Standard Grade Craft

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Standard Grade Craft Design

• Tee- Square Project

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Producing a design brief

• A design brief is a short description of what the
  problem is that you are going to try to solve.
• There are two types of design brief an open
  brief and a closed brief.
• An open brief is very vague, it does not contain
  much information. This leaves the designers
  options open, giving them free reign to design
  whatever they like.
• A closed brief has lots of information about the
  client, where it will be used, the style, etc.
  This is more restrictive for the designer but
  means that they are more likely to design
  something that the client will be happy with.

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Resources available

• This could also be referred to as a restriction
  as these are the only materials you will get and
  therefore you are restricted to designs which
  will only use these materials in these amounts.
• Acrylic sheet 540 x 70 x 3 mm
• Mahogany 240 x 60 x 12 mm

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Ideas

• You should come up with initial ideas, first
  thoughts of possible solutions to the brief. Try
  out different shapes for the stock and different
  possibilities for the blade shape.
• You should annotate your designs. This means
  that you should write notes beside them saying
  what is good and what is bad about each design.
  It is perfectly alright to have negative things
  to say about your ideas at this stage as they are
  your first thoughts and have not been thought
  through properly. That is why we develop (or
  improve) our ideas before we decide on a final
  solution.
• Your ideas will be expected to be rough in nature
  at this stage as it is the speed and amount of
  ideas we are interested in. As you work towards
  your solution however, the quality of your
  drawings is expected to improve. You should
  attempt to show form, how parts will be joined
  together, materials, colour, etc.

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Manufacture

• You should make a list of steps you will go
  through to make your tee-square, like a set of
  instructions.
• This is called a Sequence of Operations.
• Remember to include the tools you will use at
  each stage with their proper names. This is a
  good habit to get into.

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Presentation drawing

• You will produce a pictorial (3D) drawing of your
  final idea (solution). This drawing should
  resemble the real thing as much as you can. It
  should be rendered to show texture, material,
  colour, wood grain, etc.

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Materials

• Plastics
• There are two groups of plastics Thermoplastics
  and Thermosetting plastics.
• Thermoplastics soften when heated and set when
  cooled, a bit like chocolate. You can reshape
  them as often as you like. Thermoplastics have
  what is called plastic memory which means that
  they will return to their original shape when
  reheated.
• Thermosetting plastics can only be formed once.
  Once they are set they will stay that way. They
  are more heat resistant than thermoplastics and
  are a good choice for cookware. To help you
  remember how a thermosetting plastic behaves you
  can compare it to an egg. Once heated it takes
  up the shape of the mould it is in. If you let
  it cool, it sets. If you reheat it will put up
  with a lot of heat and eventually burn.

