Transcript miningcart-week6

Mining Cart
The Production of Aluminium
Properties of Aluminium
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Soft ductile material.
Corrosion resistant.
High electrical conductivity.
High strengths.
Cheap.
Weight
One of the best known properties of aluminium is that it is light, with a
density one third that of steel, The low density of aluminium accounts for
it being lightweight but this does not affect its strength.
Strength
Aluminium is one of the strongest materials used in metalwork room apart
from steel.
Machinability
Aluminium is easily worked using most machining methods – milling,
drilling, cutting, punching, bending, etc. Furthermore, the energy input
during machining is low.
Production of parts (wheels, axles, tracks)
Casting
Bench Work
Milling
Solidification (Casting of the wheels)
Crystalline Structure of Aluminium (FCC)
Health and Safety
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Classroom rules provided.
Demonstrations with in the classroom.
Work Matrix.
Group work.
Posters.
Processes
• Casting.
• Lathe work.
• Bench work.
Mining Cart - Mechanisms
Rack + Pinion
• Comprises of gears that changes from
rotary motion into linear motion.
• Cheap
• Compact
• Robust
• Easiest way to convert rotary to linear
• Easier and more compact control over a
vehicle
Real Life
Examples
Use of Rack + Pinion
Conversion of rotary motion into linear
motion
Limit Switch (How will the cart stop?)
• A switch preventing the travel of an
object in a mechanism past some
predetermined point, mechanically
operated by the motion of the object
itself.
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Ease of use
Simple visible operation
Durable housing
Well sealed for reliable operation
High repeatability
• Limit switch on cart
• Stops cart at the end of the track
• Once cart reaches the end of the track, the
limit switch will hit off a wall. The wall is in
place as a stopper that will trigger the switch.
Hinge (How is the load being tipped?)
• We decided to use a hinge for the tipping
of the cart.
• Hinge can come in various sizes
• Relatively easy to pen and close
• Compact
• Cheap
• Light weight
• Hinge located on bottom
of the cart
• Allows cart to fully tip out
DPDT Switch + Variable Resistor
• A DPDT switch will be
used to reverse the cart
once it has stopped.
• A variable resistor can be
used to alter the speed,
dependant on the load.
Forward and Reverse
Electronics
PROCESS TECHNOLOGY 3
PN 4035
Soldering the circuit.
The electronic circuit will consist of numerous components as the artefact will
have to complete a number of actions.
- Move in a linear direction
- Return to its origin.
Soldering is the number one way of attaching the fly wires to the
components, therefore completing the circuit and ensuring it works.
Welding would not be suitable for this process as it would create a too high
temperature for the fly wires and potentially damage the circuit along with
the components.
When soldering the temperature doesn’t exceed 450 degrees Celsius, this is
perfect for our designed circuit as it will not damage any part of the circuit at
this temperature.
Components of the electronic circuit
9 volt Battery.
A.C Motor.
Double Pole, Double Throw Switch.
Variable Resistor.
Limit Switch.
Limit Switch
Circuit for DPDT Switch
Clockwise
Anti - Clockwise
Circuit Diagram
• 2,4 = Clockwise
• 1,3 = Anti-clockwise
Mechanical Design
Cost
- Materials must be within the budget of the schools funding.
- Main material = Aluminium, its cheap and easy to work with.
- Simple circuit. Battery, motor, resistor, two switches.
High output and efficiency.
- Low input power, high output.
- Complete action without much waste in energy.
Strength
- Artefact should be strong enough to sustain all the forces it is designed for so that it is not damaged or
permanently deformed during its life time.
- Load conditions ( tension, compression, torsion, bending)
Wear resistance
- if there is removal of material, the component will become weaker and eventually break.
- Leading to failure of the artefact.
- Selecting the correct material. ( wheels, Rack + Pinon)
Lubrication
- Minimise wear and tear between two surfaces in contact. (Wheels and track, rack and pinion, motor and gear).
- results in the increase in life of the components of the artefact.
Operational Safety
- Safe to use. Safe to handle. ( No sharp edges, no burrs on edges)
- Should not be a health hazard.
- Electrical circuit should be safely constructed.
Mechanism used.
Motor
Rack and Pinon
http://507movements.com/mm_113.html
Linear Motion
Manufacturing Processes
Axle
 Marking
out using, vee
blocks, scribing block and
height gauge.
Threading.
Fitting and assembly of parts
using pins, dowels, rivets,
screws, bolts, nuts and
adhesives.
Main Body of Cart
Vacuum formed.
Cutting, bending, edge finishing and
bonding of sheet acrylic.
The machining of plastics.
Fitting and assembly of parts.
Cart frame/chassis
Application of practical safety methods in the use of
materials and equipment.
Joining of materials by means of adhesives.
Cutting, bending, edge finishing and
bonding of sheet acrylic.
Fitting and assembly of parts using
pins, dowels, rivets, screws, bolts, nuts
and adhesives.
Wheels
Cast in custom mould.
Making of simple dies and sand
moulds.
Turned to correct size and centre
drilled to accommodate the axles
Wiring motor and Pressure Switch
Application of practical safety methods
in the use of materials and equipment.
Joining of materials by means of solder
and adhesives.
Parameters of Project, Physical size,
Time Allocation, Within Skill Set of
Students
Physical Size
Influenced by the distance (y) which is the distance the load has to be
transported so should not be an issue.
Time Allocation
Practical project is worth 25% of the total leaving cert marks.
http://www.rte.ie/exams/Others/engineering.pdf
https://sites.google.com/site/gobanengineeringnotes/home/exam-paper-layout
Question 1 50 marks includes- machine processes, joining processes, joining materials etc.
Question 7 50 marks is entitled machining.
Day Practical= 150 marks.
Project=150 marks.
Time Allocated
October-March= 5 Months
Roughly 21.5 weeks.
2 doubles a week.
Weeks 3-4
1-2
5-6
7-8
9-10
11-12
13-14
15-16
17-18
19-20
Finalizing
design
Start work
on chassis
and axles
Complete
axles and
chassis
and begin
cast and
finish of
wheels
Finish and
thread
wheels.
Begin
vacuum
forming
process
Begin on
processes
of creating
track
platform
Complete
platform
and attach
rack and
pinion to
the
platorm.
Solder
motor to
switch and
pressure
switch and
attach
motor to
cart.
Finishing
of pieces
and begin
assembly
of
complete
d project.
Miscellane
ous,
completio
n of
assembly
Produce
drawings
and
cutting list
etc.
Skill Set of Students
For this particular brief we are to assume that all pupils are all of equal competent skill set.