Page 1 of 28
Robotics Engineering
DoDEA - Career and Technical Education
Identifying Elements of Structural Design
Exercise 1 – The History of Engineering
Objective: You will research the origin of mechanical engineering and create a detailed timeline of ten (10)
significant accomplishments in mechanical engineering throughout history. You will also research one of many
famous engineers and inventors and describe their contributions to mechanical engineering and the impact their
work has had on society.
Deliverables: Copy and paste the required deliverables to another document for submission. All deliverables
must be word processed with the required student ID information in the footer of the document. The header of the
document should contain the title of the assignment. Both the question and answer must be included in the
deliverable with the answers highlighted. All work must be complete and accurate to receive credit.
1.
2.
3.
Graphic timeline of ten significant events in engineering history from the dawn of civilization up to present day.
Detailed definitions for each of the terms found in the Nomenclature section.
An original 200 to 300 word composition identifying one engineer/inventor and describing their contributions and impact
upon our civilization. See the list of recommended individuals in Information section of this document.
Information: Cultures and societies have flourished as the result of key inventions that have reduced our
burden, increased productivity, or enriched our lives. History is built upon the people and their innovations and
there have been many contributions recognized as milestones during the history of mechanical engineering.
Milestones are placed upon timelines to mark significant events. Timelines help us realize the relationship between
as well as the sequence of these milestones. Timelines lend a greater appreciation of these accomplishments over
time. Milestones representing significant accomplishments in engineering are many. From the abacus, horse
collar, and movable type to the invention of the clock, automobile, and International Space Station there are many
contributions that engineers have made throughout time. Engineers such as:

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

Ada Byron
Al-Jazari
Archimedes
Benjamin Banneker
Bonnie Dunbar
Dean Kamen
Erna Schneider Hoover
Leonardo da Vinci
Charles Goodyear

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


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Frederick McKinley Jones
Garrett A. Morgan
Hedy Lamarr
Hertha Ayrton
Jacques de Vaucanson
Karl Benz
Alexander Parkes
Ole Kirk Christiansen
Kenneth J. Dunkley
Lillian Gilbreth
Lonnie G. Johnson
Marie Curie
Mark Dean
Nikola Tesla
Philip Emeagwali
Robert Fulton
Leo Baekeland
…and many others have all placed their milestone upon the timeline of innovation and service to this important
career field.
Research Resources: The www changes all the time. If you find a dead link, please report it to your instructor
but you should also use a search engine to find the information in another site.
Web Site
Description
http://www.history-timelines.org.uk/
http://office.microsoft.com/en-us/templates/timeline-TC001016265.aspx
http://www.black-inventor.com/
http://www.women-inventors.com/
http://en.wikipedia.org/wiki/List_of_inventors
Timelines of People, Places and Events.
Templates to produce timelines in MS Word.
Famous Black Inventors
Famous Women Inventors
List of inventors
Nomenclature: Research and develop a detailed (two to three sentences) definition for each of these terms. It’s
important to realize that many words have multiple definitions. Some of which may have nothing to do with this
course of study. Make sure your definitions fall within the context of this lesson.
 Innovation
 Milestone
 Timeline
 Mechanical Engineering
 Invention
 Inventor
Conclusion: Understanding how far civilization has come through the actions of innovative minds is nothing
short of remarkable. Regardless of nationality, race, gender or socioeconomic standing the power of innovation has
brought about marvelous inventions that have contributed to the quality of life around the globe. Innovation is a skill
within all of us that must be exercised to become practical. Through practice, you may become the inventor who
finds a cure for cancer, designs an engine that doesn’t pollute or solve the world’s energy crisis.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – The History of Engineering
Revised 15 March 2016
Page 2 of 28
Robotics Engineering
DoDEA - Career and Technical Education
Identifying Elements of Materials and
Structural Design
Exercise 2- Materials
Objective: At the completion of this exercise, you will demonstrate your knowledge of
the properties of various materials, how they are manufactured and then converted
into the products we use.
Deliverables: Copy and paste the required deliverables to another
document for submission. All deliverables must be word processed with
the required student ID information in the footer of the document. The
header of the document should contain the title of the assignment. Both
the question and answer must be included in the deliverable with the
answers highlighted. All work must be complete and accurate to receive
credit.
1.
2.
3.
Detailed definitions for each of the terms found in the Nomenclature section.
Detailed answers to the queries listed in the Questions section.
Completed table from the Materials Lab.
Closely examine the display that you’re reading this
document from. What is it made of? Undoubtedly, you’ll recognize a type of
plastic, some metal and perhaps glass. You may also notice a bit of paint here and there. Although you
cannot see inside the device, it’s pretty clear that this display was manufactured from a variety of materials using
processes that compress, stretch, mold, separate, fasten and coat the component parts needed to construct it. Of
course, this would be true for any modern product. Identifying these materials, their characteristics and
applications, as well as how they’re processed into a useable forms allow us to understand how stuff is actually
made.
Information:
Materials science is a field of study that applies the properties of matter to the areas of science and engineering.
Scientists that design new materials and discover their applications investigate the relationships between the
atomic structures within materials to better understand their properties and invent new materials.
Materials fall into the following broad categories:
 Biomaterials
 Ceramics
 Composite Materials
 Metals
 Polymers
 Semiconductors
Mechanical properties of materials include:
 Strength
 Elasticity
 Plasticity
 Hardness
 Toughness
 Fatigue
Normally, materials are first considered for their mechanical (or physical) properties. However, some materials
have other traits that could benefit or even interfere with a product’s manufacture or usefulness. Electrical
properties identify the degree of the material’s ability to conduct or oppose the flow of electricity. Optical
properties rate the materials ability to transmit light. Some materials are transparent while others are translucent
or opaque. Patterns in the material may also distort or diffuse light while pigment may be added to change the
color. Chemical properties determine how materials react with other materials. This includes oxidation or rusting.
Thermal properties determine how materials respond to forms of energy like heat and types of light. Researchers,
scientists and engineers must be knowledgeable of all these characteristics if they are to successfully design new
materials for the companies that make stuff.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – The History of Engineering
Revised 15 March 2016
Page 3 of 28
Primary manufacturers process raw (natural) materials like wood, ore, minerals, natural gas and petroleum into
industrial materials also called standard stock. The company that built the display that you’re studying purchased
the standard stock like sheet metal, circuit boards, plastic graduals and semiconductors from primary
manufactures. The display’s manufacturer processed the standard stock into the shapes and forms needed to
assemble and test the end product. The process of converting industrial stock into a finished product is called
secondary manufacturing and there are six methods involved in
this process:
 Casting and Molding
 Conditioning
“I was trying to make something
 Forming
 Assembling
really hard, but then I thought I
 Separating
 Finishing
should make something really soft
instead, that could be molded into
The materials and manufacturing industry is incredibly vast and
different shapes. That was how I
provides many opportunities for careers in Science,
came up with the first plastic. I called
Technology, Engineering and Math (STEM). For right now, let’s
it Bakelite.” Leo Baekeland - 1907
focus on just one category of materials sometimes referred to
as plastics. We’ll determine the origins of plastic, its properties
and its manufacturing processes.
Plastic is a generic name sometimes given to a category of materials more precisely known as polymers. The
word “polymer” is derived from the Greek word polumerēs, which means consisting of many parts or segments.
These segments are actually replicating molecules called monomers (mono means "one"). Polymerization is the
process by which monomers react (combine) to form long chains that link to other polymer chains forming the
material we know as plastic. It’s these linkages and the molecular structure of the polymer that determines the
material’s properties. Polymers can be synthetic but are common in nature as well. While hair, fingernails,
feathers, cellulose, proteins, rubber and starch are all naturally occurring
polymers, synthetic polymers are typically made from chemicals refined
from petroleum oil.
Partially synthetic polymers (like gum elastic) have been around since
1832 but it wasn’t until 1907 that fully synthetic polymers made the scene.
Because plastic from synthetic polymers is easier and cheaper to
manufacture and much lighter than metal, the polymer industry has become
larger than the steel, aluminum and copper industries combined. In fact, polymers
have a range of uses that substantially surpass that of any other category of material.
Applications include adhesives, solvents, coatings, and foams. Packaging, textiles, industrial
fibers, composites, electronic devices, biomedical devices, and optical devices have also been
born from advances within this industry. Polymer research has also led to the spectacular
innovations in the emerging field of high-tech ceramics. Considering the impact, polymers have upon
modern life, it’s important to understand how plastic is produced and applied in the manufacturing process.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – The History of Engineering
Revised 15 March 2016
Page 4 of 28
Acrylonitrile (C3H3N)
Butadiene (C4H6)
Styrene (C8H8)
Let’s examine just one type of synthetic polymer in greater detail. It’s the familiar material that LEGO™ uses to
make all those plastic bricks, beams, plates and wheels. It’s a polymer commonly called ABS plastic which stands
for the three monomers used to construct the material; Acrylonitrile, Butadiene and Styrene. ABS is a
thermoplastic and its molecular formula is (C3H3N · C4H6 · C8H8)n That’s a lot of carbon, hydrogen and nitrogen
atoms to figure out how to put together. The diagrams above may provide a clearer understanding of the
molecular structure of the monomer components and how they might fit together to form the small polymer chain
of ABS plastic also shown above.
