senior design ii final report
TRANSCRIPT
ENGR 4482
Senior Design II
ASU College of Engineering
Display/Box Assembly Project
Final Report
Written By:
Taylor Barnhill
Robert Bise
Kevin Muñoz
Jed Schales
Submitted on: April 20th
, 2015
REK’M Engineering
Arkansas State University-Engineering Department
105 N. Caraway Rd.
State University, AR 72467
Tel: (870) 972-2088
April 20, 2015
Attention: Dr. Tanay Bhatt
Subject: Display/Box Assembly
To Dr. Bhatt:
On August 26, 2014, REK’M Engineering was assigned the task of designing a system
capable of increasing the production rate of cardboard displays created by American
Greetings Corp as well as improving the comfort and safety of all parties involved in the
process. This report covers the material the students have studied, fabricated, and tested,
as well as the process used to develop the final design and a cost estimate for the designs.
A complete list of man-hours and Gantt chart for the fabrication and testing process is
also included.
Feel free to contact us if any questions should arise.
Sincerely,
Taylor Barnhill
Electrical Engineer
Robert Bise
Mechanical Engineer
Banthi Munoz
Mechanical Engineer
Jed Schales
Mechanical Engineer
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TABLE OF CONTENTS
Section Title Page
TABLE OF CONTENTS
ii
LIST OF TABLES
iii
LIST OF FIGURES
iv
I EXECUTIVE SUMMARY (JS)
1
II INTRODUCTION 2
Background (TB) 2
Constraints (BM)
Task Management (RB)
3
4
Methodology (RB)
5
III FINAL DESIGN ALTERNATIVE (RB) 6
Folding 6
Filling 7
Packaging 8
IV FABRICATION AND TESTING (RB) 10
Folding
Finalizing Bill of Materials (JS)
Prototype Construction (RB)
Physical Testing and Modification (JS)
SolidWorks Testing (JS)
Filling
Prototype Construction (RB)
Testing and Modification (BM)
Load Testing (BM)
Assembly Line Testing (BM)
Packaging
Prototype Construction (TB)
Assembly Line Testing (TB)
Redesigning and Construction (TB)
Packaging Chute (TB)
Box Stopper (BM)
10
10
11
15
17
21
21
24
24
26
26
26
28
29
29
30
V FINAL DESIGN (TB BM JS) 32
General Description 32
Folding Table (JS-T3) (JS)
Retractable Cart (BM-F1) (BM)
Packaging Chute (BM-P1) (TB)
32
32
33
Structural Components 33
iii
Folding Table (JS) 33
8020 Framing (BM)
Sandwiched Acrylic Table Top (JS)
33
35
Retractable Cart (BM) 37
8020 Framing (BM)
Retractable Shelf (BM)
37
37
Packaging Chute (TB) 38
Metal Framing (TB) 38
Mechanical Components 39
Folding Table (JS) 39
Linear Actuators 39
Packaging Chute (BM) 40
Spring System 40
Electrical Components 41
Folding Table 41
Arduino Uno (TB)
H-Bridge System (TB)
Joystick User Interface (TB)
Accelerometer (TB)
Rechargeable Battery (TB)
41
42
44
45
47
VI DESIGN IMPLEMENTATION 48
Cost Estimate (RB)
Safety Precautions (TB)(JS)
Operation and Maintenance Procedures (TB)(JS)
48
49
52
VII CONCLUSIONS/RECOMMENDATIONS (TB)(BM)(JS) 55
VIII LIST OF REFERENCES (TB RB BM JS) 58
IX APPENDICES
Man-Hours Table (RB) A-1
Gantt Chart (RB) B-1
Descriptive Diagrams (TB RB BM JS) C-1
Control System Code (TB) D-1
Personal Resumes (TB RB BM JS) E-1
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LIST OF TABLES
Table 1. Cost Estimate for Folding Table 48
Table 2. Cost Estimate for Retractable Cart 49
Table 3. Cost Estimate for Packaging Chute and Box Stopper 49
LIST OF FIGURES
Figure 1. Cardboard Display 2
Figure 2. Folding Table (JS-T3) 7
Figure 3. Retractable Cart (BM-F1) 8
Figure 4. Packaging Chute (BM-P1) 9
Figure 5. Constructed Folding Table 13
Figure 6. Actuator Position 13
Figure 7. Position of Control System 14
Figure 8. Control System Materials 15
Figure 9. Folding Table with Braces 15
Figure 10. Completed Fabrication of JS-T3 17
Figure 11. Acrylic Tabletop 18
Figure 12. Stress Visualization of Acrylic Tabletop 18
Figure 13. Deformation Visualization of Acrylic Tabletop 19
Figure 14. First Draft of JS-T3 19
Figure 15. Final JS-T3 Model 20
Figure 16. Final Model Stress Visualization 20
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Figure 17. Final Model Deformation Visualization 21
Figure 18. Drawer Shelf 23
Figure 19. Finished Retractable Cart 24
Figure 20. Static Testing 25
Figure 21. Cart Shelf Clearance 26
Figure 22. 4 Hole 90° Joining Plate 27
Figure 23. Top and Bottom View of Chute Redesign 29
Figure 24. Final Packaging Chute Design 30
Figure 25. Box Stopper Implementation 31
Figure 26. 7-Hole 90̊ Joining Plate 34
Figure 27. Truss Attachments 34
Figure 28. Actuator Attachment 35
Figure 29. SolidWorks Model of Acrylic Table Top 36
Figure 30. Cart Assembly 37
Figure 31. Retractable Shelf 38
Figure 32. Linear Actuator 39
Figure 33. Box Stopper Spring System 40
Figure 34. Arduino Uno Programmable Board 41
Figure 35. H-Bridge Setup 42
Figure 36. Dual Channel H-Bridge 44
Figure 37. Dual-Axis Joystick 44
Figure 38. Dual-Axis Accelerometer 46
Figure 39. Cart Warning 53
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I. EXECUTIVE SUMMARY
For factory workers and their employers, safety is of the utmost concern when
designing any manufacturing process that the worker must perform in their daily routine.
Recently brought into consideration is the manufacturing process associated with creating
a display unit for greeting cards and other seasonal goods that can be found at most
grocery stores during the holiday season. An example of the display making process can
be found at American Greetings in Osceola, AR where workers construct display units in
three basic steps. First, flat cardboard sheets are folded into an empty display unit on top
of a table. Next, workers slide the empty unit along a dummy conveyor to a filling
station where products are then placed into the unit. Finally, the unit is moved to the
packaging station where a box is built from a second flat cardboard sheet, fitted around
the display unit, and then sealed and sent on its way to the shipping department via an
automated conveyor. Due to the size of the cardboard displays, the number of
components associated with a filled and packaged unit, and the vastly different worker
profiles of employees, this process is not currently optimized for worker comfort.
The following report by REK’M Engineering details the fabrication and testing of a
proposed solution to the problem that not only increases worker comfort, but also makes
the process safer overall by removing some of the physical strains imposed on a worker’s
body due to the repetitive nature of the process. While the design is based upon research
conducted at American Greetings, the devices fabricated by REK’M Engineering were
designed to be applicable to any manufacturer that uses a similar process.
To produce designs that optimized worker comfort and safety to the fullest extent
possible, the group started by appropriately defining the problem and listing constraints
based on the limitations imposed due to the Occupational Safety and Health
Administration (OSHA), the American National Standards Institute (ANSI), the Code of
Federal Regulations, the National Society of Professional Engineers’ (NSPE) code of
ethics, the physical restrictions that arose from the layout of the factory floor, and the
nature of the manufacturing process. Once this task was completed, and narrowing
techniques were employed, the group was left with the proposed final solution consisting
of a table for folding that features an adjustable height based on user inputs, a cart for
product boxes featuring a slide-out platform that will aid with the filling process, and a
chute that holds packaging boxes in place that will improve the packaging portion.
During the second semester of the Senior Design course at Arkansas State University,
the group manufactured and tested each of these components in order to further optimize
worker safety and other important criteria so that the final design of each of these
components could be fully and properly specified. Some of the solutions required a full
redesign of the proposed solution from the previous semester, while others remained the
same as the proposed solution. Fabrication was made possible through the American
Greetings plant located in Osceola, AR which provided the materials necessary to build
each solution and gave advice on the feasibility of the solutions and construction of each
device. Testing was performed on ASU campus and at the same American Greetings
facility to gather high quality data regarding the usefulness of the solutions and their
potential implementation on the assembly lines at American Greetings. This report
details the fabrication and testing of each of the proposed final solutions from the
previous semester and also the specifications of the final designs by REK’M Engineering.
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II. INTRODUCTION
Background
Over the years, American Greetings (AG) has provided many different ways to
communicate with friends and family through the use of greeting cards. These cards
range from congratulating graduates or wishing someone a happy Mother’s Day. The
market for these cards has spread to many large businesses such as Wal-Mart and Target
along with various smaller businesses. In addition to the large quantities of cards that AG
manufactures, it has started to build cardboard displays and pre-pack the cards into the
displays’ pockets before sending them to stores. Figure 1 shows a typical cardboard card
display that AG builds to send to its buyers.
Figure 1. Cardboard Display
These cardboard displays are built completely by employees standing at a table.
This process requires repetitive movements and muscular endurance by each employee
working at the station. First, a stack of flat cardboard is loaded onto the table from a
separate pile. Then, one employee folds one piece of cardboard into the shape of the
display and pieces together smaller portions to create pockets for the different cards.
After the display has been created, it is passed off to another worker who then inserts the
various cards in their respective pockets. Finally, the completed display with all the cards
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inserted into it is slid into a shipping box and stacked on a pallet waiting to be stretch-
wrapped.
This process of building, filling, and prepping each single display for shipment is
very time consuming. The current setup has also been reported to cause back and
shoulder problems for employees that work on a table that is not at a comfortable height
for them. Workers also have to pick up multiple stacks of flat cardboard to place on the
workspace every shift which can fatigue the body.
The goal of the project is to redesign the process of collecting all the necessary
pieces of a display, building it, stocking it with cards, and finally packaging it. By
designing a whole new process with workplace ergonomics in mind, the group hopes to
lessen the fatigue employees experience by reducing the amount of physical work
required. Another outcome the group is looking for is the increase in the production rate
of display units. This project will be designed and completed in compliance with state
and federal regulations such as OSHA and other agencies and organizations that deal
with worker safety.
Constraints
The conditions that will limit the solution are called constraints. These constraints
need to be met for a successful solution to be developed. The constraints for this project
have been defined as follows:
1. The solution must not create fumes that are hazardous to employee health (OSHA
1910.14(a)(1)(vi)).
2. Moving parts must be concealed in order to prevent employees from experiencing
bodily harm (ANSI B11.19-2003).
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3. The solution must be available for use with different employee physical profiles.
4. The design must optimize the use of industrial floor spacing without exceeding
the floor space that the current process uses.
5. All electric motors must have average full load efficiency specified in the Code of
Federal Regulations (CFR 431.446).
