Scrapheap challenge
Scrapheap
challenge
Geevor
Scrapheap challenge
Your challenge...
Prizes
To create a waterwheel powered winder from scrap
materials in 60 minutes. The winder that pulls a tram the
furthest in two minutes wins.
Winning school
Trophy for the year
£100 for school science or technology club
Team name:
Winning team members from each school
Free family entry to Geevor for a year
(5 people per family)
Team members:
NSEW Certificate for every participant
Build rules
If you want to win...

You must complete the waterwheel winder in 60 minutes.

You can only use the scrap materials and tools provided by
Geevor.

Once the timer starts– no outside help. So get all your ideas
and questions sorted out by working through this document
and don't forget to bring it on the day.
use the following pages to come up with the best design before you come.
© Geevor 2014
Scrapheap challenge
Geevor
Parts of a waterwheel powered winder
Waterwheels were used as an early source
of power in mining. The picture below was
published in 1566.
Winder
Look a the picture and the diagram opposite to see the different parts that you will
need to put together .
Scrapheap challenge
Wheel
Shaft
Paddle
Stand
String tied to the
tram (provided )
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© Geevor 2014
Scrapheap challenge
Geevor
Testing your design
Scrapheap challenge
After building your winder it will be tested. If it pulls the tram the fastest you
win.
Test rules

Each team will get a tank with the same head of water supplied through a
hose which they will be able to point at their wheel (see diagram).
Tank of water

The string and tram will be provided and will be attached to the winder with
tape before testing.

The tram must be resting against the base of the ramp before the timer
starts.

The timer starts as soon as the tram starts moving.

Teams can support the water wheel stand and direct (not pull) the string on
to the winder, but can not touch the wheel or winder.
Hose to direct
water
Winder

The final distance will be measured from the base of the ramp to the
position of the front wheel of the tram after 2 minutes.
Finish line
Stand
String from
winder to tram
Tram in start
position
Container to
collect water
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© Geevor 2014
Scrapheap challenge
Geevor
Scrapheap challenge
Winder
Your design choice
Shaft as
winder
Narrow shaft as winder
You need a winder to pull the tram.
One option is to use the shaft as a
winder (as long as it is fixed to the
winder and not the stand).
Another option is to attach a larger
winder. Make sure to think carefully
about how and what it needs to be
attached to, to turn.
Think carefully about if you will have
enough power to turn it.
How much string will
wind in per turn ?



Already part of design
Lightweight
String winds in small
amount per turn
Winder attached
Attach larger winder
How much string will
wind in per turn ?



Extra thing to build
String winds in more with
each turn
Adds weight to winder
Your choice
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© Geevor 2014
Scrapheap challenge
Wheel
Geevor
Scrapheap challenge
Weight
Your design choice
A light wheel needs less energy to turn.
Which wheels have a good balance of low weight and high leverage?
Leverage
The leverage is how much of a push will be given to
the wheel by the water hitting the paddle.
The larger the diameter of the wheel (distance from
centre to where water is pushing down, the greater
the leverage.
However, this will also result in a bigger and much
heavier wheel.
How can you best balance the two?.
Your idea
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© Geevor 2014
Scrapheap challenge
Geevor
Scrapheap challenge
Paddles
Your design choice
Which type of paddles would you choose?
To harness the most power from the water
the paddles should be:
Draw your best
paddle idea below
1. Shaped to catch as much water as
possible.
2. Angled to hold on to the water for as long
as possible on the way down.
3. Angled so as to empty out the water on
it’s way back up.
4. Strong enough to hold the water (this
means a strong attachment too).
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Scrapheap challenge
Geevor
Scrapheap challenge
Shaft
Movement and friction
Your design choice
The shaft allows the design to turn.
Friction (rubbing) around the shaft will slow any turning.
Turning shaft
You need to decide if you will have a fixed shaft or turning
shaft( see diagram opposite)
On a fixed shaft– only the winder and wheel turn and are
not attached to the shaft.
Fixed shaft
On a moving shaft, winder, wheel and shaft are joined
together and turn together.
Friction can be reduced by :

keeping the parts that rub against the shaft as small
as possible (low surface area)
I will reduce unhelpful friction by:

making the parts that rub smooth
using smooth materials for rubbing parts

reducing the pressure (or weight) on the shaft
reducing the weight of the moving parts
Draw your design choice below.
reducing the contact area of parts that will encounter friction (rub)
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© Geevor 2014
Scrapheap challenge
Geevor
Scrapheap challenge
The Stand
The stand needs to:

be strong and stable,

hold the wheel and winder off
the ground so they can turn
freely

have enough clearance space
around the sides of the wheel
and winder so that they do not
rub against the stand
Your design
Which of the following stand ideas look
good to you?
Base attachment…. Or…. Free-standing?
Wide-bottomed
Thin
supports
Draw your stand choice here
Wide-apart supports... Or…. Close supports?
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© Geevor 2014
Scrapheap challenge
Geevor
Scrapheap challenge
Head of water
The head is measured as the
difference between the height
where the water enters the
wheel and the height where it
exits the wheel.
Your design choice
Which type of water wheel design would you build to harness the most energy from the water and
where will you need to point the hose?
4
3
Undershot Water wheel
Direct hose along the bottom of
wheel
2
The greater the head, the
more power.
1
0
NB: At Geevor, you will have a
tank of water with a hose. It
will be up to you where you
point the hose.
Head = 0
4
3
2
Breastshot Water wheel
Direct hose at the middle of the
wheel
1
0
Head = 2
4
3
2
Overshot Water wheel
Direct water at top of wheel
1
0
9
Head = 4
© Geevor 2014
Scrapheap challenge
Geevor
Scrapheap challenge
Materials
Your design choice
Light
There will be a selection of scrap
materials provided on the day
Scissors, tape, staples, pens
and measuring devices will be
available to help you put them
together.
Plastic bottles
There will also be someone with
a drill and saw to help you.
Yoghurt pots
What qualities do the scrap
materials in the table have?
What part of your design would
they be most suited for wheel,
paddle, winder, shaft and stand?
Strong
Comes
in useful
shapes
Easy to
cut to
right
shape
Easy to
join to
other
parts
Waterproof
Smooth
(reduces
friction)
What parts would you use
it for?
Corrugated
plastic sheets
Cartons
Plastic &
polystyrene
trays
Metal pipe
Metal wire
Wooden pole
Plastic and
cardboard
tubes
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© Geevor 2014
Scrapheap challenge
Geevor
Your design
Scrapheap challenge
Now put together all your ideas in a sketch.
Include winder, wheel, paddles, shaft and stand.
Label the parts with an explanation of why you think they will make your design win.
Good luck!
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Good luck!
© Geevor 2014
Scrapheap challenge
Geevor
Scrapheap challenge
To be completed on the day
Results
Distance:
Time:
Observations:
What happened to your waterwheel? Did it stand up to the challenge? How could you improve it?
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© Geevor 2014