pantherbot tool changer pdr

8/6/2019 PantherBot Tool Changer PDR

1/31

Page 1 of31

PantherBot Tool ChangerMAE 4193 Mechanical Design 1

Senior Design Preliminary Design Review Report

Prepared by: 2009 PantherBot Team

Jameson L. Tai, William Rae, Justin Nunn

Florida Institute of Technology

150 West University Boulevard,

Melbourne, Florida 32901

Submitted: 22 October 2008

Website:http://my.fit.edu/~ltai/pantherbot/
http://my.fit.edu/~ltai/pantherbot/http://my.fit.edu/~ltai/pantherbot/http://my.fit.edu/~ltai/pantherbot/http://my.fit.edu/~ltai/pantherbot/


2/31

Page 2 of31

Table of Contents

List of Tables ................................................................................................................................... 3

List of Figures .................................................................................................................................. 3

Introduction .................................................................................................................................... 4

Purpose ....................................................................................................................................... 4

Goals ........................................................................................................................................... 4

Background ................................................................................................................................. 5

Design Objectives ............................................................................................................................ 6

Design and Analysis ......................................................................................................................... 7

Button Pusher (Tool 1) ................................................................................................................ 7

Analysis Results ....................................................................................................................... 8

Door Handle Twister (Tool 2) .................................................................................................... 10

Analysis Results ..................................................................................................................... 10

Doorway Clearance Tool (Tool 3) .............................................................................................. 13

Analysis Results ..................................................................................................................... 13

Tool Storage Rack ...................................................................................................................... 16

Planning..................................................................................................................................... 16

Detailed Drawings ......................................................................................................................... 18

Fabrication and Testing Plan ......................................................................................................... 22

Budget ........................................................................................................................................... 23

Team Organization ........................................................................................................................ 28

Scheduling ..................................................................................................................................... 29

Gantt Chart................................................................................................................................ 29

Milestones and Deadlines ......................................................................................................... 30

Conclusion ..................................................................................................................................... 31

References ....................................................................................... Error! Bookmark not defined.


3/31

Page 3 of31

List of TablesTable 1-Analysis Results for Tool 1 ................................................................................................. 8

Table 2-Analysis Results for Tool 2 ............................................................................................... 11

Table 3-Analysis Results for Tool 3 ............................................................................................... 14

Table 4-Material Selection Chart for Gripper Sleeves .................................................................. 23

Table 5-Material Selection Chart for Solid Metal Block ................................................................ 24Table 6-Material Selection Chart for Links in Tool 2 ..................................................................... 25

Table 7-Total Estimated Budget.................................................................................................... 27

List of FiguresFigure 1-Comprehensive list of features on the PantherBot, Courtesy MobileRobots, Inc. .......... 4

Figure 2-Basic dimensions of the PantherBot, Courtesy MobileRobots, Inc. ................................. 5

Figure 3-Elevator buttons, door handles, and door-opener panel................................................. 6

Figure 4-Schunk Robotic Arm with parallel gripper and webcam attachment .............................. 7

Figure 5-Tool 1 ................................................................................................................................ 7Figure 6-Tool 1 Stress-Stress Analysis ............................................................................................. 8

Figure 7-Tool 1 Displacement-Displacement Analysis .................................................................... 9

Figure 8-Tool 1 Strain-Strain Analysis ............................................................................................. 9

Figure 9-Tool 2 .............................................................................................................................. 10

Figure 10-Tool 2 Stress-Stress Analysis ......................................................................................... 11

Figure 11-Tool 2 Displacement-Displacement Analysis ................................................................ 12

Figure 12-Tool 2 Strain-Strain Analysis ......................................................................................... 12

Figure 13-Tool 3 ............................................................................................................................ 13

Figure 14-Tool 3 Stress-Stress Analysis ......................................................................................... 14

Figure 15-Tool 3 Displacement-Displacement Analysis ................................................................ 15

Figure 16-Tool 3 Strain-Strain Analysis ......................................................................................... 15Figure 17-Tool Rack ....................................................................................................................... 16

Figure 18-Tool 1 Detailed Drawing ............................................................................................... 18

Figure 19-Tool 2 Detailed Drawing ............................................................................................... 19

Figure 20-Tool 3 Detailed Drawings .............................................................................................. 20

