Download 2015 Mechanical Engineering

Mechanical Engineering:
Robochime Exhibit
Materials:
Different diameter & density hollow metal
tubes
Something to strike the tubes with
Magnets
Magnetic (i.e. paper clips) & non-magnetic
materials (i.e. pennies)
Container of Water (bowl or tank)
Foam Ball
Rock
Other miscellaneous materials and objects
Activities
Place different objects in a container filled with water. A rock
may sink in the water, but the foam ball will float. This shows
that the objects that sink have a larger density than the
water, whereas the objects that float will have lower
densities.
Try to find a magnetic object. Touch a magnet to different objects to see which
ones stick to it. Objects that stick to the magnet have a magnetic field. Magnets
often have two sides called magnetic poles. In order for the object to stick to the
magnet, the magnetic field in the object has to be the opposite of the
magnetic field of the magnet.
Strike different objects to test for vibrations. Vibrations
cause movement in objects, and they are also what
causes sound. It does this by creating sound waves that
flow from the object through the air.
Applications to Engineering
• Density is important and used in many applications of engineering. For example, in
order to float, ships have tanks that hold air, which has a lighter density than water.
Submarines, on the other hand, empty these tanks, which allows them to sink.
• Magnets are used daily in electric motors, such as in a toy or even an electric car,
rollercoaster brakes, microphones, speakers, and in computers.
• Many times, vibrations are not wanted within a system. Vibrations can cause problems
in mechanical systems, such as within an aircraft. However, sometimes vibrations are
wanted. In the robochimes, the vibrations are needed in order to make sound.
Vibrations are sometimes used to sort materials, model earthquakes, and sometimes
even used to prevent damage from earthquakes.
• Knowing the properties of materials is very important to engineers. Having this
knowledge helps to prevent wear, cracks, and breaking.
Sites to Visit
http://www.sciencekids.co.nz/gamesactivities/materialproperties.html
http://www.mrs.org/science-enthusiast-do-something/
Mechanical Engineering
Robotics
What part of a robot is mechanical?
The job of a mechanical engineer working on a robot is to design the robot’s body. Each robot is
designed to do a specific job or solve a specific problem. A mechanical engineer works with a team of
other engineers to determine the problem and come up with a design for a robot to solve it. Mechanical
engineers design the robot’s frame, joints, determine the motors used to control the joints, tools the
robot may have, and what it is made of. They would also work with constraints like size and weight. If the
robot has to be a certain size or weight, a mechanical engineer would work with all components from all
other disciplines to help make everything fit together and make sure that the robot is below the allowed
amount.
Motors: Mechanical engineers work with types of other engineers to determine the right type of motor for a
robot. The right motor depends on many things. What type of job will the robot be doing? Moving, lifting,
sorting, or something else? How much will the robot need to lift or move? How much does the motor cost?
These are just some factors that help a mechanical engineer decide what motor is right for the job.
Materials: Mechanical engineers, material specialists, and other types of engineers work together to decide
what a robot should be made out of. They have to think about how much strength the robot needs, what kind
of environment it will be in, budget, and many other factors. The Mars Rover needs specific and costly materials to function in the harsh environment of Mars, but a robot working in a lab or a warehouse would probably
be made out of cheaper, more common materials.
Joints: Joints and any part of the robots that moves can be designed by a mechanical engineer. It’s
important to know what kind of joint will work for what that part of the robot needs to do. A simple claw
that opens and closes will work for moving boxes from place to place, but a robot built for surgery would
need much more precise joints and tools.
How can I get involved?
There are many ways to get involved in engineering and robotics. Listed below are a few opportunities, but search, explore, and
create on your own as well!
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At Home: Listed below are a few websites where you can buy your own robotics kits. There are kits for every style and budget to encourage hands on exploration and creativity.
- http://www.robotshop.com/
- http://www.scientificsonline.com/
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Guided Learning: Listed below are some local opportunities to get involved with learning about robotics, and even participating in team events.
- http://www.usfirst.org/ - FIRST organizes robotic events for all ages. It’s a national organization, but there are
local teams you can look to join, or even start within your own school district.
- http://vistateach.biz/ - Vista Teach is a local business that runs summer camps for all the STEM fields. If you’re
interested in robotics, they have summer camps geared towards learning about and building robots.
Mechanical Engineering:
Simple Machines & Mechanical
Advantage
Materials:
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6 pulleys with hooks
1 long rope/cable
1 large mass (maybe 100 lbs, will be split 6
ways) and a way to grab onto it in 3
locations
Large frame
Wooden spools
Thick straws
Wooden dowels
Rubber bands
Washers
Tape
Paperclips
Cylinder
Thin tubing
Handle
Tub/Bowl of water
Activities
1. Create the pulley system as shown. The force
necessary to lift a mass on the other end
should be approximately 1/6 the amount of
weight.