6. The design must be able to compensate for multiple types of folding techniques
for various displays.
7. The solution must be able to work for an entire shift without breaking down or
needing maintenance.
8. The solution must have a minimal learning curve.
9. The design must be moveable by no more than three personnel for slight
relocations and be moveable by forklift for large distances such as during
installation and removal.
10. The production rate cannot fall below that of the current process with the
implementation of the solution.
11. The design must include space to carry all necessary equipment required in the
display making process.
12. There should be justification for return on investment.
13. The solution should not solely be limited to American Greeting’s specifications.
The design should be able to be marketed to any card distribution company so that
potential conflicts of interest are avoided and so that a quality solution is found.
(NSPE Rule #3.1)
14. The process must conform to pre-determined cardboard flat dimensions.
Task Management
Throughout the semester, each member of REK’M Engineering worked with one
another to accomplish the eight project tasks. Each week, the design group met with the
project advisor, Dr. Tanay Bhatt. Each group member kept a logbook to keep record of
the hours and also to record details of the individual work completed. A man hour table
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showing the number of hours completed by each member for each task is located in
Appendix A, and a Gantt chart is shown in Appendix B.
Methodology
The previous semester, REK’M Engineering started the design process to make
the display box assembly at American Greetings more efficient and less hazardous to
employees. The team started by defining the problem. The problem focused on the pain
that many employees have after working on this line for several years. Also, the team
noticed that the assembly of the display boxes could be more efficient with designs that
could assist the employees. The team created constraints that were used for the designing
of alternatives. The team then brainstormed ideas for each section of the assembly line,
folding, filling, and packaging. Each idea met the constraints, and all were considered.
Next, the design group created selection criteria to base the selection of the best
alternatives off of. The group used the criteria to narrow all the entire alternatives down
to four for each of the stages of the display box assembly. The team then created
preliminary designs for each of the remaining alternatives that included parts lists and
3D-drawings. To further the narrowing process to the final alternatives for the each stage,
the group applied weight to each of the criteria. To apply weight to the criteria, the team
created a survey and had employees, management and display box assembly workers,
take the survey in order to receive outside feedback. Based off the surveys, the team
applied weights to the criteria, and from the preliminary designs, chose the best
alternatives for each stage of the display box assembly. The chosen alternative for the
folding stage was a height-adjusting table (JS-T3), for the filling stage was the retractable
cart (BM-F1), and for the packaging stage was the packaging box chute (BM-P1).
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III. FINAL DESIGN ALTERNATIVE
The following designs were created by REK’M Engineering. Each design is to be
used to create the display box assembly more efficient and safer for the employees that
work on this line at American Greetings. There is one design for each stage of the display
box assembly.
Folding Table (JS-T3)
This design allows the employee to fold and construct the display boxes at a
comfortable height. Figure 2 shows a SolidWorks drawing of the originally designed
folding table. The folding table design answers the need for the employee to have safer
way of constructing the display boxes. With a table that can adjust its height, the
employee can put the table height at the appropriate position to where they do not have to
bend their trunks or have to move their arms at a 30-60° angle from the side of their
body.
The initial design of the table had an aluminum tabletop, but this was replaced
with a fiberglass top when the materials were finalized. The legs were to be made with
pneumatic cylinders and were to be supplied with a compressor that was attached to the
underside of the tabletop. However, actuators also replaced these. The cart is to be
controlled by a control system with a joystick used for the employee input. The folding
table is designed to have lockable caster wheels to allow for it to be able to be moved
easily and locked into position when it is being used.
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Figure 2. Folding Table (JS-T3)
Retractable Cart (BM-F1)
To assist the assembly line worker when placing goods into the display box,
REK’M Engineering designed a retractable cart. Figure 3 shows a SolidWorks model of
the originally designed retractable cart. The retractable cart will be able to allow the
employee to receive and carry more goods from the pallet of merchandise to the assembly
line. With the cart full of merchandise, the employee can follow these steps to fill the
display box.
With one hand, the operator pulls the display box down the conveyor line coming
from the folding station.
With the other hand, the shelf on the cart is pulled to its extended position.
Without twisting at the trunk, the operator reaches from the hip area, grabs the
merchandise, and almost sliding it off of the cart, places it into the display box.
This motion requires the arm, as opposed to the torso, to move 10o-90
o in the xy-
plane (parallel to the floor).
Once the display box is filled, it is then pushed down the conveyor line to the
packaging station.
8
These steps allow the employee to have proper movement that is safe based on
REBA/RULA. The cart holds up to 20 display box’s merchandise.
The retractable cart is base is a standard service cart. The retractable shelf’s
drawer is made out drawer slides that are attached to metal and the metal is attached to
the top of the service cart. The drawer top is designed to be made out of metal, but any
material may be suitable. The cart includes lockable caster wheels to prevent the cart
from moving while an employee is using it to fill the display boxes.
Figure 3. Retractable Cart (BM-F1)
Packaging Chute (BM-P1)
To assist the assembly line worker when he or she is placing the filled display box
into a packaging box for shipping, REK’M Engineering designed a packaging chute
assist. Figure 4 shows an Inventor model of the originally designed packaging chute. This
design allows the employee to place a shipping box onto the chute. The chute keeps the
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flaps out of the way and helps the employee place the filled display box into it. This
design is expected to reduce the amount of time required to fully complete the display
box assembly. This chute removes the physical pain for the employee that has to struggle
stuffing the display box in the shipping box while trying to hold the shipping box in
place.
This design includes a metal chute made out of two metal plates that the shipping
box fits onto. The distance between the plates can be adjusted based on the size of the
shipping box. The packaging chute can be moved to different parts of the assembly line
as needed. The packaging chute also has a footboard that is placed behind the shipping
box that offers resistance to the shipping box and doesn’t allow it to move when the
employee applies pressure to it by shoving the display box into it.
Figure 4. Packaging Chute (BM-P1)
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IV. FABRICATION AND TESTING
This semester, REK’M Engineering fabricated the final design alternatives that
were designed last semester. American Greetings agreed to fund the fabrication of the
designs on the agreement that they would get to keep the designs. American Greetings
offered their services of their machine shop, available materials that they already had on
hand, and up to $1000 toward materials that needed to be ordered. The team decided to
bring all of the materials back to the machine shop at Arkansas State University to
fabricate the designs at an area that was easier for the team to access. The materials that
were used to construct the designs can be found in the design implementation section.
Once the designs were fabricated, the team proceeded to test the designs and make any
modifications based on the testing.
Folding
The design associated with the folding portion of the display manufacturing
process is JS-T3. The following main tasks were performed during the second phase of
the Senior Design process: Finalizing Bill of Materials, Prototype Construction, Physical
Testing and Modification, and SolidWorks Testing.
Finalizing Bill of Materials
In order to fabricate JS-T3, a more accurate bill of materials needed to be created.
It was deemed by the group during one of the several advisor meetings that changes
should be made to this design in order to alleviate several fabrication, safety, and general
operation issues.
11
One of the most troublesome components of the original design was the
pneumatic system that would allow the table to rise and fall to the user’s level of
comfort. The system was originally comprised of two aluminum pipes that would
telescope with each other to create the table supports. Because of the difficulties
associated with the pressurized air and the telescoping system, it was decided to change
the supports to pressure-rated pneumatic cylinders. After running this idea by American
Greetings, their design team suggested that the group do some research over linear
actuators that are relatively the same price and would alleviate several of the group’s
concerns. After deliberation and looking at the benefits of using linear actuators in place
of pneumatic cylinders, the actuators were chosen to provide the support for the table
surface.
Along with this main change, another large design change was made to substitute
acrylic in place of aluminum for the table surface. This would cut down on weight and
cost while maintaining a solid and rugged surface on which to perform folding
operations. Other changes that were made to JS-T3 include removal of the “C-Box”
space due to the limitations of the acrylic sheets and the addition of structural members
between the table supports and within the table surface to provide more rigidity and
stability.
Prototype Construction
Once all of the materials for the folding table was finalized, ordered, and received,
the design team started construction on it. To begin, the base of the table had to first be
constructed. Using the Aluminum 8020 1010, the 1 in by 1in square structural aluminum
that the team received from American Greetings, the team constructed a rectangular base
12
for the actuators to connect to. On the four corners of the base were right angle brackets.
The team drilled holes in these brackets for the lockable rotating to screw into and for the
actuators to sit into. Once the base was completed, the actuators were set into the holes on
it and the team then turned their attention to the tabletop.
The tabletop is built from two pieces of acrylic. The team first drilled the holes
into the acrylic where the bolts were to go to connect them together. The team placed 1
inch pieces of PVC pipe between the two pieces of acrylic and bolted them together with
round head bolts. With the tabletop built with two pieces of acrylic that are 1 inch apart,
the table is lightweight compared to using another material and allows the tabletop to be
more rigid than having just one piece of acrylic. Next, the team cut the holes into the
tabletop for the actuators to be placed into and then placed and secured the tabletop onto
them. To add structural support to the tabletop to allow it not to bend as much, pieces of
Aluminum 8020 1010 were placed between the two pieces of acrylic. Figure 5 shows the
tabletop and table base. Figure 6 shows the position of the actuators and how they are
connected to the tabletop and to the table base. When the team first constructed the table,
they noticed that the table swayed and was not very stable. To add structural support to
the table, the team added trusses that extended from the tabletop to the actuators in the
length and width directions. These kept the table from moving as much when it was
bumped and allowed the table to still move up and down. The actuators were connected
to the control system.
13
Figure 5. Constructed Folding Table
Figure 6. Actuator Position
14
The team constructed a box made of 1010 for the control system to be housed in.
The box has acrylic was that has holes drilled in it to allow air to flow through for the
control system. The team then attached the control box to the bottom side of the tabletop
using 1010 bolts. A 12V DC deep cycle battery powers the control system. To control
each actuator, two dual H-bridges were used. These H-bridges receive an input from the
Arduino that stores the code for that controls the system. The user input is done using a
joystick. Taylor Barnhill was in charge of writing and implementing the code for the
control system which can be seen in Appendix C. Figure 7 shows where and how the
control system is attached to the tabletop. Figure 8 shows the battery, the H-bridges, and
the Arduino that make up the control system for the table.
Figure 7. Position of Control System
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Figure 8. Control System Materials
Physical Testing and Modification
After fabrication of the JS-T3 prototype, the stability of the table and the rigidity
of the table’s surface became design concerns that needed to be addressed. Before
further modification of the design, at the table’s lowest working height, the table would
sway laterally and longitudinally more than four inches away from its designed center
position. The table’s surface also deflected more than previously expected from
SolidWorks simulations. At the table’s ends, the working surfaced dipped two inches
beneath the working surface’s relaxed neutral plane.