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Thermoplastics
NAME PROPERTIES USES
HIGH DENSITY POLYTHENE (HDPE) TOUGH, RESISTS CHEMICALS, FEELS WAXY RIGID BUCKETS, BOWLS, STERILISED CONTAINERS
LOW DENSITY POLYTHENE (LDPE) SOFT PLIABLE, ELECTRICAL INSULATOR FLEXIBLE BAGS, BOTTLES, CABLE SHEATHING, TOYS
POLYPROPYLENE (PP) RIGID, LIGHT, GOOD CHEMICAL RESISTANCE, RESISTANCE TO FATIGUE BENDING CRATES, SEATS, STRING, ROPE, MEDICAL EQUIPMENT, HINGES, KITCHENWARE, FILM
POLYSTYRENE (PS) LIGHT, BUOYANT, STIFF, WATER RESISTANT PACKAGING, CONTAINERS, INSULATION, TOYS
POLYVINYL CHLORIDE (uPVC) RIGID, ABRASIVE RESISTANT, WATER/WEATHER RESISTANT PIPES, GUTTERS, BOTTLES, ROOFING, WINDOW FRAMES
PLASTICISED PVC SOFT, FLEXIBLE, ELECTRICAL INSULATOR WIRE INSULATION, WALL COVERING, HOSEPIPES
ACRYLIC (PMMA) STIFF, HARD, CLEAR, DURABLE, SCRATCHES EASILY, EASILY MACHINED POLISHED SIGNS, LIGHTING, REFLECTORS/LENSES, CASES, JEWELLERY
NYLON (PA) TOUGH, DURABLE, MACHINES WELL, SELF-LUBRICATING BEARINGS, GEARS, BRISTLES, TEXTILES, CLOTHING, UPHOLSTERY
ABS STRONG, LIGHT, DURABLE, SCRATCH/CHEMICAL RESISTANT, HIGH SURFACE FINISH KITCHENWARE, TOYS, CASES, CRASH HELMETS, TELEPHONES
CELLULOSE ACETATE HARD, TOUGH, CAN BE MADE FLEXIBLE, LIGHT, TRANSPARENT PHOTO FILM, PACKAGING, LIDS, CONTAINERS
FROM HIGHER PRODUCT DEIGN COURSE NOTES LECKIE
LECKIE
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Thermosetting plastics
NAME PROPERTIES USES
EPOXY RESIN (ER) EXCELLENT ADHESIVE QUALITIES, LOW SHRINKAGE, STRONG WHEN REINFORCED BONDING, ENCAPSULATION, LAMINATING, SURFACE COATING
MELAMINE FORMALDEHYDE (MF) WATERPROOF, TASTELESS, ODOURLESS, MARK SCRATCH RESISTANT WORKTOPS, TABLEWARE, BUTTONS, ELECTRICAL INSULATION
UREA FORMALDEHYDE (UF) GOOD ADHESIVE QUALITIES, STIFF, HARD, BRIITLE, GOOD ELECTRICAL INSULATOR ELECTRICAL FITTINGS, PAPER TEXTILE COATING, WOOD ADHESIVE
POLYESTER RESIN (PR) STIFF, HARD, BRITTLE, RESILIENT AS LAMINATED GRP, FORMED WITHOUT HEAT OR PRESSURE PANELS FOR CAR BODIES AND BOAT HULLS, CASTING, EMBEDDING
FROM HIGHER PRODUCT DEIGN COURSE NOTES LECKIE
LECKIE
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Shaping the plastic.

• Once you have cut out the shape of the blade for
  your tee-square with the coping saw, the edges of
  the plastic will be very rough. Before you can
  join the blade to the stock you will have to
  finish the edges of the acrylic.
• There are a few steps in this process and you
  must follow them in order or you will just give
  yourself more work.

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Finishing the edges of acrylic

• Cross file
• Round the corners for safety
• Draw file
• Dry, wet and dry paper
• Wet, wet and dry paper
• Metal polish