ABS plastic is a common thermoplastic used to make lightweight and rigid products such as pipe, musical
instruments, automotive body parts, helmets, and toys. Thermoplastic melts to liquid when heated and typically
hardens to a strong, glasslike material when it’s cooled. Polymers are broken down by breaking the intermolecular
bonds between them. This can be done by either heating the material or introducing other monomers (like
solvents) to substitute existing reactions in the material. The result is a reshaping or disintegration of the polymer
chains in the polymer material.
It’s all about how the monomer molecules are structured and how they react to produce polymer chains.
Engineers can choose the characteristics of the materials they develop by tweaking the monomers used to build
the material. The longer the polymer chains and increased intermolecular bonding between the chains… the
stronger the material becomes. Also, the closer the chains are packed together the more rigid the material
becomes. The polymerization of Acrylonitrile, Butadiene and Styrene creates a tough and safe material suitable
not just for LEGO™ but for many consumer products we use today. Heated thermoplastic can be blow and
vacuum formed, extruded, as well as injection, thermo-set, compression, insert, and transfer molded into a wide
variety of objects that serve a multitude of applications.
Research Resources: The www changes all the time. If you find a dead link, please report it to your
instructor but you should also use a search engine to find the information in another site.
Web Site
Description
http://science.howstuffworks.com/plastic.htm
How Stuff Works - How Plastics Work
http://entertainment.howstuffworks.com/lego.htm
How LEGO™ Bricks Work
http://www.youtube.com
YouTube - How do they do it? LEGO
http://www-materials.eng.cam.ac.uk/mpsite/default.html
Univ. Cambridge - Materials Selection and Processing
http://pslc.ws/
PSLC - Polymer Science Learning Center
http://www.pbs.org/wgbh/buildingbig/lab/index.html
PBS - Information about force/load upon materials/shapes.
See Instructor for Document
ITEA – HITS Manufacturing Processes
http://www.materialsworldmodules.org/modules/polymers.shtml
Materials World Modules - Polymers Module
http://www.wolframalpha.com/
Wolfram Research - Computational Knowledge Engine
http://www.sciencegeek.net/eChem/eChem.html
eChem - 3D Molecule Model Builder
Nomenclature: Research and develop a detailed (two to three sentences) definition for each of these terms.
It’s important to realize that many words have multiple definitions. Some of which may have nothing to do with this
course of study. Make sure your definitions fall within the context of this lesson.
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Secondary manufacturing
Primary manufacturing
Industrial Stock
Casting/Molding Processes
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Forming Processes
Separating Processes
Conditioning Processes
Assembling Processes
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016




Finishing Processes
Monomer
Polymerization
Composite Materials
Page 5 of 28
Questions:
1. Partially synthetic polymers (gum elastic) have been around since 1832, but there wasn’t a strong interest to
move away from natural polymers until the 2nd World War. Why?
2. How would you categorize the mechanical properties of a pencil eraser?
3. How does the choice of materials affect the usefulness of an object?
4. Using terms from the Nomenclature section of this lesson… From nature to your book bag… Describe the
manufacturing process and life cycle of a pencil.
5. From the video, “How do they do it? LEGO™”… In 1999, when the video was produced our planet had 6 billion
people on it. At that time there were 62 bricks for every man, woman and child on Earth. Assuming the number
of bricks per person is the same… Calculate the approximate number of LEGO™ bricks that are on our planet
today. How many towers could you build to the Moon with that number of bricks?
Procedure: Materials Lab
In this activity, you’ll closely examine and then categorize various materials according to their mechanical
properties. Each sample that you’ll evaluate is identified with a number. Complete the table below rating each
material from 0 to 3 (3 being the highest) and identify the name and type for each material sample.
Required Materials and Equipment: Volt-Ohm-Milliammeter (Multimeter)
Get the following samples from your instructor:
1
1
2
1
1
2
 Aluminum
 Glass
 Plastic (Acrylic)
0
Opacity
Conductivity
Fatigue
Toughness
 Plywood
 Steel
 Cardboard
Hardness
Plasticity
Strength
Sample
ID #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
 Wood
 Fiberglass
 Cotton
Elasticity
 Particleboard
 Brass
 Rubber
3
Material Name
Cardboard
 Plastic (PVC)
 Ceramic
 Wax
Material Type
Biomaterial
Conclusion:
Our stuff is made from the raw materials harvested from our Earth’s natural resources. Primary manufacturers
convert these natural supplies into industrial materials or standard stock. Standard stock like sheet metal, thread,
wood, fibers, plastic granules, and other materials are purchased by secondary manufactures where it’s casted,
molded, formed, separated, conditioned, assembled and finished into the products we purchase from stores.
Knowing the characteristics of these materials, how they’re produced and processed helps engineers realize the
limitations of materials as they design solutions to modern engineering problems.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 1 of 28
Robotics Engineering
DoDEA - Career and Technical Education
Identifying Elements of Materials and
Structural Design
Exercise 2b – Making Plastic From Milk
Objective: At the completion of this experiment, you’ll demonstrate the
polymerization process using the monomer called casein that’s found in milk. You’ll
create an organic plastic and mold it into a pair of dice.
Deliverables: Copy and paste the required deliverables to another document for
submission. All deliverables must be word processed with the required student ID
information in the footer of the document. The header of the document should
contain the title of the assignment. Both the question and answer must be
included in the deliverable with the answers highlighted. All work must be
complete and accurate to receive credit.




Detailed definitions for each of the terms found in the Nomenclature section.
Detailed answers to the queries listed in the Questions section.
Completed casein dice project.
eChem – 3D molecular model of:
a. Acrylonitrile (C3H3N) Molecule (Required)
b. Casein (OH)C18H14N2O3C(=O)x Molecule (Optional) This is Extra Credit
because it’s a difficult task and will take a significant amount of time to
build the molecular model. You’ll need to use carbon rings and you may
have to experiment with different starting points for the model to fall into
place.
Information: Casein plastics have been around since Leonardo da Vinci’s time. He
used the material to gesso his canvas before painting a masterpiece. The first plastic
buttons for clothing were made of casein, but the milk based plastic had not been
considered for large scale manufacturing until 1897 in an attempt to manufacture white chalkboards. The raw materials
(milk) used in the process were expensive compared to synthetic polymers. So when polymers from petroleum were
invented, the production of casein plastic was mostly abandoned. It’s still used today to make paper glossy and glues
stronger for bookbinding.
Casein Formula: (OH)C18H14N2O3C(=O)x
Structural Diagram
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
3D Structure (Ball and Stick)
Page 2 of 28
Milk is colloid, or globs of the protein casein suspended in water. Doesn’t that sound yummy? In this state, the casein
is essentially a monomer that can be processed to make plastic, but only if the molecules could get close enough to
combine. This process is called polymerization. Polymers are formed by combining (associating) small molecules or
monomers into long chains of molecules. Although most plastics are produced from petroleum products and natural
gas, plastic from casein is just one of thousands organic polymers that exist in nature. Since most of cow milk is made
up of the protein casein under the right conditions this protein can be processed into a natural form of plastic. Adding
an acid like vinegar to milk causes the casein molecules to unfold freeing the monomers to replicate and produce long
chains of the polymer. This process is called denaturing. Adding heat speeds up the reaction and causes a more
complete separation of the casein molecular chains from the water.
Research Resources: The www changes all the time. If you find a dead link, please report it to your instructor but
you should also use a search engine to find the information in another site.
Web Site
Description
http://www.youtube.com
Making Plastic From Milk Easy
http://www.sciencegeek.net/eChem/eChem.html
eChem - 3D Molecule Model Builder
http://www.wolframalpha.com/
Wolfram Research - Computational Knowledge Engine
Nomenclature: Research and develop a detailed (two to three sentences) definition for each of these terms. It’s
important to realize that many words have multiple definitions. Some of which may have nothing to do with this course
of study. Make sure your definitions fall within the context of this lesson.
 Gesso
 Colloid
 Denaturing
 Casein
 Acid
 Associating
Questions:
1. What are the differences in casein content between 1%, 2% and whole milk?
2. What other foods could be used as an acid to perform the denaturing process in this activity?
3. What atoms are represented by the grey, white, red and blue balls in the 3D structure of the casein model?
Procedure: Pair of Dice Lost? Pair of Dice Regained
Required Materials and Equipment: This experiment can be performed at home.
 9 Ounces of 2% milk
 4 Tablespoons of White Vinegar
 Small Mixing Bowl (Microwave Safe)
 1” x 4” Cardboard Strip, 2 Each
Steps: Complete each of the following steps in this order:
1. Study the video, “Making Plastic from Milk –Easy” listed in the Research Resources section.
2. Pour the milk into a microwave save bowl and heat in the microwave on high for two (2) minutes.
3. Pour the vinegar into the heated milk and stir until the casein finishes polymerization.
4. Strain the casein and knead the material into a ball while mixing it into a smooth consistency.
5. Set it aside on a paper towel to drain for about 30 minutes or more. The material should not be watery.
6. Fold and tape the two cardboard strips into forms to make two separate cubes.
7. Allow the cubes of casein to dry for a day or two.
8. Remove the casein cubes from the forms and mark them as dice.
Conclusion:
Knowing what polymers are and making them yourself are two distinct learning experiences. In this activity you applied
your knowledge of polymerization and created plastic from the casein in milk. You also used a CAD program to design
a polymer molecule. In doing so, you learned that monomers can be made to recombine in long molecular chains by
changing the molecules’ shape through the process of denaturing. You also learned that thermal energy can speed up
the reaction process. It may be interesting to note that we ingest polymers every day. Cheese makers use a similar
process to produce some of world’s finest cheeses. There may not be much difference between those single slices of
cheese you find in the grocery store and the plastic that keeps them separated.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 3 of 28
Robotics Engineering
DoDEA - Career and Technical Education
Identifying Elements of Materials and
Structural Design
Worksheet 3 – Fasteners, Fastening and Bonding
Objective: After completing this exercise, you’ll demonstrate your knowledge and the proper use
of fasteners and fastening. You’ll model various types of fastening systems using
our robotics trainer. You’ll also become familiar with other methods the
manufacturing industry uses to fasten materials together.