In order to address these issues, seven excess pieces of aluminum 8020 were
placed longitudinally-oriented into the sandwiched sheets of acrylic. This quick solution
16
greatly reduced the amount of sag in the table to a level that is much less noticeable (<
1/2”). Several solutions were proposed to address the stability of the working surface due
to the wobbling of the table supports. One of the first attempts at stabilizing the device
was to expand the base of the table so that the legs would all point inward to the center so
that there would be more resistance to motion that would move the table from its
equilibrium position. While this did solve the problem to an extent, the base would need
to be expanded greatly in order to reduce the wobble to an acceptable level by this
method. A second attempt was made to secure the table by using an assembly consisting
of two set screws, an aluminum cylinder, and a washer at the bottom of each table leg to
firmly clamp the leg to the bracket. This solution did not fix the problem very well, since
movement of the table sometimes caused the set screws to fall from their vertical position
and lose pressure on the clamped joint. A third solution was proposed to brace each table
leg in both the longitudinal and lateral directions. These braces would inhibit the
wobbling since it would effectively act as a second rectangular brace directly beneath the
table. Before implementing any solutions, the table could wobble over a two inch range
in either direction. After adding braces in both the longitudinal and lateral directions, the
table could only wobble over a ¾” range in either direction. A picture of the final version
of JS-T3 is given below in Figure 10.
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Figure 10. Completed Fabrication of JS-T3
Additional testing was planned to take place to determine the speed and sag at
various points along the working surface under 25 lbf increment loads up to 450 lbf. This
was not possible to perform, however, since the H-bridge motor controllers were
damaged during some of the electrical system setup. Additional testing will take place
during the week between completing the final report and giving the final presentation so
that results can be discussed during the presentation.
SolidWorks Testing
During the finalization of the bill of materials for this design, preliminary
SolidWorks studies were performed to analyze how the proposed changes would affect
the operation of the table and to see how the table would react under the design loading
conditions. The newly designed tabletop with all dimensions given in inches is shown in
Figure 11. A stress analysis was performed on the tabletop, and the stress and
deformation visualizations can be seen in Figures 12 and 13 respectively. The first draft
of the completed table is shown in Figure 14.
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Figure 11. Acrylic Tabletop
Figure 12. Stress Visualization of Acrylic Tabletop
19
Figure 13. Deformation Visualization of Acrylic Tabletop
Figure 14. First Draft of JS-T3
These preliminary models were further developed into more realistic models
based on the materials acquired from American Greetings. Furthermore, after noting how
much the table sagged under its own weight, it was decided that the “C-Box” bracket
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would not be built. A second stress analysis was performed on the final model of the
table shown in Figure 15, and the results can be seen for the stress visualization and
deformation visualization in Figures 16 and 17 on the following page.
Figure 15. Final JS-T3 Model
Figure 16. Final Model Stress Visualization
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Figure 17. Final Model Deformation Visualization
The results of these studies show that no part of the entire folding table
experiences significant stress and that the edges of the table sag the most in the
longitudinal direction where the maximum is nearly 0.5” under the design load. Since no
part is subjected to forces close to its yield stress or its rated value for operation, the low
values for stress are to be expected. The relative values for resultant displacement shown
in Figure 17 correspond closely to those values found by the group after fabrication.
After fabrication, the group recorded significant deformation of the acrylic sheets in the
middle (~0.25”) and also at the far ends of the folding tables (~0.5”).
Filling
Prototype Construction
The initial design for the retractable cart was to have the cart base be a standard
service cart. However, when the team went to American Greetings for materials, they had
a large supply of Aluminum 8020, a structural aluminum that they were to provide the
22
team with. The team decided to build the cart out of the structural aluminum because it
could be fastened in different ways. After discussing more with American Greetings, they
provided a cart that they had built out of Aluminum 8020 1515, which is the 1.5 in by 1.5
in square Aluminum 8020, for a previous project. Originally, the cart had severally small
shelves but being built out of Aluminum 8020, the team was able to customize the cart to
how they wished. The team kept the original top shelf that was built out of plywood and
stripped the cart of all shelving to just have a basic cart. The cart has two non-rotating
caster wheels on the front and two lockable rotating casters toward the back where the
user pushes the cart. The team used to a piece of 1515 to build a handle for the user to be
able to push it around.
Once the base cart was constructed, the team then turned their focus onto the
drawer shelf that would extend over the assembly line. To begin, the team placed two
pieces of Aluminum 8020 1010, which is the 1.0 in by 1.0 in square Aluminum 8020, on
top of the plywood shelf top that the drawer slides would connect to. The team secured
the two pieces by drilling holes into the plywood shelf top and using bolts and 8020 nuts.
The team then placed the drawer slides on top the two pieces 1010 and attached them
with 1010 bolts and nuts. Once the slides were in place, the team extended them to attach
the drawer top. The drawer top was originally a plywood shelf that was on the cart. A 2x4
piece of wood was used to create sides on the drawer top. The drawer top was attached to
the slides using the fastener screws that came with the slides. Figure 18 shows a side
view of the drawer shelf on the top of the cart.
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Figure 18. Drawer Shelf
To prevent the drawer slides from bending when the drawer is completely
extended, the team bolted another piece of 1010 toward the back of the shelf top. The
team used an L-bracket that was connected to the back piece of 1010 to connect the shelf
top to this piece. The L-bracket can be tighten to allow the drawer shelf to be locked into
place and can be loosened to move the drawer in and out. When the drawer is completely
extended, the L-bracket piece adds resistance and holds the back of the drawer down and
doesn’t allow the front of the drawer that is extended from bending. Next, to add more
shelving, the team cut a piece of plywood and secured it on the bottom of the cart with
1515 bolts and nuts. Figure 19 shows the finished retractable cart in its extended position
with materials that would be used at American Greetings. A cost estimate of the cart can
be found in Design Implementation section.
24
Figure 19. Finished Retractable Cart
Testing and Modification
The retractable shelf cart was tested for two main functions. The two functions
were the physical and ergonomics aspects.
Load Testing
In order to determine the static properties of the filling design (BM-F1) the team
ran a static analysis. The load testing consisted of a load at the end of the retractable
shelf. This was used to find which would happen first the breaking of the shelf or the
tipping of the cart. Figure 20 shows the results from the static test. The first part, (a),
shows the shelf on the x-axis with point load and its respective reaction forces. Second
part, (b), shows the shear force diagram and the third part, (c), is the bending moment
diagram.
25
According to the static analysis, the largest moment in magnitude occurs at the
middle, 120 lb. ft. Treating the shelf as a beam, the stress of the shelf was calculated.
Equations 1 and 2 were used to determine the maximum stress on the shelf. The stress
with a 60 lb. load at the end of the extended shelf was calculated at 640 psi. The shear
strength of plywood is about 899 psi [1]
. This test was designed to determine what would
occur first the tipping of the cart or the breaking of the shelf. Since at 60 lb. load the cart
tipped over and the stress did not exceed the shear strength of the plywood, the load on
the shelf will have to be limited.
𝜎 =𝑀𝑦
𝐼𝑥 (Eq. 1)
𝐼𝑥 = 𝑏ℎ3
12 (Eq. 2)
(a
)
(c
)
(b
) Figure 20. Static Testing
26
Assembly Line Testing
The cart design was taken to American Greetings to put to use on the line to
observe the usefulness. The cart use was compared to the current method of filling the
box displays. Originally, the cart had been built to fit the use of a fairly short box. In the
assembly line test the team realized that the heights of all the different models of boxes
that are use are not the same. To relieve this issue, the team raised the legs of the cart up
8 inches. The 8 inches gave the enough clearance for most if not all display box designs
to pass under the shelf with no problem. Figure 21 (a) shows the shelf height over the
conveyor. Figure 21 (b) and shows the cart prior and Figure 18 shows after the
modification.
Packaging
Prototype Construction
The team started out constructing the cross member that reaches over the
conveyor to allow workers to adjust the width of the chute. This cross member was built
out of the aluminum 8020 material that American Greetings had given to the group. From
(a) (b)
Figure 21. Cart Shelf Clearance
27
the design that Taylor created last semester, the team made the cross member out of two
rods of 8020. The horizontal shaft had to be attached to the other vertical shaft in a way
that allowed it to be adjustable for multiple box heights. This was solved by using a 4
hole 90° joining plate to fasten the two rods together, shown below in Figure 22.
Figure 22. 4 Hole 90° Joining Plate
This way, a worker would only have to loosen the two screws along the vertical
rod to adjust the height of the horizontal member, then tighten the screws back to lock it
in place. The horizontal member needed to be long enough to stretch out across the
conveyor, which is 18”, so the team decided that 24” was a desirable length for it. At the
time, the team had not found a solid way to attach the contraption to the assembly line, so
they started fabricating the metal flaps for the actual chute.
The flaps were constructed out of the spare sheet metal that was taken from the
American Greetings supply. First, two flaps needed to be traced out and cut with a
plasma torch. These flaps needed to be large enough to hold a cardboard box, yet small
enough to be easily moved by the smaller employees. The team agreed on a 10” tall, 12”
wide surface that had a 3”x3” flap at the bottom that was bent at a 30° angle to make the
flaps act as a funnel. Once the two were traced, the team used a plasma cutters to cut
28
them from the sheet metal, and a band saw to make the final precise cuts. To allow the
flaps to move along the cross member, a 1.5”x1.5” square hole was cut 1” from the top to
weld a 2” section of square tubing to. This square tubing acts as a sleeve for the chute,
allowing each plate to be individually adjusted by loosening a bolt between the tubing
and the aluminum rod. With the flaps constructed, the preliminary work for the
packaging chute was completed, and ready to test on some boxes at the AG plant in
Osceola.
Assembly Line Testing
On the 27 of February, the team went to American Greetings to test the
functionality of the packaging chute. Chris Walker took the team to the packaging
department, and the members got a couple boxes to help test the chute. While testing, the
team noted a couple of design flaws:
There were not many places to attach the cross member to: the assembly line was
connected to something else on the back of it, leaving a small number of openings
The cardboard boxes kept slipping off of the chute while the display box was
being pushed inside of it
The flaps protruded over the assembly line on the side of the workers, making it a
hazard for people walking near it
The horizontal arm was pretty heavy, and hard to adjust with just one person
The horizontal arm was not long enough to allow the flaps to widen enough for
the bigger boxes
Chris did say that he liked the idea of something holding a box while a worker
pushes the display into it, but the team needed to make some adjustments to the design to
fix the noted issues
29
Redesigning and Construction
Packaging Chute
Mr. Barnhill came up with a new, simpler design that consisted of a plate that sits
on top of the assembly line and has smaller funnel plates. He created an Inventor file to
show the group, and a picture of it is shown below in Figure 23.
Figure 23. Top and Bottom View of Chute Redesign
This design would be able to be placed anywhere on the assembly line, and
moved around easily. Also, nothing would hang over the line to pose a threat to anyone,
and allowed a larger area for the flaps to adjust. Two 3”x3” squares were welded onto the
bottom of the base plate on each side to keep it from moving around once placed on the
assembly line. The original plates were cut down to 5” tall, 2” wide still with the existing
3”x3” inner flaps kept at a 30° angle. The plate itself was cut into an 8”x20” rectangle,
with an 8” slot cut out for the adjustable flap. One flap was screwed tightly onto the plate
to keep it stationary, while the other flap was welded to a small 2” piece of angle iron,
and then screwed to the base plate through the slot. This allowed the flap to be able to
move to make the chute wider or narrower. A picture of the final design is shown in
Figure 24 on the next page.