Figure 21-Tool Storage Rack Detailed Drawing ............................................................................ 21

Figure 22-Organization Breakdown Flowchart ............................................................................. 28

Figure 23-Gantt Chart showing project progress ......................................................................... 29
http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401476http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401476http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401477http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401477http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401478http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401478http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401479http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401479http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401480http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401480http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401484http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401484http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401488http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401488http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401492http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401492http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401493http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401493http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401494http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401494http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401495http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401495http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401496http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401496http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401496http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401495http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401494http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401493http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401492http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401488http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401484http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401480http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401479http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401478http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401477http://u/public_html/pantherbot/internal/Sr%20Design/PDR/PantherBot%20Tool%20Changer%20PDR.docx%23_Toc212401476


4/31

Page 4 of31

Introduction

Purpose

The purpose of our project is to retrofit the PantherBot in order to give it the capability to open

doors and press wall panel buttons, so that it can roam autonomously inside the F. W. Olin

Engineering Complex. The PantherBot will be tested for these capabilities in May 2009.

Goals

The 2009 PantherBot Team currently has the following goals for

this project:

To apply our knowledge gained in class and properlyapply them to this project

To apply technical skills, communication skills, and theengineering design process into the project

To operate safely while protecting the PantherBot, its operator(s), and any persons orobjects the PantherBot may come in contact with

To research on appropriate tools for the defined objectives and to adapt to current 6-DOF robotic arm

Figure 1-Comprehensive list of

eatures on the PantherBot, Courtesy

MobileRobots, Inc.


5/31

Page 5 of31

Background

The robot we will be operating on is the newest

robot at Florida Techs Robotics and Spatial

Systems Laboratory (RASSL). PantherBot, its

name, is essentially a PowerBot, manufactured

by MobileRobots, Inc. The current equipment

has the ability to autonomously map terrain, plot coordinates, as well as performing

miscellaneous functions at a certain location after a full map is acquired. The robotic arm

attached to the PantherBot platform is made by Schunk Intec, Inc. has a 6-DOF (degrees of

freedom) work area equipped with a set of parallel jaw grippers as well as a webcam to ensure

proper job handling. Also, there is a WiFi antenna in which jobs may be sent to the robot

wirelessly.

The PantherBot has a PIC microcontroller which controls the two main wheels which gives the

PantherBot mobility as well as the emergency stops. There is a higher-level computer which

processes functions such as the optical sensors which keep track of distance, SONAR sensors,

the PTZ camera, as well as the laser range finder. There is also a higher-level PC, operated on

Debian Linux operating system, which interfaces with the operators GUI as well as serving

MobilEyes, ACTS and guiserver functions via 802.11b WiFi. This allows the user to send

commands, view live webcam video feed, and other GUI-related functions wirelessly.

Figure 2-Basic dimensions of the PantherBot, Courtesy

MobileRobots, Inc.


6/31


7/31

Page 7 of31

Design and Analysis

To open doors and push buttons, there will be three tools

used to properly perform the functions. The first is a

button pusher, which the parallel gripper will squeeze the

button pusher to press elevator buttons and door panels.

The second is a door handle opener, which will open the

door and let the PantherBot into the doorway. The third is

a door clearance tool, which provides enough clearance between the doorway and the door for

the PantherBot to successfully move through the opening.

Button Pusher (Tool 1)

The button-pusher, henceforth named as Tool 1, will be used to

push elevator buttons as well as push a handicap-accessible

door-opener panel. Tool 1 will conform to the design

objectives, in which neither the PantherBot base nor the Schunk

robotic arm will be pressing the button. The only motion will be generated by the parallel

gripper, which will ensure that a limited amount of force will be exerted, protecting the

PantherBot, the robotic arm, as well as the buttons.

Tool 1 is operated via a spring-controlled sleeve over the parallel gripper. As the parallel

gripper closes, the button-pressing contact, a soft foam cylinder will press the button. The

webcam mounted adjacent to the parallel gripper will ensure accuracy of the contact point.

Figure 4-Schunk Robotic Arm with parallel

gripper and webcam attachment

Figure 5-Tool 1


8/31

Page 8 of31

Analysis Results

The following are the results of a finite element method study of the button pushing tool. The

study restrained the tool in the same way that it will be held by the gripper and exposed the

tool to a five pound force on the button contact surface. This force exceeds the maximum force

that would be put on the button by 150% which gives us an acceptable factor of safety and still

meets our requirement of having the tool break before exerting enough force to damage the

robot or the button it is interacting with.