Deliverables:
Copy and paste the required deliverables to another
document for submission. All deliverables must be word processed with the
required student ID information in the footer of the document. The header of
the document should contain the title of the assignment. Both the question and
answer must be included in the deliverable with the answers highlighted. All work
must be complete and accurate to receive credit.
1.
2.
Detailed definitions for each of the terms found in the Nomenclature section.
Detailed answers to the queries listed in the Questions section.
Information: Temporary and (various degrees of) permanent are the two basic types of fastening methods to
consider during product assembly. The method best chosen is determined by many factors. You certainly wouldn’t
want to weld or glue parts of an assembly together that may need to be taken apart later for maintenance or repair.
The same is true for using nails when the design specifically calls for woodscrews and glue. It’s very important to
follow the design specifications when selecting the fastener that’s appropriate for the work being done. The application
and types of materials being fastened together often determine the kind of fasteners that are used.
There’s one final distinction regarding the types of fasteners and fastening methods in regards to permanence… No
fastening method is actually permanent. Even welds and adhesives can be removed if there’s no regard for the
components that are fastened by them. When materials are fastened together, their joining is designed to form
continuity between the components. The goal is to make the components act as one. Therefore, it’s important to
consider the various mechanical stresses that manufactured products must endure without deformation or failure.
These forces are:
1. Compressive Stress results when an object is squeezed along the same axis.
2. Tensile Stress occurs when an object is being pulled along the same axis.
3. Shear Stress can be related to the stress caused by a pair of scissors as they cut through an object. Shear
stress is a sliding force represented by one material moving in parallel along another object.
4. Torsion Stress represents a twisting motion applied to an object.
It’s important to remember that the strength of joining materials together is only as strong as the fastener and material
that’s being joined. Bolting cardboard together seems inappropriate when you consider the metal fastener is thousands
of times stronger than the material surrounding it. Although the bolt itself may stronger, glue may be the better
fastening method in this situation.
Threaded Fasteners – These are pretty common fasteners that are available in a variety of sizes and are made from
array of materials including steel, stainless steel, brass or plastic depending on the application of the fastener. These
are temporary fasteners that are manufactured in the Imperial and Metric measurement schemes. Screws have
external threads and nuts have internal threads. The thread can be course or fine, but the actually thread sized is
standardized based upon the screws diameter and the pitch of its threads. It’s important for you to know the names of
these screws as well as their proper application. Caution: Most threaded fasteners use a right-hand thread meaning
the fastener will tighten if it’s turned to the right (clockwise) and loosen if it’s turned to the left (counter clockwise). The
old axiom is, “Righty Tighty… Lefty Loosey.” Over tightening any fastener can strip its treads. Some specification
require fasteners be tightened to a specific torque. In addition, using the wrong tool or the wrong size tool can damage
the head of the fastener making it difficult to install or remove.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 4 of 28
Socket Cap Screw
Cap Screw (Hex)
Machine Screw
Set Screws
The Socket Cap Screw typically
features a Hex or Torx head
socket allowing for a greater
transfer
of
power
during
tightening. This type of fastener
is also tamper resistant.
The common Hex Cap Screw
features a hexagonal head that
can be gripped with either a boxend, open-end, adjustable, or
socket
wrench.
Add
the
corresponding
nut
and
it
becomes the common bolt.
Machine Screws are available in
flat, pan, oval, round and button
head varieties using either
slotted
or
Phillips
driving
systems. They are the most
common type of screw used in
manufacturing coming in a vast
array of sizes. Some even come
complete with a built in lock
washer.
Tapping Screw
Wood Screw
Hex Standoff
Set Screws do not have a head.
They’re used in situations where
a head would interfere with the
product’s function. The top of
setscrew has a hexagonal socket
that fits an Allen Wrench or Hex
Key. The other end typically
comes to a dimpled point and
usually tightens so the point
drives into a recess or keyway.
Hex Nut
Is it called a bolt or is it a screw? It’s not a settled
argument, but essentially a screw becomes a bolt when it’s
used with a matching nut. Why? It’s due to U.S. trade and
tariff laws. It’s actually cheaper to import and export bolts
when they’re called screws.
Drive Styles
Phillips
Head Styles
Socket Cap
Slotted
Pan
Hex
Flat (Countersunk)
Torx
Lock Nut
Oval
The Tapping Screw is sometimes
called a sheet metal screw and has
sharp threads for cutting into the
material it’s securing. The threads
run completely up to the head of the
screw.
Wood Screws can have pan, flat,
round or oval heads with either a
slotted or Phillips recess for driving
the screw. The shaft of the screw is
partially threaded so the fastener
can draw the materials closer
together when the screw is
tightened. They’re not just for wood.
Hex Standoffs are a nifty little
invention that allows the designer
setup a platform that’s stood-off
from another surface. They’re
frequently used with printed circuit
boards (PCB) to keep the PCB
solder joints on the bottom of the
board safely away from a metal
chassis or case. They can be made
of insulating plastic (Nylon) or
conductive metal.
The Hex Nut is the female
counterpart to the screw or more
accurately, the bolt. It has internal
threads that match the diameter and
threads per inch (TPI) of the mated
screw. Nuts must be started at a
right angle to the screw otherwise
they’ll cross-thread
and bind
damaging both the nut and screw.
Some hex nuts include built-in lock
washers.
Locknuts are used to secure the
nut on to the bolt to keep it from
coming loose. The cap of the nut is
constricted requiring more torque to
tighten and loosen the nut. Some
locknuts are split while others use a
plastic insert to secure the nut in
place.
Tip Styles
Round
Cup
Low Profile
Cone
Hex
Flat
Note: It’s always best to turn the nut while holding the screw
instead of the other way around. The nut requires less torque to
tighten than the screw giving more accurate torque readings.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 5 of 28
Unthreaded Fasteners are permanent fasteners that require special tools for installation. Actually, these types of
fasteners can be removed but they often require cutting or drilling to do so. Unthreaded fasteners work by shortening
and deforming one end of the fastener to cinch the materials together. Although they require effort to install and
remove their degree of permanence and low cost may be most desirable for specific applications. Aircraft
manufactures prefer rivets over threaded fasteners because they are permanent, low cost, light weight, easy to inspect
and install.
Blind Rivet
Blind Rivet Nut
Blind Rivet Gun
Blind Rivets The term “Blind” means
that one end of the rivet is not
accessible during installation. To
install a Blind Rivet, a hole is first
drilled through the materials being
fastened. The rivet is inserted into the
hole and the Rivet Gun onto the
shank of the blind rivet. As the
handles of the rivet gun are
squeezed, the shank of the blind rivet
is drawn up through the rivet body as
its mandrel head deforms the rivet
body and draws the materials closer
together. After a prescribed force is
applied to the rivet gun, the shank of
the blind rivet will break at the break
notch and eject the remaining shank
making the popping sound. The Rivet
Nut can be installed just like a blind
rivet, but this device leaves behind a
threaded hole that accommodates a
machine screw. It’s a very cool way to
add a nut to a fastener point. To
remove blind rivets, you simply drill
off the head and punch the rivet out
with a drift punch and hammer.
Domed Head
Solid Rivet
Flat Head Solid
Rivet
Solid
Rivets
work
like
any
unthreaded fastener. It has a smooth
shank and a manufactured head.
They can be made from aluminum,
brass, copper or steel and may be
solid
or
hollow
tipped.
The
manufactured head can be either
domed, flat or countersunk, but
regardless of the rivet type or style,
solid rivets require a punch (setter)
and anvil to install them.
The anvil is used to form the tail end
of the rivet. The anvil is rigidly held in
place while the rivet is driven into a
recess on the surface of the anvil.
The shape of the recess determines
the shape of rivet’s tail. The punch is
used to drive the rivet through a hole
in the joined materials and then into
the recess on the anvil. The punch
(Setter) is struck with a hammer to
deform the tail of the rivet and in-turn
bind the materials together.
Flat (Countersunk)
Solid Rivet
Fabric
Snaps
are
installed
essentially the way rivets are set.
There is a male and female part of
the snap assembly and they both
require different punches and anvils
for installation. Otherwise, the mating
parts of the snap will become
deformed and will not be able to snap
Rivet Punch or Setting Tool
Rivet Anvil
Fabric Snap
together.