30
Figure 24. Final Packaging Chute Design
After the team finished the chute redesign, they needed to figure out how to keep
the cardboard box on the chute while a worker slides the display into it.
Box Stopper
The team’s end goal with the packaging chute was to prevent the associate
working the line from handling two boxes at once. An observation that was made during
the testing of the first chute design; it was that the chute did not have a method of
securing the packaging box. To secure the box to the chute the team designed and built a
stopper with a spring system. Figure 25 shows the box stopper under implementation
with the packaging box secure (a) and resealed (c) in the assembly line. The pedal in
Figure 25 (b) is the release mechanism for the box stopper.
31
(a)
(c)
Fig
ure
25
. B
ox
Sto
pper
Im
ple
men
tati
on
(b)
32
V. FINAL DESIGN
General Description
Folding Table (JS-T3)
The folding table was a design created and developed by Jed Schales and built by
every member of the REK’M Engineering Team. It began as an aluminum table that
would use a pneumatic system to lift and lower a flat, level surface so that a worker could
comfortably work throughout the day without leaving the factory with aches and pains.
The final design still accomplishes the goal, but does so in a much more controlled and
efficient manner by minimizing the weight of the device and implementing a more
sophisticated lift system. The user manipulates a joystick controller to send a signal
through various electrical components in such a manner that four linear actuators act in
unison and the table rises or lowers while remaining level. The table is relatively light
since it is made of acrylic and PVC in place of heavier alternatives such as aluminum or
wood. JS-T3 consists of 25 different types of components, features a four foot by eight
foot working surface which adjusts to elbow level for 95%+ of the human population,
weighs 172.3 lbs., and costs just under $1,600 to fabricate.
Retractable Cart (BM-F1)
The retractable cart is 2 ft. wide by 3 ft. long by 46 in. tall cart that will be used to
decrease the ergonomically discomfort that employees experience while working on an
American Greeting’s assembly line. It works under the foundation that the cart will carry
everything and the employee will do minimal bending at the torso.
33
Packaging Chute (BM-P1)
The packaging chute was a design created by Banthi Muñoz, worked on by Taylor
Barnhill, and built by the REK’M Engineering Team. At first, it started with the idea of
funneling a filled display box into a packaging box that was stationary in order to cut
down on time spent by a worker trying to hold the box down while simultaneously
pushing the 15+ pound display into it. The final design does just this. It holds a
packaging box in place, keeps it from slipping with the addition of the box stopper, and
allows a worker to seamlessly slide a display box into said packaging box. All the worker
has to do next is press down on the foot pedal to lower the box stopper and allow the
finished box to slide to its next location.
Structural Components
Folding Table
The folding table, JS-T3, consists of two very important structural components
that form the working surface and standing base of the design. The standing base has
been named “8020 Framing” and consists of twelve of the twenty-five components that
comprise the entire table. The working surface is named “Sandwiched Acrylic Table
Top” and consists of seven of the twenty-five components that comprise the entire
device.
8020 Framing
The frame of the folding table consists of 52”X 28” frame of 1010 joined with 7-
hole 90̊ joining plate and a 26” section of 1010 in the middle of the 52” sides. The legs,
34
linear actuators, sit in the 7-hole 90̊ joining plate. The 7-hole 90̊ joining plate had a 7/8”
hole milled out to inset the ends of the legs, as shown in Figure 26 below.
Trusses were a key point in the design of the table; these gave stability to the
table. The team had to figure out a special method to attach trusses to the linear actuators
in a manner that did not damage the interior components. The team designed a truss brace
that acted much like a C-clamp and used a hex nut and bolt to tighten around the surface
of the linear actuator, Figure 27.
Since the actuators were only set inside the 7-hole 90̊ joining plate. The team
needed to find a method of securing the actuators to the bottom frame. A 2” aluminum
Figure 26. 7-Hole 90̊ Joining Plate
(b) Figure 27. Truss Attachments
(a)
35
rod was lathed down to 31/64” to fit inside the horizontal hole shown in Figure 28 (a). A
34 size drill bit was used to mill holes on both ends of the pin and the holes were
threaded with a 6-32 tap, Figure 28 (c). With the table being a big unit a custom washer
needed to be fabricated. This prevented the pin from turning and releasing the set screws.
Sandwiched Acrylic Table Top
The working surface of the folding table consists of two 4’ x 8’ acrylic sheets that
have sixteen 1” long slices of 1-1/4” schedule 40 PVC tubing fastened between them to
act as spacers. Through these PVC spacers, there are screws that attach the two pieces of
acrylic together and maintain a relative position for the PVC to support. At the bottom of
(c)
Set Screws
Figure 28. Actuator Attachment
(a) (b)
36
the lower acrylic sheet, several other important components are fastened such as the
actuator trusses of the 8020 framing and the electrical component box which is attached
at the center of this lower sheet. Four 1.5” diameter holes were cut in a central 2’ by 4’
rectangle shape from this bottom sheet so that the linear actuators can sit in these holes
and support the table firmly. With only the PVC spacers, the group noticed that the table
sagged significantly along its longest dimension, but with the addition of more 8020 1010
members parallel to the table’s longest side, the sag was greatly lessened and the working
surface became a much more solid surface to work upon. A SolidWorks rendering of this
tabletop is given in Figure 29 below.
Figure 29. SolidWorks Model of Acrylic Table Top
37
Retractable Cart
8020 Framing
The cart frame was made from 1010 extruded aluminum. From the bottom shelf is
26” above the top shelf. The width and length of the cart are 24” and 36” respectively.
The corners use 4-hole 90̊ joining plates as shown in Figure 30 (a). The entire frame sits
on top of 5” casters the front two have 360̊ rotation and the rear two do not rotate. Figure
30 (b) displays the modeled frame, the actual frame is shown in Figure 30 (c).
Retractable Shelf
For the retractable shelf the team used a set of Richelieu 18” Drawer Slides. The
slides attached each to a 12” section of 1010 that then attached to the 8020 Frame. The
sliding section of the drawer slides were screwed onto the bottom side of a 24” by 36”
section of ¾” plywood; the plywood served as the retractable shelf that hovered over the
(a) (b)
Figure 30. Cart Assembly
38
box display on the conveyor. To prevent the back end of the shelf from lifting when a
load was added, the team incorporated a third 24” section of 1010 at the rear of the shelf.
A lose was sliding nut in the 1010 section that could be tightened to enable the shelf to be
locked in any position needed, Figure 31 (a). Two sections of 2”X4” were used as an
elevated edge to prevent items from falling off of the opposite side that the employee is
operating on, Figure 31 (b).
Packaging Chute
Metal Framing
The packaging chute is made out of 1/8 inch sheet metal that is rigid and will not
bend under normal use. It sits on top of the conveyor and is easy to pick up and place
somewhere else if needed. It is mostly welded together, and the flaps are fastened onto
the base plate with 1010 screws for easy disassembly.
(a) (b)
Figure 31. Retractable Shelf
39
Mechanical Components
Folding Table
The folding table, JS-T3, consists of one main mechanical component that forms
the leg supports of the overall design. This main component is the set of linear actuators
that work together to change the table’s height. This component is just one of the twenty-
five that comprise the entire device.
Linear Actuators
The four linear actuators are pre-fabricated devices that came from Firgelli
Automations. They are specified to operate under a static or dynamic force of 400 lb.,
operate at 0.4”/s under this full load, and draw a maximum of 5A of current at 12V DC.
On its own, the device weighs 7.4 lbs., and its length is 30.88” while retracted and 54.88”
while extended. In their configuration within JS-T3, these devices allow the table to sit at
its lowest at 36” and its highest at 50”. Within the device, there is a factory preset limit
switch that will shut off operation if it reaches either of these limits. A SolidWorks
rendering of the actuators is given in Figure 32 below.
Figure 32. Linear Actuator
40
Packaging Chute
Spring System
The spring system of the box stopper consisted of one compression spring and
two tension springs. The compression spring resides inside a cylinder to prevent
buckling. The compression spring as well as the two tension springs attach at the same
vertical position but are 1 ½” apart in the horizontal direction. The opposing end of the
tension springs are attached to a chain that follows to the floor level. At the floor level
there is a foot pedal that used body weight to compress the compression spring, lower the
stopper, and release the packaging box. The tension springs are necessary to prevent
excessive force from being used on the pedal. For example, a person presses the pedal
beyond the compressed length of the compression spring. Instead of breaking the welds
or bringing the conveyor system down the tension springs will elongate. This could
happen with the pedal getting out of place as well. Figure 33 (a) displays a diagram of the
spring system, and (b) shows the tension springs and the incased compression spring.
Tension
Springs
(a) (b)
Figure 33. Box Stopper Spring System
Stopper
Compressi
on Spring
Pedal
41
Electrical Components
Folding Table
The folding table, JS-T3, consists of five electrical components that together form
the control system for the table. These components are the Arduino Uno, the H-bridge
system, the joystick user interface, the accelerometer, and the rechargeable battery.
These are five of the twenty-five total components that make up JS-T3.
Arduino Uno
The Arduino Uno is a programmable board that handles multiple analog and
digital inputs, and sends digital and PWM outputs to whatever devices are being used in
conjunction with the board. For the table, it has two inputs, a joystick and an
accelerometer, and four outputs, four individual actuators. It is programmed in a language
resembling the C language and is fairly easy to use. The Arduino website has an array of
sample code to look at for many different devices. The board runs off of a 9V battery,
AC/DC outlet converter, or the USB that is connected to the PC or Mac used to upload
the code. A picture of the board used for the project is shown below in Figure 34.
Figure 34. Arduino Uno Programmable Board
42
H-Bridge System
The H-Bridge has been the number one way to control both the direction and
speed of a motor ever since the transistor was created. The concept behind it is extremely
simple, and it can be applied to almost all typed of DC powered motors. It all has to do
with the four transistors that are in the circuit. A transistor is a semiconductor device used
to amplify and switch electronic signals as well as electrical power. Depending on the
type of transistor (bipolar junction transistor, metal oxide semiconductor field effect
transistor, or other types) they can perform many different functions, however, they all
have one similar quality – they act as a switch. When current flows into a certain one lead
of the three they have, they allow current to flow through the other two. For example, in
the case for the BJT, its three leads are the emitter, base, and collector. When placed in a
circuit, it will not allow current to flow from the collector to the emitter until it detects
current in the base lead. From then on, it allows the circuit to be complete. By using this
idea, engineers came up with the idea of placing four transistors in a circuit in order to
control the direction and speed of a motor. The circuit looks something like the figure
below in Figure 35.