Name Type Min Location Max Location

Stress1 VON: von MisesStress

1.81338e-007N/m^2

Node: 17020

(-0.0566606 in,0.326697 in,

-1.26209 in)

1.97135e+006N/m^2

Node: 7912

(0.989925 in,-1.1163 in,

1.56981 in)

Displacement1 URES: Resultant

Displacement

0 m

Node: 13444

(0.0683394 in,

-0.349484 in,

-1.26209 in)

3.5681e-006 m

Node: 96

(0.632369 in,

-0.777007 in,

4.07072 in)

Strain1 ESTRN:

Equivalent Strain

8.44084e-012

Element: 863

(0.953545 in,

-1.03112 in,

3.96925 in)

2.18046e-005

Element: 4903

(0.937067 in,

-1.19041 in,

1.66872 in)Table 1-Analysis Results for Tool 1

Figure 6-Tool 1 Stress-Stress Analysis


9/31

Page 9 of31

Figure 7-Tool 1 Displacement-Displacement Analysis

Figure 8-Tool 1 Strain-Strain Analysis


10/31

Page 10 of31

Door Handle Twister (Tool 2)

The door handle twister, henceforth named as Tool 2, will be

used to twist the door handle to open the door and provide

initial the opening for the PantherBot. Because the parallel

grippers output force is not enough to open the door by itself,

Tool 2 will contain a sleeve for one of the grippers jaws, and use a perpendicular motion given

by the Schunk robotic arms last cube.

The J-shaped hook will help secure the arms grip of the handle as well as help pull or push

the door open. There are a couple of variations to this design, including an L-shape option

instead of the J-shape, as well as making the hook rounded. We will proceed analysis with the

current J-shape, and will revise our selection as our analysis continues.

Analysis Results

The following are the results of a finite element method study of the hook door opening tool.

The study restrained the tool in the same way that it will be held by the gripper and exposed

the tool to a five pound force on the outermost contact surface of the tool. This force exceeds

the force required to rotate a standard door handle by 150% which gives us an acceptable

factor of safety and still meets our requirement of having the tool break before exerting

enough force to damage the robot or the door handle it is interacting with. Depending on the

results of our physical testing we may determine that it is necessary to increase the strength of

this component to work with other doors.

Figure 9-Tool 2


11/31

Page 11 of31


Stress1 VON: von Mises

Stress

9.43383e-006

N/m^2

Node: 11781

(-0.421822 in,

2.3125 in,

0.688976 in)

7.24765e+006

N/m^2

Node: 14029

(6.04217 in,

1.34375 in,

-0.25 in)

Displacement1 URES: ResultantDisplacement

0 mNode: 171

(0.617126 in,2.3125 in,

-0.813976 in)

0.000249353 mNode: 1520

(6.61713 in,0.90625 in,

-3.5 in)

Strain1 ESTRN:

Equivalent Strain

6.61644e-011

Element: 4673

(-0.275081 in,

2.28463 in,

0.736424 in)

8.00352e-005

Element: 4153

(6.04024 in,

1.23454 in,

-0.217835 in)

Table 2-Analysis Results for Tool 2



12/31

Page 12 of31




13/31

Page 13 of31

Figure 13-Tool 3

Doorway Clearance Tool (Tool 3)

The third tool is the doorway clearance tool, henceforth named

Tool 3, which will provide the PantherBot enough clearance in

the doorway such that it will not trip the PantherBots SONAR

sensors as an impassable obstruction. The tool uses only one of

the two jaws of the parallel gripper, similar to Tool 2s concept.

Tool 2 has a freely rotating axis with two wheels, which, once the

robotic arm opens the door the rest of the way, the tool will help guide the door and help keep

the door from prematurely closing on the robot.

Analysis Results

The following are the results of a finite element method study of the wheel tool. The study

restrained the tool in the same way that the gripper will hold it and exposed the tool to a ten-

pound force on the wheels. This force exceeds the maximum force that would be put on the

tool by 150% which gives us an acceptable factor of safety and still meets our requirement of

having the tool break before exerting enough force to damage the robot or the button it is

interacting with. As with the hook tool we may find it necessary to improve this structure to

allow it to work with doors that have more spring force than the average door.


