Paddle Maker Design and Material Optimization
EML 4905 Senior Design Project
A SENIOR DESIGN PROJECT
PREPARED IN PARTIAL FULFILLMENT OF THE
REQUIREMENT FOR THE DEGREE OF
BACHELOR OF SCIENCE
IN
MECHANICAL ENGINEERING
Paddle Maker Design and Material Selection
Final Report
Nestor Vega
Jorge Ramon
Orena Danoa
Advisor: Dr. Sabri Tosunoglu
This report is written in partial fulfillment of the requirements in EML 4905. The
contents represent the opinion of the authors and not the department of Mechanical
and Materials Engineering.
Paddle Maker Machine and Material Selection
Ethics Statement and Signatures
The work submitted in this project is solely prepared by the team consisting of Nestor
Vega, Jorge Ramon, and Orena Danoa, and it is original. Excerpts from others‟ work have been
clearly identified, their work acknowledged within the text and listed in the list of references. All
of the engineering drawings, computer programs, formulations, design work, prototype
development and testing reported in this document are also original and prepared by the same
team of students.
Nestor Vega
Jorge Ramon
Orena Danoa
Team Leader
Team Member
Team Member
Dr. Sabri Tosunoglu
Faculty Advisor
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Paddle Maker Machine and Material Selection
Acknowledgments
The members of our team would like to thanks the following advisors and persons for
their support and guidance during the last five month:
1. Advisor Dr. Tosunoglu, Ph.D. Undergraduate Program Director for the Department of
Mechanical and Materials Engineering at Florida International University.
2. Dr. Bao and Dr. Tsukanov for their advice on Solidworks
3. Dr. Levy for his guidance in the Vibrations Analysis
4. Professor Richard Zicarelli. Coordinator for Engineering Manufacturing in Florida
International University.
5. Dr. Agarwal and his Staff. Department of Mechanical and Material engineering in Florida
International University.
6. Professor Neal Ricks and his staff. Nanofabrication Lab Manager for guidance on
material testing.
7. Mr. Clemente Dieguez, owner of Grainman Corporation
8. Mr. Alan Arch, owner of Southern Gear Inc for tour.
9. All fellow engineers that at one point or another help us and/or commented on the work
being done.
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Paddle Maker Machine and Material Selection
Table of Contents
Ethics Statement and Signatures ................................................................................................. 2
Acknowledgments ......................................................................................................................... 3
List of Figures................................................................................................................................ 8
List of Tables ............................................................................................................................... 10
Nomenclature .............................................................................................................................. 11
Abstract........................................................................................................................................ 12
1. Introduction ............................................................................................................................. 13
1.1 Problem Statement ......................................................................................................... 13
1.2 Motivation ...................................................................................................................... 14
1.3 Literature Survey ........................................................................................................... 15
1.3.1 Material ............................................................................................................... 16
1.3.2 Plastic Cutting Machines ..................................................................................... 19
2. Project Formulation................................................................................................................ 22
2.1 Project Objective ............................................................................................................ 22
2.2 Design Specifications..................................................................................................... 23
2.2.1 Motor Selection ................................................................................................... 23
2.2.2 Drilling Control ................................................................................................... 24
2.2.3 Movement Control .............................................................................................. 24
2.3 Constraints and Limitations ........................................................................................... 25
2.3.1 Paddle Material.................................................................................................... 25
3. Design Alternatives ................................................................................................................ 26
3.1 Overview of Conceptual Designs Developed ................................................................ 26
3.2 Cutting............................................................................................................................ 26
3.2.1 Design Alternative 1- Water Jet Robotic Platform ............................................. 26
3.2.2 Design Alternative 2 -Laser Cutter ..................................................................... 27
3.2.3 Design Alternative 3 –Circular Saw Workstation ............................................... 27
3.3 Drilling ........................................................................................................................... 29
3.3.1 Design Alternative 1 – Mechanical Drilling Assembly ...................................... 29
3.3.2 Design Alternative 2 – Drilling WorkStation ...................................................... 30
3.4 Material Movement........................................................................................................ 31
3.4.1 Design Alternative 1 – Roller Table.................................................................... 31
3.4.2 Design Alternative 2 – Automatic Material Handling Table .............................. 32
3.5 Feasibility Assessment .................................................................................................. 33
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Paddle Maker Machine and Material Selection
3.6 Design Process Diagram ............................................................................................... 36
3.6.1 Material Selection Logic Diagram ...................................................................... 36
3.6.2 Proposed Machine Design Logic Diagram ......................................................... 37
3.7 Proposed Machine Design ............................................................................................. 38
4. Project Management............................................................................................................... 39
4.1 Timeline ......................................................................................................................... 39
4.2 Team Breakdown of Responsibilities, Tasks and Roles ................................................ 39
4.3 Patent/Copyright Application ........................................................................................ 40
4.4 Commercialization of the Final Product ........................................................................ 42
4.5 Discussion ...................................................................................................................... 42
5. Engineering Design and Analysis .......................................................................................... 43
5.1 Structural Design ........................................................................................................... 43
5.2 Dimensions .................................................................................................................... 44
5.3 Material Selection .......................................................................................................... 44
5.3.1 Paddle Material.................................................................................................... 44
5.3.2 Machine Major Components ............................................................................... 45
5.4 Force Analysis ............................................................................................................... 46
5.5 Dynamic/Vibration Analysis ......................................................................................... 48
5.6 Deflection Analysis........................................................................................................ 50
5.7 Material Analysis for Machine Assemblies ................................................................... 51
5.7.1 Stress Analysis .................................................................................................... 52
5.7.2 Strain analysis...................................................................................................... 53
5.7.3 Displacement ....................................................................................................... 53
5.7.4 Factor of Safety analysis ..................................................................................... 54
5.8 Cost Analysis for One Paddle ........................................................................................ 54
6. Prototype Construction .......................................................................................................... 56
6.1 Description of Prototype ................................................................................................ 56
6.2 Parts List ........................................................................................................................ 56
6.2.1 Motors and Stepping Motors ............................................................................... 56
6.2.2 Gears and Timer Belt .......................................................................................... 57
6.2.3 Bearings ............................................................................................................... 57
6.2.4 Linear Stage ......................................................................................................... 57
6.2.5 Rods and Supports ............................................................................................... 58
6.2.6 System‟s Driver ................................................................................................... 58
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Paddle Maker Machine and Material Selection
6.2.7 System‟s Software ............................................................................................... 60
6.2.8 Saw Assembly ..................................................................................................... 61
6.2.9 Drill Motor .......................................................................................................... 62
6.2.10 Roller Table ....................................................................................................... 64
6.3 Construction ................................................................................................................... 64
6.4 Prototype Cost Analysis ................................................................................................. 67
7. Testing and Evaluation ........................................................................................................... 70
7.1 Design of Experiments ................................................................................................... 70
7.1.1 Mack 3 CNC controller Input Verification ......................................................... 70
7.1.2 G-Codes ............................................................................................................... 73
7.1.3 Plan and Recommendation for Material Testing ................................................. 77
7.1.4 Theory Testing .................................................................................................... 78
7.2 Test Results .................................................................................................................... 80
7.2.1 Paddle Material Comparison ............................................................................... 80
7.2.2 Paddle Maker Calibration .................................................................................... 84
7.3 Evaluation of Experimental Results............................................................................... 84
7.3.1 Material ............................................................................................................... 84
7.4 Improvement of the Design ........................................................................................... 88
7.4.1 Material Wear Resistance .................................................................................... 88
7.4.2 Overall Machine Components and Design.......................................................... 94
8. Design Considerations ........................................................................................................... 95
8.1 Assembly and Disassembly ........................................................................................... 95
8.2 Safety and Maintenance Procedure ................................................................................ 95
8.3 Environmental Impact .................................................................................................... 96
8.4 Risk Assessment ............................................................................................................ 97
9. Conclusions ........................................................................................................................... 100
10. Future Work ........................................................................................................................ 102
11. References ........................................................................................................................... 103
12. Appendices .......................................................................................................................... 106
Appendix A-Paddle Material Data Sheet ........................................................................... 106
Appendix B-Data Sheets From Different Vendors ............................................................ 109
Appendix C-New vs. Damaged Paddle ............................................................................. 111
Appendix D-RBT Drag-A-Flight Conveyor ...................................................................... 112
Appendix E-Water Jet Machining Illustration ................................................................... 113
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Paddle Maker Machine and Material Selection
Appendix F-Drill Bit and Saw Blade Description ............................................................. 114
Appendix G-Safety Manual ............................................................................................... 117
Appendix H-Paddle Maker‟s User Manual........................................................................ 127
Appendix I-Linear Stage Specifications ............................................................................ 131
Appendix J-Torques Calculation ....................................................................................... 132
Appendix K-Deflection Analysis of Linear Shaft ............................................................. 134
Appendix L-Drill Motor Options ....................................................................................... 135
Appendix M- Material Lab Notes ...................................................................................... 139
Appendix N-Material Testing Data Samples ..................................................................... 141
Appendix O-Bearings, Gears and Belt Specification ........................................................ 142
Appendix P-Lead Screws and Linear Shaft ....................................................................... 147
Appendix Q-Vibration Analysis ........................................................................................ 150
Appendix R-Rockcliff Pin Assignment ............................................................................. 153
Appendix S-Machine Shop and Field Snapshots ............................................................... 154
Appendix T-Snapshots Visit to Grainman Corporation..................................................... 158
Appendix U-Electronics Set Up......................................................................................... 160
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Paddle Maker Machine and Material Selection
List of Figures
Figure 1-Si3N4 Ball and UHMW-PE Disk Contact Schematic [1] ............................................... 17
Figure 2-Kaltenbach‟s Drill, Cutting, Roller Table [30] .............................................................. 21
Figure 3-Hinged Roller Conveyor [30]......................................................................................... 21
Figure 4-Drilling Assembly [30] .................................................................................................. 22
Figure 5-Circular Saw Workstation Design Alternative ............................................................... 28
Figure 6-Round Corner Router ..................................................................................................... 28
Figure 7-Mechanical Drilling Assembly Design .......................................................................... 30
Figure 8-Drilling Workstation Design .......................................................................................... 31
Figure 9-Roller Table Design Alternative .................................................................................... 32
Figure 10-Automatic Table Design Alternative Trimetric View .................................................. 33
Figure 11-Automatic Table Design Alternative Inclined View .................................................... 33
Figure 12-Overall Design ............................................................................................................. 34
Figure 13-Section View of Proposal Design ................................................................................ 35
Figure 14-Exploded View of Proposal Design ............................................................................. 35
Figure 15-Targeted Finished Paddle ............................................................................................. 36
Figure 16-Steps for Material Optimization Process...................................................................... 36
Figure 17-Machine Design Process .............................................................................................. 37
Figure 18-Project Timeline ........................................................................................................... 39
Figure 19-Dunkerley‟ Formula Used for the System ................................................................... 49
Figure 20-Deflection Analysis of Linear Shaft ............................................................................. 51
Figure 21-High Performance 4 Axis CNC Motor V10 Drive....................................................... 59
Figure 22-Schematic Diagram for Rockcliff V10 ........................................................................ 59
Figure 23-Mach3 Screen Shot Features [39] ................................................................................ 61
Figure 24-Circular Saw Specifications and Features [38] ............................................................ 62
Figure 25-Prototype‟s Motor ........................................................................................................ 63
Figure 26-Belt Length Determination ........................................................................................... 64
Figure 27-Roller Table.................................................................................................................. 65
Figure 28-Shaft Centricity Test Gage ........................................................................................... 65
Figure 29-Machining of Shaft to Precise Tolerance ..................................................................... 66
Figure 30-Motor and Linear Stage Assembly ............................................................................... 66
Figure 31-Paddle Maker Team‟s Total Hours .............................................................................. 69
Figure 32-Conector Pins Assignment ........................................................................................... 70
Figure 33-X-axis for Drill Assembly (Horizontal Direction) ....................................................... 71
Figure 34-Y-axis for Saw Assembly (Horizontal Direction) ........................................................ 71
Figure 35-Z-axis for Drill Assembly (Vertical Direction) ............................................................ 72
Figure 36-A-axis for Wheels (Angular movement) ...................................................................... 72
Figure 37-X, Y, Z, A Axis Positive Movement ............................................................................ 73
Figure 38-Double Angle vs Single Angle ..................................................................................... 79
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Paddle Maker Machine and Material Selection
Figure 39-Tribometer Tester Setup ............................................................................................... 82
Figure 40-Ceramic Abrasive Ball on UHMW-PE Disc Test ........................................................ 82
Figure 41-Tested Samples............................................................................................................. 82
Figure 42-Wear Volume Loss Comparison .................................................................................. 83
Figure 43-Coefficient of Friction Comparison ............................................................................. 84
Figure 44-Volume Loss Formulas ................................................................................................ 85
Figure 45-Profiliometer ................................................................................................................ 90
Figure 46-Average Delta Surface Roughness ............................................................................... 90
Figure 47-Uneven Roughness ....................................................................................................... 91
Figure 48-OMM ............................................................................................................................ 92
Figure 49-Travel Time Using Precision Lead Screw ................................................................... 94
Figure 50-New vs. Damaged Paddle .......................................................................................... 111
Figure 51-Drag a Flight Conveyor from RBT ............................................................................ 112
Figure 52-Precise Cutting, Clean and Smooth Finish of Water Jet Machining .......................... 113
Figure 53-Paddle Maker Prototype ............................................................................................. 127
Figure 54-Electronic Controls..................................................................................................... 160
Figure 55-Power Supplies ........................................................................................................... 161
Figure 56-Emergency Stop and Controlling ............................................................................... 161
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Paddle Maker Machine and Material Selection
List of Tables
Table 1-Numbers of Hours Spent ................................................................................................. 40
Table 2-UHMW Cost .................................................................................................................... 45
Table 3-Paddle Production Cost ................................................................................................... 55
Table 4-Power Saws Comparison [38] ......................................................................................... 61
Table 5-Final Design Cost ............................................................................................................ 67
Table 6-Initial Design Cost ........................................................................................................... 68
Table 7-Wear Measurements for Double and Single Angle Paddles ........................................... 79
Table 8-Axis Function and Direction ......................................................................................... 128
Table 9- Tribometer Data Sample............................................................................................... 141
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Paddle Maker Machine and Material Selection
Nomenclature
Symbol
Description
Units
UHMW-PE
Ultra High Molecular Weight Polyethylene
N/A
RBT
Rail Barge and Truck
N/A
RH
Relative Humidity
%
UMT
Universal mechanical Tribology Tester
N/A
PP
Isotactic Polypropylene
N/A
PFD
Percent Fast Decay
%
COF
Coefficient of Friction
N/A
R&D
Research and development
N/A
MR
Millions of Rads (unit of radiation)
MR
USPTO
United States Patent and Trademark Office
N/A
OMM
Optical Magnification Microscope
N/A
LVDT
Linear Variable Differential Transformer
Mm
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Paddle Maker Machine and Material Selection
Abstract
Construction paddles are an important part of the functioning of the “Drag- a- Flight
Conveyor”, shown in Figure 51 of Appendix D. These conveyors are devices through which
powder cement is transported from rail cars to trucks, and the paddles are an essential part of the
conveyor system. However, these paddles are made of polyethylene and due to friction against
the frame of the machine they wear out quickly and are expensive. Due to the lack of vendors
producing the required cut-to-length product, orders usually get back stocked and companies end
up paying extra shipping fees and delaying their operations. In an ever expanding society like
ours, in which new buildings and houses are constructed every day, this is unacceptable. To
improve this situation, a machine that autonomously produces these paddles was developed. The
design will allow for the interested companies to produce them in-house with little effort, great
efficiency and at a lower price. As part of our project, testing with new, more friction resistive
materials, was conducted.
The objective of this project is to find the best material possible for the task at hand - and
have the best price to quality ratio in addition to building an autonomous machine to produce
these paddles under $2000. The prototype has been designed to employ a combination of several
mechanical and electronic systems to accomplish the final output product. The major systems
included in the prototype were a drilling system, a cutting mechanism, and a rolling table, all of
which are equipped with the appropriate electronic controls.
Some elemental components used in the prototype were bought, and the great majority
custom built by the members of the team with the support of the FIU students machine shop, to
meet the design requirements. Several friction tests were performed on samples of different
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Paddle Maker Machine and Material Selection
materials to evaluate their performance under conditions similar to those that the paddles are
exposed to.
Machine safety rules and regulations were researched extensively to assure that the
prototype complies with all standards applicable to such a mechanism. Elemental environmental
impact and material recycling plans were explored and are presented below.
After the assembly of the Paddle Maker was completed, several calibration trials were
performed, without feeding raw material, to assure that all the systems were behaving properly.
Finally, several paddles were fabricated and some final adjustments were done. The machine
functioned as expected and the quality of the output paddles was acceptable for the application.
After working on this project during last few months, the main objectives were met.
Although satisfactory performance was achieved given the time constraints, several
recommendations for future work are stated in Section 10 of this report.
1. Introduction
1.1 Problem Statement
Construction paddles used in a “Drag-a-Flight Conveyor” to load powder cement to
incoming trucks are made of polyethylene. Due to friction between the paddles and the metal
frame of machine these paddles wear at a relatively fast rate, resulting in unwanted maintenance
costs and delays. In addition, paddle orders usually get back stocked due to the lack of producers
and the inconsistency of the orders. Expectations are to solve this problem by building a machine
to fabricate these paddles. The paddles need to be 37¼” long, ½” thick and 1¾” wide, and with
six holes 7/16” in diameter each, spaced by a distance of 5½” in between. The current design of
the paddle also features an angle cut in one of the sides to decrease friction. This machine needs
to be autonomous and to be able to produce the paddles from a given sheet of raw material. Thus,
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Paddle Maker Machine and Material Selection
the machine will need to first convey the sheet of raw material to the place where by means of a
mechanical system the holes will be drilled. Then a circular saw being moved by a stepper motor
will do the cutting. Finding a material that is resistant to friction and has a better quality to price
ratio than polyethylene is also one of our main objectives.
In addition, our goal will be to modify and strengthen the wear of the current paddle
material and test it in the field. The paddles are made of Ultra High Molecular Polyethylene,
which has the highest impact strength among all classes of plastic products. Even though it is an
extraordinary material for industrial uses in wear and sliding applications, it wears fast in the
current function. This can be observed in Figure 50 Appendix C.
1.2 Motivation
Vulcan Materials, Miami Quarry division, offers mining, processing, and distribution
services as well as services in sand, gravel and crushed stone retailing. Being the biggest
producer of construction aggregates and a top producer of cement in Florida, there is no room for
inefficiencies or delays in such a busy operation. That‟s why the company is interested in a
feasible improvement or solution to this ongoing issue at a cost effective price.
Vulcan operates a “Drag-a-Flight Conveyor” in their Miami Quarry facility that uses
polyethylene paddles as a way of transporting the cement powder from the rail cars to the trucks.
It usually takes twenty minutes to load a truck with cement powder when the paddles are new;
however, when they are worn out, loading time could take up to one hour and twenty minutes.
Furthermore, orders of these construction paddles sometimes get back stocked, and subsequently
the operation gets delayed due to the inefficiency of the machine. To make matters even worse,
these paddles cost $13 dollars apiece, and the conveyor requires 114 of them in order to function
properly. It takes about 2 months for the paddles to completely wear out. However, if a more cost
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Paddle Maker Machine and Material Selection
effective material or a more friction resistant material were to be used for this application,
efficiency and productivity of the machine could dramatically improve. Moreover, if Vulcan
Materials Company were able to produce these paddles independently, the company would not
need to buy them anymore, reducing delays to a minimum and boosting its productivity in this
part of the facility. This could represent savings of more than ten thousand dollars a year at the
Miami Quarry division alone.
Finding the right paddle material and creating a machine that manufactures them,
represents a real life solution to a challenging industry problem. There is a need for improvement
and we are ready to answer the call with extraordinary effort and dedication while employing
knowledge and resources gathered in the course of our engineering studies.
1.3 Literature Survey
Several terms, processes and/or machines, whose understanding is of great importance
for the realization of this project, are mentioned throughout the report. Familiarity with these
terms was essential for the realization of this project. UHMW-PE (Ultra high Molecular Weight
Polyethylene) has one of the highest impact strengths of any thermoplastic and has excellent
abrasion resistance, tensile strength, energy absorption, stress resistance, and friction coefficient
properties. In this section, an overview of the work done on improving the material‟s
performance by other engineers and scientists will be reviewed.
In addition, there is a need for an in-house machine that can make paddles out of this
material. A large UHMW-PE sheet will have to undergo various processes including drilling and
cutting. Also means for conveying this raw sheet material need to be incorporated into the
machine. A review is conducted here on the brainstorming, and information gathering that lead
to the development of such machines over time.
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Paddle Maker Machine and Material Selection
1.3.1 Material
UHMW-PE has become the material of choice in hip and knee joint prostheses in human
body. In addition, it is used in many industries where moving and conveying materials presents
challenge of finding solution to abrasion, sticking and wear. It is the answer in applications such
as drag flights and paddles, side rails and skirt- boards. When compared to other polymers,
UHMW-PE possesses superior mechanical toughness and wear-resistance. Despite the success in
surgical applications, implanted components produce wear debris, and it is necessary to repeat
the surgery and revise the prosthesis. In the case of the Drag Flights application, UHMW-PE
paddles wear out quickly after being constantly rubbed against the steel counter face.
Cross-linking of UHMW-PE has been shown to improve its wear resistance by 70%
when compared to conventional material. Cross-linking changes the chemical characteristics of
the material. It alters the bond between molecular chains, reduces crystalline processes, alters the
free radical content of the material and influences the surface properties significantly.
Many experimental tests were done trying to understand the wear behavior and wear
debris distribution of UHMW-PE when rubbed against other material. A literature survey of
these tests will aid in gathering all the necessary parameters pertaining to our tests. The chosen
parameters will be used to test and compare the new improved material to the current one being
used by Rail Barge and Truck Company. In addition, it will be tested and compared with
UHMW-PE that was exposed to the cross-linking process.
An experiment on friction and wear behavior of nitrogen ion implanted UHMW-PE
against ZrO2 ceramic was studied in China University [1]. The Ball-On-Disc (Figure 1) wear
tests were performed using an UMT tester in Campbell, CA. The tester combined linear and
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Paddle Maker Machine and Material Selection
rotary motions in a coordinated manner while taking measurements of tribological parameters
such as friction forces, friction coefficient, and wear depth.
Parameters and material used in the study were:

The material had a disk shape with 10mm thickness, and a diameter of 30mm.

Roughness of the sample was polished to 0.2 - 0.4µm.

Ultrasonic bath and acetone as a fluid were used to clean the sample.

Si3N4 balls with 4mm diameter were used to simulate the wear of the artificial joints.

Wear tests were operated in a 25% plasma solution for 10,000 cycles.

A Sinusoidal Normal load of 20N - 25N was applied on the Si3N4 balls.

UHMW-PE disk reciprocating at fixed frequency of 0.5 Hz.

The Si3N4 ball load frequency varies from 0Hz to 1.5Hz.

Four tracks of wear were formed, and the testing results were measured by the wear mass
loss using an electronic scale having 0.01mg accuracy.

𝑀𝑠 =
Specific wear rate (Ms) determined by:
𝑀𝑤 −𝑀𝑐
𝑛𝑙
Where Mw is mass loss of worn disc, Mc is mass loss of dipped disc, and n is number of
tests.
Figure 1-Si3N4 Ball and UHMW-PE Disk Contact Schematic [1]
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Paddle Maker Machine and Material Selection
A different study conducted in China University was related to friction and wear behavior
of nitrogen ion implantation on UHMW-PE [3]. A UHMW-PE disc was put in contact against a
ZrO2 ceramic ball. The disc rotated and the ceramic ball was fixed on the load arm. The
electrical motor was controlled by frequency converter. The tribometer tester measured the
tribological behaviors of ion implanted UHMW-PE against ZrO2 ceramic. The results showed
that nitrogen ion implantation improved the hardness of the surface of the material, and increased
friction coefficient values.
Test parameters and material selection for N+ implantation were:

UHMW-PE disc of 5mm thickness and 45mm diameter.

