: Hi,
: I am a structural/mechanical design engineer and get involved in all types of structures
for the Theatre and Stage industries. While I would agree with you all, that a structural
grade of aluminium can be as strong, or even stronger than steel, this is only one
consideration to cater for. What about the deflection of the structure?
: The modulus of elasticity of aluminium (whatever grade) is only about 1/3 that of steel.
So the deflection of an aluminium structure will be 3x that of a similar steel structure. If
deflection is important you will need 3x more `second moment of area` (approx 3x more
weight) of aluminium in order to achieve the same deflection as the steel structure.
Aluminium is also 1/3 the weight of steel so both structures would now weigh the same.
: There is only an advantage in using aluminium where deflection is un-important. Steel
is also easier to weld than aluminium.
: Regards,
: Neil Moran
In tensile applications where deflection is a consideration there is no advantage of
aluminum over steel. Aluminum is 1/3 the density but is 1/3 the modulos so PL/AE is the
same for the same weight.
In bending the advantage is usually to aluminum. For a given weight aluminum will be 3
times thicker and therefore have 27 times the 'I'**. That aluminum is only 1/3 the
modulos reduces the advantage to 3:1 over steel. Its why there are few steel skinned
airplanes. The stength and deflection of a thin steel skin would be much greater than that
of aluminum (9X!)
In compression it is also better. The aluminum part will, for the same weight, be much
more resistant to Euler buckling - where the stress due to load is much lower than the
compressive ultimate load for the material but the part folds - stamp a soda can
lengthwise or push on the end of a soda straw. It also prevents the wing skins on airplanes
from wrinkling and failing when carrying compressive loads.
** I = (1/12)*width*thickness^3 for a rectangular section being bent the thin way. I is the
moment of inertia.
1
Al can withstand 150 pounds in weight
1. Recycling aluminum cans saves 95 percent of the energy used to make aluminum
cans from virgin ore.
2. In 1972, 53 million pounds of aluminum cans were recycled. Today, that amount
is exceeded by 1,612 million pounds.
3. Aluminum cans distinguish themselves as the most recycled and most recyclable
beverage container in the world. An awesome 105,784 cans are recycled every
minute nationwide.
4. Used aluminum cans are recycled and returned to a store shelf as a new can in as
few as 60 days. That means a consumer could purchase basically the same
recycled aluminum can from a retailer's shelf nearly every 9 weeks or 6 times a
year.
5. The weight of 1,665 million pounds of aluminum cans recycled in 2001 was equal
to the weight of 14 aircraft carriers.
6. Americans earn about $1 billion a year recycling aluminum cans. A used
aluminum can returned to a recycling center is worth about a penny to consumer
recyclers.
7. For each pound of aluminum recovered, Americans save the energy resources to
generate about 7.5 kilowatt-hours of electricity. That's enough energy to meet the
electric needs of a city the size of Pittsburgh, PA for six years.
8. Beverage containers represent less than 20 percent of the materials collected in
curbside recycling programs and they generate up to 70 percent of total scrap
value. Aluminum cans are the most valuable commodity to curbside programs
helping to pay for the collection of other containers.
9. Aluminum can recycling rate is better than 1 out of 2 cans.
10. Recycling diverted 1.7 billion pounds from landfills.
11. Using recycled aluminum beverage cans to produce new cans allows the
aluminum can industry to make up to 20 times more cans for the same amount of
energy.
12. It's estimated that since 1972 some 18.7 million tons of aluminum have been
recycled. These 1,099 billion aluminum cans placed end-to-end could stretch to
the moon and back some 174 times.
13. Aluminum cans have amazing strength. Four six-packs (24 cans) can hold a
4,000-pound aluminum-bodied sedan.
14. In 2003, Americans recycled 62.6 billion aluminum cans. Those cans, placed endto-end, could make 171 circles around the earth.
15. America recycled enough aluminum cans last year to stretch to the moon and
back 8 times.
16. Since 1972 Americans have recycled 37 billion lbs. or 1,099 trillion aluminum
cans and earned over $25 billion by recycling aluminum beverage cans.
17. Every minute of everyday, an average of 105,800 aluminum cans are recycled.
2
18. When you think it is hot, consider the following: Did you know that aluminum
begins to melt at a whopping 1220 degrees Fahrenheit
19. Over the past 10 years, the number of aluminum cans recycled has doubled
20. The average employee consumes 2.5 cans of soda each day at work.
21. Recycling one aluminum can saves enough energy to run a television for three
hours.