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Precautions
Acrylic is a strong but brittle plastic. This
means that it will crack or break very easily
when cool. As a result you will have to be very
careful when filing, drilling or bending. When
filing it is important that the area you are
working on is as close to the vice as possible to
minimise the amount of movement and reduce the
risk of breakage. When drilling there are a few
ways you can reduce the risk of it breaking or
cracking. One is to put masking tape over the
area you are about to drill to stop the drill
piece sliding about on the surface of the
plastic. Another is to use a step drill and
another way is to drill gently, dont apply too
much pressure to the plastic as you bring the
drill down.
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Processes
The sheet acrylic is suitable for heating in
order to bend or mould it into shape. There are
two ways this can be accomplished. Using a strip
heater to heat the plastic along a line for line
bending. Using an oven to heat the plastic all
over if you want to bend or mould it into more
complex shapes such as twisting it or using a
former or jig. It is important to get the
temperature of the plastic right before
attempting to bend. Too hot and it will burn and
blister. Too cold and it will break or crack.
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Safety
As with all processes there are some safety
considerations when working with plastic. When
using the drill safety goggles on, guard in
place, chuck key out, drill bit secure, long hair
tied back, loose clothing removed or secured, one
person at a machine at a time.
http//www.technologystudent.com/
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When using the strip heater or the oven
heat-proof gloves on, loose clothes removed or
secured, long hair tied back, one person at a
time.
http//www.technologystudent.com/
Focus educational software
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Ergonomics
Ergonomics is the study of how humans interact
with their environments and the products in them.
There are three main areas to consider in
ergonomics anthropometrics, physiology and
psychology. Anthropometrics is the study of the
measurements and dimensions of the human body.
It is important to realise that the dimensions of
any product must have a direct relationship with
the dimensions of the user. Physiology is an
understanding of the human bodies capabilities so
as to avoid stress, strain, fatigue and possible
injury to the user. It is important to consider
factors such as strength, muscle control,
posture, flexibility, joint movement and reaction
times of the user when designing a
product. Psychology it is important to have an
understanding of how products can make the user
feel when using them in order to make them more
appealing to the user and easy to use. When
looking at the psychology of a product we should
consider how it will stimulate our senses, i.e.
sight, sound, taste, touch and smell.
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Percentiles Percentiles are shown in
anthropometry tables and they tell you whether
the measurement given in the tables relates to
the 'average' person, or someone who is above or
below average in a certain dimension. If you
look at the heights of a group of adults, you'll
probably notice that most of them look about the
same height. A few may be noticeably taller and a
few may be noticeably shorter. This 'same height'
will be near the average (called the 'mean' in
statistics) and is shown in anthropometry tables
as the fiftieth percentile, often written as
'50th ile'. This means that it is the most
likely height in a group of people. If we plotted
a graph of the heights (or most other dimensions)
of our group of people, it would look similar to
this                                         
                          
http//www.ergonomics4schools.com/lzone/anthropome
try.htm
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First, notice that the graph is symmetrical so
that 50 of people are of average height or
taller, and 50 are of average height or smaller.
The graph tails off to either end, because fewer
people are extremely tall or very short. To the
left of the average, there is a point known as
the 5th percentile, because 5 of the people (or
1 person in 20) is shorter than this particular
height. The same distance to the right is a point
known as the 95th percentile, where only 1 person
in 20 is taller than this height. So, we also
need to know whether we are designing for all
potential users or just the ones of above or
below average dimensions. Now, this depends on
exactly what it is that we are designing. For
example, if we were designing a doorway using the
height, shoulder width, hip width etc., of an
average person, then half the people using the
doorway would be taller than the average, and
half would be wider. Since the tallest people are
not necessarily the widest, more than half the
users would have to bend down or turn sideways to
get through the doorway. Therefore, in this case
we would need to design using dimensions of the
widest and tallest people to ensure that everyone
could walk through normally. Deciding whether to
use the 5th, 50th or 95th percentile value
depends on what you are designing and who you are
designing it for.
http//www.ergonomics4schools.com/lzone/anthropome
try.htm
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Usually, you will find that if you pick the right
percentile, 95 of people will be able to use
your design. For instance, if you were choosing a
door height, you would choose the dimension of
people's height (often called 'stature' in
anthropometry tables) and pick the 95th
percentile value in other words, you would
design for the taller people. You wouldn't need
to worry about the average height people, or the
5th percentile ones they would be able to fit
through the door anyway. At the other end of the
scale, if you were designing an aeroplane
cockpit, and needed to make sure everyone could
reach a particular control, you would choose 5th
percentile arm length because the people with
the short arms are the ones who are most
challenging to design for. If they could reach
the control, everyone else (with longer arms)
would be able to.
http//www.ergonomics4schools.com/lzone/anthropome
try.htm
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Aesthetics
Aesthetics is concerned with how a product looks.
There are lots of factors which contribute to
the look of a product e.g. colour, pattern,
texture, harmony, contrast, shape, form. Colour
can have a huge impact on how the user reacts to
a product. Red for instance suggest speed,
danger, passion, excitement, etc. It is also a
warm colour and can be used on parts of a product
to show that they will get hot, e.g. a glue gun
nozzle. Harmony and contrast can be achieved in
many ways, through colour choice, texture,
pattern, shape, material and light. For example,
in a mobile phone handset you can have a dark
case with light coloured buttons to create
contrast and make the buttons easier to find, the
case can be smooth in texture while the buttons
are rough, the case can be curved in shape while
the screen is square. All of these while achieve
contrast. For harmony the opposite would be the
case, you would choose similar shapes, colours,
etc.
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Function
Function is the job that a product is designed to
do. A product may have more than one function.
The main job that a product is designed for is
called its primary function, anything else that
it can do in addition to this is called a
secondary function, even if it is more than one
thing. For example, a mobile phone, its primary
function is to make and receive calls. Secondary
functions of the phone can range from text
messaging, picture messaging, internet, camera,
video, etc. These secondary functions are not
essential to make the phone work but they do make
it more likely to sell.
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Joining methods