Application Note: It’s not a good idea to mix materials when using fasteners. Regardless of the type of fastener, all materials
expand and contract with variations in temperatures. If you use a brass nut with a steel bolt the fastener will tighten or loosen with
changes in temperature. Copper and aluminum fasteners can also deteriorate due to electrolysis if they are used with another
metal or alloy.
Miscellaneous Fasteners include hardware and other devices that are either used as or used with other fasteners.
There are nearly as many types of fasteners than there are things to fasten and more are being invented every day.
The purpose of this exercise is to expose you to the fasteners and fastening methods predominately used in robotics
engineering and technology.
Washer
Standard Washers are most often
used with screws or bolts. They are
designed to protect the materials that
are being fastened together by
distributing the crushing force of the
screw-head or nut. They also provide
a slipping surface for spinning
fasteners so they don’t damage the
joined material as they twist and
tighten.
Split Lock Washer
External Tooth Lock
Washer
Internal Tooth Lock
Washer
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Lock Washers are used to make it
more difficult for the nut or screw to
work its way loose through vibration
or stress. The lock washer creates
friction that works to keep the
fastener stationary. There are many
different types of lock washers and
they’re made of the same materials
that many nuts and screws are made
of.
Page 6 of 28
Shim
Thrust Washer
Cotter Pin
Clevis Pin
Spring Pin
The Shim is more than just a thin
washer. Shims are added or taken
away from an axle to change the
distance between two surfaces while
still allowing them to rotate on the
axel. The height of a room door is a
good example. The door that swung
freely before the room was carpeted
can swing freely again when shims
are added to the door’s hinge to lift
the door.
The Thrust Washer is more than just
a thick washer. It’s designed as part
of a drive system for a wheel or gear
to keep it spinning without wobbling
when it’s under angular stress. The
thrust washer is sandwiched between
a drive gear or hub and the wheel or
gear it’s trying to turn. The trust
washer typically turns with the drive
system.
Cotter Pins are easily replaceable
fasteners that are passed radially
through holes in a wheel hub and
axle to hold the wheel in place. The
end of the pin is split and bent out to
keep the pin from sliding back
through the pin hole. The cotter pin
also acts as a safety device called a
shear pin. If the wheel jams and the
drive continues to turn, the cotter pin
with shear off and protect the drive
from binding.
The Clevis Pin is a smooth pin that’s
passed through holes in joining
materials or assemblies to make a
temporary joint. The clip on the end of
the pin keeps the clevis pin from
falling out of the hole. Pull the clip
and then the pin and the assembly
can be quickly disconnected.
Spring Pins are a more permanent
and low profile adaptation of the
cotter pin. It’s installed the same way
with matching holes in the wheel (or
gear) hub and axle except the
diameter of the pin is somewhat
larger than the hole in the hub and
axle. The spring pin is driven through
the holes with a hammer and drift
punch. It’s held in place by the
friction of the expanding pin. The
head and tail of the spring pin does
not extend beyond the outer diameter
of the wheel hub hence… low profile.
External Retaining
Ring
Internal Retaining
Ring
E-Ring
External / Internal
Ring Pliers
Push Nut
Adhesive Tape
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Retaining rings are used to secure
wheels and bearings to shafts or in
bores. Special tools called (oddly
enough) retaining ring pliers are used
to expand or compress retaining rings
for self-lock installation into groves
carved onto shafts or in bores or
housings.
There are three basic types of
retaining
rings.
The
External
Retaining Ring is spread apart,
slipped over a shaft or axle and then
locked into a grove on the shaft. ERings are shaped like the letter “E”
and are also external retaining rings.
They’re pushed onto shafts or axles
and self-lock into grooves carved
onto the shaft. Internal Retaining
Rings are compressed and inserted
into a bore (hole) or housing and
locked into place as it’s released to
expand into a groove.
E-Ring Installation Tool
Push Nuts are designed for specific
diameter shafts or axles. They’re
made of hardened spring steel and
are pressed onto the ends of axles to
keep wheels on the shaft. The teeth
of the push nut bite into the shaft to
keep it in place. You can use a nut
driver and hammer to tap the push
nut into place.
Adhesive Tape comes in a wide
variety of materials, adhesives and
applications. Most adhesive tapes are
named
appropriate
to
their
application. Masking tape is most
often used to mask off areas where
paint should not go. Electrical tape is
used to isolate and insulate electrical
connections. Duct tape is used to
seal the air-duct joints used in heating
and
air-conditioning
systems.
Whether it’s packaging, carpet, antiseizing, or sealing tape there is a
tape for nearly every fastening
requirement.
Page 7 of 28
The Quick-Release Pin works
precisely like a clevis pin except there
is no clip to keep it in place. Instead
there is a spring loaded ball bearing
at the end of the pin. When the pin is
pushed into its hole, the ball bearing
locks into a groove holding it
temporarily in place. A good pull on
the ring pulls the ball bearing out of
the groove and the pin pulls easily out
of the hole.
Quick-Release Pin
Machine Key
Cable Tie
Machine Keys are used to transfer
torque between a shaft and a wheel
hub or gear. The key locks the wheel
hub to the shaft and is sometimes
held in place with a set screw.
Machine keys are inserted into a
lateral notch in the hub and shaft
called a key-way. If the machine key
is not installed or falls out, the wheel
would simple free-wheel. They come
in standard sizes and lengths and are
made of hardened steel.
Hook and Loop
The Cable Tie or Zip Tie was
invented
as
a
low-cost
and
disposable method to organize and
bind cables. They’ve become a
simple way to bind nearly anything
together and come in many sizes and
colors. Cable ties have a one-way
locking mechanism that prevents the
tie from loosening. They are simply
cut-off to remove them. Never use a
cable tie on a body. Since they can
only tighten, they have caused
serious injuries
Hook and Loop fasteners are
sometimes known by the trademark
name, Velcro. Lots of companies now
manufacture
Hook
and
Loop
fasteners providing the material in
various sizes, shapes, colors and
strengths. It comes in self-adhesive
and sewn applications. One side of
the fastener is covered with rows and
columns of tiny, stiff, plastic hooks.
The other side is covered with fabric
loops. The sides interlock when
pressed together but can be pulled
apart with some effort.
Adhesives – Glues have been around for thousands of years. Initially, adhesives were sticky biomaterials like
beeswax, tree sap, and tar, as well as animal hides and bones. As technology and materials manufacturing evolved,
other adhesives were created to meet the emerging needs of industry. From beeswax to superglue, adhesives are
fastening methods that are vitally important to the manufacturing process.
Glues have two properties; How well it sticks to materials (adhesion) and how well it sticks to itself (cohesion). When a
glue bond breaks at the surface of the material, it’s due to a failure in adhesion. When the bond breaks in the glue
itself, it’s due to a failure in cohesion. There are two prominent explanations describing how glue works. The Van der
Waals Forces describes how molecules in the adhesive align observing polarity to create a strong molecular bond
while Mechanical Bonding describes how glue fills even the tiniest nooks and crannies in the material to get a better
grip on the materials surface.
It’s important to note that some adhesives work better with specific materials. Matching the type of adhesive to a
particular material is an important consideration. However, the key to a successful adhesion and cohesion is the same
regardless of type of adhesive being used. Remove any interference to the Van der Waals Forces or Mechanical
Bonding affect. Note: The following images do not represent an endorsement for a specific product or brand name.



Material surfaces need to be clean before adhesive is applied.
Adhesives need to be used under the conditions prescribed by the manufacturer (Material, Temperature and Humidity).
The glue joint can’t be moved until the adhesive has fully cured.
Thread-lock
Thread-lock is designed for the locking and sealing of threaded fasteners which require normal
disassembly with standard hand tools. The product cures with or without air. It prevents loosening from
shock and vibration. Thread-lock comes in a variety of colors indicating its strength and durability. Blue
is particularly suited for applications where disassembly is required for servicing. Red thread-lock
requires heat to disassemble the fasteners. Don’t have thread-lock, nail polish will work in a pinch.
Feature
Protects threads
Medium strength
Locks threads
Benefit
Prevents rusting of threads
Can be removed with hand tools
Prevents loosening of metal fasteners caused by vibrations
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 8 of 28
Safety Precautions: Keep out of reach of children.
Preparation:
Protect work area. Parts to be sealed must be clean and dry. Shake the product thoroughly before
use.
Note: To prevent the product from clogging in the nozzle, avoid touching the bottle tip to the metal
surface.
Application:
For Thru Holes - Apply several drops of the product onto the bolt at the nut engagement area.
For Blind Holes - Apply several drops of the product down the internal threads to the bottom of the
hole.
For Sealing Applications - Apply a 360° bead of product to the leading threads of the male fitting,
leaving the first thread free. Force the material into the threads to thoroughly fill the voids. For bigger
threads and voids, adjust product amount accordingly and apply a 360° bead of product on the female
threads also. Assemble parts and tighten as required. Sets in approximately 10 minutes and fully
cures in 24 hours.
For disassembly, shear with standard hand tools and remove with methylene chloride. In rare
instances where hand tools do not work because of excessive engagement length, apply localized
heat to nut or bolt to approximately 482°F (250°C). Disassemble while hot.
Cleanup:
Clean adhesive residue immediately with a damp cloth. Cured product can be removed with a
combination of soaking in methylene chloride and mechanical abrasion such as a wire brush.