Figure 35. H-Bridge Setup
43
In this setup, one can control the direction of the motor in the middle by allowing
current to flow into certain transistors. To go forward, current needs to flow into the
transistors at the top left and bottom right. That would turn the transistor “on”, and allow
the circuit to be completed. Conversely, the motor can turn in reverse by taking the
current away from the two previously stated transistors, and connected to the top right
and bottom left ones instead.
Also, one can control the speed of the motor. This is done by applying a pulse
width modulated (PWM) signal to the transistors instead of a constant flow of electricity.
A PWM is a square signal that varies its duty cycle (ratio of how long the signal stays
high in a single period over the entire period) based on the input to the system. For
example, a duty cycle of 75% means that the signal is on for three-quarters the time, and
off the rest of the time. The reason a PWM signal is needed for the H-Bridge is that, by
connecting the PWM to the transistors, the motor will only be supplied its needed voltage
at a rate desired by the user. Otherwise, the motor will run at full speed the entire time the
transistors detect current. The higher the duty cycle, the closer to full speed the motor
will run, and it will turn slower and slower while the duty cycle reaches 0%.
The actual H-Bridges used in the project are dual channel, and built to withstand
up to 30A peak current, which is more than enough to support two 5A actuators per
board. Each board can support two different motors connected to the same power source,
and able to control both motors’ speed and direction individually. The project required
two boards to control all four actuators at once. A picture of the H-Bridge is located on
the next page in Figure 36.
44
Figure 36. Dual Channel H-Bridge
Joystick User Interface
The ability to adjust the table height seamlessly lies with the easy-to-use 2-axis
joystick from Parallax Inc. This joystick is simple to use, and requires very little
instruction to learn the basics. A picture of the joystick used in the project is shown in
Figure 37.
Figure 37. Dual-Axis Joystick
In technical terms it has two different outputs that operate on a binary system. The
two different outputs deal with the orientation that a user presses the joystick: up versus
45
down, and left versus right. The output for both directions is a number ranging from 0 to
1023, or 0000000000 to 1111111111 in binary. The binary is sent to the Arduino board,
which is programmed to convert the binary numbers into decimal numbers that are easy
to code with. In the L/R output, 0 means the joystick is pushed all the way to the left, and
1023 means it is leaning right. For the U/D situation, 0 is all the way down and 1023 is
all the way up. For both directions, a number of 511 means that it is in the resting
position, meaning nobody is pressing it in any direction.
With this information, it is easy to get the Arduino to output both PWM and
direction signals to each H-Bridge. Based on the direction and magnitude the joystick is
pressed, the Arduino can tell the actuators to go up or down at varying speeds. The code
was written to handle four situations that the joystick will operate in:
1. If nobody is tilting the joystick, the board sends a PWM signal of “0” to each H-Bridge,
making each actuator stop.
2. If someone tilts the joystick in the up direction, the board will send out a “High” signal to
the direction pins and a PWM signal that is mapped between 0 (always off, stop) and 255
(always on, full speed) depending on the magnitude the joystick is pressed, telling the
actuators to extend at a certain speed.
3. If the joystick is tilted down it will do the same as the previous situations, but the
direction output will be “Low”, telling the actuators to retract, making the table go down.
4. When a user presses the joystick all the way to the right, the accelerometer will initialize,
and start to stabilize the table automatically until the user lets go of the joystick.
Accelerometer
An accelerometer is a device that measures the tilt, speed, and acceleration of an
object. In this case, it is used to measure the tilt of the table, in the case of one of the
actuators not rising/falling at the same rate as the other three. It is a very small device,
46
and the group used the product from Parallax Inc. for the project. A picture of the
accelerometer used is shown below in Figure 38.
Figure 38. Dual-Axis Accelerometer
For this project, the accelerometer is used to determine the direction that the table
is tilting if there is any, and the Arduino uses that information to stabilize the table. It is
called dual-axis because it reads the tilt on the horizontal x and y axes. It sends a signal, a
number in between -4000 to 4000 for each axis, to the Arduino board, and the board is
programmed to convert that number to the amount of g’s the device is experiencing.
Based on the tilt that the board reads, it will do one of 9 actions:
1. No tilt – nothing is sent to the actuators, device does not move
2. Tilts forward – back two legs go down
3. Tilts backwards – front two legs go down
4. Tilts left – right two legs go down
5. Tilts right – left two legs go down
6. Tilts forward-right – front left and back two legs go down
7. Tilts forward-left – front right and back two legs go down
8. Tilts back-right – back left and front two legs go down
9. Tilts back-left – back right and front two legs go down
47
There is a 0.1 second delay in readings, so the accelerometer will wait for the legs
to move for 0.1 seconds before making another reading in case the situation changes.
Rechargeable Battery
The power source for the actuators is a deep cycle 12V 35Ah rechargeable
battery. It is able to supply an entire Ampere of current to a device for 35 straight hours
before needing to be recharged. In this case, the four actuator use 5A a piece under full
load conditions, so that is 20A total. The battery will be able to power the four actuators
for a total of 1 hour and 45 minutes. At first, that doesn’t sound great at all, but that isn’t
how the setup works. The actuators only use the battery’s charge to operate when there is
a signal coming from the Arduino telling the H-Bridges to turn on. Otherwise, the circuit
is not complete and the battery is not being used at all. When a person wants to adjust the
table, he or she will only use the joystick for around 10 seconds. With that information,
the battery should have enough capacity to handle 630 height changes.
48
VI. DESIGN IMPLEMENTATION
Cost Estimate
Below, Tables 1, 2, and 3, are the cost estimates for the each of the designs. The
team used several different resources to acquire the building materials. These resources
included 80/20 Inc., Lowes, and Amazon. The total costs for each design were $1,592 for
the table, $460.92 for the cart, and $85.04 for the packaging chute. Altogether, the three
designs totaled $2137.96.
Material Quantity Price/Quantity Price
Aluminum 8020 1010 T-Slotted (in) 350 $0.23 $80.50
1010 Bolt and Nut Pair 60 $0.50 $30.00
10 S 5 HOLE 90 DEGREE JOINING PLATE 4 $6.30 $25.20
10 S 7 HOLE 90 DEGREE JOINING PLATE 4 $7.65 $30.60
1-1/4". x 2 ft. PVC Pipe 1 $2.15 $2.15
Round Head 3/8in x 2in Bolt 16 $0.37 $5.92
3/8in Lock Washers 16 $0.23 $3.68
3/8 in Fender Washers 16 $0.55 $8.80
3/8 in Hex Nuts 24 $0.22 $5.28
Flexion Lock Rotating Casters 4 $23.50 $94.00
Firgelli 24 in Stroke Actuator 4 $141.68 $566.72
4 ft x 8 ft Plexiglass Sheet 2 $215.56 $431.12
Dual Channel Motor Controller 2 $32.89 $65.78
Auduino UNO R3 Board 1 $14.49 $14.49
12V 3.5Ah Rechargeable Battery 1 $74.90 $74.90
1in Square Steel Tubing (in) 16 $0.31 $4.96
1in OD Round Steel Tubing (in) 8 $0.27 $2.16
2 Axis Parallax Joystick 1 $4.99 $4.99
2 Axis Parallax Accelerometer 1 $29.99 $29.99
10 S 2 HOLE JOINING STRIP 2 $3.40 $6.80
2'x2' Acrylic 1 $11.98 $11.98
1'x1' Plywood 1 $6.29 $6.29
10 S 2 HOLE INSIDE CORNER BRACKET 8 $2.90 $23.20
2" ID Aluminum Rod (in) 16 $1.49 $23.84
1'x1'x1/4" Aluminum Plate 1 $25.22 $25.22
Set Screws 10 pack 1 $13.43 $13.43
Total Cost= $1,592.00
Table 1. Cost Estimate for Folding Table
49
Safety Precautions
Safety Precautions
JS-T3 is designed to support a 500 lbf load imparted to the table’s working
surface. Although the load ratings for the linear actuators and caster wheels are
significantly greater than this (400 lbf per leg and 250 lbf per wheel), the expected
Material Quantity Price/Quantity Price
Aluminum 8020 1515 Lite T-Slotted (in) 425 $0.45 $191.25
Aluminum 8020 1010 T-Slotted (in) 57 $0.23 $13.11
1515 Bolt and Nut Pair 66 $0.60 $39.60
1010 Bolt and Nut Pair 5 $0.50 $2.50
15 S 5 HOLE 90 DEGREE JOINING PLATE 4 $7.10 $28.40
15 S 4 HOLE 90 DEGREE JOINING PLATE 4 $5.60 $22.40
15 S 4 HOLE INSIDE GUSSET CORNER GUSSET 4 $6.25 $25.00
15 S 2 HOLE INSIDE CORNER BRACKET 6 $2.95 $17.70
Flexion Lock Rotating Casters 2 $23.50 $47.00
Flexion Rigid Casters 2 $13.08 $26.16
23/32 x 4 x 8 Plywood 1 $28.72 $28.72
2'x4'x96" Stud 1 $3.11 $3.11
Richelieu 2-Pack 18in Drawer Slides 1 $15.97 $15.97
Total Cost = $460.92
Table 2. Cost Estimate for Retractable Cart
Material Quantity Price/Quantity Price
11ga 1'x2' CR Steel Sheet 2 $25.39 $50.78
1010 Bolt and Nut Pair 4 $0.50 $2.00
1" OD Aluminum Tubing (in) 6 $0.55 $3.30
Hillman Compression Spring 11/16"x3" 1 $3.49 $3.49
Hillman Tension Spring 5/8"x3-1/4" 2 $4.57 $9.14
Gate House 3-1/2" Hinge 1 $2.78 $2.78
Blue Hawk 15' #3 Double Loop Chain 1 $6.97 $6.97
Quick Link 1/8" 3 $1.78 $5.34
Chain S-Hook 1/8" 1 $1.24 $1.24
Total Cost= $85.04
Table 3. Cost Estimate for Packaging Chute and Box Stopper
50
deformation along the acrylic sheets with loads greater than 500 lbf causes a significant
problem for a worker who intends to use this device for an extended period of time. The
table will not keep a level surface and will be difficult to perform accurate folding
operations upon. The table was not tested for impact tests. From analysis of the
components of JS-T3 during physical testing and SolidWorks studies, it appears that
upon failure, the table’s acrylic sheets will be the first to fail by shearing, but remain
stationary since there are multiple layers and several underside brackets. Since the entire
table can move, a crushing hazard exists if any part of the worker is rolled upon by the
caster wheels while they are not locked in place. There should be no pinching hazards
present while using the device due to the configuration of the linear actuators and their
trusses. There may be the danger that a worker could scrape their hands or knuckles on
the working surface due to the bolts that were left exposed on the top sheet of acrylic that
forms the tabletop. This can be addressed by drilling small sections out of the acrylic
surface so that the screw heads can sit at the same level as the working surface. As of
now, there are no barriers between the electrical components and a worker, so a shocking
hazard may also exist if the worker attempts to disconnect or tinker with any electrical
components while the device is powered.
