Social Issues

7Designing & Making Principles

7.1Investigation & Data

7.1.1Iterative Design

7.1.2Primary & Secondary Data

7.1.3Market Research

7.1.4Ergonomics

7.1.5Specifications

7.1.6End of Topic Test - Investigation & Data

7.1.7Exam-Style Questions - Specifications

7.2Environmental, Social & Economic Challenges

7.2.1Challenges

7.2.2Your Research

7.3The Work of Others

7.3.1Designers

7.3.2Architects

7.3.3Product Design

7.3.4Industrial Designers

7.3.5Product Design Companies

7.3.6Textile Design Companies

7.3.7End of Topic Test - The Work of Others

7.4Design Strategies

7.4.1Design Strategies

7.5Communication of Design Ideas

7.5.1Design Communication

7.6Prototype Development

7.6.1Prototype Development

7.7Selection of Materials

7.7.1Materials

7.8Tolerances

7.8.1Tolerances

7.9Material Management

7.9.1Managing Material

7.9.2Tools

7.10Specialist Equipment

7.10.1Health & Safety

7.11Specialist Techniques & Processes

7.11.1Specialist Techniques & Processes

7.11.2Surface Finishes

7.11.3End of Topic Test - Designing & Making

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