• Screws, pilot hole, etc

Focus educational software
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Planes, planing
SMOOTHING PLANE A shorter version of the steel
jack plane. It is used for general work such as
smoothing short pieces of wood. It is lighter and
smaller than the jack plane
http//www.technologystudent.com/
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BASIC GUIDANCE ON THE USE OF THE PLANE   1. The wood must be placed level and firmly in the vice. 2. Always plane in the direction of the grain. Examine the wood carefully, it may be obvious which way the grain is flowing. 3. If the plane sticks whilst in use, turn the wood the opposite way round in the vice. Now the grain may be pointing in the right direction. 4. Rub a little candle wax on the bottom of the plane. This will help the plane glide across the surface of the wood. 5. Make sure that little of the blade is sticking out off the bottom of the plane. Too much of the blade will make using the plane very difficult and it may damage the surface of the wood. 6. Always place the plane at the end of the piece of wood and push it firmly across the entire length, without it lifting off the surface. Lift the plane back to the starting position. Pulling the plane back along the wood surface will 'blunt' the blade quickly. 7. Always use a sharp blade. BASIC GUIDANCE ON THE USE OF THE PLANE   1. The wood must be placed level and firmly in the vice. 2. Always plane in the direction of the grain. Examine the wood carefully, it may be obvious which way the grain is flowing. 3. If the plane sticks whilst in use, turn the wood the opposite way round in the vice. Now the grain may be pointing in the right direction. 4. Rub a little candle wax on the bottom of the plane. This will help the plane glide across the surface of the wood. 5. Make sure that little of the blade is sticking out off the bottom of the plane. Too much of the blade will make using the plane very difficult and it may damage the surface of the wood. 6. Always place the plane at the end of the piece of wood and push it firmly across the entire length, without it lifting off the surface. Lift the plane back to the starting position. Pulling the plane back along the wood surface will 'blunt' the blade quickly. 7. Always use a sharp blade.
http//www.technologystudent.com/
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COUNTERSUNK - SLOT HEAD This can be used for
general woodworking for example fitting hinges to
doors. Because the screw is countersunk it can be
tightened 'flush' to the surface of the material.
POZIDRIV HEAD Used with special screw drivers
which will not slip when pressure is applied.
This is ideal when using screws in corners or
confined spaces.
http//www.technologystudent.com/
ROUND HEAD SCREW These are used for fixing
pieces of material together where countersunk
holes are not being used. Round head screws can
look quite decorative especially if they are made
of brass.
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RAISED HEAD SCREW Used to fit door handle plates
and decorative features that must look good.
ROUND HEAD SCREW These are used for fixing
pieces of material together where countersunk
holes are not being used. Round head screws can
look quite decorative especially if they are made
of brass.
http//www.technologystudent.com/
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Finishes
The two materials used for the tee square require
different kinds of finishes.
The mahogany should be sanded to a smooth
finish. If you want to keep the look and colour
of the wood then there are two choices of finish
to achieve this Varnish and wax. Varnish apply
a thin coat, allow to dry, rub down lightly with
steel wool, repeat. Wax apply a thin layer with
a cloth, rub down with a clean cloth or paper
towel, repeat. For the acrylic once the edges
are smooth and scratch free, the acrylic should
be polished using metal polish to achieve a high
shine and remove any faint scratches from the
surface.