Surface polished to 0.3 µm.

ZrO2 ceramic ball of 3mm diameter.

Contact load 5N.

Sliding speed was 0.19 m/s.

Human plasma as lubricant.

Test time: 110 minutes for dry friction, and 200 minutes for plasma.

Room temperature RH 55%.

UHMW-PE implantation: accelerated energy of 450KeV. Three different N+ doses.
The experiment resulted in a change in color of the original white UHMW-PE. For 5 x 1014
cm2 density the color changed to orange. For 2.5 x 1015 cm2 ion density the color changed to
bright black.
A study conducted at The Regional Research Laboratory in India was related to sliding
wear of PP/UHMW-PE composition blend [2]. UHMW-PE was melted and blended with PP in
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Paddle Maker Machine and Material Selection
different proportions. A pin-on-disc tester apparatus was used where the pin was made of
polymer sample and the disc was made of EN-24 steel. The test was done at different pressures
and sliding speeds.
Parameter and material were:

Cylindrical pin size 8 mm diameter and 53mm length.

Disc is made of EN-24 steel with hardness of 305Hv.

1.06-6.34 M Pascal pressure.

Sliding speed of 0.28-1.09 m/s.

300m sliding distance.
The results showed that the wear volume increases uniformly with applied pressure and
sliding distance.
The parameters used for those studies will serve a guide in selecting parameters that will
be needed to compare the current material to the purchased material. A ball-on-disk Tribometer
wear tester at FIU Plasma Lab was used.
1.3.2 Plastic Cutting Machines
Because plastics are thermoplastic processed organic materials with high molecular
weight, cutting them requires specialized cutting equipment. In general a plastic cutting machine
must possess the following features:
•
High level of precision
•
Good edge quality
•
Energy efficient
•
Low maintenance requirements
•
Facility of cutting virtually any shape
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Paddle Maker Machine and Material Selection
However since the design of the Paddle Maker machine is intended for a very
specialized function, only a few tasks are of key importance to the design and development of
our paddle maker. Among these tasks are:
•
Ability to move a sheet of the chosen material to the section where holes are to be made.
•
Six 7/16” equally spaced holes are to be drilled.
•
The machine must be energy efficient.
•
It must have low maintenance requirements and be autonomous.
The current manufacturer of these paddles uses a water jet cutter to produce them. A
water jet cutter is a device that enables cutting materials like metals and plastics by means of a
high speed and pressure water jet, or a mix of water and an abrasive substance. The process is
very similar to that of water erosion, yet significantly accelerated and concentrated. It is usually
implemented in manufacturing and industrial plants, especially when the material that needs to
be cut is sensitive to high temperatures. It is suitable for various kinds of materials such as heat
sensitive, delicate and hard ones. Water jet cutting is used for operations such as cutting,
shaping, carving, and reaming. Rubber, foam, plastics, composites, stone, tile, metals, food,
paper are just some of the materials commonly sliced by water jetting, while tempered glass,
diamonds and certain ceramics cannot be cut with it. The versatility, precise cutting and clean
finish of abrasive water jet machining, displayed in Appendix E Figure 52, avoids the need for
expensive secondary finishing. However, our team believes that due to the material being soft
and precision not a big factor, appropriate cutting could be done using conventional cutting tools
such as a circular saw. This tool can easily be found in any of the major hardware stores such as
Home Depot, Ace Hardware or Grainger.
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Paddle Maker Machine and Material Selection
After doing an extensive search and literature review a company that manufactures
machinery with similar processes and principles as those of the Paddle Maker was found. Its
name is, Kaltenbach [30] - a 4th generation family owned company and a world leader in metal
sawing technology. The company uses CNC for steel beam drilling and metal fabricating (Figure
4). The CNC features contain vertical and horizontal drilling units with a combined saw (Figure
2). A spindle has three axes for drilling with an option to change the tool automatically on each
axis. A computer control interface allows the integration of the sawing operation. In addition, the
company has a CNC robotic machine designed for coping beams and square tubes. One of its
features is material fed pusher conveyor (Figure 3)
Figure 2-Kaltenbach’s Drill, Cutting, Roller Table [30]
Figure 3-Hinged Roller Conveyor [30]
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Paddle Maker Machine and Material Selection
Figure 4-Drilling Assembly [30]
A local business, Grainman Machinery Corporation, was visited to check for systems that
could relate to our proposed machine design. The Company supplies equipment for the grain
industry and has several old and new machines, some of which are very similar to the design of
the here presented machine. Some pictures of conveyors with end processes like bag sawing, and
bag sealing are shown in Appendix T.
2. Project Formulation
2.1 Project Objective
As mentioned earlier, this project will be based on two central objectives. First, the
development of a fairly simple machine, capable of making these paddles from a sheet of raw
material while maintaining a lower cost per paddle. Secondly, as time allows, our team desires to
optimize the current material being used and find a more efficient, cost effective one.
The current paddle material provided by the Gund Company has a tensile strength of
2,500 PSI. However, in an effort to obtain a better wear resistance UHMW-PE, it was found that
the current vendor can provide the same material having the same specific gravity, with a higher
tensile strength of 5,500 PSI. One of the objectives was to apply a gamma radiation process to an
UHMW-PE sheet as time allows. Since cross-linking has been shown to improve the wear
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Paddle Maker Machine and Material Selection
resistance of ultra-high molecular weight polyethylene [2], we investigated the wear loss of
radiation cross-linked material.
The development of the machine presented in the conceptual design of this project was
the central goal of this project while at the same time research for a better material was
conducted as mentioned above. In the process of developing this machine, several sub objectives
arose and as they were executed they enhanced the central topic of this project. A few existing
technologies used in the manufacturing of plastics were explored to learn crucial information
about this topic. Improving the cost of the end product by exploring different vendors and
material properties was one of the major objectives underlying our main tasks.
Concentrating on building a functional mechanism that will perform the above mentioned
tasks while keeping the complete process at a cost efficient price and safe environmental
conditions, was the focus of this project.
2.2 Design Specifications
In this section all the specifications gathered while designing the system are presented.
Specifications are separated into different categories for better understanding.
2.2.1 Motor Selection
Throughout this project, when selecting motors, many questions arose. What kind of
motor should be used; DC, AC, or stepper motors? What Torque and Power are these motors
going to need to accomplish their respective tasks? What RPM will they need to run at? To
answer all of these questions an extensive literature survey was conducted so that the team could
have an understanding of similar machinery already on the market. Further detailed explanation
on motor selection is included in Section 6 of this report and in Appendix J: Torque Calculations.
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Paddle Maker Machine and Material Selection
2.2.2 Drilling Control
The paddle design currently being used in the RBT conveyors features seven 7/16” holes
spaced at 5”, however Nestor has noticed that while replacing old paddles with new ones, that
the middle hole is located where the paddles break most of the time. Therefore we are going to
avoid making this middle hole in order to make the paddle‟s design more lasting and stable. This
will also reduce drilling time and therefore the cost of producing one paddle. Based on this
specification the drill bit was selected and the G-code program written to instruct the Mach 3
how to move the stepper motors.
The fabrication of the finished product was influenced heavily by the way the three
different processes operate simultaneously; namely, first the roller table, then the drilling
operation, then the cutting, finally the roller table moves the thickness of the paddles and the
whole cycle starts over.
2.2.3 Movement Control
The Paddle Maker machine has three main moving parts: the roller table, the drilling
station and the saw station. Specifications for the roller table were to move a sheet of UHMWPE of 37¼” by 38” by ½” weighing about 40 lbs. Based on these sizes the rollers were bought
and the table frame built. Also a Torque analysis was done to find the required torque needed to
move the sheet forward by a stepper motor. Details are found on Section 6 and in Appendix J,
named “Torques Calculation”. To move the drilling assembly up and down a linear stage was
acquired. Selection criteria for this element were a travel distance of at least 2 inches and to be
able to carry at least nine pounds which is what our drilling assembly weighs. Also a torque
calculation was done to be able to select an appropriate stepper motor. To move the drilling
assembly in the x-axis, a much smaller torque would be required since the weight of the
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Paddle Maker Machine and Material Selection
assembly would be supported by two high precision shafts and the whole thread rod that moves
the piece. The same applies to the stepper motor that moves the circular saw assembly
horizontally. Thus a kit of four stepper motors was purchased to meet the highest torque
requirement given by the vertical linear stage. By buying them together we guaranteed the
functioning of the system would be appropriate and the cost of the machine is reduced.
2.3 Constraints and Limitations
Constraints and limitations were explained in detail in the previous subsections, where
the specifications for every component of the machine were discussed. Some of the limitations
not discussed previously were that the drilling station would take about 2 minutes to perform the
drilling of the six holes, which is mainly due to the chosen setup of the assembly and the speed
of the stepper motors. Also the table was built to fit one specific size of sheet (37¼” by 38”),
thus the machine is limited to this size of raw material, bigger sheets would have to be cut to size
before being input into the Paddle Maker. Future work will solve this issue by having an
adjustable table workstation.
2.3.1 Paddle Material
The current paddle material is UHMW-PE. This material is good for friction resistance
and has proven to perform adequately when used in Flight a Drag Conveyors. Thus our team
tried to find a material similar or better to the one being currently used and that is economically
feasible. It was found that UHMW-PE can be in fact improved when exposed to different
procedures explained in detail in the materials section of this report.
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Paddle Maker Machine and Material Selection
3. Design Alternatives
3.1 Overview of Conceptual Designs Developed
The process of developing and selecting several conceptual designs for the desired
machine that would produce the needed paddles was a crucial step in the advancement of this
project. During the first stage of brainstorming, many ideas defining the requirements were
considered while keeping in mind the end product requirements. After recording ideas for several
days the first informal drawings were discussed and several changes were recommended as
everyone in the team agreed.
Because the machine is composed of three subsystems, namely: drilling, roller table and
cutting, the conceptual design section is also divided into three sections that expose different
approaches to designing the Paddle Maker.
3.2 Cutting
3.2.1 Design Alternative 1- Water Jet Robotic Platform
The first design discussed was a robotic platform equipped with a water jet specially
designed to cut through the materials selected in the Material Selection part of this report. Water
jet systems typically have very unique capabilities that make them more advantageous and
effective over traditional machining. Their ability to cut while keeping low temperatures makes
them practically attractive to industries handling flammable materials, such as natural gas and
petroleum. In addition, material cut by water jet has a smooth satin-like finish. Although highly
efficient and popular in industrial applications, where versatility is an essential factor, these
modern systems have complex controls and functionality and are relatively expensive. Since our
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Paddle Maker Machine and Material Selection
application does not require high accuracy, and because of the high cost of this alternative, it will
not be considered for our design.
3.2.2 Design Alternative 2 -Laser Cutter
Another typical system widely used in modern manufacturing to cut almost any type of
material and discussed while brainstorming was laser cutters. Basically, laser cutting consists of
a high power laser guided by a computer to burn a groove in the material near the emitting
component. The material being removed can be melted by the high temperatures and or blown
away by high velocity fluids, usually gases. Laser cutters present several advantages over the
majority of the traditional cutter systems, consequently making them especially popular as an
innovative emerging technology. They produce extremely smooth surfaces as well as very
precise cuts and usually cut fairly fast if the material thickness is not extreme. The single most
attractive characteristic of a laser cutter is the lack of physical contact between the tool and the
piece being worked on, completely eliminating the wear and tear factor present in traditional
processes. Furthermore laser cutting requires considerably high electric power thus increasing
the operation cost of the machinery. Because the main objective of this machine is to reduce the
paddle cost, it is not feasible to include this technology into the machine given that high
precision is not required.
3.2.3 Design Alternative 3 –Circular Saw Workstation
The cutting along the width will be done by a circular saw blade specially designed to cut
plastic (Figure 5). This particular blade has unique features like the sharpening of the tooth that
allows for a cleaner and faster cut, which makes it highly efficient when cutting plastic. The
width of the cut done by the blade is also a parameter that will be studied carefully, since a wider
27
Paddle Maker Machine and Material Selection
cut means more wasted material. The cutting blade will travel along the complete width of the
plastic sheet, powered by an electric motor that will rotate in both directions moving the blade
back and forth.
Figure 5-Circular Saw Workstation Design Alternative
The angle in the scraping corner of the paddle was going to be cut by a corner round
router (Figure 6) powered by a motor turning it and is to be installed in an assembly together
with the saw, which in turn will be moved by a stepper motor. The installation of the router and
the powering motor are not done in the current prototype but will be integrated in the machine in
the near future.
Figure 6-Round Corner Router
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Paddle Maker Machine and Material Selection
Feed rate for all components were analyzed theoretically and then tested physically,
particularly those of the cutting tools, to assure that the material did not burn in the process
damaging the tools or the machine.
3.3 Drilling
3.3.1 Design Alternative 1 – Mechanical Drilling Assembly
Another approach for our machine was to build a straightforward combination of
mechanical components, equipped with electrical controls. This design is depicted in Figure 7.
As raw material will be obtained in the form of sheets cut to the required width the cutting
performed by the machine will be along the width of the sheet. In this design the holes were
going to be drilled by a set of six drill bits mounted in a supporting base and pre-set to the
desired measurements. By having all the drill bits mounted on fixed positions, the accuracy of
the distances between holes, which is the only critical dimension in the complete part, is assured.
This will also improve drilling time since all holes will be drilled simultaneously. The drill bits
used will be specifically designed for drilling hard and soft plastics and they also feature
characteristics, such as point and rake angles, which minimize or eliminate left-overs from the
material being removed while cutting the holes, resulting in a smoother internal surface. More
details about this drill bit can be found at Appendix F of this report. Some of the concerns with
this design are the force required to press all drills at once against the material being drilled and
the vibration created by all the drill bits acting on the material simultaneously.
The six drill bits should be interconnected by a mechanical system and driven by an
electric motor mounted in the center of the frame supporting the drill bits and connected to the
center chuck. The up and down movement will be provided by a stepper motor. The two systems
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Paddle Maker Machine and Material Selection
considered were a belt system or a chain and sprocket combination. Both of these systems are of
considerably higher cost and complexity. Hence their construction and assembly would take
longer than that of the final design presented in the next section.
Figure 7-Mechanical Drilling Assembly Design
3.3.2 Design Alternative 2 – Drilling WorkStation
The last major design explored was a “CNC–like” system, also referred to in this report
as a drilling station (Figure 8). The concept of CNC goes back to the 40‟s and 50‟s when the
combination of existing machines with electrical controls started to become popular. The rapid
development of electronics in the last few decades has affected the CNC technology accordingly.
This has revolutionized the manufacturing industries making almost every process faster, more
accurate, and consistent. A great deal of knowledge has been gathered by industries through all
these developments and a considerably large number of applications are in use today, making the
components of CNC available in almost every possible form. The concept discussed for this
project was based on the combination of a cutter and a drill, mounted on two linear motion
systems, moved by stepper motors and controlled by a driver connected to a computer. Some of
the concerns when discussing this design were the price of accurately controlling the position of
30
Paddle Maker Machine and Material Selection
the drill when moving from one position to the next, and the constant movement of the electrical
wires connected to all the moving devices.
Figure 8-Drilling Workstation Design
3.4 Material Movement
3.4.1 Design Alternative 1 – Roller Table
Since early in the conception of this project it was realized that some sort of mechanism
to move the UHMW-PE sheet from point A to B while controlling the rate of movement as
required. One approach to solving this issue was to build a roller table as seen in the picture
below. This design includes nine galvanized steel rollers, purposely separated at different
distances to minimize the torque required to move the work piece forward. A stepper motor was
selected that would easily overcome this torque, and both the legs and frame were made of
standard 1” x 2” steel tubing.
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Paddle Maker Machine and Material Selection
Figure 9-Roller Table Design Alternative
3.4.2 Design Alternative 2 – Automatic Material Handling Table
The table illustrated below was one of the alternatives discussed while brainstorming on
how to move the sheet of material to the specified position where the other processes were going
to be conducted. The way this works is having two sliders, one long the x-axis, through which a
pusher slides, and another on the side that holds the sheet of polyethylene and moves with it at
the same rate the pusher displaces the sheet forward. Both of these mechanisms are moved by
stepper motors turning two lead screws. They lay in an aluminum table to provide system
stability and accuracy. One of the biggest disadvantages of this design is that it requires a lot of
machining to bring this model to life and in the process a lot of material would be needed, thus
the price of developing this model would be high.
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Paddle Maker Machine and Material Selection
Figure 10-Automatic Table Design Alternative Trimetric View
Figure 11-Automatic Table Design Alternative Inclined View
3.5 Feasibility Assessment
Research of all these possible options, while keeping in mind cost, availability,
complexity and material being handled among other factors led us to choose the design presented
below. As can be seen the roller table was chosen for moving the work material and the CNC –
like approach using, lead screws and stepper motors, was used for both the drill and sawing
33
Paddle Maker Machine and Material Selection
station. This design was the most time effective and cost efficient approach for doing a Paddle
Maker machine.
Figure 12-Overall Design
Some small details are not included in this drawing. A section view of the first draft is
shown below.
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Paddle Maker Machine and Material Selection
Figure 13-Section View of Proposal Design
Next an exploded view (Figure 14) is presented to help identify the different components
that make up the whole assembly.
Figure 14-Exploded View of Proposal Design
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Paddle Maker Machine and Material Selection
A drawing of the finished paddle (Figure 15) was done to help visualize the needed
proccesses.
Figure 15-Targeted Finished Paddle
3.6 Design Process Diagram
3.6.1 Material Selection Logic Diagram
Figure 16-Steps for Material Optimization Process
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Paddle Maker Machine and Material Selection
The optimization process involved the four steps mapped above and detailed as follows.
Step 1: Recognized the need- the improvement of the product (obtaining a better friction
resistant material) is the most important part of the entire process.
Step 2: Research material for new current test- this part of the process included finding a
product with similar or improved properties to that of polyethylene.
Step 3: Test the new material- after receiving the material it was tested and compared to
polyethylene wear.
Step 4: Improve the design- As a result of the test performed on the new material, quantitative
measure were obtained and results are presented in following sections.
3.6.2 Proposed Machine Design Logic Diagram
Figure 17-Machine Design Process
Step 1: The machine was designed such that the plastic sheet will be easily rolled over a
platform (roller table) to the drilling area.
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Paddle Maker Machine and Material Selection
Step 2: A table workstation consisting of two linear stages and a drill system, moved by stepper
motors, were designed to create holes on the plastic sheets.
Step 3: A saw moving by means of a linear stage and stepper motor cuts the paddle to required
dimensions. Also a round corner router, not included in the prototype, moving by the same
system as the saw could do the side angle.
Step 4: Evaluation of the process was performed on the accuracy of the design.
Step 5: Improvements were done until the final product was obtained successfully.
3.7 Proposed Machine Design
After considering all of the above mentioned systems and procedures, the final
conclusions were:

The design preference for drilling was Design Alternative 2 - Drilling
WorkStation.

The design preference for material movement was Design Alternative 1 - Roller
Table.

The design preference for cutting was Design Alternative 3 – Circular Saw
Workstation
The complete design included a table with rollers that facilitated the movement of the
sheet toward the drilling station. This table consists of several, free motion rollers, and one driver
roller that pulls the raw sheet forward by a prescribed distance, which is the desired width of the
paddle. Then the drilling system moves through linear stages in the horizontal and vertical
directions to make the six holes needed.
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Paddle Maker Machine and Material Selection
4. Project Management
4.1 Timeline
Figure 18-Project Timeline
4.2 Team Breakdown of Responsibilities, Tasks and Roles
The timeline and responsibilities table is an approximation of the time spent in the
different tasks and it only reflects the most important subjects. The team members names
appearing in the arrows just represent the person in charge of that specific category. The team
members‟ tasks reflected below just show the team member‟s main responsibilities; however
every member participated in every specific area and in the report as a whole.
The table below shows the approximated number of hours each member spent for each
category.
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Paddle Maker Machine and Material Selection
Table 1-Numbers of Hours Spent
Category
Literature Survey
Machine Design
Machine Drawing
Calculations
Material Search
Material Test
Nestor
85
61
55
9
3
5
Jorge
83
58
55
26
2
4
Orena
90
46
12
19
19
51
Machine Components
Ordering
Construction
Machine Testing
Software Installation
Software Verification
Paddle Testing
Presentation
10
55
48
3
4
2
6
8
48
46
3
4
1
7
4
39
40
3
3
1
9
Report Structure and
Contents
Total Hours
50
396
48
393
53
389
4.3 Patent/Copyright Application
For an invention to be patented such idea needs to be novel and the inventor must show
how the invention works. In addition, it is important to keep records of all details; including
drawings, brainstorming and dates of importance. To ensure it is a new idea one must search the
US (sometimes foreign) patents, and technical journals for related inventions. One tool usually
used by lawyers when they want to research whether an invention is original or not is
google.com/patents.
A US patent cost depends on the technology involved.
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Paddle Maker Machine and Material Selection

The initial cost to have a patent searched, and to have an opinion if the idea is
patentable is $650 to $1000.

A patent application which includes 2-3 drawings costs $150 per one drawing for
a total of $450.

Next, an abstract and detailed description has to be prepared for the application.
The fees in simple mechanical cases are $4500. The fees for software,
computers, and electrical systems are $7000. For a more complex system such as
shock absorbing prostatic device the cost is $15,000. For highly complex such as
telecommunication networking system the fee would be $15,000 +.

Next, the application filing fee costing $355

An amendment for the application can cost up to $2000 in attorney fees.