14/31

Page 14 of31


Stress1 VON: von Mises

Stress

6.77429e-005

N/m^2

Node: 14768

(-2.77861 in,

1.79842 in,

2.99409 in)

4.41638e+007

N/m^2

Node: 1106

(-2.47159 in,

1.69049 in,

-0.431397 in)

Displacement1 URES: Resultant

Displacement

0 m

Node: 8447

(-3.78084 in,

1.89842 in,2.99409 in)

0.000626395 m

Node: 8141

(-1.84843 in,

-1.08279 in,-1.44372 in)

Strain1 ESTRN:

Equivalent Strain

7.08916e-011

Element: 6509

(-3.11646 in,

1.84842 in,

2.9528 in)

0.00384754

Element: 3844

(-2.31324 in,

-1.09599 in,

-0.395416 in)Table 3-Analysis Results for Tool 3



15/31

Page 15 of31




16/31

Page 16 of31

Tool Storage Rack

The tools need to be stored on the robot so that the arm can

easily access them and they do not impede any of the robots

onboard sensors. The storage system that we will be using for

the tools is a static bracket which takes advantage of the spring

system in the tools to hold them in place until the gripper squeezes and releases the pressure.

In addition we will have a hanging rack that allows us to hold Tool 2 so that it is both accessible

and maintains the necessary clearance from sensors despite its large footprint.

Planning

To efficiently design tools that will meet our objectives we are using a combination of computer

aided design and physical prototyping. Using CAD allows us to visualize different mechanism

options and ensure that they are able to meet our requirements for each task. Using a CAD

model also allows us directly translate our designs into finite element analysis software for

structural analysis and optimization. Physical prototyping is also important because it allows us

to test mechanisms for fit and function before finalizing design and investing time and

materials.

The analysis is a combination of computer finite element analysis and hand calculations. For the

tools with motion, the analysis starts with calculating optimal mechanics to produce the desired

range of motion and to ensure that appropriate forces are being generated for the task.

Computer models of the tools are then studied using FEA to determine if the components are

Figure 17-Tool Rack


17/31

Page 17 of31

capable of safely handling the forces placed on them. These studies also allow us to determine

if the components are overbuilt and have areas that can be lightened or redesigned to improve

the design. From this data, we are able to study the forces that will be put on the arm as it goes

through a full range of motion. If the design falls outside of any of the requirements, we are

able to determine that at an early stage and go through a series of optimizations before we put

time and money into production.


18/31

Page 18 of31

Detailed Drawings

Figure 18-Tool 1 Detailed Drawing


19/31

Page 19 of31

Figure 19-Tool 2 Detailed Drawing


20/31

Page 20 of31

Figure 20-Tool 3 Detailed Drawings


21/31

Page 21 of31

Figure 21-Tool Storage Rack Detailed Drawing


22/31

Page 22 of31

Fabrication and Testing Plan

Fabrication will be performed at the Florida Institute of Technology Machine Shop, located in

Building 538. Certain fabrication of parts will be unnecessary, as they are readily available off-

the-shelf at a price that would be lower than fabricating in-house. If this situation occurs, this

team will purchase these parts instead. All team members have already passed machine shop

training, as required by the Director of Laboratories at Florida Institute of Technology College of

Engineering. In addition, all team members have gone through hands-on training interacting

with the PantherBot, learning and understanding the safe usage, programming abilities, and

remote access via the MobilEyes software.

Since one of the design objectives of this project is to not block the normal operations of the

robot nor create safety hazards from the use of the tool changer, the PantherBot, its Schunk

robotic arm, its tools, and its tool changer must not damage any doors or wall panel buttons.

Therefore, a testing rig will be necessary consisting of a replica of a handicapped-accessible

door opener button, two sets of elevator buttons (one set to call an elevator, one set to direct

the elevator to go to which floor), and a door handle similar to those used inside the Olin

Engineering Complex.

This testing rig will provide feedback to the team on the repeatability of the tools, ease of

operation, and storage functions of the tool changer. This will also help optimize and fix any

design flaws before any live testing interacting with doors and elevators inside the Olin

Engineering Complex.