22. Enough aluminum cans were recycled in 2002 to fill a hollow Empire State
Building 24 times.
23. Each year Americans receive enough money from recycling aluminum cans that
every kid in the U.S. could buy two movie tickets.
24. The number of cans recycled every 30 seconds equals the number of people who
could fill an entire pro football stadium.
25. Every 3 seconds a baby is born. In that time, 140 cans were born.
26. If the 2003 Corvette convertible was on a seesaw, it would take 107,214 used
aluminum cans on the other side to balance the car.
27. In 2001, beverage cans delivered 9,409 billion gallons of pure refreshing
beverage—enough to fill 37,634 Olympic pools.
28. 10,433 empty aluminum beverage cans weigh as much as Shaq O'Neal.
29. In 2001, Americans bought 351 aluminum beverage cans per person, twice as
many as in 1980.
30. The average American family recycles 150 six packs of aluminum cans a year.
31. Used aluminum cans are melted down into ingots that can weigh as much as
30,000 tons. That's enough aluminum to make 1.6 million cans.
32. Aluminum never wears out, it can be recycled forever.
33. Americans drink an average of 380 beverages in aluminum cans each year.
34. Recycling 1 aluminum can saves enough electricity to run your TV for 6 Jimmy
Neutron Episodes.
35. If Californians recycled all the aluminum cans they buy in one day, we would
have enough aluminum to make 17 Boeing 727 jets.
36. Recycling 1 ton of aluminum saves the equivalent in energy of 2,350 gallons of
gasoline. This is equivalent to the amount of electricity used by the typical home
over a period of 10 years.
37. Using recycled aluminum beverage cans to produce new cans allows the
aluminum can industry to make up to 20 times more cans for the same amount of
energy.
38. The energy saved each year through recycled cans could light the city of
Washington, DC for 3.7 years.
39. All aluminum cans recycled since 1972 would stretch from New York to Los
Angeles and back 15,939 times.
40. Recycling aluminum creates 97% less water pollution than producing new metal
from ore.
Aluminum Can Wasting Facts
In 2001, Americans bought 351 aluminum beverage cans per person (twice as many as in
1980) and wasted 70 more cans per person than in 1980. The quantity of cans wasted in
3
2001—759,625 tons—was equivalent to the entire annual production capacity of four
major aluminum smelters in the Pacific Northwest and greater than the amount used
nationally for trucks, buses, bridges, street and highway applications combined. Since
the first Earth Day in 1970, Americans have wasted over 910 billion cans worth over $15
billion. If current trends continue, we will have squandered one trillion cans by 2003—
or almost 3,600 wasted cans for every man, woman and child in America. Between 1990
and 2000, Americans wasted 7.1 million tons of cans: enough to manufacture 316,000
Boeing 737 airplanes. Laid end-to-end, the 50.7 billion cans wasted in 2001 would
encircle the Earth 153 times.
Energy and Environmental Facts
Recycling used cans into new cans takes one third as much energy as making them from
raw materials. The energy required to replace the aluminum cans wasted in 2001 was
equivalent to 16 million barrels of crude oil: enough to meet the electricity needs of all
the homes in Chicago, Dallas, Detroit, San Francisco, and Seattle. If 9 out of 10
aluminum cans were recycled, we could save the energy equivalent of 50% of the annual
oil production anticipated from the Arctic National Wildlife Refuge. Replacing one
wasted can requires the energy equivalent of about 0.5 kWh: enough to light a 100-watt
bulb for 5 hours, or to power an average laptop computer for 11 hours. For every sixpack of cans wasted, the energy equivalent of one beverage can full of gasoline is
squandered. Over 3 million tons of greenhouse gases were produced to replace the
aluminum cans trashed in 2001 with new cans made from virgin materials. Over two
hundred thousand indigenous people have been relocated to make way for
hydroelectric reservoirs in nine aluminum-producing countries.
Recycling Facts
After peaking at 65% in 1992, the aluminum beverage can recycling rate dropped to
49.2% in 2001—the lowest rate in 15 years. In 2001, Americans consumed 9 billion
more aluminum beverage cans than they did in 1991, yet recycled 6 billion fewer.