Contact Cement
Contact Cement is a versatile high-performance adhesive sealant formulated for all-purpose projects
and repairs. This semi-flexible crystal-clear adhesive is designed to address the daily needs of the
homeowner, both indoor and outdoor.
Feature
All-purpose adhesive
Dries crystal clear
Thick gel-like consistency
Waterproof
Benefit
Great for everyday projects and repairs
Eliminates obvious bond lines achieving invisible repairs
Will not run or drip; Reduces clean-up
Forms a tight, waterproof, weatherproof bond for a superior seal;
Great for plumbing repairs
Dries to a semi-flexible bond Ideal for bonding flexible materials such as fabric or leather
Gap filling
Will fill and seal uneven surfaces
Safety Precautions: Wear gloves. Wash hands after use. For interior applications, use in a well ventilated area.
Preparation:
Protect work area. Surfaces to be sealed or bonded must be clean and free from grease. For improved
adhesion, roughen very smooth surfaces. Pre-fit all materials before applying product.
Application:
As an adhesive - Apply adhesive to both surfaces to be bonded. Wait for 5 minutes until adhesive is
tacky and then press surfaces together. Clamp if necessary. Sets in approximately 10 minutes and
dries in 24 hours. Dry time is dependent upon temperature, humidity and amount of adhesive used.
As a sealant - Apply a layer 1/4' (6 mm) thick bead over the area to be sealed. Tool if desired. Let dry
for 24 hours. If necessary apply a second coat.
Cleanup:
Clean tools and uncured product residue immediately with mineral spirits or acetone. Cured product
may be carefully cut away with a sharp-edged tool.
Spray Adhesive
Spray Adhesive is an aerosol version of Contact Cement. It dries clear and has strong adhesive and
cohesive characteristics. It dries quickly and is ideal for a wide range of projects including photo and
art mounting. Spray Adhesive will work on a variety of porous and nonporous substrates. It is
recommended for bonding paper, wood, metal, acrylic, foam, fabric, polyethylene and polypropylene,
PVC, cardboard, leather, felt, carpet, corkboard, glass, foil rubber and most plastics. Certain plastics
and elastomeric substrates can exhibit bond failure due to plasticizer migration. High humidity and
high temperature can also promote bond failure.
Feature
Benefit
Repositionable or permanent bonding
Variety of applications
Dries clear and will not yellow with age Invisible bond
Can apply multiple coats
Increases bond strength
Does not bubble
No reworking
Acid Free
Will not damage photographs
Safety Precautions: Apply in a well-ventilated area, wash hands after use.
Preparation:
Apply adhesive between 65°F (18°C) and 95°F (35°C). Shake can well before using. Surfaces must be
clean, dry and free of foreign materials. Protect finished surfaces. Pre-fit all materials. Testing of
substrates for compatibility is recommended. Turn spray tip so that the black dot is aligned with the
nozzle.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 9 of 28
Application:
Cleanup:
Hold can in a vertical position. Point valve towards surface and spray from a distance of 8' to 10' (20 to
25 cm). Keep the can moving to create an even coat and avoid build-up on the surface. Start and stop
the spray just off the work to prevent runs and sags. For repositionable/temporary bonds: Apply a very
light even coat to one surface. After 15 seconds, join with light pressure only.
For a permanent bond: Apply a medium coat to one surface. Allow to dry to tack and join.
For stronger permanent bonds: Apply a medium coat to both surfaces. Allow to dry to tack (1 to 10
minutes). Porous surfaces will require more than one coat.
After use, invert spray can and spray for approximately 2 seconds (or until spray is free of adhesive) to
clear valve and spray tip. Clean spray tip with turpentine or mineral spirits. Note: When using solvents
for cleanup, use proper precautionary measure.
Rubber Cement
Rubber cement is a latex polymer combined with a solvent like acetone. It’s well suited for applications
that prefer relatively weak adhesion and cohesion. It’s predominantly used in graphic arts for
positioning and repositioning paper flatwork. Rubber cement is inexpensive and easy to use. Excess
glue or drips can be easily peeled away leaving no sign of the adhesive.
Feature
Application Brush In Cap
Repositionable or permanent bonding
Can apply multiple coats
Benefit
No additional tools required for use
Variety of applications
Increases bond strength
Safety Precautions: Apply in a well-ventilated area. Do not use near an open flame. Some rubber cement uses benzene, a
cancer causing agent.
Preparation:
Protect work area. Surfaces to be bonded must be clean and free from grease. For improved
adhesion, roughen very smooth surfaces. Pre-fit all materials before applying product. Use the
applicator brush to apply the adhesive.
Application:
Apply adhesive to one surface for a repositionable bond and on both surfaces for a more permanent
bond. Wait for 1 or 2 minutes until adhesive is tacky and then press surfaces together. Sets in
approximately 10 minutes and dries in 2 hours. Dry time is dependent upon temperature, humidity and
amount of adhesive used.
Cleanup:
Excess glue and drips can be peeled away.
Glue Stick
The glue stick is a solid Polyvidone adhesive that is delivered in a twist up or push-up applicator. The
Polyvidone adhesive has high adhesion and moderate cohesion affect well suited for paper and paper
products. The glue can be applied smoothly and evenly, and allows sufficient time to reposition the
object. The applicator helps keep fingers clean. An airtight cap+tube-system, the glue stick keeps
fresh and can be used for several years.
Feature
Twist-up or push-up applicator
Repositionable or permanent bonding
Non-toxic adhesive
Benefit
Clean and hands-off application
Variety of applications
Well suited for school and office use
Safety Precautions: Wash skin with soap and water.
Preparation:
Surfaces to be bonded must be clean and free from grease.
Application:
Apply adhesive to one surface for a repositionable bond and on both surfaces for a more permanent
bond. The adhesive sets in approximately 10 minutes and dries in 2 hours. Dry time is dependent
upon temperature, humidity and amount of adhesive used.
Cleanup:
Excess adhesive on work surfaces or clothing can be cleaned up with soap and water.
Super Glue (Cyanoacrylates)
Cyanoacrylates can bond just about any plastic, metal and wood project. Because it bonds in seconds
it is well suited for impatient craftsmen that would normally have to use clamps. Super Glue is not
recommended for use on cloth, Styrofoam, vinyl or CLEAR PLASTIC parts. Super Glue can ignite
cotton, dissolve Styrofoam, and fog clear plastic. Super Glue bonds instantly to skin. Super Glue has
a similar molecular structure of the same adhesive that mussels use to cling to rocks in the ocean.
Scientists synthesized the natural protein and learned how to mass produce it for commercial use. Its
first uses were in medicine as a skin and organ adhesive for field surgery during the Vietnam conflict.
It had great tensile strength but can be easily twisted or sheared to break the bond. Baking soda can
be added to it to make it a filler.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 10 of 28
Feature
Gel formulation
Dries transparent
Sets in seconds
Benefit
No mess, no drip formula; Ideal for vertical applications
Invisible repairs
No clamping required
Safety Precautions: Wear gloves (non cotton). Protect work area.
Preparation
Surfaces to be bonded must be close fitting, clean, dry and free from oil, wax and paint. For best
results, lightly roughen smooth surfaces. Pre-fit parts to be joined as you won’t have much time to set
them.
Application:
Puncture the nozzle and squeeze the bottle to dispense the adhesive. Only one drop of adhesive per
square inch of surface is required. Excess glue may take much longer to dry. Press surfaces together
immediately and hold for 60 seconds. Do not attempt to reposition the parts. Immediately after use,
clean tip with tissue and replace cap. For increased strength, leave the parts undisturbed for at least
10 minutes. Full cure in 24 hours. Note: Cure time is dependent upon temperature, humidity, porosity
of surfaces and amount of adhesive applied.
Cleanup:
Cured adhesive may be cut away with caution using a sharp blade, removed with mineral spirits or
with boiling water.
Epoxy and Epoxy Putty (5 Minute)
Epoxy and Epoxy Putty is a two-part adhesive consisting of an epoxy resin and a
hardener. When mixed in equal amounts resin and hardener react to produce a
tough, rigid, high strength bond, which starts to set in 5 minutes and reaches
handling strength in 1 hour. The resin and harder must be uniformly mixed for proper
bonding. It’s a great adhesive for a wide range of materials or for a versatile filler
(Putty), gap bonding, surface repairs and laminating. Epoxy does not shrink during
hardening and is resistant to water and most common solvents. It can be tinted with
earth pigments, cement or sand for color matching and can be sanded and drilled.
Feature
Benefit
Can be drilled
Will not crack when drilled
Can be tinted
Matches surrounding materials
Water resistant
Can be used outdoors
Does not shrink
One-time application
Sets in 5 minutes Quick completion of project
Safety Precautions: Mix and use in a well-ventilated area using gloves.
Preparation:
Protect work area. Surfaces must be clean, dry and free from oil, wax and paint. For better adhesion,
roughen smooth surfaces prior to cleaning. Pre-fit parts to be joined.
Application:
Dispense equal amounts of hardener and resin directly onto surface to be filled or bonded. Putty can
be cut into equal amounts and kneaded together to mix. Place objects together within 4 minutes of
adhesive application. Bond sets in 5 to 7 minutes at 68°F (20°C) to 77°F (25°C). For best results in
butt joints, apply adhesive as a reinforcing fillet or splint over the joint for additional support. Remove
any excess adhesive immediately with mineral spirits. Usable strength is obtained within 1 hour.