23/31

Page 23 of31

Budget

Rectangular Tube stock Overall Rating

Design Requirements Selection Factors

(1*A+5*B+4*C

+3*D+2*E)/15

Yield strength

(kpsi) (Budynas

& Nisbett,2008)

SurfaceFinish Cost/unit length (in)

Machinability(%) Availability

Abs Rel Abs Rel Abs Rel Abs Rel Abs Rel

Al 5052-H32 34 0.85 80 0.8 40 0.8 0 0 0.483333333

Al 3003 24 0.6 60 0.6 45 0.9 0 0 0.42

Al 6061 35 0.875 100 1 0.275 0.9527273 50 1 10 1 0.979060606

Stainless Steel

(304) 40 1 85

0.8

5 0.571 0.4588441 27 0.54 10 1 0.713691769

Steel (1018) 32 0.8 80 0.8 0.262 1 35 0.7 9 0.9 0.846666667

Carbon Fiber 50 0.5 15 0.3 0 0 0.226666667

Table 4-Material Selection Chart for Gripper Sleeves

The weight factors for the materials are 1 for yield strength, 5 for finish, 4 for price, 3 for

machinability, and 2 for availability. The forces that the tools will be experiencing are very

small, and all the selections for the materials far exceed what is needed. Since part of the

requirements for the tools used is that they have to be aesthetically pleasing, a high value is

used for the finish of the parts. Price is always a weighty consideration. Since currently the

total budget isnt known, we must assume very few funds and plan for keeping cost to a

minimum. The parts we will need to create will only need basic machining. Since many

prototypes will be needed though, the ability to easily produce these is important.

Rectangular Tubing Pricing

Al 6061 Steel Stainless Steel

VendorBase

Price Price/lengthBase

Price Price/lengthBase

Price Price/length

McMaster-

Carr(36") 18.65 0.518055556 41.81 1.161388889 31.28 0.86888889

Metals Depot(48") 13.2 0.275 12.56 0.261666667 63.36 1.32OnlineMetals(36") 11.05 0.306944444 N/A N/A 20.58 0.57166667

Table 5-Cost Analysis Table for Rectangular Tubing


24/31

Page 24 of31

Al 6061 is the optimum choice for this part. It is easily obtained in the desired size we want, and

it will visually match the robot very nicely. Tube sizes used were what were closest to our

projects needs. Both McMaster-Carr and Online metals offered 36 long tubes, while Metals

Depot offered 48 tubes. For AL 6061, the dimensions were 1"x 1.5 and .125 thick. For Steel

the dimensions were 1x1.5x36 from McMaster-Carr, and 1.25x1.25 from Metals Depot, Online

metals not have a usable size. Stainless Steel tube sizes were 1.25x1.25 from all three

manufacturers. For the material selection chart, the best price was used in the cost comparison

between the other materials.

Solid metal block Overall Rating

Design Requirements Selection Factors

(1*A+5*B+4*C+3*D+2*E)

/18

Yield

strength

(kpsi)(Budynas &

Nisbett, 2008)

Surface

Finish

Cost/unit volume

(in^3)

Machinability

(%) Availability

Abs Rel Abs Rel Abs Rel Abs Rel Abs Rel

Al 5052-H32 34 0.85 80 0.8 40 0.8 0 0 0.447222222

Al 3003 24 0.6 60 0.6 45 0.9 0 0 0.4

Al 6061 35 0.875 100 1 0.802 1 50 1 10 1 0.9375

Stainless Steel (304) 40 1 85 0.85 7.17 0.111855 27 0.54 9 0.9 0.586523322

Steel (1018) 32 0.8 80 0.8 1.37 0.5854015 35 0.7 10 1 0.718978102

Carbon Fiber 50 0.5 15 0.3 0 0 0.205555556

Table 6-Material Selection Chart for Solid Metal Block

The weight factors for the blocks of metal are 1 for yield strength, 5 for surface finish, 4 for

price, 5 for machinability and 3 for availability. The forces that this tool will undergo are very

small in comparison to the yield strength of the part. Since all tools used for this project must

be aesthetically, surface finish is quite important. Since large blocks of metal are hard to

acquire, price for this was very heavily weighted. Machining solid blocks of metal down into the

final shape can take quite some time. Having a material that is fast and easy to machine is very


25/31

Page 25 of31

important for us in this regard, thus it was given a very high weight factor. As previously

mentioned blocks of metal are not as readily available, so availability is very important.