Aluminum Recycling
About 65 percent of America's aluminum is being recycled, yet, more than one million
tons of aluminum containers and packaging (soda cans, TV dinner trays, aluminum foil)
are thrown away each year.
Although aluminum is less than one percent of the nation's municipal solid waste stream,
it remains one of the most valuable recyclable materials. Used aluminum beverage cans
remain the most recycled item in the U.S., but other types of aluminum, such as siding,
gutters, storm window frames and lawn furniture, can also be recycled. Aluminum has a
high market value and continues to provide an economic incentive to recycle.
Recycled materials, such as aluminum, also provide manufacturers with valuable
feedstock. For example, recycled aluminum cans are used to make new cans. In fact,
nearly 55 percent of a new aluminum can is made from recycled aluminum. The first all4
aluminum beverage can appeared in 1963. The act of recycling used cans began in 1968
in California. One million pounds of aluminum cans were recovered that year, an amount
that is melted in about four hours today.
Here's some more facts about aluminum:
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Discovered in the 1820s, aluminum is the most abundant metal on earth.
Twenty years ago it took 19 aluminum cans to make one pound, but today,
aluminum beverage cans are lighter and it takes 29 cans to make a pound.
Americans throw away enough aluminum every three months to rebuild our entire
commercial air fleet.
In 1994, Americans recycled 64.7 billion aluminum cans, two billion more than in
1993.
Every minute of every day, an average of 123,097 aluminum cans are recycled.
Today, the national average of aluminum can recycling is two out of every three
cans.
Tossing away an aluminum can wastes as much energy as pouring out half of that
can's volume of gasoline.
Making new aluminum cans from used cans takes 95 percent less energy and 20
recycled cans can be made with the energy needed to produce one can using
virgin ore.
Recycling one aluminum can saves enough energy to keep a 100-watt bulb
burning for almost four hours or run your television for three hours.
Because aluminum lying in our landfills will still be around in 200 or more years,
recycling cans and scrap aluminum makes sense. Recycling aluminum is so easy--just
rinse and store until your next trip by the Anchorage Recycling Center or a drop-off area.
By recycling aluminum, you will be helping to complete the recycling loop--an
aluminum can recycled today will be back on the grocery shelf in about 90 days.
Aluminum Can Crusher 12 oz. Size Recycle all of your aluminum beverage cans, soda
pop cans, beer cans, etc., with a simple, reliable, easy to use aluminum can crusher. The
aluminum can crusher is designed to help recycle all aluminum beverage, soda pop, and
beer cans by compressing the aluminum can down to approx. 20% of its original size. In
this day and age we all need to recycle whenever we can, and an aluminum can crusher is
an economical, reliable, and convenient way to help in this effort.
The aluminum can crusher is quick and easy to use to recycle aluminum cans of all types,
beer cans, soda pop cans, etc. Simply lift the handle with one hand, place an aluminum
beer can, soda can, or other aluminum beverage can into the crusher, and pull down on
the handle. The aluminum can crusher operates using the principle of leverage, and
requires little effort to completely crush the aluminum can. The whole process is quick
and easy, and only takes a few seconds to process each can. Once the aluminum can is
5
crushed, you simply push it out of the crusher into a waiting receptacle below, add the
next can and so on.
Can Crusher Recycling Center
Part Number: 02-0229
Price: $145.00
38-gallon container holds up to 500 crushed cans;
perfect for high traffic areas such as office break
rooms, bars, restaurants
- Size: 33.5in Hx18.5in Wx18.5in D
- Black or Gray
- Manual - non electric
- Remember you MAKE MONEY by taking your
crushed cans to the local
aluminum scrap facility.
- IMPORTANT: Folks; unfortunately the manufacturer has discontinued this
item except in lots of 100 pcs. Since we think it's a great item, we are giving our
commercial customers the option to buy in this quantity. Call us for more
information.
Ashok Bhandary and Mike Quinn test their electromagnetic can crusher.
Can Crusher in Operation!
Here are some cool pictures taken when we fired the Can Crusher...
This is a picture of a gas discharge tube that was inserted into the coil of the Can Crusher.
You can see as the can crusher fires, there is a concentration of plasma near the coil. You
can also notice the cathode spot on the needle shape electrode.
This picture was taken by a double exposure. The first exposure was taken in the dark
while the spark gap of the Can Crusher triggered. The second one was taken in normal
conditions. Note the the copper coil was shorted for some reason which also gave a
gorgeous spark around it.
