1.pass in your technical drawing lab and your final paper mousetrap (someone else’s that you...
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1. Pass in your Technical Drawing Lab and your final Paper Mousetrap (someone else’s that you constructed).
2. If you are missing either assignment (or both), pass in a piece of paper with your name and missing assignment title on it.
“Give me a lever long enough and I shall move the world.” Archimedes
Unit 3: Engineering Design
http://www.math.rochester.edu/u/faculty/doug/UGpages/archimedes_lever.gif
Isometric Section Standard View Development Perspective Oblique
Cut-away Pictorial
Com
mun
icati
on T
echn
olog
y A B C
D E F
G
E
B
C
F
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D
A
[REVIEW]
Which of the following images are parallel projections?
TECHNICAL GRAPHICSTe
chni
cal G
raph
ic C
omm
unic
ation
[REVIEW]
– Print Graphic Communication Visual, lingual messages that include printed media
– Photographic Communication Using photographs, slides, or motion pictures to
communicate a message– Telecommunications
Communicating over a distance– Technical Graphic Communication
Specific information about a product or its parts
Classes of Communication Technology
[REVIEW]
– Major Processes:• Relief
– A modeled work that is raised (or lowered) from a flat background.
– Cuneiform by the Sumerians ~6000 years ago. – Wood block printing ~200 C.E.– Movable type printing ~1040 C.E. (Gutenberg ~1450)– Intaglio (in-tal-yo) ~1430– Rotary printing press ~1843
• Lithography (offset printing) ~1796– The source and destination are not on raised surfaces– Grease and water do not readily mix– A chemical process– Most modern books and newspapersPr
int G
raph
ic C
omm
unic
ation Intaglio
(in-tal-yo)
1. Depressions cut into printing plate
2. The plate is covered in ink
3. Excess ink is removed from surface
4. Paper placed on plate and compressed
5. Paper is removed and ink has been transferredLow ReliefHigh Relief
Communication Technology
Cuneiform
[REVIEW]
• Telecommunication– Communicating over a distance
Tele – Greek, “far off” Communicare – Latin, “to share”– Rely on the principles of electricity and magnetism – 2 types:
• Hardwired systems (telephone, cable, fiber-optic)• Broadcast systems (radio and t.v., mobile phones)
– Point-to-point: • One transmitter and one receiver
– Broadcast:• One powerful transmitter to numerous receiversTe
leco
mm
unic
ation
sCommunication Technology
[REVIEW]
– Smoke signals and drums– Chains of beacons (Middle Ages)
• Navigation signals• Enemy troops approaching
– Homing pigeons • Carrier pigeons used as early as 1150 in Baghdad• Olympic victors, Greece; Stock options, Europe
– Optical telegraph (semaphore, 1792, France)• Towers with pivoting shutters• Information encoded by the position of the mechanical
elements
Tele
com
mun
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ons
Communication Technology
[REVIEW]
Standard Views
Sectional Views
Auxiliary Views
Developments
Working Drawings
MULTI-VIEW DRAWINGSTe
chni
cal G
raph
ic C
omm
unic
ation
[REVIEW]
Show a likeness of an object as viewed by the eyeIsometric
Perspective
Oblique
Exploded Assembly
Cutaway Pictorial
Tech
nica
l Gra
phic
Com
mun
icati
onPICTORIAL DRAWINGS
[REVIEW]
Essential Elements of Engineering
1. Thorough understanding of scientific principles• Mechanics, Electricity and Magnetism, Thermodynamics, etc.
2. Practical and useful designs• Based on design requirements• KISS – Keep It Short and Simple
3. Good communication skills• Great design is worthless if not effectively communicated
ORAL WRITTEN DRAWINGS [REVIEW]
[REVIEW]
TEST FRIDAYTEST FRIDAYIncluding multiple choice, isometric and orthographic Including multiple choice, isometric and orthographic
drawing, and 2 algebra problemsdrawing, and 2 algebra problems
UNIT 2: Engineering CommunicationUNIT 2: Engineering Communication
Topics Covered
1. Force, Energy, Work, Power, and Efficiency2. Topics in Mechanical Engineering3. Topics in Electrical Engineering4. Engineering Design Process5. Teams and Projects6. PROJECT: Mechanically Controlled Electromagnetic Crane
Unit 3: Engineering Design
1. A push, pull, twist (or bend)2. A vector quantity
1. Magnitude2. Direction
3. Thrust – increases velocity4. Drag – decreases velocity5. Torque – changes rotational speed
Units: Newton (N), Pound-force (lbf)
FORCE
1. Inertia“Objects continue to move in a state of constant velocity unless
acted upon by an external net force.”
2. Fnet = ma“An unbalanced force acting on an object will result in the
object’s momentum changing over time.”
3. Reciprocal Actions“Forces always occur in action/reaction pairs.”
Newton’s Laws of Motion
1. Energy1. A scalar quantity2. The amount of work that is (or can be) performed by a
force
2. Potential Energy1. Energy stored within a physical system with the potential
to be converted into other forms of energy (e.g., kinetic, thermal, sound, light)
2. Types:Gravitational, Elastic, Chemical, Electrical, Nuclear
3. Kinetic EnergyThe energy an object possesses due to its motion
“Energy can be transformed, but cannot be created or destroyed.”
ENERGY
1. Work1. “The amount of energy transferred to a system by a force
acting through a distance.”2. The change in kinetic energy of a system
2. W = F x d1. The work done on an object is the product of the
component of the force in the direction of the displacement and the magnitude of the displacement.
2. A force does no work if the object doesn’t move
Units: Joule (J), Newton-meter (Nm), Foot-pound (ft-lb)
WORK
1. Power1. “The rate at which work is performed or energy is
converted.”2. The rate of change of work or energy.
2. P = W / t
Units: Watt (W), Foot-pound per second (ft-lb/s), Horse power (hp)
POWER(Mechanical)
1. Efficiency1. The ratio of the energy delivered by a system to the energy
supplied to it.2. The ratio between the output of a system and the input
2.
3. When is efficiency 100%?2. Never – 2nd Law of Thermodynamics3. Some of the input energy is converted to heat, sound,
light, etc.
Units: Dimensionless or %, Situational
EFFICIENCY
EFFICIENCY = x 100%OUTPUT INPUT
1. Equations1. W = F x d2. P = W / t3. F = m x a4. Eff = (output / input) x 100%
2. Problem Solving Process1. Write Given, Assign Variables, Sketch and Label Diagram2. Write Formulas / Equations3. Substitute and Solve4. Check Answer, THEN Box Answer
Engineering Problems
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