JCB loader the lever for mechanical engineering.pdf

This is for mechanical engineering students

1. LITTLE PEOPLE WITH BIG IDEAS
JUNIOR INNOVATORSJunior Innovator enquiry
LOAD THE LEVER
Physics knowledge development
Big idea
Prior learning
To identify the effects of friction, water
resistance and air resistance, that acts
between moving surfaces.
Levers are simple machines. Simple machines are devices that change the direction or size of a force. Levers work by reducing the force you
need to apply to lift/move a heavy object by making the distance over which you apply the force larger than the distance the object moves.
To recognise that some mechanisms,
including levers, pulleys and gears, allow a
smaller force to have a greater effect.
To be able to define a moment as the
turning effect of a force.
To be able to calculate moments in real-life
situations.
New learning Future learning
Target audience: upper KS2 Science curriculum links: forces and working scientifically
Enquiry type: fair test enquiry
Working scientifically skills development
Prior learning
To make systematic and careful
observations and, where appropriate, take
accurate measurements using standard
units, using a range of equipment, including
thermometers and data loggers.
To use results to draw simple conclusions,
make predictions for new values, suggest
improvements and raise further questions.
To plan a fair test to answer questions,
including recognising and controlling
variables where necessary.
To record data and results of increasing
complexity using scientific diagrams and
labels, tables and line graphs.
To report findings from enquiries including
conclusions and causal relationships in
written form.
To apply mathematical concepts and calculate
results.
New learning Future learning
JUNIOR INNOVATORS

2. Mastery of subject specific vocabulary
Prior learning
push, pull, force, newtons, newton meter,
weight, gravity
mechanism, simple machine, lever, pivot,
effort, load
moment, turning effect, mechanical
advantage
New learning Future learning
D&T knowledge and skills development
Prior learning
Design
To generate, develop, model and
communicate their ideas through talking,
drawing, templates, mock-ups and, where
appropriate, information and
communication technology.
Make
To select from and use a wide range of
materials and components, including
construction materials, textiles and
ingredients, according to their
characteristics.
New learning Future learning
Evaluate
To evaluate their ideas and products against
design criteria.
Technical knowledge
To explore and use mechanisms including
levers, sliders, wheels and axles in their
products.
Design
To generate, develop, model and
communicate their ideas through
discussion, annotated sketches,
cross-sectional and exploded diagrams,
prototypes, pattern pieces and computer
aided design.
Make
To select from and use a wide range of
materials and components including
construction materials according to their
functional properties.
Evaluate
To investigate and analyse a range of
existing products.
Technical knowledge
To understand and use mechanical systems
in their products including gears, pulleys,
cams, levers and linkages.
Design
To develop specifications to inform the
design of innovative, functional, appealing
products that respond to needs in a variety
of situations.
Make
To select from and use specialist tools,
techniques, processes, equipment and
machinery precisely, including
computer-aided manufacture.
Evaluate
To test, evaluate and refine their ideas and
products against a specification, taking into
account the views of intended users and
other interested groups.
Technical knowledge
To understand how more advanced
mechanical systems used in their products
enable changes in movement and force.
JUNIOR INNOVATORS