Can Crusher
Science Concept: Pressure.
Air pressure causes the Aluminum can to crush.
Materials:
6
*Aluminum pop can
*Hot plate, or hot stove
*Large beaker of ice cold water
*Beaker tongs or hot pad holder
*Safety goggles
Directions:
*Fill large beaker with ice cold water.
*Pour 20 mL water into the pop can.
*Place pop can with the water on the hot plate.
*Let can stay on the hot plate until the water inside begins to boil. You must see steam
coming out of the can for this to work.
*When water begins to boil, quickly pick up can with tongs on the bottom of the can, and
place can upside down into the cold water.
Introduction:
How many of you like watching a pop can shrivel up without having to crush it yourself?
Here is a better way of crushing cans the easy way.
Explanation:
When water boils, it produces steam which is actually very tiny droplets of liquied water.
We are really interested in the idea that boiling water produces water molecules in the gas
state which are invisible. The water gas molecules occupy all of the space in the can since
the air molecules have been pushed out. The hot gas molecules in the can are at the same
pressure as the air on the outside of the can.
Graphic of model gas molecules behavior
When the can is put in the cold water upside down, the hot gas water molecule are very
rapidly cooled. Some of the gas molecules are condensed back to the liquid water, so
there are less gas molecules present. Cold water also cools the remainingt gas molecules,
which makes the molecules slow down, then there are fewer collisions with the walls of
the can, which in turn causes less pressure inside of the can. The air pressure on the
outside of the can is stronger. This causes the can to crush.
Higher air pressure on the outside of the can is the main reason for the can crushing.
Real Life Demo of Railroad Tank Car Crushed.
Reference: In the Public Domain.
Get
rid of your beer can
mountain and
release your
7
frustration at the same time with the Can
Crusher. It even features a bottle opener!
There's nothing like a night in with the lads
watching the footie with a few dozen cans. But
there's only one problem – a bin overflowing
with cans the next morning, which you'll have
to go out in the rain to empty. But with the Can
Crusher, even the efforts of George Best and
Johnny Vegas combined couldn't fill the bin.
The Can Crusher is a simple but effective
wallmounted device. Just place your empty can
on the crusher shelf, pull down the soft grip
handle, and the can is crushed to
approximately a fifth of its size! You can then
fit more cans in your bin than Lisa Riley can fit
Chelsea buns in her mouth. As well as being
useful, the Can Crusher is great fun, and brilliant for stress relief. Maybe the footie didn't
go your way. Just imagine the ref in the crusher instead of a can, pull the handle and
marvel at how satisfying it feels. Never again will your other half nag you to death about
an overflowing bin. And as an extra bonus, the Can Crusher has a builtin bottle opener
for when you run out of cans to guzzle (please don't try crushing the bottles though.) To
paraphrase Stu Francis, ‘Ooh, I could crush a can!' On a serious note, the Can Crusher is
ideal for the environmentally minded amongst you too, as it makes storing old cans and
carrying them to the recycling centre a lot easier. Measures 32 x 10cm. Suitable for cans
up to 3” wide and 6.5” tall. Comes with screws for wall mounting. Please note that the
can crusher will only crush aluminium cans.
Can Crusher and Object Shrinker
Can Crusher
This project clearly demonstrates the powerful mechanical forces due to a pulsed
magnetic field. A simple coil consisting of several turns is formed to allow fitting of an
aluminum beer or pop can. A high peak current is switched into the coil at f(t) and now
induces a current flow in the periphery of the can that now generates its own magnetic
field in opposition causing the can to constrict into the familiar hour glass configuration.
This project is an excellent demonstration and is used in several museums where students
are encouraged to bring in their cans and subject to these forces. Safety is enhanced by
the positive grounding of the inducing coil eliminating any steady state potentials.
Operator simply places can into the coil, depresses the charge button, waits for the green
light and now presses the fire button. Deformed can is removed and system is ready for
the next operator.
For Museums, Attention Getting Displays, Action Science Projects and Serious
Research. We will assist in installation and setup. Call for details.
The Can Crusher requires our HEP90 Pulser/Ignitor or similar. Also required are
capacitors, such as our 96Mfd/4.5Kv Capacitor Bank or similar.
CANCRUC10 - Can Crusher Accessory.....................$24.95
8
HEP90 plans include plans for the Mass Launcher, Plasma Thermal Gun, Wire Exploder
and Can Crusher.