Metal Block Pricing

Al 6061(8x8x2)in Steel(8x8x2)in Stainless Steel(9x6x3)in

VendorBase

Price Price/VolumeBase

Price Price/VolumeBase

Price Price/Volume

McMaster-

Carr(36") 102.69 0.802265625 174.97 1.366953125 581.81 3.591419753Table 7-Cost Analysis Table for Metal Block

Al 6061 clearly exceeded all other material selection for this product. It was significantly

cheaper than all other material selections, and its ability to be easily machined makes it an ideal

choice. Only provider that was found that carried Metal blocks of sufficient size was McMaster-

Carr. The desired size for the metal block was 8x5x2. For each material the closest match

was found. The cost per volume was used for comparing the prices of the different materials.

Material Selection Chart for Links

Overall

Rating

Design Requirements Selection Factors(5*A+4*B+3*

C+2*D+1*E)/

15Yield strength Surface Finish

Cost/unit

length (ft)

Machinability

(%) Availability

Item#

Size

(LxWxT) Abs* Rel Abs Rel Abs Rel Abs Rel Abs Rel

Al 5052-H32

9135K

116

72x1x0.1

25 28 0.233 80 0.888 5.801 0.065 20 0.25 7 0.7 0.407914499

Al 3003

9134K

116

72x1x0.1

25 16-21 0.154 60 0.666 5.635 0.067 20 0.25 6 0.6 0.315987134

Al 6063

(rounded)

4490T

14

72x0.25x

0.125 25 0.208 85 0.944 0.38 1 80 1 10 1 0.721296296

Stainless

Steel (304)

8992K

11

72x0.5x0.

125 30-45 0.312 85 0.944 1.911 0.198 40 0.5 9 0.9 0.52244107

Steel (W1)

8895K

219

72x0.25x

0.125

55-

100 0.645 90 1 1.736 0.218 80 1 10 1 0.725706441

Carbon Fiber

2153T

28

12x0.5x0.

125 120 1 50 0.555 13.34 0.028 10 0.125 4 0.4 0.530511966

* Using mid-range for relative

calculation

Table 8-Material Selection Chart for Links in Tool 2

The weight factors for the materials are 5 for yield strength, 4 for finish, 3 for price, 2 for

machinability, and 1 for availability. The purpose of these links will be to hold the mechanism

together as the robotic arm squeezes the parallel grippers. Therefore, yield strength will be of


26/31

Page 26 of31

upmost importance. Since the links will need to be smooth, a relatively higher value is used for

the finish of the parts. Cost is then factored, followed by the ease of machining the metal bars

into the right size, followed by availability.

Since Al 6063 and Steel W1 are only 0.004 apart in the overall ratings, the determining factor in

material selection will come from modeling analysis of Tool 2. If Al 6063 will not place the tool

in harm by buckling, then Al 6063 will be a very cost-effective alternative. However, if Al 6063

has a danger of buckling within our operating range, then Steel W1 will be used, as it has a yield

strength of almost four times that of Al 6063.

While performing material selection, the team also attempted to find aluminum and steel stock

for specified size requirements besides McMaster Carr, but could not find similar sizing for

comparison. This is most likely because our application of using 1/8 by 1/4 links is not a very

popular size, which makes acquiring quotes for price comparison difficult. List of websites

attempted includedhttp://www.onlinemetalsupply.com/,http://www.saf.com,

http://www.hardwareworld.com,http://newyorkmetal.com, and others online including eBay

and other outlets.

Overall Budget

For this project we have an estimated budget of $950. That majority of this money will be

needed for the metal that will be used to build the PantherBot tools. We expect to need

bushings for the construction of the different tools, as well as bearings for at least one of our

designs (specifically, Tool 3). Once the tools have been constructed, they will need to be coated
http://www.onlinemetalsupply.com/http://www.onlinemetalsupply.com/http://www.onlinemetalsupply.com/http://www.saf.com/http://www.saf.com/http://www.saf.com/http://www.hardwareworld.com/http://www.hardwareworld.com/http://newyorkmetal.com/http://newyorkmetal.com/http://newyorkmetal.com/http://newyorkmetal.com/http://www.hardwareworld.com/http://www.saf.com/http://www.onlinemetalsupply.com/


27/31

Page 27 of31

to prevent damage to both the PantherBot and the school facilities. We plan on using materials

such as plywood for our prototyping as it is cheap and easy to build with. We will require an

assortment of screws, bolts, washers, and springs to hold our prototypes and final designs

together, as well as material to weld some pieces together. Currently these are all that we

foresee us needing, but as our designs develop and change, we may be required to garner

materials not previously foreseen.