BM-F1 is designed to support 40 lbf of goods when fully extended across the
conveyor, and can support two more boxes of goods on the lower shelf of the cart. The
cart should not be loaded with more than this in order to ensure the worker’s safety. The
criteria for failure for this design is not fracture of a component, but rather the cart
tipping over and not serving its purpose. The cart begins to do so right at 59.4 lbf; this is
why the design is specified to only hold 40 lbf of goods on its top shelf. Since the
51
retractable cart moves with use, a crushing hazard exists if any part of the worker is
rolled upon by the caster wheels. There should be no pinching hazards since there are
very few moving components, and the clearances between these are less than ¼”.
The packaging chute, weighing 6lbs, consists of an 8”x20” metal base plate, a 5”
tall stationary funnel flap, and another 5” flap that is able to slide across the base plate to
adjust the width of the chute. When placing this device, it is possible to get fingers stuck
in between the plate and the assembly line, so make sure no extremities are under the
base while placing it. Also, the base has a ¼” wide slot for the adjustable flap to move
around, so keep fingers out of the area while moving the flap. Finally, do not slide any
body part across the top of either flap as the flaps are made of metal, and can cause
discomfort along the affected areas.
The box stopper weights around 11lbs and it needs some proper setup before
using. It needs to be placed on top of the assembly line, with the lower half raised up
below the line to screw into the top part. To lower the sliding plate, a worker must press
down on the foot pedal attached to the bottom of the plate. The assembly process will
need a worker with some technical skills, and can pose a threat to those who do not
possess them. Some arm fatigue might occur during installation. Also, there is a ¼” gap
in the top area for the sliding plate to fit into. Make sure to not place any extremities in
the gap during operation. Following these procedures correctly will keep any worker
from experiencing any kind of discomfort.
52
Operation and Maintenance Procedures
JS-T3 consists of several components that undergo work cycles and as such
require maintenance after an extended period of time. Two primary components that
undergo these working cycles and exhibit a considerable amount of strain because of
them are the linear actuators and the rechargeable battery. No specifications were given
as to the life of the actuators, but Firgelli Automations offers a twelve month warranty.
Since the table legs are not a part that leads to a critical or catastrophic failure of the
device, it is simply recommended to replace the faulty part as it is noticed. The
rechargeable battery can provide enough power to handle 630 height changes. If it is
estimated that a worker will change the height of the table ten times in one shift, then it is
recommended that the battery be recharged twice every month for a five day three shift
work week. To operate JS-T3, two users should position the table into a useable position
at the assembly line and then lock each of the four casters into place. Once this is done,
the battery’s power should be turned on so that the system can operate. These two steps
are part of the initial set up and will not need to be repeated unless the device is relocated.
The user is then to operate the joystick on the underside of the table by pushing it away
from them or toward them to lift or lower the table. Once the table is at a comfortable
level, nothing more must be done to use the table for its intended purpose. To avoid any
injuries due to the previously mentioned safety hazards, it is not recommended to lift the
table to its maximum height, place fingers into any of the devices trusses or electrical
components while the device is powered or raised, or put any force onto the table such
that the resultant load is more than 450 lbf (90% of the rated design load). While
53
relocating the device, it is recommended to wear steel-toed boots which are
commonplace on factory floors so that workers will not sustain any foot injuries.
BM-F1 consists of one main component that will receive wear and tear during its
useful life. This component is the slide rails which allow the table to extend across the
conveyor belt. No other components should fail during this cart’s lifetime, since no other
parts are fatigued nearly as much as the slide rails are. No information was found
regarding the lifetime of these components, so it is simply suggested to replace them at
the first sign of damage. To operate BM-F1, the user should lock the wheels of the cart
near a product pallet, load the top shelf with one box, and place two more on the bottom
shelf if they desire to do so. They should then unlock the wheels and roll the cart to the
assembly line. The worker must then lock the wheels and then extend the cart across the
line and perform the filling process. Once a box is emptied, the shelf should be retracted
and boxes from the bottom shelf may be placed one at a time on the top of the cart to
continue filling until the cart is completely empty. The worker should then unlock the
wheels, return the cart to a product pallet, and repeat the process. While using this
device, it is recommended to wear protective footwear to avoid any worker injuries.
Figure 39 shows an example of the warning sticker for the cart.
Figure 39. Cart Warning
54
As for the packaging chute, the one part that may need proper maintenance is the
lock screw that is used to move the adjustable flap. After many shifts and width changes,
the screw might experience some wear and tear, and might strip when too much force is
applied. To avoid this, it is recommended that the lock screw be replaced every six
months.
The box stopper is meant to be stationary. That alleviates the need for
maintenance on all the locking mechanisms. Also, springs do not require any
maintenance, so there is no need for maintenance on the box stopper.
55
VII. CONCLUSIONS/RECOMMENDATIONS
Regarding JS-T3, the group fell on hard luck since acquiring the materials took
much more time than anticipated. The group did not receive the materials for the folding
table until the middle of Spring Break vacation, and a problem arose with one of the H-
bridges which required another part to be ordered which finally came in on the day that
the final report was due. This meant that the only physical testing mentioned in the final
report took place in the course of one day. Jed Schales spent much of the beginning of
the semester trying to finalize the bill of materials with American Greetings so that the
design could actually be plausible and constructible, but communication problems
between REK’M and AG caused a few weeks of delays as seen in the Gantt chart’s
schedule. Through these less than desirable circumstances of which no one is at fault, the
table was successfully built and serves its purpose. The group concludes that much more
time should have been spent on the testing of the device for different loading conditions
and for testing on the assembly line to gather worker feedback. Without any testing
results to go on besides SolidWorks analyses, the group can recommend little. REK’M
recommends that future groups appropriately plan for the worst and build in some
cushion time within their Gantt charts. The group also recommends to future groups
studying elevating tables, such as American Greetings design teams, that specific
attention be paid to keeping the table’s working surface stationary while the worker is
performing high-motion folding operations. Kevin Muñoz and Ethan Bise worked hard
to address this problem, but a better solution may be realized if this specific aspect is kept
in mind during the design phase instead of as a correction during the fabrication phase.
56
The retractable cart did exactly what it was designed to do; nevertheless the
design could be improved with noted observations. A recommendation for work in the
future would be to test a prototype of the shelf, where the shelf extended to its side
instead of to the front. This idea was brought up in one of the trips to American Greetings
by Chris Walker. The statics of that design would be different and more in-depth analysis
would have to be conducted. Another recommendation that was also noted in an AG trip
is to incorporate the linear actuator legs into the cart to adjust to any size box that is being
pushed through the line.
Regarding the packaging chute, while testing the final design, the team noticed a
couple of areas that the design was lacking in. First, the base plate was laid on top of the
rollers in the assembly line, so the entire device is about 1/8” above the conveyor. This
might cause a display box to catch on the base plate and force a worker to lift the box
before sliding it into the packaging box. In the future, the design could be altered to allow
the beginning of the base plate to be lower than the top of the rollers to allow the display
boxes to be easily slid across the surface. Also, a floor worker noted that the flaps were
considered to be hazards since the edges were not sanded down. The team could have
sanded down the edges, and made some more intricate cuts to make the design safer if
given enough time. Finally, Chris Walker noted on the difficulty of adjusting the width of
the chute with the Allen wrench. If the design is further implemented, a knob could be
attached to the lock nut, allowing an easier way to tighten and loosen the lock nut.
The box stopper was a key part of the packaging chute that was constructed as a
recommendation in the initial testing. One recommendation that would better the design
would be to add an attachment system to the top platform similar to the rollers on the
57
conveyor. This would decrease the installation and replacement time marginally. Another
recommendation would be to add a pulley system to the pedal. This would allow the
pedal to be placed at a comfortable location for the user.
58
VIII. LIST OF REFERENCES
1. 80/20 Catalog. Vol. 18. 2015. Print.
2. "Lowe's Home Improvement Store." Web. 20 Apr. 2015. http://www.lowes.com
3. "Firgelli Technologies - Micro Linear Actuators." Linear Actuators. Web. 20 Apr.
2015. http://www.firgelli.com/
4. "Caster and Material Handling." Flexion. Web. 20 Apr. 2015.
<http://www.flexionmaterial.com/>.
5. "Parallax Inc | Equip Your Genius." Parallax Components. Web. 20 Apr. 2015.
https://www.parallax.com/
6. "Aluminum Tube, Pipe, & Plate | 6061 Aluminum Tubing ..." Web. 20 Apr. 2015.
<http://www.speedymetals.com/c-8342-aluminum.aspx>.
7. "Speedy Metals - Steel." Web. 20 Apr. 2015. http://www.speedymetals.com/c-
8209-steel.aspx
8. http://www.matweb.com/search/datasheet.aspx?matguid=bd6620450973496ea25
78c283e9fb807&ckck=1
9. http://www.gearhob.com/eng/design/drill_eng.htm
10. http://www.farmandfleet.com/products/065494-steelworks-square-tubing.html
11. https://grabcad.com/library/caster-5-inch-wheel
12. http://absurdwordpreferred.deviantart.com/art/Chain-PNG-160294848
13. "Arduino - ArduinoBoardUno." Arduino - ArduinoBoardUno. N.p., n.d. Web. 20
Apr. 2015.
14. "ECE476 Spring 2005 Final Project." ECE476 Spring 2005 Final Project. N.p.,
n.d. Web. 20 Apr. 2015.
15. "Learn.parallax.com." 2-Axis Joystick. N.p., n.d. Web. 20 Apr. 2015.
16. "Memsic 2125 Dual-axis Accelerometer." Memsic 2125 Dual-axis
Accelerometer. N.p., n.d. Web. 20 Apr. 2015.
17. "Robot Check." Robot Check. N.p., n.d. Web. 20 Apr. 2015.
18. Wray, James, Eric Romero, Ethan Clark, and Daniel Brooks. Pedestrian Transport
System Go-By. ASU College of Engineering. Print. 10 Feb. 2014.
19. "Engineering Course Standards." Engineering Course Standards. Arkansas State
University College of Engineering, Fall 2013/2014. Web. 4 Sept. 2014.
20. Bradshaw, Caleb, Jordan Collins, William Marler, Cody Milburn. Portable
Maintenance Lift Time Schedule Go-By. ASU College of Engineering. Print. 25
Apr. 2008.
21. Walker, Chris. "Research Trip to Osceola #1." Personal interview. 6 Feb. 2015.
22. Walker, Chris. "Research Trip to Osceola #2." Personal interview. 27 Feb. 2015.
23. Walker, Chris. "Research Trip to Osceola #3." Personal interview. 17 Apr. 2015.
24. "Dimensions of Socket Button Head Cap Screws." Dimensions of Socket Button
Head Cap Screws. Fairbury Fastener, n.d. Web. 7 Feb. 2015.
59
25. "Fastener Type Chart." Bolt Depot. Bolt Depot, n.d. Web. 7 Feb. 2015.
26. "Dimensions - Schedule 40 & 80 Pipe - PVC Industrial & Industrial PLUS."