Progressive International Can Crusher
Features
Wall mounted
Compacts cans to 1 inch
Soft grip handles help you crush cans comfortably
Fits 12 ounce cans and smaller
Long lasting durable frame
Product Description:
Make your recycling less "waste"-ful with the Progressive Can Crusher. Compact your
aluminum cans to just 1 inch.
Easy use Can Crusher
Crushes cans down to 20% of their original size!
It couldn't be easier to use, simply put the can in and pull the lever. Each model can be
wall mounted.
Standard Model
This model crushes up to 16oz cans and features a built in bottle opener. the main
crushing part is made from heavy gauge steel and a soft grip handle. It couldn't be easier
to operate simply put the can in position and pull the lever it doesn't even require allot of
pressure to operate because of the lever system used.
This model also crushes up to 16oz cans and features the same rugged build quality. The
difference between this and the standard model is that this one can easily crush up to six
cans in rapid succession. it features a top mounted loading basket which holds six cans,
when each can is crushed it drops out the bottom of the crusher. If you mount this crusher
over your recycling bin the cans will just drop straight into the bin.
£60 (inc P&P)
CAN CRUSHER
9
In keeping with BETA's commitment to reduce solid waste, we have contracted Art's Mobile
Service and Steel Fabrication to develop a manual heavy duty can crusher for commercial and
household use. Cans often account for up to 1/3 of the volume transported to land fills. The tins
are not only bulky, but act as reservoirs for water, creating breeding habitats for mosquitoes and
other health hazards.
The can crusher allows you to reduce the volume of tins by up to 80%; the flattened cans can
then be buried in foundations of new buildings, pathways, or other construction projects you might
have in progress, or taken to the land-fill greatly reduced in size.
It takes one person only five minutes a day to crush the number of tins produced by an average
size hotel or restaurant. The crusher can handle tins from one-gallon down to the smallest with no
problem.
BETA is encouraging all hotel owners and as many households a s possible to be a part of this
initiative, and through their actions, persuade others to do their part in helping to make Belize
greener and more environmentally sound. The crusher, made from 3/16 inch steel deck plate,
with 5/8 inch stainless steel shafts, is fully guaranteed and ready to mount on any wall surface. it
costs BZ$400.00, a one-time investment which will last for years.
Design Prototypes
"The Super-Cool Can-Crushin' Tool"
10
Description: This is a very basic can crusher using vertical force applied by the user to
crush the can. it was built out of PVC piping and pipe caps. Although this device was
under the one and a half pound limit, it was not as fast, efficient, or effective as our final
model.
"The Mechanical Arm of Can Crushing Demise"
Description: This is a more sophisticated can crusher. It uses a type of lever arm
connected by 16 gauge wire to the pipe base to create vertical downward force upon the
can. The crushing action is all done in PVC piping to improve stability and crushing
efficiency. This model crushed cans faster than the "Super-Cool Can-Crushin' Tool ," but
lacked strength in its crushing arm, and was not very easy to operate due to stability.
"The Master of Can-Crushing Disaster"
11
Description: This
is a simplistic, yet
innovative design
that follows the
KISS (Keep is
Simple Stupid)
method. It uses a
combination of
mechanical and
physical energy to
crush cans. Can
grippers are used
to hold the can in position while the crushing action is taking place. The
screws holding the can grips in place are left loose to more efficiently
hold the can.
Prototype Sketches
Sketch 1:
This is a foot operated can crusher. The design would
be to place the can into the cylinder on the right. The
cylinder on the left would then be put inside the larger
one on the right. Force would then be applied to crush
the can. A small screw would be attached to the bottom
of the smaller cylinder to puncture and stick into the
can. The idea is to pull the smaller cylinder out after
crushing with the can stuck to the end for easy removal.
Sketch 2:
This is a sketch of a hand operated can crusher. It
uses lever action to create great force near the hinge.
The force is still great with little effort pressing
down on the handle crushing the can. The crusher
itself consists of a free swinging arm with a circular
piece of wood on it to crush the can.
12
Sketch 3:
This can crusher is a spin-off of sketch number two. The same lever is there creating the
great force with little effort, but now instead of being hand operated, foot operating has
been chosen. More force could be generated by the foot to crush the can. The crusher
itself is identical to that above, but is mounted out further to control its movement.