Final patent issue to the USPTO costs is up to $1300

Maintenance fees range $2995-$5790, and it increases over the life of the patent.
The patent process is relatively expensive. An inventor can spend up to $10,000 in order
to obtain a US patent. An additional fee of $20,000 for a patent protection in a foreign country
can be expected. Moreover it takes about 36 months for the complete process.
A search for an automated plastic cutting, drilling, and saw machine, using US patents
web sites[28], led to no results for these specific combined functions. The new paddle maker
machine is a unique design for a very particular application that will indeed save time and money
to any company using Drag-a-Flight Conveyor.
Even though the design has a low cost and provides a unique application, the team has no
intention of filing for a patent at this point since this project was supported and thus intended for
the Miami facility of Vulcan Material. Furthermore the possible clients soliciting for this
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Paddle Maker Machine and Material Selection
machine is limited, which makes profiting from it a risky venture. In addition, the Paddle Maker
is composed of many different mechanisms that have long been patented, namely: drills, circular
saws, roller table and CNC workstations, which could also make obtaining a patent even harder.
4.4 Commercialization of the Final Product
In order for The Paddle Maker to be commercially ready many different parts need to be
optimized, for instance, the drilling assembly motor and the two lead screws of the saw and
drilling assembly respectively.
The prototype presented in this report, was built just to demonstrate that our design
works, thus some parts were substituted to be able to meet our budget. In order to transform this
prototype into a commercially viable product, the drilling motor needs to be substituted with the
one suggested in Appendix L, also the whole thread rods need to be substituted with lead screws
shown in Appendix P, so that both the saw and drill assembly run smoothly and more accurately.
Also a slider table as proposed in the future work section should be included to the machine as an
accessory to be able to collect the paddles.
4.5 Discussion
Management is one of the most important tasks of any engineering project. Weekly
meetings were held to discuss tasks to be accomplished, and to ensure that the Table of
Responsibilities was being followed in a timely manner. Different tasks were split between
members according to their abilities, yet the more intensive tasks like design, construction,
optimization and testing were mostly accomplished by group work. Cost was an important factor
affecting nearly every decision throughout the realization of this project. To meet the budget and
time deadlines some concessions had to be made as mentioned in section 4.4 and Future Work in
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Paddle Maker Machine and Material Selection
section 10, yet because of having had a well timed and organized breakdown of tasks, our
prototype was successful and both the machine and the paddles met expectations.
5. Engineering Design and Analysis
5.1 Structural Design
Structural design and analysis in the engineering process of creating functional
machinery are extremely important steps that need to be revised thoroughly. Sometimes
restricted by the objective conditions and specifications of the output product, the challenge
presented in designing structures goes beyond the scope of this project. Based on practical
knowledge, information gathered from numerous sources and the help of computational
software, such as SolidWorks, Beam 2D 3.1 and Excel, a logical design and analysis of the here
presented structure and mechanism was conducted. Some preliminary analyses were done and
are presented in the following section of this paper.
Selecting major components for the machine being designed was a fundamental step in
the task of designing and engineering a working device that could operate under the presented
restrictions and conditions. Some of the factors considered for component selection were the
cutting speed and the feed speed of the drill bit.
For the construction of the frame, standard rectangular 2”×1” tubing was used in
combination with several other small structural steel parts. Several pieces were made of
aluminum to reduce weight, cost and to increase durability of the completed mechanism.
The selection of the main electrical components for this machine was a challenge that
was directly discussed with the team advisor, other professors and several of our electrical
engineering colleagues before buying the motors and controller kit.
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Paddle Maker Machine and Material Selection
Fundamentals of mechanics of materials and material properties were applied in the
search for a material that would have better performance when operating under the specified
conditions.
5.2 Dimensions
Some the dimensions of interest in this project have already been mentioned in previous
sections. Production time of a paddle, machine cost including maintenance, and raw material cost
are some of the most significant fundamental aspects of the project.
The final cost of the completed machine was intended to be kept under $2000 USD for
future commercialization purposes. Quotes from several different companies and materials were
obtained and are presented in the following section with the intension of reducing material cost.
5.3 Material Selection
5.3.1 Paddle Material
E-Beam Services Inc. provides cross-linking and chain session services for a price of
$900 to any sheet size. The cross-linked cost per sheet shown in the table from Horn Plastic Inc.
is not expensive because this was an exchange with other vendor‟s material. The cross-linked
UHMW-PE could not be welded and therefore was traded off with regular UHMW-PE sheet. We
were not able to get information on the data sheet. However the sample color is Orange which
indicates that the UHMW-PE had undergone through a process.
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Paddle Maker Machine and Material Selection
Material Cost for UHMW-PE Sheet
Table 2-UHMW Cost
Vender Name
Size TxWxL
Cost per Sheet
Cut to length Cost
($)
(CTL 37-1/4”)
Interstate Plastic.com
½” X 48” X 72”
471
500
RPlastic.com
½” X 48” X 120”
356
395
The Gund Company Inc.
¼” x 38” x 48”
216
250
Horn Plastic Inc.
¼” x 60” x 96”
*242
285
(With Crosslink Process)
5.3.2 Machine Major Components
The proposed system is composed of several mechanical and electrical components that
work simultaneously to achieve the targeted end product. The major components are as follow:
 Beginning with a DC electric motor that provides rotational motion to the drill
assembly.
 A DC motor that provides rotational motion for the saw assembly.
 A belt and timing gear system that transfers the rotating motion and torque from the
motor to the drill bit assembled in a custom made shaft.
 The drill bit shaft has a simple chuck machined on it, so that the drill bit can be
removed if necessary. This shaft was machined to custom fit the existing assembly to
reduce vibrations created by centricity differences.
 A drill bit specially design for drilling hard and soft plastics.
 High speed bearings that support the shafts holding the chucks.
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Paddle Maker Machine and Material Selection
 Four stepper motors that provide linear motion to the drilling workstation in the
vertically and horizontally direction and to the cutter in the horizontal direction
parallel to that of the drilling, and rotational motion to the roller table.
 A 6½” circular saw powered by an electric motor, to make the horizontal cut to the
desired width.
 A table composed of several rollers where the sheet of raw material slides towards
the cutting machine.
As mentioned above, these are some of the most essential components included in the
assembly of the present machine; as improvements are made more components will be required.
5.4 Force Analysis
The force analysis is mostly covered in Appendix J: Torque Calculations section. Here
the torque needed for the two main stages of the machine was analyzed, namely: the linear stage
and the roller table. The torque for the roller table stepper motor was found to be approximately
0.23 Newton per meter (Nm) or 32.7 ounces per inch (OPI); while the torque that the stepper
motor on the linear stage would need to exert was found to be around 17.7 ounces per inch (OPI)
for the worst case scenario - which is when the drilling assembly is going up; this torque is called
raising Torque or TR. All assumed values specified in Appendix J were those of worst case
scenarios taken from mentioned sources.
In the case of the circular saw motor, the drilling motor and the stepper motors providing
the horizontal movement for the drilling assembly, finding the necessary torque was
accomplished as follows.
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Paddle Maker Machine and Material Selection
First we looked at different similar saws in the market and found that the best one to
compare to was a cordless one - since we are going to use a DC motor to power the saw. Usually
cordless saws range around 1/20 horse power (HP) and have a torque of about 7.5 (OPI). Then
Mr. Zicarelli from the Engineering Manufacturing Center at Florida International University
recommended using Machinist Toolbox, which is known computer software, to find an estimate
of what power would take to cut UHMW-PE. Using this program it was found the horsepower
and torque would be 1/10 HP and 15 (OPI) respectively. Then tests were done using a DeWALT
cordless saw. Several pieces of the material to be used were cut successfully and then from the
specs of the machine, the power was found to be 1/20 HP. Thus after doing this set of tests a
range of power and torque required to cut this material was estimated. For simplicity, it was
decided to use an existing cordless saw and just replace the blade with one for plastics,
guaranteeing success for the given case.
For the drilling motor similar steps as those for the circular saw motor were undertaken.
From the literature survey it was found that similar cordless power drills usually range from 1/20
to 1/5 HP and 50 to 200 OPI for the torques, while from the Machinist Toolbox the estimation
was ¼ HP and 214 OPI. To find the correct RPM to operate the drill bit a drill press was used.
Several holes were drilled letting the speed of the driller vary. It was found that anywhere in the
range of 700 to 1300 RPM the sheet could be drilled and good finished holes would be obtained.
Then tests to find torque and horsepower were done by using a Dewaltt cordless drill whose
specifications were 1/10 Hp and 100 OPI. Combining this information, it was decided that a
motor capable of providing 1/8 HP and 170 OPI was acceptable. Yet this motor speed was much
greater than needed, so as part of the assembly a gear pulley system was included to reduce the
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Paddle Maker Machine and Material Selection
speed of the assembly to approximately 1300 RPM, which is the fastest speed achieved in our
testing, while still obtaining quality holes.
Since the stepper motors torque requirements for the roller table and the linear stage were
the ones expected to be higher than those used in the horizontal movement of the saw assembly
and the drilling assembly, a kit was purchased to exceed the specifications of the higher torque
component, in this case the linear stage (17.7 OPI). The drill assembly and saw assembly require
less torque due to their providing displacement in the x direction and not carrying as much load
and having two high precision rods and bearings supporting them. The kit bought was a great
decision since it saves us time and money. A single package provided us with everything needed
for controlling the displacements of the machine: a driver, four (270 OPI) stepper motors, one
power source and a controlling board. Another major reason why these steppers were chosen is
because their compatibility with the mounting of the linear stage.
5.5 Dynamic/Vibration Analysis
The team consulted Dr. Levy on how to conduct vibration analysis on the system. Dr.
Levy recommended a simple method of analysis in order to find an approximation of the first
natural frequency that could be compared to the frequency that the motors are running at. He
suggested that if the natural frequency of the system is different than the natural frequency of all
motors then no resonance will occur and the design would be safe of critical vibrations. If the
system frequency falls within ± 10% of the natural frequency of any motor, it is not considered
safe and a simple vibration absorber composed of springs and mass should be used.
The paddle maker machine is formed by several subsystems: namely the drilling station,
sawing assembly and a roller table. For that reason it was chosen to use Dunkerley‟s formula
[31] to determine the system‟s final natural frequency. Dunkerley‟s formula gives approximate
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Paddle Maker Machine and Material Selection
values of the fundamental frequency of a composite system in terms of the natural frequencies of
its components. The fundamental frequency showing in Figure 19 was used to include all
subsystems.
Figure 19-Dunkerley’ Formula Used for the System
The natural frequency formula is 𝝎 =
𝒌/𝒎 where k is the spring coefficient and m is the
mass.
 k equivalent and total Mass for each subsystem was calculated:

Roller Conveyor assembly- The legs experience the same deflection; thus the k
equivalent is in parallel. They were simulated as fixed beams of circular crosssection. The nine rollers were modeled as rods experiencing the same deflection,
hence they were considered in parallel. The frame of the roller table was divided into
frame L and frame W, and both were modeled as fixed beams with a thin walled
thickness cross-section. The legs, frame and rollers can be taken as in series since
they all experience the same load.

Drilling assembly- The two support rods are considered fixed, and the lead screw is
considered as a free rod. The drill station which includes: electrical motor, stepper
motor, rods, and linear bearings are considered as one mass. The two rods and lead
screw carry the same load, namely the weight of the assembly, thus they are
considered to be in series.
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Paddle Maker Machine and Material Selection

Sawing assembly- Includes the same parts as the drilling assembly. The only
difference is the length of the rods and lead screw. The saw blade and motor are
considered as one mass. The rods and lead screw carry the same load, namely the
weight of the assembly, thus they are considered to be in series.

Sheet mover assembly- the stepper motor and wheels move the sheet to be cut to
length very slowly. The wheels only turn approximately 3/4 of a revolution to move
the sheet the prescribed distance and thus this assembly including its respective motor
is deemed stationary and is excluded from the vibration analysis, though its mass is
included in the roller‟s table mass.
 The total natural frequency for the system was calculated to be 1.009 rad/sec.
 All motors frequency was obtained by converting RPM to Rad/sec. The smallest natural
frequency for the drilling stepper motor calculated to be 5.236 rad/sec
 Since ω system is different than any ω any motor , and since the value does not fall within
± 10% of any motor‟s frequency value, the machine should have no resonance.
5.6 Deflection Analysis
Member deflection is a considerably important topic in the design of any structure. Even
though the system here presented consists of a combination of simple structures, determining the
deflection of the key parts of the machine was of interest.
The linear shafts holding the drilling assembly, being the thinnest and longer members,
were the components where the major deflection was expected. The deflection and other
properties of interest for these supporting shafts were calculated using the very well known
software Beam 2D version 3.1 and are presented in Appendix K. The two tentative dimensions
for these shafts were 3/8” and 1/2". The load carried by two of these shafts at any time is 8 lbs,
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Paddle Maker Machine and Material Selection
but to be on the safe side, a 10 lbs load, located at the center, was simulated on a single shaft.
After performing this analysis the ½” shaft was picked based on minimum deflection
specification. The maximum deflection was found to be 0.03746543” at the center of the shaft
where the load was being applied (Figure 20).
Figure 20-Deflection Analysis of Linear Shaft
5.7 Material Analysis for Machine Assemblies
Structural analysis involves the consideration of physical properties in the effort to
predict and study the response of a structure to the adversities of the environment in which it is
operating. Involving the fundamental of material failure theories, mechanics, as well as non static
loading, the fundamental goal of structural study is the estimation of stresses, internal forces and
physical deformations. This portion of the engineering design process has become essentially
important as a result from the demand to save money in the realization of direct testing.
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Paddle Maker Machine and Material Selection
When building any kind of machinery, it is of great importance to estimate the life span
of the design by predicting failure using theoretical analysis. Structural analysis to all possible
components was done using SolidWorks Cosmos Works in order to determine their performance
under continuous applied loads. Finite element analysis was used to make sure the structure is
safe. Obtaining a high factor of safety will guarantee reliability of the Paddle Maker and
minimize vibrations. Furthermore Deflection Analysis was applied to determine how much the
different parts of the machine displace when under stress and the results are presented in the
following.
5.7.1 Stress Analysis
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Paddle Maker Machine and Material Selection
5.7.2 Strain analysis
5.7.3 Displacement
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Paddle Maker Machine and Material Selection
5.7.4 Factor of Safety analysis
Stress and Strain analysis results show a very safe and stable table model .Deflection
Analysis shows that the center of the side of the table is the one experiencing the most deflection,
yet this value is very small, approximately 6.31 *10-6 inch, thus the current design it also a good
one on this aspect. The factor of Safety is very big, which is desirable for a machine that is
expected to have a long lifespan.
5.8 Cost Analysis for One Paddle
Below you will find a Table that estimates the cost of producing one paddle with the
proposed design, the Paddle Maker. As it can be seen the cheapest option will imply a saving of
$7.75 per paddle, when compared with what the actual manufacturer (The Gund Company)
charges Vulcan Materials, $13 per paddle. Charges which multiplied by the 114 paddles needed
for the conveyor belt would represent a saving of almost $884 per paddle shipment. Considering
that a new set of paddles must be installed every month, in order to efficiently load with powder
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Paddle Maker Machine and Material Selection
cement the trucks, the total savings for the company would be around $10,606 a year. This is
only in the Miami Facility. If every facility that uses Drag-A-Flight conveyors today for load
product from trains to trucks can save that much money, the paddle maker could mean huge
savings not only for Vulcan Materials but also for any company in the construction field
interested in this technology.
Table 3-Paddle Production Cost
Machine
Machine
Polyethelene Sheet
Functioning Cost Functioning Cost
Provider
Size
Cost per sheet Time(minutes)
($ per hour)
($ )
Interstate Plastic.com 1/2" x 37" x72"
$500
205.714
0.256
0.877
Rplastics.com
1/2" x 37" x120"
$395
342.857
0.426
2.436
The Gund Company 1/2" x 37" x72"
$215
205.714
0.256
0.877
Current Price
1-paddle
Production Cost
($)
12.174
5.796
5.247
13
Below a discussion of the equations used to produce this table is presented.

