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Schools & Manufacturing
Design &Technology departments in schools are increasingly expected
to work in ways which reflect up-to-date industrial practices. These case
studies give you some insights into state-of-the-art manufacturing, so
you should think about how they could influence your work.
The English national curriculum 2000 says pupils should be taught:
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2b
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to use a range of industrial applications when working with familiar
materials and processes
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2c
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to manufacture single products and products in quantity . . .
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2e
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to simulate production and assembly lines . . .
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4c
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how materials are prepared for manufacture and how pre-manufactured
standard components are used
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To see two outstanding examples of schools which have worked with companies
at a highly professional level see Chapter 5 of the RCA Schools Technology
Project's book: 'Advanced Manufacturing, Design and Technology', 1999,
published by Hodder & Stoughton.
Could you benefit from using industrial production methods?
If you are designing a product you should consider how you can make its
production easier, more efficient or cheaper. In particular you should
be asking yourself: 'How is this going to be made?'. As you look through
these case studies you can learn ways that designs are refined for better
manufacturing. Some of these are:
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reducing the number of parts (The Mono Bug Clamp)
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using 'off-the-shelf' components (Shadow Air Muscle)
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avoiding labour-intensive assembly techniques (The Mono Bug Clamp)
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design for rapid production (Bumper Nut)
Look for yourself to identify:
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What production advantages each product's design has
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When and why automated or computer-controlled processes are used
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Parts suitable for manufacture under jig control for accuracy
In schools we mostly only make prototypes - unless we follow one with
a batch of identical products.
However, even in the case of 'one-offs' it is always necessary to model
your ideas before committing yourself. The main way you can do this, cheaply,
quickly and with very little waste is through drawing. Drawings are models
of ideas. But what if you can't draw very well? Or what if a drawing won't
show what you need it to? Then there are very cheap and quick ways of
modelling ideas in three dimensions (3D). What materials to use will depend
on what you want to do. For something like a moulded handle shape, a mouldable
material like PlasticeneTM is ideal. Paper, card and Styrofoam are other
quick modelling materials that are used a lot. You can't beat seeing a
good model of your idea for helping you to get all aspects of it clear
and really imagine what the real thing will be like.
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 Y10
students modelling the handle for horses' hoof
scrapers in 3D and drawings
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A finished scraper
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Making a model may take some time but it's usually quicker in the long
run as it means that you have sorted out the best ways to go ahead with
the real thing before you start on it.
The more complex the product, the more important a model may be. But the
model should concentrate on the aspects that matter. You may need a messy
looking model of an electrical circuit (on breadboard or similar) to check
that it works and a different smooth looking model that doesn't work but
shares the product's intended appearance. Decide what you are trying to
prove before you start to model - whether this is in 3D or a drawing.
If you're going to make a batch of products then you could waste a lot
of time, materials and money if you don't get the design right before
committing yourself to manufacture. This is why industrial products almost
always have several stages of prototype:
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working mock-ups - to test functionality
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aesthetic models - to test appearance
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presentation prototypes - to show others such as senior managers
giving the go ahead to a project, or to show to a customer - to test
the methods that will be used for manufacturing in bulk.
Of course, really complex products like a new aeroplane will have many
prototypes, as mistakes repeated in each production plane would be so
expensive. And one-offs like bridges cannot be tested as full scale prototypes
but will be modelled by very sophisticated means using computer-aided-design
(CAD) (G).
For one-offs, the equivalent of a production prototype could include making
a test joint, so you'd know how to do it before attempting the real thing.
It's always wise to practice.
Industrial production methods
There are three main categories of industrial production:
Job production
Job production is otherwise called 'custom' or 'one-off' production. The
last of these explains its main feature. This is the method most commonly
seen in schools where only one item is being made and it is customised
to one person's needs or intentions. It's also how huge things, like bridges
and oil rigs, or very special things like big, posh boardroom tables are
made. The Shadow Air Muscle Company's robots are examples of job production,
but what about the muscles themselves? These fall into the next category.
As the word suggests, this describes the process of making a batch of
one type of object at one time. Shadow makes around ten to 30 small muscles
at any one time - depending on the orders it is receiving, as you can
see here. Even for small
numbers of the same product it is worth using volume production techniques
so that each product is produced accurately to the design specification.
These techniques most importantly include jigs - used to ensure that each
time a process is carried out in making one of a batch, it is always the
same.
Mass production is a commonly used term but it really applies to batch
production techniques as well as techniques used for making larger numbers
of products. The term is very commonly used but people in manufacturing
usually refer to it as 'high volume manufacturing' as this makes clear
the difference from 'batch' production. For example, Technical Moulded
Systems make 66 million Hurricane Grip pegs a year. At these volumes,
and because production hardly ever needs to be stopped it is called 'continuous
flow production', and as you can see from the case study, it is achieved
through automation.
Some of the key features of high volume manufacturing are shown in the
peg case study where 'automated continuous flow' production is featured.
These include:
If you are not clear about any of these terms look them
up in the glossary
(G).
Ask yourself: do any of the bullet points above apply to the Shadow Company's
robots? Or does the exact opposite of each (every?) bullet point apply
there?
This diagram from the 'Design & Technology Routes Core Book' in the
RCA series from Hodder and Stoughton set out these and other factors to
compare different aspects of production methods.
Task 1 - Features
of Volume Production
To see some high volume products that are made for inclusion in larger
high volume products see the bumper
nut case study. If you compare the tools used to put these nuts into
the bumper and the pictures of tools in the Shadow
Air Muscle Company case study you will clearly see the difference
between types of tooling: specialised for the bumper nuts and general
purpose tools for the robots.
Is everyone in your class making the same thing?
Some schools give their students experience of batch or even high volume
production. For example, when a whole class is making some original designs
but they all use the same electronic circuit, a production
line (G) can be set up to produce the circuit. Other schools give
their students experience of high volume through simulations where they
set up mini production lines making simple things like folded envelopes.
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Here's
some advice from a winning team of school envelope makers. This
comes from D&T Routes Core Book published by Hodder & Stoughton
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Some of the techniques of volume production are useful even when only
one product is being made - these will be true if there are a number of
parts in a product which are all exactly the same as each other, or if
a number of similar tasks have to be carried out accurately. If this applies
to one of your projects you should treat it like a mass production exercise
and plan the necessary jigs etc for production.
If you understand how jigs help make sure every similar part is exactly
the same as the others then you will see that jigs play a part in assuring
quality. All the parts will be up to the expected quality, at least in
terms of size, shape etc. There are plenty of other ways in which quality
can go down though. Industrial production used to rely on quality
control (G) which meant checking parts after they'd been produced
and throwing away ones which were not good enough (did not meet the specification).
This is wasteful and companies now try to achieve quality
assurance (G). That is, they try to assure themselves that each part
will be of good quality.
Quality assurance involves more monitoring of production in-process, earlier
rectification of mistakes and learning from what goes wrong - to make
sure it doesn't happen again.
This is how your work should be in school - taking care, making test or
practice pieces, planning carefully to assure quality.
Industrial production uses control systems very widely. For example, TR
uses cameras to check the profile of every BMW bumper nut. Any nut identified
as faulty is automatically diverted into a bin by the quality assurance
system. By this means TR makes sure that no faulty nut leaves its factory.
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