Schedule 40 & 80 Pipe Dimensions. Georg Fischer Harvel, n.d. Web. 7 Feb.
2015.
27. “2.5x24x0.75 DA AIR CYLINDER." 2.5x24x0.75 DA AIR CYLINDER. Surplus
Center, n.d. Web. 7 Feb. 2015.
28. "Occupational Health and Safety." Occupational Health and Safety. Alberta.ca,
n.d. Web. 4 Feb. 2015.
29. "68–95–99.7 Rule." Wikipedia. Wikimedia Foundation, n.d. Web. 4 Feb. 2015.
30. "NCEES: FE Reference Handbook." NCEES. NCEES, n.d. Web. 4 Feb. 2015.
31. "Aluminum Distributor." Aluminum Distributor. ASM Aerospace Specification
Metals, Inc., n.d. Web. 20 Jan. 2015.
32. "Product Details." Product Details. Colson, n.d. Web. 9 Feb. 2015.
33. "3 Gal. 1/3 HP 100 PSI Oilless Pancake Air Compressor." Harbor Freight Tools.
Harbor Freight Tools, n.d. Web. 9 Feb. 2015.
34. "Products & CAD." Original Line® with Adjustable Cushions. Bimba, n.d. Web.
9 Feb. 2015.
35. "Learn How to Cut, Drill and Finish the Edges of Plexiglass (acrylic)." Learn
How to Cut, Drill and Finish the Edges of Plexiglass (acrylic). Basic Car Audio
Electronics, n.d. Web. 4 Feb. 2015.
36. "Fluid Power Cylinders." Unit 24: Applications of Pneumatics and Hydraulics
(n.d.): n. pag. Free Tutorials on Engineering and Science. Free Study. Web. 4 Feb.
2015.
60
APPENDIX A
Man-Hours Table
A-2
Table A-1. Man-Hour Schedule
Man-Hour Schedule Individual Hourly Breakdown
Task Estimated
Hours Actual Hours
Percent Complete
Estimated Hours Per
Person
Taylor Barnhill
Robert Bise
Banthi Munoz
Jed Schales
1. Develop Proposal 40 21.25 100 10 4.5 9 2.75 5
2. Fabrication and Testing
Develop Cost and Material Estimate 32 37.5 100 8 7 10 8.5 12
Fabrication 100 249 100 25 66 67 85 31
Testing 100 72.5 100 25 19 16.5 10 30
3. Progress Report 1 24 26 100 6 6 6 8 6
4. Progress Report 2 24 20.5 100 6 6 7 7 0.5
5. Final Design 60 20 100 15 5 8 2 5
6. Final Report 100 60 100 25 14.5 20.5 10 20.5
7. Final Presentation* 40 40 0 10 10 10 10 10
8. Record Keeping/Advising 80 52 90 20 12 12 12 16
Total Man-Hours 600 598.75 150 150 166 155.25 136
* These are just an estimate of the hours each team member will contribute to the Final Presentation
APPENDIX B
Gantt Chart
B-2
1/14/2015 2/3/2015 2/23/2015 3/15/2015 4/4/2015 4/24/2015
1. Develop Proposal
Actual Period
2. Fabrication and Testing
Actual Period
3. Progress Report 1
Actual Period
4. Progress Report 2
Actual Period
5. Final Design
Actual Period
6. Final Report
Actual Period
7. Final Presentation
8. Record Keeping/Advising
Actual Period
Figure B-1. Gantt Chart Schedule
APPENDIX C
Control System Code
C-2
int legpwm1 = 10; //pwm output to first leg
int legpwm2 = 9; //pwm output to second leg
int legpwm3 = 6; //pwm output to third leg
int legpwm4 = 5; //pwm output to fourth leg
int dir1 = 12; //direction for first leg
int dir2 = 8; //direction for second leg
int dir3 = 7; //direction for third leg
int dir4 = 4; //direction for fourth leg
int joypin0 = A0; //joystick analog input to pin A0
int joypin1 = A1; //L/R input from joystick at pin A1
int value1 = 0; //variable to read the value from pin A0
int value2 = 0; //variable to read the value from pin A1
const int xpin = 2; //x output from accelerometer
const int ypin = 3; //y output from accelerometer
void setup() {
Serial.begin(9600);
pinMode(legpwm1, OUTPUT); //pin10 is an output
pinMode(legpwm2, OUTPUT); //pin9 is an output
pinMode(legpwm3, OUTPUT); //pin6 is an output
pinMode(legpwm4, OUTPUT); //pin5 is an output
pinMode(dir1, OUTPUT); //pin12 is an output
pinMode(dir2, OUTPUT); //pin8 is an output
pinMode(dir3, OUTPUT); //pin7 is an output
pinMode(dir4, OUTPUT); //pin4 is an output
pinMode(xpin, INPUT); //pin13 is an input
pinMode(ypin, INPUT); //pin11 is an input
}
void loop() {
value1 = analogRead(joypin0); //read joystick input, 0 being all the
way down, 1013 being all the way up)
value2 = analogRead(joypin1); //read joystick input on L/R pin
delay(50);
if (value1 < 480) //if reading is less than 480
{
value1 = map(value1, 480, 0, 0, 255); //maps the joystick values to
pwm values
digitalWrite(dir1, LOW); //direction for motor 1 to be down
digitalWrite(dir2, LOW); //direction for motor 2 to be down
digitalWrite(dir3, LOW); //direction for motor 3 to be down
digitalWrite(dir4, LOW); //direction for motor 4 to be down
analogWrite(legpwm1, constrain(value1, 0, 255)); //pwm for motor 1
speed
analogWrite(legpwm2, constrain(value1, 0, 255)); //pwm for motor 2
speed
analogWrite(legpwm3, constrain(value1, 0, 255)); //pwm for motor 3
speed
analogWrite(legpwm4, constrain(value1, 0, 255)); //pwm for motor 4
speed
Serial.print("LOW ");
Serial.println(value1); //print pwm value
}
else if (value1 > 550) //if reading is greater than 550
{
C-3
value1 = map(value1, 550, 1023, 0, 255); //maps the joystick values to
pwm values
digitalWrite(dir1, HIGH); //direction for motor 1 to be up
digitalWrite(dir2, HIGH); //direction for motor 2 to be up
digitalWrite(dir3, HIGH); //direction for motor 3 to be up
digitalWrite(dir4, HIGH); //direction for motor 4 to be up
analogWrite(legpwm1, constrain(value1, 0, 255)); //pwm for motor 1
speed
analogWrite(legpwm2, constrain(value1, 0, 255)); //pwm for motor 2
speed
analogWrite(legpwm3, constrain(value1, 0, 255)); //pwm for motor 3
speed
analogWrite(legpwm4, constrain(value1, 0, 255)); //pwm for motor 4
speed
Serial.print("HIGH ");
Serial.println(value1); //print pwm value
}
else
{
//initialize all the directions to low and pwm to 0
digitalWrite(dir1, LOW);
digitalWrite(dir2, LOW);
digitalWrite(dir3, LOW);
digitalWrite(dir4, LOW);
analogWrite(legpwm1, 0);
analogWrite(legpwm2, 0);
analogWrite(legpwm3, 0);
analogWrite(legpwm4, 0);
Serial.println("0");
}
int pulsex, pulsey; //variables to read pwm from accelerometer
int accx, accy; //variables to assign the acceleration
while (value2 > 800)
{
pulsex = pulseIn(xpin, HIGH); //read pwm from xpin
pulsey = pulseIn(ypin, HIGH); //read pwm from ypin
accx = ((pulsex / 10) - 500) * 8; //converts pwm into acceleration of
earth's gravity
accy = ((pulsey / 10) - 500) * 8; //converts pwm into acceleration of
earth's gravity
if (accx < -185 && accy < -80 && accy > -105) //if tilting forwards
{
//tell legs 3, 4 to go down
digitalWrite(dir3, LOW);
digitalWrite(dir4, LOW);
///speed of legs are half speed
analogWrite(legpwm3, 127);
analogWrite(legpwm4, 127);
Serial.println("3 4 LOW");
}
C-4
else if (accx > -160 && accy < -80 && accy > -105) //if tilting
backwards
{
//tell legs 1, 2 to go down
digitalWrite(dir1, LOW);
digitalWrite(dir2, LOW);
///speed of legs are half speed
analogWrite(legpwm1, 127);
analogWrite(legpwm2, 127);
Serial.println("1 2 LOW");
}
else if (accx < -160 && accx > -185 && accy < -105) //if tilting
left
{
//tell legs 2, 4 to go down
digitalWrite(dir2, LOW);
digitalWrite(dir4, LOW);
//speed of legs are half speed
analogWrite(legpwm2, 127);
analogWrite(legpwm4, 127);
Serial.println("2 4 LOW");
}
else if (accx < -160 && accx > -185 && accy > -80) //if tilting
right
{
//tell legs 1, 3 to go down
digitalWrite(dir1, LOW);
digitalWrite(dir3, LOW);
//speed of legs are half speed
analogWrite(legpwm1, 127);
analogWrite(legpwm3, 127);
Serial.println("1 3 LOW");
}
else if (accx < -185 && accy < -105) //if tilting forward left
{
//tell legs 2, 3, 4 to go down
digitalWrite(dir2, LOW);
digitalWrite(dir3, LOW);
digitalWrite(dir4, LOW);
//speed of legs are half speed
analogWrite(legpwm2, 127);
analogWrite(legpwm3, 127);
analogWrite(legpwm4, 127);
Serial.println("2 3 4 LOW");
}
else if (accx < -185 && accy > -80) //if tilting forward right
{
//tell legs 1, 3, 4 to go down
digitalWrite(dir1, LOW);
digitalWrite(dir3, LOW);
digitalWrite(dir4, LOW);
//speed of legs are half speed
analogWrite(legpwm1, 127);
C-5
analogWrite(legpwm3, 127);
analogWrite(legpwm4, 127);
Serial.println("1 3 4 LOW");
}
else if (accx > -160 && accy < -105) //if tilting back left
{
//tell legs 1, 2, 4 to go down
digitalWrite(dir1, LOW);
digitalWrite(dir2, LOW);
digitalWrite(dir4, LOW);
//speed of motors are half speed
analogWrite(legpwm1, 127);
analogWrite(legpwm2, 127);
analogWrite(legpwm4, 127);
Serial.println("1 2 4 LOW");
}
else if (accx > -160 && accy > -80) //if tilting back right
{
//tell legs 1, 2, 3 to go down
digitalWrite(dir1, LOW);
digitalWrite(dir2, LOW);
digitalWrite(dir3, LOW);
//speed of motors are half speed
analogWrite(legpwm1, 127);
analogWrite(legpwm2, 127);
analogWrite(legpwm3, 127);
Serial.println("1 2 3 LOW");
}
else
{
digitalWrite(dir1, LOW); //direction for motor 1 to be down
digitalWrite(dir2, LOW); //direction for motor 2 to be down
digitalWrite(dir3, LOW); //direction for motor 3 to be down
digitalWrite(dir4, LOW); //direction for motor 4 to be down
analogWrite(legpwm1, 0); //pwm for motor 1 speed
analogWrite(legpwm2, 0); //pwm for motor 2 speed
analogWrite(legpwm3, 0); //pwm for motor 3 speed
analogWrite(legpwm4, 0); //pwm for motor 4 speed
}
Serial.print(accx); //print x accelerration
Serial.print(" "); //print some space
Serial.print(accy); //print y acceleration
Serial.println(); //end line
value2 = analogRead(joypin1);
delay(50);
}
}
APPENDIX D
Descriptive Diagrams
D-2
Figure D-1. JS-T3 with Dimensions
D-3
Figure D-2. Circuit Schematic for Control System
D-4
Figure D-3. Block Diagram for Control System Flow
D-5
Figure D-4. BM-F1 With Dimensions
D-6
Figure D-5. BM-P1 with Dimensions
APPENDIX E
Personal Resumes
E-2
Taylor Barnhill 1216 Highway 236 W | Lonoke, AR 72086 | (501) 628–1139 |
Career Summary Recent college graduate with degree in electrical engineering experienced in the design, engineering and quality improvement of electronic components, computer networks, and communication theory. Excellent at multi-tasking with proven ability to handle diverse electrical and mechanical duties.