3. Big question
Where is the best position to apply the effort
force to a robotic arm to lift a heavy object?
Context
After huge protests, Seapark, a marine animal zoo, has decided that they
should release their killer whales back into the wild. The whales are very
heavy and need to be loaded onto trucks for the short journey back to the
ocean. The marine biologists need help from engineers to find the easiest
and safest way to lift the whale onto the truck using a robotic arm as a lever.
Challenge the children to be engineers and research the easiest way to lift the
whale using the JCB Junior Innovator machine.
Teacher notes
The context of this project could be linked to any real-life situation where a heavy load needs to be lifted and
moved. This enables the enquiry to be easily adapted to fit with thematic learning.
Safety tips
CLEAPSS has identified the potential choking hazard represented by the small components in the JCB Junior Innovator kit. Teachers should always fully risk assess
any practical enquiry work carried out using this kit.
Equipment
Junior Innovator machine – constructed with hydraulic system removed • Newton meter (0-20N) • Ruler • String • Scissors
Background science
A lever comprises a pivot, effort force and a load. Levers make use of moments – the turning effect of a force. Moments act about a point (pivot) and cause an object to
turn clockwise or anticlockwise about that point. Levers are also described as force multipliers which means they cause a larger force to act on the load than is applied to
the lever by the effort force – this reduces the force needed to move heavy objects. There are a number of levers in the JCB Junior Innovator machine. For example: the
horizontal robotic arm laid across the vertical primary arm; the pivot is the connector hole where the wingnut joins them, and the grabber is the load. When the position
of that pivot is changed by moving it to different connector holes, the force required to lift the grabber arm changes.
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4. Method
1.
2.
3.
4.
5.
6.
7.
Set up the JCB Junior Innovator machine by tightening the wingnuts so that the primary arm is
vertical. Ensure that the horizontal robotic arm is connected in the centre, leaving at least four
holes on the opposite side of the pivot to the grabber holding the load. The hydraulic system is
not required for this enquiry.
Tie a loop of string through each of the four holes on the opposite side of the pivot to the load.
Place a load in the claw to represent the whale (a plastic toy whale would be ideal).
Use a newton meter to pull on the loop furthest from the pivot and measure the force (N) to
hold the arm horizonal. Use a ruler to measure the distance from this loop to the central wingnut
pivot.
Record measurements in a table and ask other members of the team to repeat the measurement.
These should also be recorded in the table.
Repeat the process for each of the other loops, gradually getting closer to the pivot. In each case
measure the horizonal distance from the pivot and the force required to hold the robotic arm
horizonal.
Analyse the data using a graph and describe any trends, patterns or causal relationships in the
data. This information can then be used to give advice on lifting the whale.
JUNIOR INNOVATORS
English
• Write a report to present findings from the enquiry.
• Write a letter to Seapark to advise them how to lift the whales onto the trucks.
Maths
• Make and record measurements of distance and force using standard units.
• Plot a line graph and use it to identify causal relationships in the data.

5. “The data shows that the further away from the pivot you
pull, the less force you need to lift the whale. For example,
you only need to pull with 4. 4N at a distance of 14cm from
the pivot whereas you need to pull with over 18N if you are
really close to the pivot (3.5cm). I predict that by moving
the pivot even closer to the whale and making the distance
between the whale and the pulling force as big as it can
possibly be that the force needed to lift the whale could
be even less than 4. 4N.”
Ideas for reporting
Results table
Scatter graph
Conclusion
Variables
The distance from the pivot (cm)
A graph to show the force needed to lift the
lever changes with the distance from the pivot
average force (N)
The force to lift the arm (F)
The positions of the primary arm and robotic
arm, the weight of the object in the grabber
(load), the distance from the pivot to the load
Independent variable
Dependent variable
Control variables
Distance from
pivot (cm)
14
4.5 4.4 4.2 4.4
6.3 6.3 6.3 6.3
9.1 9.0 9. 2 9.1
18.2 18.4 18.3 18.3
10
7
3.5
Force needed to hold lift the robotic arm horizontally (N)
Test 1 Test 2 Test 3
Mean
average
JUNIOR INNOVATORS
distance from the pivot (cm)

6. The ideas associated with simple machines can easily be related to many
familiar real-life applications. Examples of levers include nut crackers,
wheelbarrows, crowbars, tweezers, nail clippers and a claw hammer.
Links with everday life
Remembering
Understanding
Applying
Analysing
Evaluating What do we call a simple machine that has a pivot, effort and load force?
Why do levers make work easier?
How are levers useful in our everyday lives?
What is the relationship between the amount of effort
force needed and the distance from the pivot?
The further from the pivot the lower the effort force
needed to make the lever move.
What problems could there be with using a machine to
move a whale?
Children could identify a number of potential problems
to think about and begin to offer solutions eg The
whale moving around, water and electronics in the
machine, the whale being too heavy for the materials in
the machine and causing them to bend, buckle or
break.
JUNIOR INNOVATORS
Creating
Can you design and make a device to add to the JCB Junior Innovator machine to help make sure that the whale is safe and
comfortable when it is moved?