Warmer temperatures will shorten the set time and cooler temperatures will lengthen it.
Cleanup:
Clean excess glue immediately with mineral spirits or acetone. Cured adhesive may be cut away with
caution using a sharp blade. Prolonged immersion in paint stripper will soften the cured adhesive to
aid removal.
Acrylic Solvent Cement
Use on Polystyrene and ABS plastic. Bonds plastic by dissolving and cementing. Precision plastic
needle, dropper, and brush applicator makes easy work of gluing even small intricate detailed parts.
Application can be drawn into seams through capillary action to make and clean and neat bond.
Feature
Clean and seamless adhesive method
Low viscosity
Nearly instant and strong bond
Benefit
Smoother and more complete bonding
Small amounts provide for strong bonds
Quick and clean assembly
Safety Precautions: Keep out of the reach of children. Keep away from heat, spark, open flame and other sources of
ignition. Contact with hot surfaces may produce toxic effects. Keep container closed when not in use.
Store in the shade below 80ºF. Use only in adequate ventilation. Avoid breathing of vapors.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 11 of 28
Preparation:
Application:
Cleanup:
Preassemble parts without cement to insure proper fit. Trim or file where necessary so parts meet
without a gap. When cementing painted or plated parts, scrape away paint or plating from surfaces to
be joined.
Apply cement sparingly with a syringe, dropper or brush to one surface and press firmly together.
Avoid cement of finger tips, as glue smudged on areas not to be joined cannot be removed. It will also
discolor or “cloud up” clear parts. Do not use on clear parts.
Wipe solvent from work surface. Allow extra adhesive on bonded materials to cure. Do not wipe
excess.
Model Cement
Cement for plastic models is specially formulated polystyrene cement for joining all
polystyrene and ABS plastics. Cement for wood models is better choice for wood
models. Cement for models can be used in the construction of model kits and may
also repair many common household products.
Feature
Strong adhesion and cohesion
Polystyrene solvent
Benefit
Strong bonding
Welds plastics together
Safety Precautions: Keep out of the reach of children. Keep away from heat, spark, open flame and other sources of
ignition. Contact with hot surfaces may produce toxic effects. Keep container closed when not in use.
Store in the shade below 80ºF. Use only in adequate ventilation. Avoid breathing of vapors.
Preparation:
Preassemble parts without cement to insure proper fit. Trim or file where necessary to insure a gap
free interface.
Application:
Use solvent cements sparingly. Too much glue will dissolve plastic. When cementing painted or plated
parts, scrape away paint or plating from surfaces to be joined. Apply cement sparingly to one surface
and press firmly together. Avoid cement of finger tips, as glue smudged on areas not to be joined
cannot be removed. It will also discolor or “cloud up” clear parts. Do not use on clear parts.
Cleanup:
Cement can be cleaned from work surfaces with acetone or mineral spirits.
White / Wood Glue
Today’s white glue is primarily made from polyvinyl acetate latex (PVA), water
and some “Elmer”. Wood glues are made using a slightly altered formula called
Aliphatic Resin. When the water in the adhesive evaporates, the bond is made.
White glue is sometimes called “Craft Glue” and is well suited for crafts (Duh)
while wood glue is primarily used in carpentry. These adhesives are
recommended for use on porous materials -- wood, cardboard, cloth, porous
pottery, and wood-to-wood bonds. It is not water resistant. Because of wrinkling, it
is not suitable for bonding light weight paper. Do not allow these adhesives to
freeze. Store them in a tightly closed container in a cool and dry place.
Feature
Non-Toxic
Easy Cleanup
Good construction adhesive
Good adhesion
Precautions:
Preparation:
Application:
Cleanup:
Benefit
Safe for children to use
Use water for cleanup
Resists solvents, heat and moisture
Works well on porous materials
Some types of wood glue contain formaldehyde. Don’t use them if possible. Work in a well ventilated
area and avoid getting the glue on your skin. Wash away with soap and water.
Use above 40°F (4°C). Surfaces must be clean, dry and free of frost, grease, dust and other
contaminants.
Apply the adhesive evenly to both surfaces to make a more secure bond. Clamping is required for 30
minutes to 1 hour to set the glue; curing time is 18 to 24 hours. PVA glue dries clear.
Cleanup with soap and water.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 12 of 28
Construction Adhesive
Polyurethane construction adhesive is a one component, polyurethane based, moisture-curing
adhesive. It can be used for interior or exterior projects and is also waterproof, paintable and cures in
cold or warm temperatures. It is a strong adhesive and is ideal for wide range of construction projects
including sub floor installations.
Feature
Waterproof
Low odor
Strong and versatile
High strength
Broad Service Temperature
Benefit
Great for interior or exterior applications
No strong solvent odor; Great for interior use
Permanently bonds together almost any substrate
Stronger than many substrates it joins together.
Suitable for use in hot and cold environments
Safety Precautions: Wear gloves. Cured adhesive on bare skin will not come off immediately with washing and will cause
skin to darken. Cured adhesive and discoloration will come off in about 3 days.
Preparation:
Use above 40°F (4°C). Surfaces must be clean, dry and free of frost, grease, dust and other
contaminants. Pre-fit all materials and protect finished surfaces. If using cartridge format, cut nozzle at
a 45° angle to desired bead size and puncture inner seal. Be very careful not to allow construction
adhesive to cure on a finished (painted) surface.
Application:
Apply adhesive to one surface of the material being bonded. Press the surfaces firmly together.
Materials may be repositioned within 45 minutes after applying the adhesive. If bonding two nonporous surfaces (such as foam, metal and fiberglass), add water in the form of a very light or atomized
spray from a plant mister bottle to the extruded adhesive. The repositioning time will then be reduced
to less than 30 minutes. Use mechanical support or clamps for 24 hours while the adhesive cures.
Cleanup:
Clean tools and uncured adhesive residue immediately with mineral spirits in a well-ventilated area.
Remove cured adhesive by carefully scraping with a sharp-edged tool.
Silicone
Silicone is a multipurpose adhesive and sealant which creates a waterproof, protective seal that is
ideal for metal, glass, rubber, tile and porcelain. It is designed to be used indoors and outdoors to
repair everything from electrical connections to seams on boots to stop leaks in wet weather. Silicone
can be used to bond or repair saltwater or freshwater aquariums.
Feature
Extreme temperature resistance
Waterproof
No cracking, peeling or shrinking
Gap filling
Flexible bonds
Benefit
All-season use
Indoor and outdoor use
One-time application
Excellent for imperfect surfaces
Impact resistant and flexes with materials
Safety Precautions: Wear gloves. Respiratory, skin and eye irritation possible.
Preparation:
Use between -35°F (-37°C) and 140°F (60°C). Protect work area. Surfaces must be clean, dry and
free of old adhesive, grease, dust and other contaminants. Note: Paint will not adhere to silicone. If
desired, paint items prior to gluing. Remove cap. Puncture inner seal with other side of cap. Attach
nozzle and cut to desired bead size.
Application:
As an adhesive: Apply to one of the surfaces to be bonded. When bonding rubber or plastic surfaces,
lightly roughen surface for best results. Press materials together. If possible, clamp parts together for
full cure time of 24 hours. As a sealant: Apply with a steady pressure, forcing sealant into the joint.
Tool within 5 minutes. Do not use in joints deeper than 12 mm (1/2") without the use of a backer rod.
Use in joints between 1/4" and 3/4" wide. For aquariums: Apply a 1/4" bead to the edge of glass,
covering the thickness of the glass edge. Set glass on base and repeat procedure for all sides. All
joints must be glass to sealant to glass with no entrapped air bubbles. Apply additional sealant to
inside joints. Do not use in aquariums larger than 30 gallons (114 L) and/or aquariums containing
water greater than 18" (46 cm) in height.
Cleanup:
Clean tools and adhesive residue immediately with mineral spirits. Cured sealant may be carefully cut
away with a sharp-edged tool. There is no solvent for silicone.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
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Hot-Melt Adhesive (Hot Glue)
Hot glue is a thermoplastic adhesive typically provided in solid cylinders which are commonly referred
to as glue sticks. Glue sticks come a few diameters and lengths designed to fit a specific type of hot
glue gun or pistol. The glue gun houses a heating element that heats the glue stick to a liquid while a
trigger mechanically advances the glue stick through the heater and out the nozzle of the gun. The
temperature required to prepare the glue depends on the makeup of the polymers in the glue stick.
Adhesion also varies depending on the materials being bonded. Cohesion can be strong, but some
brands and types of hot-melt adhesives are brittle in certain applications. Glue guns and adhesive
come in low-temperature and high-temperature varieties. Low temperature glue guns operate at 250°F
(121°C) while high-temperature versions operate at 380°F (193°C).
Feature
Heat from hot air gun softens glue
Quick hardening
Insulator
Benefit
Disassembly and reassembly possible
Fast assembly
Safe for electrical stress relief
Safety Precautions: The temperature of a hot glue gun and the glue out of the nozzle is hot enough to cause serious
burns. Use leather gloves to protect hands and never touch the glue unless it has cooled. Do not leave
the hot glue gun plugged in for a prolonged period of time. Don’t use any electrical device with a
damaged power cord. Keep glue guns out of reach of children.