Work Experience Industrial Engineering Intern, AMERICAN GREETINGS, Osceola, AR
5/14 – 8/14
Generated a time study analysis on process to ship product to plant in UK ; proposed new plan to save time and money (increased amount of product per shipment by 12%)
Worked with third party contractors to install large scale polyester printer; created startup/shutdown procedures to teach new employees
Farm Field Hand, BARNHILL ORCHARDS, Lonoke, AR
5/06 – 8/13
Handled large equipment such as tractors to move supplies
Supervised workers to obtain maximum efficiency
Calculated the amount of fertilizer and chemicals needed for acreage and dispersed accordingly
Provided irrigation in new fields
Maintained motors in water pumps, ATVs, and tractors
Worksite Maintenance Specialist, UNDERWOOD CONSTRUCTION, Lonoke, AR
5/05 – 8/05
Maintained job site safety by removing materials that were potential hazards to construction workers
Computer & Technical Skills Systems / Languages: Windows XP, Windows 7, Windows 8, Linux Ubuntu, C++ Software: MicroCap, MultiSim, PowerWorld, AutoDesk Inventor, AutoCAD, Microsoft Office 2013 Equipment: Oscilloscopes, multimeters, DC power supplies, function generators, Arduino Skills: Creating circuits, building computers, C++ programming, excellent team player, innovative and
motivated
Education Arkansas State University, Jonesboro, AR (ABET Accredited) May 2015 Bachelor of Science, Electrical Engineering Minor: Mathematics GPA: 3.57 Fundamentals of Engineering Electrical and Computer Exam – Passed December 2014 Technical Projects:
Wireless Directional Speed Motor Controller
• Constructed a Pulse Width Modifier with IC 555 Timer and potentiometer to increase/decrease duty
cycle; Transmitted output signal wirelessly using infrared LEDs; Amplified signal by negative
feedback amplifier, sent to H-Bridge motor controller to power motor in desired direction
E-3
Ergonomic Table
• Designed a table to conform to various worker heights in order to lessen physical pain caused while working on said table; Placed two car jacks on opposing ends of table, welded together to cause synchronous up/down movement, hold up the workspace, while perforated steel tubing lock into a desired height
Marble Sorter
• Built machine and designed control system to sort marbles based on photoconductivity produced by photo resistor when light is shined through said marbles
Honors and Affiliations: Dean’s List – 3 terms Chancellor List – 2 terms Member, Student Chapter of the Institute of Electrical and Electronic Engineering (IEEE) Captain of numerous Intramural Sports, Arkansas State Ultimate Frisbee team
E-4
Robert Ethan Bise
Address: P.O. Box 220, Weiner, AR 72479 Phone: 870-930-0466
Email: [email protected] Looking For: Full-Time
Objective: To further expand and apply my skills, knowledge, and experience by obtaining a full- time job in Mechanical Engineering
Education
Arkansas State University, Jonesboro, AR: Fall 2011-Present
Bachelor’s degree in Mechanical Engineering (BSME)
Minor degree in Mathematics
3.856 GPA
Graduation Date: May 2015 Passed the Fundamental of Engineering (FE) Exam: Nov. 24, 2014
Work Experience
R. Keith Bise Farming, Fisher, AR: 2011-Present
Position: Farm Hand
Maintained and ran farm machinery
Owner: Keith Bise o Phone: 870-930-7385
Student Project, etc. o Senior Design I Project
Involved in an Engineering Design Process to design assists for the process of building greeting card displays at American Greetings
Purpose was to decrease the amount of injuries to employees and increase production rate
Used SolidWorks to model designs
Worked with others to accomplish tasks toward a common goal o Robotics
Sumo robot was designed, built, and programmed
Infrared sensors told robot where to move
Robot was built for a robotics competition
Relevant Mechanical Engineering Courses
Thermodynamics II Intro to Manufacturing Processes
Machine and Mechanical System Design Finite Element Analysis
Process Monitoring and Controls Solid Modeling for Engineers
Mechanical Vibrations Control Systems for ME
Heat Transfer Fluid and Thermal Systems
HVAC Robotics
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Professional Organizations
American Society of Mechanical Engineers (2013-Present) (Chapter Vice-President)
The American Society of Heating, Refrigerating and Air Conditioning Engineers (2013-Present) (Member)
Honors/Awards
Honors College at Arkansas State University (2011-Present)
Who’s Who at Arkansas State University
Riceland’s President Scholarship
Arkansas State University Pride Scholarship
Dean’s List: Fall 2011, Spring 2012, Spring 2013
Chancellor’s List: Fall 2012, Fall 2013, Spring 2014 Technical Skills
o SolidWorks - Design and Simulation
Built and tested assists for the AG Display building process
Designed a water bottle and found the natural frequencies when full and empty.
o MATLAB
Graphed data and solved matrices for several different applications o LabVIEW
Data acquisition software
Created .vi files to analyze signals from transducers and sensors
Preformed vibrations, frequencies, modes, pressure, strain, etc. tests o Proficient in Microsoft Excel, Word, and PowerPoint o PLC and Controller Concepts (Course to be taken in Spring 2015) o Design of HVAC Systems (Course to be taken in Spring 2015
References
Dr. Shivan Haran (Director and Associate Professor, Mechanical Engineering, Arkansas State University, Jonesboro, AR)
o Phone (870) 972-3413, Email: [email protected]
Dr. David Kwangkook Jeong (Assistant Professor, Mechanical Engineering, Arkansas State University, Jonesboro, AR)
o Phone (870) 680-8593, Email: [email protected]
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Banthi Kevin Muñoz
Address: 3600 Northwood Dr., Jonesnoro, AR 72401 Phone: 870-882-9571
Email: [email protected]
Employment Arkansas National Guard: November 2008 – Present
Petroleum Supply Specialist/Team Leader(SGT) o November 2008 – Present o 875th ENGR BN FSC Co. o Supervisor: SFC James Russell o Phone:870-847-1865 o Email:[email protected]
Retention NCO o September 2013 – July 2014 o Supervisor: SFC Wendy Forbs o Phone: 501-212-7060 o Email: [email protected]
ASU-Information & Technology Services: August 2009-Present
Campus Switchboard Operator o August 2009-September 2011 o Supervisor: Dana Slatton o Phone:870-972-3033 o Email: [email protected]
Cellular Customer Services Representative o September 2011-April 2012 o Supervisor: Dana Slatton o Phone:870-972-3033 o Email: [email protected]
Billing Customer Representative o April 2012-May 2013 o Supervisor: Dana Slatton o Phone:870-972-3033 o Email: [email protected]
Assistant Technician o May2013-Present o Supervisor: David Engelken o Phone: 870-972-3033 o Email: [email protected]
Awards
Won “Logistics Warrior Hero” out of 600 soldiers in training
875th
BN Forward Support Company for Soldier of the Year
875th
BN Forward Support Company for NCO of the Year
875th
BN for NCO of the Year
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Education Arkansas State University, Jonesboro, AR: Fall 2011-Present
Seeking degree in Mechanical Engineering
131 Hours Completed
Graduation Date: May 2015 List of Mechanical Engineering Courses Taken
Solid Modeling, Dynamics, Thermodynamics I, Fluid Mechanics, Thermodynamics II, Engineering Economics, Machine Design, Introduction to Manufacturing Processes, Fluid and Thermal Energy Systems, Heat Transfer, Design of HVAC Systems, Mechanical Systems Design, Mechanical Vibrations, Process Monitoring and Control, and Senior Design I, Control Systems for ME, Finite Element Analysis,
Organizations
American Society of Mechanical Engineers (2013-Present
The American Society of Heating, Refrigerating and Air Conditioning Engineers (2013-Present)
ASU’s Men’s Soccer Club (2012-Present) (President) References
Available upon request
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Jed Schales
Address: P.O. Box 1642, State University, AR, 72467 Phone: 870-761-5724
Email: [email protected]
Employment CESUR/ASU Research Assistantship: April 2013-Present
Analytical Study on Photonic Crystals and Waveguiding o April 2013 – April 2014 o Supervisor: Mechanical Engineering Professor Ilwoo Seok o Phone: 870-680-8589 o Email: [email protected]
Simulation of Particle Arrays for Optical Bandgap Control o May 2014 – Present o Supervisor: Electrical Engineering Professor Brandon Kemp o Phone: 870-972-4302 o Email: [email protected]
Hytrol Engineering Internship: March 2014 – June 2014
Configurations Design Engineer o Supervisor: Configurations Design Leader Tiffany Hayden o Phone: 870-935-3700
Education Arkansas State University, Jonesboro, AR: Fall 2011-Present
Seeking degree in Mechanical Engineering
138 Hours Completed
4.00 GPA
Graduation Date: May 2015 List of Mechanical Engineering Courses Taken
Solid Modeling, Dynamics, Thermodynamics I, Fluid Mechanics, Thermodynamics II, Engineering Economics, Machine Design, Introduction to Manufacturing Processes, Fluid and Thermal Energy Systems, Heat Transfer, Design of HVAC Systems, Mechanical Systems Design, Mechanical Vibrations, Introduction to FEA, Process Monitoring and Control, Control Systems for Mechanical Engineers, Senior Design I, and Senior Design II
Organizations
American Society of Mechanical Engineers (2013-present) (Chapter President during Fall 2014)
The American Society of Heating, Refrigerating and Air Conditioning Engineers (2013-Present) (Chapter Vice President from 2014-2015)
The Society of Women Engineers (2013-Present)
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Additional Information
Passed the Fundamentals of Engineering Exam (October 2014)
Two years of High School Education in Spanish, French, and German
Proficient in SolidWorks, MATLAB, Inventor, and COMSOL
Proficient in Microsoft Word, Excel, and Powerpoint
Current Honors College Member at Arkansas State University