Sketch 4:
This crusher in this sketch
is probably the most
complicated that we've
come up with. It uses a
piece of PVC piping and
some sort of wooden
handle passing through the
pipe in the middle to improve stability. The handle is tethered to the bottom of the
crusher to create the force needed to crush the can. A swinging arm exists, shown in the
inside view, mounted to the handle. The crusher comes down and crushes the can when
the handle is depressed.
Sketch 5:
This sketch is of a hand operated can crusher design.
force is applied on the two arms to create force on the
can. The can is held in place by two loosely mounted can
holders, these holders are left loose to allow for the can
movement when the two handles come closed. A hinge
type mechanism is used at the
top to hold thearms together
and create stability when
crushing the can.
aluminum soda cans. This
high voltage capacitors and
Mr. Crunch
Use of laws of
electromagnetism and highvoltage capacitors to crush
exhibits allows visitors to use
solenoids to reduce common
13
soda cans to rubble.
Ball launcher
Tennis players and cricketers sometimes use
mechanical ball launchers that serve balls using a
machine with two fast spinning wheels. The same
kind of machine can launch table tennis balls either for practise or as part of a target game.
This device comprises two rapidly spinning wheels
driven by 3-volt electric motors. When a tabletennis ball is passed between them, it is ‘nipped’
and thrown out at high speed.
Can crusher
The classic experiment of crushing a can using
atmospheric pressure is now cheap and easy!
Simply attach the special moulded top to any
empty drinks can and reduce the pressure inside
the can using a large syringe or a vacuum pump.
Alternatively, let a small amount of water vapour
cool inside, then watch the can collapse. The top
can be re-used any number of times.
14
Can Crusher Plans
This project clearly
demonstrates the powerful
mechanical forces due to a
pulsed magnetic field. A
simple coil consisting of
several turns is formed to
allow fitting of an aluminum
beer or pop can. A high
peak current is switched
into the coil at f(t) and now
induces a current flow in
the periphery of the can
that now generates its own
magnetic field in opposition
causing the can to constrict
into the familiar hour glass
configuration. This project
is an excellent demonstration and is used in several museums where students are encouraged to
bring in their cans and subject to these forces. Safety is enhanced by the positive grounding of
the inducing coil eliminating any steady state potentials. Operator simply places can into the coil,
depresses the charge button, waits for the green light and now presses the fire button. Deformed
can is removed and system is ready for the next operator. For Museums, Attention Getting
Displays, Action Science Projects and Serious Research. We will assist in installation and setup.
Call for details. The Can Crusher requires our HEP90 Pulser/Igniter or similar. Also required are
capacitors, such as our 96Mfd/4.5Kv Capacitor Bank or similar.
PROJECT CAN CRUSHER 1999, WORKS ON AIR
Sophomore Engineering Clinic I
THE CAN CRUSHER
SPONSORED BY THE DEPT. OF MECHANICAL ENGINEERING
15
*Note: design module originally developed by Prof. Jawa Mariappan, Fall 1997
Philosophy
The mechanical design module of Sophomore Clinic I introduces
students to the process of engineering design, and guides them
through the design of a real-world mechanical product from concept
to completion as a means of practicing the steps and tools required
by a typical design process.
In this engineering clinic module, students will also be introduced to
Product Realization Process (PRP). This process consists of a
structured approach to different stages of engineering design
involving 1) Conceptual, 2) Configuration and 3) Parametric Design.
The design module will guide the students through each stage of the
design process in a team environment. Concepts from Statics, Solid
Mechanics and other courses will be used and reinforced. Finally
students have to build a working model of their design. During the
course of this project, design teams are expected to follow the
various design stages as outlined in this handout.
Grading Policy:
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Concept and Configuration Design 30%
Parametric Design (detailed design) 35%
Prototype 35%
References:
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John Dixon and Corrado Poli, Engineering Design and Design for
Manufacturing, Field stone Publishers, Conway, MA, 1995
Stugart Pugh, Creating Innovative Products Using Total Design,
Addison Wesley, New York, 1996
Hauser and Clausing, The House of Quality, Harvard Business
Review, May-June, 1988
16

Robert Pirsig, Zen and the Art of Motorcycle Maintenance, William
Morrow and Company, New York, 1974
Mechanical Design Problem
Recycling is a meaningful and sensible approach to protect our
environment and improve the quality of our life. As part of improving
and increasing recycling efforts, you have been requested to design
and prototype a can crusher device for use at home. The can crusher
must be compact, efficient, inexpensive, easy to use and safe to
operate. The crusher must be able to crush popular 12 oz. soda
cans. The can crusher must generate significant mechanical
advantage such that an elderly or handicapped customer can
perform the task of crushing a can.