Preparation:
Protect work area. Surfaces must be clean, dry and free of grease, dust and other contaminants.
Application:
Insert a glue stick and plugin the hot glue gun allowing it to heat-up for about five minutes. Place the
glue gun on a non-combustible surface while plugged in. Place something under the nozzle to catch
the oozing adhesive. Place the nozzle on the surface being bonded and squeeze the trigger for the
desired amount of glue. Quickly press the materials together to make the bond.
Cleanup:
Hot glue can be removed with scraping. Heat from a hot air gun can make the job easier.
Research Resources: The www changes all the time. If you find a dead link, please report it to your instructor but
you should also use a search engine to find the information in another site.
Institution
Web Site
Description
Industrial Press
Gesipa USA Fasteners
YouTube
Valley Fastener Group
Mlevel3.com
YouTube
HowStuffWorks.com
Grainger
McMaster
http://buku-ku.com/machinerys-handbook-27th-edition/
http://www.gesipausa.com/blind_rivets_basics.html
http://www.youtube.com/watch?feature=player_detailpage&v=9aoX
mzdSf_I
http://www.valleyfastener.com/solid-rivets.html
http://www.youtube.com/watch?v=1hB3rIECtxM&feature=player_det
ailpage
http://www.youtube.com/watch?v=wvL0AC37NOw&feature=player_d
etailpage
http://home.howstuffworks.com/plastic-glues.htm
http://www.grainger.com
http://www.mcmaster.com
Machinery’s Handbook – Hardware Specifications
Online lesson on how blind rivets work.
Video - How Do Blind Rivets Work?
Online lesson on how solid rivets work.
Aircraft riveting video lesson
Glues for Plastic Models Parts 1 and 2 – Videos
describe how to properly use modeling adhesives.
Online tutorial regarding plastic glues and cements
Industrial supplier of hardware, tools & materials
Industrial supplier of hardware, tools & materials
Nomenclature: Research and develop a detailed (two to three sentences) definition for each of these terms. It’s
important to realize that many words have multiple definitions. Some of which may have nothing to do with this course
of study. Make sure your definitions fall within the context of this lesson.
 Screw
 Nut
 Retaining Ring
 Rivet
 Bolt
 Punch
 Lock Washer
 Pin
 Keyway
 Adhesion
 Cohesion
 Cyanoacrylates
 Polyvinyl Acetate
 Bead (of glue)
Questions:
1. Research and develop a detailed definition for each of the terms found in the Nomenclature section of this
document. Many words have multiple definitions. Some of which may have nothing to do with the field of Robotics
Engineering. Make sure your definition falls within the context of this lesson.
2. Name three examples of threaded and non-threaded fasteners. Include images in your answer.
3. What’s the difference between a bolt and a screw?
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 14 of 28
4. Match the following action and bicycling activity with the appropriate terminology to describe the type of stress:
Action
Pulling or Stretching
Twisting or Turning
Squeezing or Pressing
Sliding or Cleaving
Activity
Cranking Peddle
Sitting on Seat
Rolling Tires
Using Hand Brake
Stress
Shearing
Tensile
Compressive
Torsion
5. Examine the inventory card that’s found in the cover of the Tetrix Robotics Parts Kit. Create a table listing the
correct names and quantities of the fasteners included with the kit. Include an image from this lesson identifying
the fastener into the table you created.
6. Describe three methods or fasteners used to keep a nut from vibrating loose.
7. Describe three methods or fasteners used to keep a wheel on the end of a shaft or axle.
8. Generally speaking… What three conditions must be met to insure the best possible adhesive bond?
9. Indentify three adhesives that are best suited to bonding a paper poster to a cardboard placard.
10. Describe the difference between adhesion and cohesion.
11. How do solvent and plastic cements work differently than adhesives?
12. What is the origin of Super Glue?
13. What types of adhesive are not appropriate for bonding clear plastic?
14. How do you remove silicone from a work surface or joint?
15. What type of adhesive will most rapidly lose cohesion when exposed to hot sunlight?
Conclusion:
Assembly is one of the final stages of the secondary manufacturing process. Complex manufactured products are
typically comprised of lots of individual components or parts that must be fastened together to build the final product.
Wheels and gears may need to be bolted or pinned onto shafts while electronic circuits may need to be soldered
together. Ultimately, covers and cases may have to be glued in place or perhaps they simply snap together to make
the final product safe and presentable for sale. Whether it’s bolting, screwing, pegging, pinning, gluing, soldering, or
welding knowing the proper fastener or fastening method can make component assembly safer for you and provide a
quality product to the customer.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
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Robotics Engineering
DoDEA - Career and Technical Education
Identifying Elements of Structural Design
Exercise 3 – Fasteners and Fastening
Deliverables: Copy and paste the required deliverables to another document for submission. All deliverables must
be word processed with the required student ID information in the footer of the document. The header of the document
should contain the title of the assignment. Both the question and answer must be included in the deliverable with the
answers highlighted. All work must be complete and accurate to receive credit.
1.
2.
Each Study Model should be constructed, tested and then presented to the instructor for inspection.
Analysis of each Study Model regarding its Strength Rating and type of stress weakness.
Required Materials and Equipment: Get these materials and tools from your instructor.
Mindstorms Lego Kit
Mindstorms Resource Kit
Steps: Build and evaluate each of the following models. Rate the strength of the fastening method from 1 to 5 with 5 being the
strongest. You’ll also need to identify if the fastening method is most susceptible to Compressive, Tensile, Shear or Torsion stress.
Using the online image gallery of the fasteners will provide for greater detail and may better help you properly assemble these
joints. You may have to retrieve some special parts from the Mindstorms Resource Kit.
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
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Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Rating: 1 – 2 – 3 – 4 – 5
Weakness:
Conclusion:
By design, the types of fasteners that are used with the Lego modeling system are essentially limited to snap together
pins or pegs. Regardless of their combination and configuration, Lego components are held together by simple friction.
This is intentional and because of this design Lego models are temporary constructions which easily fall to pieces
under the most moderate forms of stress. Despite this limitation, clever use of fasteners and fastening methods can
make even Lego machines as strong as the ABS plastic they’re made of. Keep this sheet for future reference as you
use the Lego system of components to design various robots using your imagination and an ever expanding
knowledge of engineering.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 17 of 28
Robotics Engineering
DoDEA - Career and Technical Education
Identifying Elements of Structural Design
Exercise 4 – Trusses in Chassis Design
Objective: Students will investigate various methods of reducing the
weight of a robot chassis while maintaining function. They will
construct and evaluate models of various trusses and
construct study models of a swing as a proof of
concept for various fasteners, fastening methods
and truss designs.
Deliverables:
Copy and paste the
required deliverables to another document
for submission. All deliverables must be
word processed with the required student
ID information in the footer of the
document. The header of the document should
contain the title of the assignment. Both the question
and answer must be included in the deliverable with the
answers highlighted. All work must be complete and accurate to
receive credit.
1.
2.
3.
4.
Each Study Model should be constructed, tested and then presented to the
instructor for inspection.
Analysis of each Study Model regarding its Strength Rating and type of stress weakness.
Working Study Model of the Swing.
Tetrix Mantis (Indirect Drive) or Ranger Bot Chassis
Information: One of the major components of a robotics system is its chassis. Although the
chassis is much more visible in mobile robots, practically every
robotics system requires something to hold motors, wheels,
actuators and circuitry as well as control and power systems. This is
essentially what the chassis does. It’s a platform for robot
operations and an important consideration in any robot design.
The professional goal of any engineer is to create designs that
take into consideration not only function, but the type and amount
of materials (and in turn the cost) used to develop the product.
This is a balancing act where changes in one characteristic will
certainly affect the other. Generally speaking, the goal in
chassis design is to get the best bang for the buck or…
Producing the most cost effective and efficient design
to solve the problem at hand. Often, the solution is the
strongest of all geometric shapes… The common
triangle.
Closer examination of these CAD drawings
and the truss bridge designs reveal the
triangle as their fundamental design element.
Structures are strongest when stress is equally
distributed throughout the structure. When members of a
triangle are of equal length it is called an equilateral triangle.
Since the member lengths are the same, so are the angles where the members join. The
equilateral triangle is the strongest of the triangles because stress is equally distributed throughout
the structure. Other types of triangles are strong, but it’s a good rule that no angle should be less
than 30° or greater than 60°.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 18 of 28
When triangles are combined with straight members to build structures they are called trusses. Truss designs are
common in bridges, roofs and towers. Although truss designs vary, they are cost effective structures that deliver
strength while reducing the material required to build them. The same concept is true for a robot chassis design. The
triangular cut-outs in the robot chassis deliver suitable strength while reducing weight by eliminating excess material.
Bends in the material also add to the strength of the structure by distributing stress to other members in the structure.
Those stresses are most often referred to as compressive or tensile stress. It’s also important to remember that most
materials are stronger under compression than they are under tension.
Research Resources: The www changes all the time. If you find a dead link, please report it to your instructor but
you should also use a search engine to find the information in another site.