Figures 1 & 2: Possible Frame to Hold Pulleys and Pulley System
Figure 2: Spool Car
2. Create spool cars. This activity will demonstrate the transition of potential
energy to kinetic energy.
a. Take a spool and weave a rubber band of approximately the same length of the
body of the spool through the hole. Place a paperclip underneath one loop of the
rubber band and tape it.
b. On the other end, place a straw through the rubber band. Spin the straw until
it begins to rotate if released.
c. Place on the floor and let go of the straw. The spool should move forward.
d. Other variations of this may include a washer on the side of the spool with the
straw. Experiment with different size rubber bands and washers to try to make
your spool move the furthest!
3. Create an Archimedes’ screw.
a. Taking the cylinder, wind the thin tubing in a spiral from
the bottom to the top. Hot glue this tube to the cylinder.
b. Attach a handle to the top of the cylinder.
c. Fill a tub/bowl full of water. Place the screw in the water
and rotate. The water should begin to climb through the
tube and come out the top end of the screw.
Application to Engineering
1. Pulley systems help to redirect weight and to redirect forces. They are used within daily
life. Elevators, window blinds, flag poles, and engines all use pulleys.
2. The spool cars help to show the concept of kinetic and potential energy. Before
releasing the straw, energy is being stored within the rubber band, which is called
potential energy. After releasing it, the energy changes to kinetic energy, which is when
the rubber band begins to release and rotate the spool. One example of this is a roller
coaster. Engineers take the energies into account when designing the roller coaster.
3. There are many different types of simple machines, including the Archimedes’ screw,
lever, pulleys, and axle. Each is used in industry. The Archimedes’ screw is used within
pumps, especially those for flood control, sewage, and drainage. These pumps allow for
the movement and lifting of liquids via the rotation of the screw.
Sites to Visit:
http://easyscienceforkids.com/all-about-simple-machines/
https://www.teachengineering.org/view_lesson.php?url=collection/cub_/lessons/cub_energy
/cub_energy_lesson01.xml
Mechanical Engineering:
Marshmallow Towers
Materials:
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1 m Tape
1 m String
• 1 Marshmallow
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Problem:
Build a tall, stable tower that will be able to hold a marshmallow within
15 minutes. The highest marshmallow wins!
All materials may be used, including the bag.
20 Pieces of Spaghetti
1 Brown Bag
Suggestions
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Make spaghetti pieces stronger by taping more than one together. Single pieces of spaghetti tend to
break and flex.
Creating a base helps to make a
structure more stable.
Do not wait until the last minute to put
the marshmallow on top. It is a lot
heavier than it appears, especially in
reference to the spaghetti.
Do not spend too much time planning.
Try to use the materials sparingly.
Procedure
1. Give each group a bag of the materials.
2. Each group will have 15 minutes to create a tower that will be able to hold a
marshmallow above the ground using any of the materials given to them.
3. When the 15 minutes are complete, measure the marshmallow’s height from the
ground. The highest marshmallow wins! Tower height should not be measured.
Application to Engineering
• Structural design and engineering
o Very important part of engineering. It is part of the design process for every
building we see.
o Makes sure that buildings are strong enough to support what they need to.
o Teamwork!
o A big part of engineering is team work! How did working in a team help you build
your tower? If you worked individually what benefits would working in a team
have provided?
o Teamwork allows for the collaboration of different ideas and thinking styles
which allow for the best deigns!
Mechanical Engineering
Who can build the tallest tower?
The Challenge
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Build the tallest, freestanding tower that can hold a marshmallow using only the
materials provided
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Materials:
1 m Tape
20 Pieces of Spaghetti
1 m String
1 Brown Bag
1 Marshmallow
Time Limit: 15 Minutes
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Rules:
Participants may work in teams or individually
All provided materials can be used, including the bag . No extra materials can be incorporated
Marshmallow must be supported on the very top of the tower
Tower only need to support marshmallow until official measurement is taken
All work must stop after 15 minutes
Participants may work in teams or individually
Applications to Engineering
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Structural design and engineering
Very important part of engineering. It is part of the design process for every building we see.
Makes sure that buildings are strong enough to support what they need to.
Teamwork!
A big part of engineering is team work! How did working in a team help you
build your tower? If you worked individually what benefits would working in a team
have provided?
Teamwork allows for the collaboration of different ideas and thinking styles
which allow for the best deigns!