Teams must "purchase" needed materials from the clinic team. In
most cases, the clinic team will be able to provide precut materials.
Students will have access to basic shop tools for at least one class
period for fine-tuning operations. Approved materials and their cost
are given in the attached list. Students can procure additional
material only with prior approval from the instructor.
Engineering Science Principles:
Recall that the engineering designer "applies various formal
techniques along with proven scientific principles for the purpose of
defining a device, a process or a system in sufficient detail to permit
its realization." In this clinic module, the engineering science
principles of statics and solid mechanics will be applied during the
parametric design stage of the Product Realization Process. The
principles of statics will be applied to determine the acheived by the
can crusher. The principles of solid mechanics will be applied to
ensure that the design does not fail under loading conditions.
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Statics Example: Calculation of mechanical advantage
Solid Mechanics Example: Analysis of a simple structure
Deliverables:
Each team is expected to prepare a final design report. This report must
contain the following information:
1. Engineering design specification (House of Quality)
2. At least three different conceptual designs (sketches)
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3. Evaluation of each design and identification of a concept for
detailed design (Pugh´s evaluation chart)
4. Configuration design (sketches)
5. Parametric design and engineering analysis:
A. static analysis,
B. mechanical advantage
C. stress analysis
D. etc.
6. Cost Analysis
7. Detailed AutoCAD drawings of parts and final assembly
8. Test results
A. Force vs. time curve
B. Measured mechanical advantage
8. The manufactured device and unused material
9. Confidential peer evaluation form
Note: The final product is the property of College of Engineering, and must
be returned with the final report. If you wish to keep a copy of your written
material, make them prior to their submission.
ME Design Problem: Design Flow
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Write a detailed engineering design specification for this product.
Draw a House of Quality to illustrate the correlation between
customer attributes and technical characteristics.
Generate several possible conceptual solutions. Each conceptual
solution embodies one or more physical principles. Draw sketches
and describe the physical principles used in each concept.
Evaluate each design using Pugh´s method and identify one feasible
design for detailed analysis.
Draw sketches illustrating possible configurations for the candidate
design. Identify the optimum configuration.
Static analysis: Draw a sketch of the selected configuration. Draw
the geometry. Show all dimensions. Identify all external loads. Draw
a FBD. Calculate support reactions. Calculate the output force.
Calculate the input and output range of motion
Calculate the mechanical advantage.
Perform stress analysis. Calculate:
o normal stresses of all two force members,
o shear stresses in all pins,
o bearing stresses at each bearing surface, and
o maximum bending stress in transversely loaded members.
Compare to maximum allowable shear and normal stresses,
assuming an appropriate factor of safety.
Iterate this procedure by making changes to your system until you
get an acceptable design, considering functional requirements, size
and other factors.
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Make part drawings and bill of materials. Consider critical and noncritical dimensions and tolerances.
Estimate the total cost of the product.
Fabricate, assemble and fine-tune your product.
Test your device, measure the forces, and compare the measured
forces with your theoretical calculations.
Discuss your results.
Submit your report and prototype.
THE CAN CRUSHER
Officially Sanctioned Materials
MaterialCost ($)
Specifications
Density
Aluminum flat stock 1/8" x 3/4"
0.20/ft
Aluminum flat stock 1/8" x 1/2"
0.15/ft
s
t
ultimate
ultimate
1/8 " Steel shaft
1/4 " Steel shaft
Sheet Metal 1" x 4" x 0.023"
Plywood 3/4" thickness
Wood 2" x 4"
8
gr/cm3
1.0/sq.ft
0.37/ft
Wood 1" x 4"
0.43
gr/cm3
1/4" wood dowel
0.05/in
22.5 gr
1/2" in dowel
0.08/in
2.35 gr
PVC 3" ID
0.80/ft
Bolt & nut
0.05/unit
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Washers
Nails up to #8
0.6 7.5 gr
Nails greater than #8
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Screws
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Duct Tape (6" strip)
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Masking Tape (12" strip)
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Paper Clips
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Bearings
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Bushings
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Adhesives (for fastening only)
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