Institution
Web Site
Description
Garretss Bridges
Tetrix Robotics
Tetrix Robotics
http://www.garrettsbridges.com/design/trussdesign/
http://www.tetrixrobotics.com/Downloads/default.aspx?moid=560
http://www.tetrixrobotics.com/GettingStartedGuide/
Information on model bridge design
Tetrix Mantis Robot Instructions
Tetrix Ranger Bot Getting Started Guide
Nomenclature: Research and develop a detailed (two to three sentences) definition for each of these terms. It’s
important to realize that many words have multiple definitions. Some of which may have nothing to do with this course
of study. Make sure your definitions fall within the context of this lesson.




Equilateral Triangle
Compression
Truss
Tension


Chassis
Stress
Questions:
1. Research and develop a detailed definition for each of the terms found in the Nomenclature section of this
document. Many words have multiple definitions. Some of which may have nothing to do with the field of Robotics
Engineering. Make sure your definition falls within the context of this lesson.
2. Copy and paste the truss bridge diagrams from the previous page to a new document. Identify five of the designs.
Procedure: Exercise Instructions
Required Materials and Equipment: Get these materials and tools from your instructor.
Mindstorms Lego Kit
Mindstorms Resource Kit
Tetrix Robotics Kit
Build and evaluate each of the following models. Rate the strength of the fastening method from 1 to 5 with 5 being the
strongest. Using the online image gallery of the structures will provide for greater detail and may better help you
properly assemble these models. You may have to retrieve some special parts from the Mindstorms Resource Kit.
Rating: 1 – 2 – 3 – 4 – 5
Rating: 1 – 2 – 3 – 4 – 5
Rating: 1 – 2 – 3 – 4 – 5
Rating: 1 – 2 – 3 – 4 – 5
Rating: 1 – 2 – 3 – 4 – 5
Rating: 1 – 2 – 3 – 4 – 5
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 19 of 28
Tetrix Chassis Build
You’re going to have to choose between the Mantis (Indirect Drive) and Ranger Bot models for the Tetrix Robotics
training system. Both models work with the same tutorials and courseware and can be used to complete all the
activities slated for the remainder of this course. The Mantis robot platform is pretty robust, but it takes longer to build.
The Ranger Bot is an easy build, but it’s not as stable or maneuverable as the Mantis. Regardless of the model you
choose, once selected you cannot change your mind. Equally important is that you follow the assembly instructions
correctly and completely. There are no alternate parts nor are there optional ways to put the chassis together. Follow
the instructions carefully using the correct components and fasteners.
Important: Encoders are fragile and expensive. Your instructor will install the encoders on each DC motor
before you install them on your chassis. Do not remove the encoders once they’re installed.
You are not going to completely assemble the models at this point. You will stop at the point where the instructions
ask you to install the wiring. This should be after the motor and wheel installation. This completes the chassis portion
of the assembly. STOP when you’re asked to install wiring.
Mantis - Tetrix Platform
Ranger Bot - Tetrix Platform
Assessment Rubric:
Assessment
Item
Criteria
Student
Instructor
Prototype – Robot Chassis Design
1
2
3
Are all fasteners of the correct type and positioned correctly?
Are all members of the correct type and positioned correctly?
Is the model assembled correctly?
Yes/No
Yes/No
Yes/No
Conclusion: In completing this exercise you have recognized the importance of triangles to the design of sturdy
structures. You’ve learned that triangles and trusses are integral to the design of cost effective yet strong bridges,
roofs, towers and even robot chassis. Although the presence of triangular components is not always obvious,
structures that incorporate them into their design are strong. Materials are more often stronger under compression
than tension and good truss designs take this into consideration before construction or assemble starts.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 20 of 28
Robotics Engineering
DoDEA - Career and Technical Education
Identifying Elements of Structural Design
Exercise 5 – Designing and Analyzing Virtual Structures
The goal of the West Point Bridge Designer Challenge is
to design a structurally sound bridge that costs the
least amount of money to construct. Before you start
this competition, each team must login to a computer
workstation and create a folder for your team named
“C:\Temp\WPBD”. Next, launch the West Point Bridge
Design Software. Each team must also maintain a
design log. This will be your deliverable and evidence of
completion of this task. As you complete each new
successful bridge ask for the instructor to validate the
load test and initial next to the new bridge name on your
design log. Save each bridge with a unique file name
into your folder into the “C:\Temp\WPBD” folder. Files
should be named bridge1, bridge2, and bridge3 in order
as each new successful bridge is saved. Again… Your
bridges will be saved to the C:\Temp\WPBD folder.
1. Fill out the top of the “Design Log” with your name(s) and team name.
2. Start the West Point Bridge Designer software
3. Select “Create New Bridge Design” and use the design Wizard.
1—Read only
2—No
3—Deck Elevation = 20 meters; standard abutments; no pier; no cable anchors
4—Medium strength; standard
5—Suspension
6—Enter team name; designer: team member initials (ex. jk/rb)
7—Read, then select finish
4. Begin designing!
5. Save each design to the proper folder with the proper name.
6. Have a monitor initial each successful design.
Good luck! You have 60 minutes.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 21 of 28
WEST POINT BRIDGE DESIGNER COMPETITION
Design Log
Official Rating Sheet
Team:
Entrant Init:
Bridge
#1
New Cost
Final Ranking:
#2
Monitor’s Initials
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
Bridge
New Cost
Monitor’s Initials
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
I certify these results to be true and accurate to the best of my knowledge and ability.
Judge’s Name (Print)
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Judge’s Signature
Page 22 of 28
Robotics Engineering
DoDEA - Career & Technical Education
Identifying Elements of Materials and
Structural Design
Exercise 5b – Using the EDP to Build a Support Structure
Objective: At the completion of this exercise, you will demonstrate your knowledge of the
engineering/design process along with forces, materials, loads, and the structure of
bridges to design and build a model bridge that will support a weight designated by
your teacher while utilizing the minimum amount of resources to maintain fiscal
integrity.
Information: One of the problems that engineers face today is to build a
structure that is safe, aesthetically pleasing and provides function.
Prototypes are often used in the design process to test strength; the shape
of the structure is the most important feature for supporting its load.
Nomenclature: Research and develop a detailed (two to three sentences) definition for each of these terms. It’s
important to realize that many words have multiple definitions. Some of which may have nothing to do with this course
of study. Make sure your definitions fall within the context of this lesson.
Load
Tension
Architectural structure
Reinforced steel
Force
Compression
Civil structure
Reliability
Resistance
Shear
Steel
Research Resources: The www changes all the time. If you find a dead link, please report it to your instructor but
you should also use a search engine to find the information in another site.
Institution
Web Site
Description
http://www.pbs.org/wgbh/buildingbig/
PBS
Information regarding building various structures on
large and small scales.
US Military
Academy at
West Point
US Military
Academy at
West Point
http://bridgecontest.usma.edu/manual.htm
http://bridgecontest.usma.edu/index.htm
Provides virtual software for bridge building as well
as a physical bridge model for construction using
simple materials.
About.com
http://architecture.about.com/od/greatbuildings/Great_B
uildings_and_Structures.htm
Excellent source of information for a wide variety of
architectural structures.
Institute of
Structural
Engineers
http://www.istructe.org/Pages/default.aspx
Manual and lesson plans for file folder bridge design
activities.
Provides information on a career in structural
engineering.
Questions:
1. Research and develop a detailed definition for each of the terms found in the Nomenclature section of this
document. Many words have multiple definitions. Some of which may have nothing to do with the field of Robotics
Engineering. Make sure your definition falls within the context of this lesson.
2. Analyze the changes in structures from the ancient Egyptians to today. What differences and similarities do you
see between then and now?
3. What shapes provide more support for load bearing structures? Why?
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016
Page 23 of 28
4.
5.
6.
7.
Differentiate between tension and compression and explain how these forces are balanced on a bridge.
How does the choice of materials affect the structure? Give examples throughout history.
Why are trusses frequently used in the construction of bridges and skyscrapers?
What are the advantages and disadvantages of the truss design?
Procedure: File Folder Bridge Construction
Required Materials and Equipment: Get these materials and tools from your instructor.
File folders
Cardboard base
Wood glue
Pins
Ruler
Scissors
Wax paper
Steps: Complete each of the following steps in the assigned order:
1. Refer to the Manual and Lesson Plans for file folder bridge design activities. From the USMA – West Point
website.
2. Use the Engineering& Design Process worksheet to design a model bridge that will support a designated load.
3. Document each stage of the process fully.
4. Build your model.
5. Perform mathematical computations to predict load bearing ability.
6. Weigh your model.
7. Test your structure by adding weights incrementally. If time allows, refine and retest.
8. Perform destructive testing for maximum efficiency.
9. Report results.
Conclusion:
In completing this exercise you will be able to recognize the importance of triangles related to structural engineering.
You will see that triangles are the basic geometry involved in building structures like bridges. A truss is a structure
made of one or more triangles built using straight members connected by joints. Tension and compression are forces
that act on a truss. The forces of tension and compression must be balanced for a bridge to be stable. Different
situations require different materials based on their properties. When using members to build a truss, it is important to
identify whether the member will be subject to more tension or compression as to what type to use. Hollow members
have different characteristics than solid and steel acts differently than carbon-steel and the thickness makes a
difference in terms of support but also adding load to the structure. Combining the right elements to produce a safe,
reliable structure within the budgetary requirements is not an easy task.
Robotics Engineering – DoDEA Career and Technical Education
Identifying Elements of Material and Structural Design – Materials
Revised 15 March 2016