Category Allocated Budget

Metals $400.00

Bushings/Bearings/Shafting $100.00Miscellaneous Hardware $ 50.00

Surface finishing $ 50.00

Prototyping $100.00

Test Stand Hardware $150.00

Total Budget $850.00Table 9-Total Estimated Budget


28/31

Page 28 of31

Team Organization

Since this project only has three members, all three members will be involved in all aspects of

the design, analysis, production, and testing phases of this project. However, the following is a

main breakdown of the six key areas of the project in which we have tasked one person to

personally oversee.

Figure 22-Organization Breakdown Flowchart

As stated in the above figure, the overall financial coordination will be overseen by Justin Nunn,

who will also be in charge of overseeing the research process needed for the PantherBot to

open doors and press buttons. The ideas resulting from the research process will then be

overseen by William Rae during the design and analysis phases. Jameson L. Tai will be

overseeing the fabrication and testing of the designs and will make adjustments as necessary.

Jameson L. Tai(Team Leader)

ResearchJustin Nunn

DesignWilliam Rae

AnalysisWilliam Rae

FabricationJameson L. Tai

TestingJameson L. Tai

FinancesJustin Nunn


29/31

Page 29 of31

Scheduling

Gantt Chart

Figure 23-Gantt Chart showing project progress

As shown on the Gantt Chart, we are currently on schedule and are on track to completing the

project on-time. At this time, the project is finishing up the analysis portions and cost analysis

for material and parts ordering. We expect to begin the prototype fabrication after that,

finishing in the beginning of the spring semester along with prototype testing. Full fabrication is

expected to begin in February 2009, along with testing in March 2009. The project should be

on-time for the Senior Engineering Design Showcase in April 2009.

18/08/2008 07/10/2008 26/11/2008 15/01/2009 06/03/2009 25/04/2009

Research

Project Review Presentation

Design Research

Preliminary Design Review Presentation

Preliminary Design Review Report

Machine Shop Training

Robot Training

Design Research

Final Presentation

Final Report

Prototype Fabrication

Prototype Testing

Final Design Fabrication

Final Design Testing

Start Date

Completed

Remaining


30/31

Page 30 of31

Milestones and Deadlines

Complete research in door opening techniqueso Pushing door (September 2008)o Pulling door (September 2008)

Present tool design (October 2008) Present tool changer rack design (October 2008) Machine Shop Training (October 2008)

Robot training (October 2008)

Preliminary Design Reviewo Presentation (22 October 2008)o Report (22 October 2008)

Analysis on tools and tool changer (November 2008) Final Presentation (03 December 2008) Final Report (03 December 2008) Prototyping Fabrication (January 2009) Prototyping Testing (January 2009) Fabrication (March 2009) Testing (March 2009) Showcase (April 2009)


31/31

Conclusion

The team will continue to analysis process of this project and will continue refinement of the

designs so that it will be effective, efficient and cost-effective while maintaining our design

objectives. The project is currently on-track with our Gantt Chart and will proceed with

ordering respective materials for machining after completion of analyses. The project is to

begin its fabrication process in Spring 2009 and is scheduled to be in testing for the latter part

of Spring 2009, as well as completion of the project by May 2009.

References

Budynas, R. G., & Nisbett, K. J. (2008). Shingley's mechanical Engineering Design. NewYork: McGraw Hill Higher Education.

Callister, W. D. (2007). Materials Science and Engineering: An Introduction. New York:John Wiley & Sons, Inc.

Office of Creative Services, F. I. Florida Institute of Technology Seal and Logo. FloridaInstitute of Technology, Melbourne.

Office of Creative Services, F. I. PantherBot Logo. Florida Institute of Technology,Melbourne.

pantherbot tool changer pdr

Documents