Time(minutes)= 5 min * (sheet size/paddle size)

Machine functioning cost = Power * (hours to produce paddles)*($0.10 per KW-h)

Cost of 1 paddle = (sheet cost+ machine functioning cost) / (amount of paddles produced
from that sheet).
In the time equation, five minutes is the time empirically determined required to
manufacture a single paddle. That multiplied by the amount of paddles obtained from each sheet
gives you the time that it takes to make paddles out of that sheet.
The Paddle Maker uses 2 DC motors and 4 stepper motors that account for the total
horsepower of the machinery to be approximately 1 HP. This is converted to KW, and then to
KW-h using the time calculated in the first step. That value times the average KW per hour cost
in Florida, namely $0.10 yields the machine functioning cost.
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Paddle Maker Machine and Material Selection
In order to obtain the amount of paddles produced from a given sheet, the size of the
sheet is divided by the desired paddle size.
6. Prototype Construction
6.1 Description of Prototype
The target of this project was to build a machine that would produce construction paddles
to be fitted in a Drag-A-Flight Conveyor .These paddles needs to be 37¼” long, ½” thick and
1¾” wide, having six holes 7/16” in diameter each, spaced by a distance of 5½”. The current
design of the paddle also features an angle cut in one of the sides to decrease friction.
A machine, The Paddle Maker, was constructed to produce the paddles autonomously
from a given sheet of raw material. Thus the machine first moves the sheet of raw material to the
position where a pulley-belt system driving the drill bits makes the holes. Then a saw moves by
means of a stepper motor and takes care of the cutting.
6.2 Parts List
6.2.1 Motors and Stepping Motors
Four Nema 23 Hybrid Bipolar Stepper Motors of 270 oz-in, 1/4” dual shafts, were used to move
the different linear mechanisms. Typically controlled by a computer and driver, these motor are
among the most common systems used in machines requiring motion control. Advancements in
electronic controls have made steppers motors more popular than ever in almost every modern
industry.
The torque of these motors greatly exceeds that required by the system; the reason for
this is that these motors were bought in a complete kit, including the power supply and
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Paddle Maker Machine and Material Selection
controller. By having all stepper motors of the same size and frame will facilitate future
maintenance.
6.2.2 Gears and Timer Belt
The design of the machine required means transmitting power from the electric motor to
the drilling shaft while reducing the speed of the motor by a ratio of 3:1. To accomplish this, a
combination of two timing gears was selected since no slippage between the belt and the pulleys
was desired.
The driving pulley was chosen to be a 24 tooth, Acetal Plastic, with Aluminum Hub to
meet the size of the motor‟s shaft. The driven pulley was required to be 72-tooth to meet the
required rpm for consistent drilling and acceptable hole finishing. This last pulley was not
available in any other material but steel, which is heavier yet more lasting than plastic.
6.2.3 Bearings
All bearings used in the design and construction of the machine were picked from the
McMaster catalog while keeping in mind their availability from local vendors in case
replacements were to be needed in the future. All bearings were selected depending on their
specific function, location in the machine and load carried.
6.2.4 Linear Stage
After estimating the weight of the finished drilling assembly a suitable linear stage was
selected to withstand the torque and reaction forces created by the drilling process. The selected
linear stage is a MLPS-4-10 low profile series from Servo System Company capable of
supporting a 10 lbs dynamic load on a 4” travel rail. The manufacturer specification sheet is
attached in Appendix I of this report.
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Paddle Maker Machine and Material Selection
6.2.5 Rods and Supports
After studying the shaft deflections and internal forces presented in preceding sections
the shafts used were Linear Motion shafts made of AISI 1566 Steel, meeting surface finish
requirements for the selected linear bearings to travel smoothly.
6.2.6 System‟s Driver
An automation machine technology is used to drive the four stepping motors running the
vertical and horizontal motion for the Paddle Maker Machine. Rockcliff 4 axis CNC motor V10
Driver (Figure 21) enabled running the machines at low cost and high performance. The 4
stepping motors are Bi-Polar motors making the system more powerful. A bi-polar motor has a
single winding per phase, unlike a uni-polar one, which has two windings per phase. In a unipolar motor the magnetic pole can be reversed without switching current direction, where as in a
bi-polar one the current needs to be reversed in order to reverse the magnetic field. Hence, the
driving circuit must be more complicated.
The four colored coded wire connection shown in the schematic diagram in Figure 22
must be carefully checked, an incorrect connection will destroy the controller. The current level
can be adjusted using a potentiometer, which converts the voltage to motor output current.
Stepper motor performance is dependent on the drive circuit. The motor drive can handle 30
VDC and can generate voltage and current back into the circuitry. Motor failure can occur when
exceeding 35 VDC. The power source for the driver is a 12 or 24 volt power supply. The 24 volt
supply will reach the speed and torque twice as fast as that of the 12 volt one.
Stepper motors step from one position to the next, and their coils are constantly
energized. As a results, when running at certain speed they are prone to vibration. Motor dumper
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Paddle Maker Machine and Material Selection
or changing acceleration helps remove vibration. The Rockcliff driver board uses a PFD
adjustment setting to help remove resonance.
Figure 21-High Performance 4 Axis CNC Motor V10 Drive
Figure 22-Schematic Diagram for Rockcliff V10
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Paddle Maker Machine and Material Selection
6.2.7 System‟s Software
PC-based CNC software, the Mach 3 series, available from Artsoft USA is used to run
the Paddle maker machine. Rockcliff provides a special file name „Rockcliff4X.XML‟ to
configure Mach3 software settings to the motor drive board. Mach3 features and functions are
easy to use. Mach3 provides tutorials that cover basic knowledge, installation and configuration,
as well as many troubleshooting videos.
Mach3 minimum computer requirements are not supported by Laptops due to inherent
power saving features. To use the features and run the machine accurately a desktop PC was
used which outputs more consistent voltages to its parallel port pins.
One of the features provided by Mach3 is to allow us to use the G-code program
language in order to move the motors up, down, left and right.
Mach3 is easy to setup, and it has many great features which are easy to understand
(Figure 23). Some features used in Mach3 are: G-Code display, M-Code display, spindle speed
control, relay control. The program can control Lathe, mills, Routers, Lasers Plasma and even
engrave.
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Paddle Maker Machine and Material Selection
Figure 23-Mach3 Screen Shot Features [39]
6.2.8 Saw Assembly
A motor from a DeWALT circular saw was used to drive the carbide blade that cuts
along the length of the raw material.
The following table was developed for some of the commercially available power saws.
The cheapest of all these options was the third choice; however the HP of this machine is too
large for the required application, thus the DeWALT Cordless Circular Saw was selected. Details
of this selection are shown in table 4 and Figure 24.
Table 4-Power Saws Comparison [38]
Company/Product name
Kett Electric Plastic Cutting Saw
Dewalt Cordless Circular Saw
RIGID Circular Saw
Part #
KS-224
DC9390K
N/A
Price ($)
353.77
199.99
99
Voltage(V) Current(A) Speed(RPM) cutting Power(W) Power(HP)
120
5
2500
Plastic
600
0.8046
18
2.4
3700
Plywood 43.2
0.0579312
120
15
3000
Framing
1800
2.4138
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Paddle Maker Machine and Material Selection
Figure 24-Circular Saw Specifications and Features [38]
6.2.9 Drill Motor
Through an extensive search of similar motors on the market and while performing tests
of our own, as explained in the Design section, it was found that the motor needed to have at
least 1/10 HP and 100 ounces of torque per inch. Following this criterion some commercially
available motors were selected as shown in the Appendix L, yet their prices range from $300 to
$400. Hence for the purpose of this prototype the motor shown below was used, in part because
it has 1/8 HP and also because it was a donation from the team‟s sponsor: Vulcan Materials.
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Paddle Maker Machine and Material Selection
Figure 25-Prototype’s Motor
This motor has a speed of 3600 RPM, thus a gear reduction system was added to the
assembly to bring down the speed to about 1200 RPM, which was proven to be an effective
drilling speed yielding good quality holes in this material. Two gears were purchased to
accomplish this. The following drawing indicates the considerations for determining the correct
belt dimensions.
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Paddle Maker Machine and Material Selection
Figure 26-Belt Length Determination
6.2.10 Roller Table
The roller table was designed and manufactured to meet the size and functionality of the
cutting process. Structural analyses were presented in prior sections although the table was
expected to surpass design requirements, and this was proven by the large factor of safety
obtained from these analyses. The roller table was designed so that the distance between rollers
gradually increases along the length of the table. By doing this we are decreasing the torque
required for this stepper motor to move the sheet. Thus the motor would have to work less and
therefore its lifespan would likely be extended. Calculation details are included in Appendix J.
6.3 Construction
Construction of the machine was a very intensive and challenging task where our
knowledge and hands-on abilities were put to the test. The roller table (Figure 27) was built by
welding steels beams to form a frame 48” in length and 39” in width. Then the rollers were
installed to allow for easy displacement of the raw sheet of material.
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Paddle Maker Machine and Material Selection
Figure 27-Roller Table
For the construction of the motor assembly (Figure 30) some elemental machining was
done by one of the team members and the centricity of the gear shaft was checked using a
deflection gage (Figure 28). After doing this it was realized that the gear shaft was off-centered
by 0.002” due to the differences in diameter between the bearing inner cup and the shaft. A new
shaft was machined to fit the inner diameter of the bearing to solve the centricity issue
(Figure29).
Figure 28-Shaft Centricity Test Gage
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Paddle Maker Machine and Material Selection
Figure 29-Machining of Shaft to Precise Tolerance
Figure 30-Motor and Linear Stage Assembly
For both the drilling and the sawing assembly two supporting rods and one lead screw
attached to a stepper motor were used for movement of the assemblies. A Dewaltt 18 V circular
saw was used for cutting. For further detail refer to sections 6.2.8 and 2.2.3
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Paddle Maker Machine and Material Selection
6.4 Prototype Cost Analysis
This section reflects the total price of buying the parts, materials and tools that were
necessary for the realization of The Paddle Maker Machine.
Table 5 below represents the approximate total cost of the final design. Table 6 shows the
cost analysis of manufacturing the machine using the mechanical drilling assembly instead of the
drilling workstation. The reason we‟re showing both is that they serve as a comparison between
the two main design alternatives. As can be seen by using the drilling workstation choice, a sum
of around $400 would be saved. This ended up being an important factor on the decision of
choosing the final design: The Paddle Maker.
Table 5-Final Design Cost
Cost Analysis
Description
Item Price
Stepper Motor Kit
$405.00
DC Motor
$350.00
Linear stage
$249.00
Pulley and gear
$63.37
Wires and crimps
$50.00
Drill Bits
$23.05
Chucks
Round rods
Tubing
$22.84
Welding Rods
4 1/2 " Circular Saw Blade $25.00
3/8 "Corner round router $29.00
3/8" by 24' Shaft
$30.77
3/8" by 8' rod
$30.00
Bolts
Linear Bearings
$143.90
Ball Bearings
$19.32
Flange Bearings
$45.09
High Precision Rods
$50.00
Polyethylene Sheet
$278.00
Total
67
Qty
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4
1
Subtotal
$405.00
$350.00
$249.00
$63.37
$50.00
$23.05
$0.00
$0.00
$22.84
$0.00
$25.00
$29.00
$30.77
$30.00
$0.00
$143.90
$19.32
$45.09
$200.00
$278.00
$1,964.34
Paddle Maker Machine and Material Selection
Table 6-Initial Design Cost
Cost Analysis
Description
Item Price
Stepper Motor
$80.00
DC Motor
$250.00
Power Supply
$200.00
Wires and crimps
$50.00
Drill Bits
$23.00
Chucks
$15.00
Round rods
$30.00
Tubing
$22.84
Welding Rods
$10.00
4 1/2 " Circular Saw Blade $25.00
3/8 "Corner round router $29.95
V-belts
$20.00
Bolts
$15.00
Bearings
$20.00
Polyethylene Sheet
$278.00
Total
Qty
3
3
1
1
7
7
4
1
1
1
1
8
1
14
1
Subtotal
$240.00
$750.00
$200.00
$50.00
$161.00
$105.00
$120.00
$22.84
$10.00
$25.00
$29.95
$160.00
$15.00
$280.00
$278.00
$2,446.79
Not included in these tables is the labor cost involved in this project. After having
finished our project all hours related to design, construction and testing added up to be about 910
hours total, which multiplied by $20 per hour yields around $18,200 of prototype development
cost. The $20 per hour rate was used in these calculations since this is the average rate per hour
charged by machine shops in Miami, and is also around the average salary for in-training
engineers, such as ourselves. However of this time, 208 hours were devoted to machining the
different components; had the team contracted the services of Mr. Zicarelli at the FIU‟s
manufacturing center, this time would have been decreased to about 55 hours which would have
cost about $1375. If this prototype were to be mass produced then this price would be
significantly reduced.
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Paddle Maker Machine and Material Selection
The following graph shows the approximate amount of hours that each member worked
per week throughout the duration of these last two semesters. The peak represents the spring
break week where the team spent about 250 hours building the prototype. The total amount of
hours is as follow: Orena 389 hours; Jorge 393 hours; Nestor 396 hours.
Project Hours
70
60
Hours per week
50
40
Orena
30
Jorge
Nestor
20
10
0
0
5
10
15
20
25
30
# Weeks
Figure 31-Paddle Maker Team’s Total Hours
69
35
Paddle Maker Machine and Material Selection
7. Testing and Evaluation
7.1 Design of Experiments
7.1.1 Mack 3 CNC controller Input Verification
Using Mach3 software requires motor configuration outputs for step pin number and
direction pin number. Mach3 software is compatible with the Rockcliff CNC motor driver. The
figure below shows the pin assignment for the four steppers motors per Rockcliff manual. The
configuration is attached in Appendix R.
Figure 32-Conector Pins Assignment
Part of the setup was to obtain the correct velocity and acceleration for each stepper
motor. Figures 32-35 below are movement profile screenshots for X, Y, Z & A axis. The X axis
assigned to the drill assembly and the Y axis assigned to the saw assembly; both move in the
horizontal direction. The Z axis move the drill assembly vertically, and the A axis rotates the
wheels that move the sheet forward.
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Paddle Maker Machine and Material Selection
Figure 33-X-axis for Drill Assembly (Horizontal Direction)
Figure 34-Y-axis for Saw Assembly (Horizontal Direction)
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Paddle Maker Machine and Material Selection
Figure 35-Z-axis for Drill Assembly (Vertical Direction)
Figure 36-A-axis for Wheels (Angular movement)
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Paddle Maker Machine and Material Selection
7.1.2 G-Codes
Figure 37-X, Y, Z, A Axis Positive Movement
Simple G-code shown below was written and loaded to Mach3 software and used as
follow:

The A-axis rotates in the given amount of degrees (150), causing the sheet to move
forward the 1.75” width of paddle.

The first hole tapping drill cycle starts at zero X and at Z= -1.5 coordinates

The drill assembly goes up to Z= -1 coordinate

The drill assembly moves to X= - 5.5 to second hole position

Second hole tapping starts

The cycle continues for a total of 6 holes. The paddle center hole is not drilled

Cutter saw start to cut and moves Y= - 40, while the drill comes to X=0 zero home
position.

The sheet mover wheels go from an angle of 150 to 140 when saw finishes cutting to
guarantee that no contact takes place.

Saw and vertical axis Z of drill assembly goes to zero position at the same time

Sheet mover wheels turn 160, moving the work piece to the correct cutting position.

Program repeats for construction of next paddle.
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Paddle Maker Machine and Material Selection
PADDLE MAKER PROGRAM
g0a15(Sheet moves forward 15 degree)
(First hole tapping drilling cycle)
g0z-1.5
g0z-1.8
g0z-1.75
g0z-1.9
g0z-1.85
g0z-2
g0z-1.95
g0z-2.1
g0z-2.05
g0z-2.2
g0z-2.15
g0z-2.3
g0z-2.25
g0z-2.4
g0z-2.35
g0z-2.6
g0z-1
g0x-5.5 (Moving to second hole position)
(Second hole tapping drilling cycle)
g0z-1.5
g0z-1.8
g0z-1.75
g0z-1.9
g0z-1.85
g0z-2
g0z-1.95
g0z-2.1
g0z-2.05
g0z-2.2
g0z-2.15
g0z-2.3
g0z-2.25
g0z-2.4
g0z-2.35
g0z-2.6
g0z-1
g0x-11(Moving to third hole position)
(Third hole tapping drilling cycle)
g0z-1.5
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Paddle Maker Machine and Material Selection
g0z-1.8
g0z-1.75
g0z-1.9
g0z-1.85
g0z-2
g0z-1.95
g0z-2.1
g0z-2.05
g0z-2.2
g0z-2.15
g0z-2.3
g0z-2.25
g0z-2.4
g0z-2.35
g0z-2.6
g0z-1
g0x-22(Moving to fourth hole position)
(Fourth hole tapping drilling cycle)
g0z-1.5
g0z-1.8
g0z-1.75
g0z-1.9
g0z-1.85
g0z-2
g0z-1.95
g0z-2.1
g0z-2.05
g0z-2.2
g0z-2.15
g0z-2.3
g0z-2.25
g0z-2.4
g0z-2.35
g0z-2.6
g0z-1
g0x-27.5(Moving to fifth hole position)
(Fifth hole tapping drilling cycle)
g0z-1.5
g0z-1.8
g0z-1.75
g0z-1.9
g0z-1.85
g0z-2
g0z-1.95
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Paddle Maker Machine and Material Selection
g0z-2.1
g0z-2.05
g0z-2.2
g0z-2.15
g0z-2.3
g0z-2.25
g0z-2.4
g0z-2.35
g0z-2.6
g0z-1
g0x-33(Moving to sixth hole position)
(Sixth Hole Tapping Drilling Cycle)
g0z-1.5
g0z-1.8
g0z-1.75
g0z-1.9
g0z-1.85
g0z-2
g0z-1.95
g0z-2.1
g0z-2.05
g0z-2.2
g0z-2.15
g0z-2.3
g0z-2.25
g0z-2.4
g0z-2.35
g0z-2.6
g0z-1
g0y-40x0(Cutter saw start to cut while drill comes to zero home position)
g0a14(Sheet moves back one degree when saw finish cutting)
g0y0z0(Saw and vertical axis of drill assembly goes to zero position)
g0a16(Sheet moves 16 degrees forward)
m30(Program finished)
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Paddle Maker Machine and Material Selection
7.1.3 Plan and Recommendation for Material Testing
Plan:

First, we tested the Paddle Maker, by using small samples of similar materials such as
plastics and thin plywood sheet that are cheaper than polyethylene.

Secondly, a few sample paddles of different materials can be tested against wear
resistance by installing them in the Flight-Conveyor belt system.

After obtaining a desired material sheet Wear Resistance Test can be conducted to new
and current material using an instrument called „Tribometer‟. The highly advanced
Tribometer offers precise and repeatable wear/friction testing. The weight loss, COF and
Volume loss wear properties can be measured after some time. The less volume loss, and
the smaller the COF is, the better the material performs under friction.

Last, a tensile and hardness test will be conducted.
Recommendation:
Dr. Agarwal Arvind is the head of the plasma forming laboratory located in FIU
Mechanical Engineering department. The laboratory is a state of the art facility equipped for
tribological wear and friction characteristic of Ceramic, Metallic, Polymer, Carbon Nanotube
(CNT) Reinforced Composites and Biomaterials. He advised the group first to conduct a
literature search on wear resistance, and to determine the parameters of interest. After doing a
literature search, the parameters of interest for testing the UHMW-PE with the Tribometer were
finalized to be:
1. All Samples needed be ¼” x 1” x 1”. The size was chosen to fit in the tribometer tester.
2. Only a brief Diamond polish was suggested since material was smooth enough.
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Paddle Maker Machine and Material Selection
3. Normal load during wear 10N. It is a moderate load for a soft material when compared
to ceramic and metallic.
4. Wear distance: 300m. The distance will give consist data. A longer distance will wear
more.
5. Rotational speed: 300 rpm or 250 rpm (Considering approximately 0.1 m/s). The speed
is good for polymers were the wear loss is less than that of ceramic and metallic.
6. Wear track diameter: 6mm, Al2O3 ball. Time 50 min (3000sec). This will allowed
conducting 2 tests for each piece.
The following properties can be obtained after testing:
1. Wear volume
2. Wear Depth
3. Coefficient of friction
The Tribometer tester in FIU plasma lab features real time measurement of friction and
wear depth with a maximum load of up to 60N.
7.1.4 Theory Testing
The usage of angles on both sides of the paddle was tested since it was unclear whether
having angles on both sides instead of one would make a difference on the wearing of the paddle.
Thus a double angle was done manually to three of the existing paddles and they were mounted
in the conveyor along with the regular one sided angle design. After a month in the conveyor all
the paddles experienced the same friction and wearing action. They were dismantled from the
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Paddle Maker Machine and Material Selection
conveyor and three of the one sided angles were compared to the three with two sided angles.
Results are shown in the table and figure below seems to demonstrate that the second angle does
not contributes to the wearing of the paddle; which makes sense since this side is not in contact
with the frame of the conveyor itself as opposed to the other side angle that is in contact with the
moving material, in this case powder cement.
Table 7-Wear Measurements for Double and Single Angle Paddles
Measurements (inches)
Double angle Left Middle Right
Double 1 1.6770 1.6320 1.6560
Double 2 1.6580 1.6270 1.6655
Double 3 1.7075 1.7020 1.6625
Single angle
Single 1 1.6455 1.6325 1.6385
Single 2 1.6920 1.6565 1.6710
Single 3 1.6625 1.6690 1.6365
Original
New 1.7500 1.7500 1.7500
Figure 38-Double Angle vs Single Angle
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Paddle Maker Machine and Material Selection
7.2 Test Results
7.2.1 Paddle Material Comparison
An extensive search for an improved wear resistance ultra-high molecular weight
polyethylene sheet was conducted. The Gund Company is the current paddle supplier for RBT. It
is also the current vendor for the new and improved purchased material. A UHMW-PE sample
with crosslink process was obtained from the Horn Plastic Inc. Those three different materials
were tested, and their wear resistance properties compared.
Material:
Three physical properties for three different samples (Figure 41) were compared: Tensile
Strength, Modulus of Elasticity, and Hardness.
The current UHMW-PE used by RBT Company obtained from the Gund Company.
Physical Properties are:
Tensile Strength 2,500 PSI.
Modulus of Elasticity in tension 1.02 x 103 PSI.
Rockwell Hardness R38.
A purchased improved UHMW-PE from the Gund Company.
Physical Properties are:
Tensile Strength 5,500 PSI.
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Paddle Maker Machine and Material Selection
Modulus of Elasticity in tension 116 x 103 PSI.
Hardness, Durometer, shore “D” scale 68.
A purchased crosslink UHMW-PE sample from the Horn Plastic Inc.
Physical properties are unknown. Color is Orange.
Procedure:
1. Two pieces of each material were cut to length of ¼” x 1” x 1”.
2. Samples were diamond polished for a very short time. This was done in FIU AMRI
Lab.
3. A Tribometer Tester (Figure 39 and 40) located in FIU plasma lab was use to test and
compare wear resistance.
4. Test parameters:

Normal load during wear: 10N

Wear distance: 300m

Rotational speed: 300 rpm or 250 rpm (Considering approximately 0.1 m/s)

Wear track diameter: 6mm, Al2O3 ball

Time 50 min (3000sec)

Calculation for time and rpm:
𝑇𝑖𝑚𝑒 =
𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒
𝑉
=
81
300𝑚
0.1
𝑚
𝑠
= 3000𝑠
Paddle Maker Machine and Material Selection
𝑟𝑝𝑚 =
𝑉𝑒𝑙𝑜𝑐𝑖𝑡𝑦
𝜋∗𝐷𝑖𝑎
0.1𝑚
∗60𝑠
= 𝜋∗0.006𝑚𝑠 ∗1𝑚𝑖𝑛 = ~300𝑟𝑝𝑚
Figure 39-Tribometer Tester Setup
Figure 40-Ceramic Abrasive Ball on UHMW-PE Disc Test
Figure 41-Tested Samples
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Paddle Maker Machine and Material Selection
Results and Data:
Lab notes for weight loss obtained during test are in Appendix M. Excel data for all
tracks are included in the CD. Excel data result in Appendix N contains only a sample of 50 data
points out of 52,260. The Nanovea software for the tribometer tester gives 15 to 20 data points
per second. Total time for each track was 50 minutes. The software displays values of distance
(meters), Coefficient, and Ceramic ball Depth (mm).
The two graphs below show wear volume loss, and coefficient of friction values for all
three samples: Old Material, New Material, and Crosslink Material.
Figure 42-Wear Volume Loss Comparison
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Paddle Maker Machine and Material Selection
Figure 43-Coefficient of Friction Comparison
7.2.2 Paddle Maker Calibration
Calibration of the machine was done to assure that the right functioning of the Paddle
Maker was obtained. Through Trial and Error, all the stepper motors were calibrated, so that the
optimum speed and movement‟s distances were achieved. It took a few paddles for the machine
to get calibrated, but the end result was a coordinated machinery where all subassemblies worked
together as one. Paddles produced by this machine were of good quality and accuracy.
7.3 Evaluation of Experimental Results
7.3.1 Material
When testing different materials using a tribometer, coefficient of friction, weight loss,
and volume loss can be measured and compared. Comparing these parameters shows which
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Paddle Maker Machine and Material Selection
material has better wear resistance characteristics. Using the tribometer tester in the plasma lab at
FIU data for three samples was obtained and compared.
Volume loss formulas are shown in Figures 42. Volume data was obtained from excel
using LVDT column for depth h. The LVDT gives voltage signal when there is a small
displacement. The h data points were calculated as follows:
- The first points, up to where the graph starts having a trend of steady state, were not
considered because in the beginning of the test there is a transient higher friction causing an
increase in the curve.
- Next the average data points of the first minute, after steady state starts, were
subtracted from the last minute (the 50th minute).
Figure 44-Volume Loss Formulas
Where V - is wear volume loss.
A - is the area of sector minus triangle.
R - is the radius of Alumina ball.
r* - is the radius of wear track.
h - is the average depth (obtained from software data points)
L - is the track length
n - is the angle of the arc sector
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Paddle Maker Machine and Material Selection
Weight loss the data shown on the lab notes in Appendix N obtained using a scale before
and after each track. The scale measured in micro grams (0.0001).
Coefficient of Friction (Figure 43) obtained from the Excel data sheet.
Results:
COF Results:
New sample:

Up to the first 50 meters (Figure 43) the values are the lowest for both tracks when
compare to the other samples.

The values increased much higher for the second track only after the first 50 minutes.
Orange sample:

The values are the highest of both tracks
Old sample:

Trend is similar for both tracks. The average COF is similar in value.

For the first 50 meters the values are higher than those of the new sample
Weight Loss Results:

The data shown similar weight loss for both new and old samples.

There is an “increase” in weight loss for the cross link material.
Volume Loss Results:

The sample data for volume loss was as follow:
Old sample
2.14 mm3, 1.74 mm3
New sample
28.00 mm3, 26.54 mm3
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Paddle Maker Machine and Material Selection
Orange (crosslink) sample
1.65 mm3, 22.19 mm3
Because of the difference in the volume loss values for the orange sample another track
test done and volume loss measured 26.76 mm3
Figure 42 depicts a lower volume loss for the old material when compared to the new and
cross-link material. For each sample, old and new, both tracks were similar in values. The
Orange sample had one low and one high value and the test was repeated one more time.
The third test had high value. Only the higher values were considered for the orange
sample. It could be some experimental error which gave such lower value for the first
test.
Discussion and Conclusion:
In general, a lower COF and a lower volume loss, shows better wear resistance. The
results comparison for the three samples was not as expected. The Cross-linked and the new
material samples have higher COF and higher volume loss than that of the Old material.
However the weight loss measurements showed an increased in value and questions arose about
the test method. After further research about the subject we understood that the UHMW-PE
material does not always experience weight loss when using the ball on disk type test. Sometime
it is just compressed and the density is increased. In addition, because a load is applied on the
sample during the tribometer test and therefore compressed on the material, a question about
accuracy of the LVDT (h) values was raised.
Regarding the results for the cross linking material, in order to get a constant coefficient
of friction the molecular bonding should be good. Since data sheet for the crossed-linked sample
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Paddle Maker Machine and Material Selection
was not available from the vendor a conclusion can be made to exclude this material as a
comparison.
Regarding the new and old material, when buying it from the vender one cannot be sure
of the preparation and process the polymer was exposed to or if the material is homogenous or
not.
In conclusion, even though the COF is not that important, the concern is with the total
volume loss. With the ball being compressed and with the results not as expected, the conclusion
was that the volume loss data might not be accurate. Thus, a different method of measurements
needed to be obtained and is illustrated in section 7.4.1. Also, since polymers have good
bonding and can be compressed, whereas a ceramic material, for example, wears out because of
poor bonding, a different test method such as pin on disk and not a ball on disk must be
considered for the obtained polymer sheet. A Pin on disk abrasive type test method, where the
pin is made of the UHMW-PE and the disk is made of Aluminum oxide, will be closer to wear
conditions.
7.4 Improvement of the Design
7.4.1 Material Wear Resistance
The results shown in Section 7.2 and 7.3 prove that a search for a better wear resistance
material and a use of a different kind of test must be followed up. It is clear from the literature
survey and many studies done on that subject that cross-linked process on UHMW-PE can
improve wear resistance. The cross-linked sample tested in this experiment was shipped to us at
no cost and did not have any data sheet available. We contacted Electron Technologies
Corporation (ETC), a 47 year irradiation processing provider in New England, to ask their
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Paddle Maker Machine and Material Selection
expertise on how to improve wear resistance for UHMW-PE. The information gathered made
clear that research and development for different radiation doses on different samples must be
obtained and tested. In general, irradiation can improve the physical properties of cross-link bisection, or can degrade and make it brittle. Hence, depending on the level of the cross-linking
will give different physical properties. Radiation will increase the melting temperature and will
make it more solvent resistance, and a better heat resistant.
In ETC R&D facility they will apply three different radiation doses of 2.5MR, 5MR and
7.5MR. Testing of those samples, will determine which doses improve wear volume and COF.
However, the cost for one hour lab in R&D at their facility is $400. Since the budget is limited it
will be left for future evaluation. Additional information gathered from ETC about the price was
that once the radiation doses will be determined by us the cost for production at their facility will
be $20 per sheet.
Since the data obtained with the current ball on disk volume measurements were not as
expected, and since we concluded that this test is inappropriate for the polymer in use, three
approaches to measure the depth of the tracks were considered, as well as one different test
method.
1.
The three samples tested using the tribometer were cut vertically across the tracks using a
diamond cutter, and the depth of the track was measured using an optical comparator. Those
tools are available in AMRI lab in FIU. However, the high speed diamond saw was out of order
so this method was not an option.
2.
The Profiliometer tester located in AMRI lab (Figure 45) was used to measure surface
roughness. Using the Stylus 12.5 µ curved tip contact to measure surface roughness.
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Paddle Maker Machine and Material Selection
Figure 45-Profiliometer
Parameters input:

2000 µ m (2 mm) length of scan

0.2 samples per µ

8 sec
Output:

∆- average between upper and lower surface (Figure 45)
Figure 46-Average Delta Surface Roughness
Results:
There were inconsistent results measuring the same track. This relates to the fact that the
assumption is that the roughness outside the groove is at the same level. The stylus is a technique
for a smoother surface. Figure 47 depicts how the applied force pushed the material more
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Paddle Maker Machine and Material Selection
towards the track inner circle when using ball on disk tester. Hence, it is difficult to decide where
to take the average when the surfaces outside of the groove are not at the same level. Also, the
drop down groove of the tested sample is barely wide enough for the 12.5 micron Stylus
technique. The stylus has to travel some distance to give accurate results rather than just going
through a narrow groove.
Figure 47-Uneven Roughness
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Paddle Maker Machine and Material Selection
3.
An Optical Magnification Microscope
Figure 48-OMM
MX40 Olympus Optical Magnification Microscope (Figure 48) was used as other
technique to measure the track depth of the three samples. The upper and lower grooved surface
was measured using a focus adjustment gradation of 0.1mm minimum per increment.
Input:

A 2000 Magnification
Output:

New sample:
-First track measured average difference of 16 between upper and lower surface
-Second track measured average difference of 13 between upper and lower surface

Old sample:
-First track measured average difference of 17.5 between upper and lower surface
-Second track measured average difference of 20 between upper and lower surface

Orange sample:
-First track measured average difference of 33 between upper and lower surface
-Second track measured average difference of 18 between upper and lower surface
Results:
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Paddle Maker Machine and Material Selection
Smaller numbers mean the groove is less deep and therefore less volume loss. With the
Optical Magnification Microscope the new samples exhibit smaller volume loss; just the
opposite of the results that were obtained by calculation the volume loss using the
tribometer. (Appendix M – lab notes)
4.
A Pin on Disk test mentioned in the literary survey is being considered as an alternative
to the Ball on Disk test. Here the Pin is made of UHMW-PE and the Disk is made of Aluminum
Oxide Ceramic abrasive material. The weight loss will be measured in the same manner as in the
Ball on Disk test where the pin - and not the disk - is weighted.
The Optical Magnification Microscope depicts that the new samples has the smallest
volume loss and not the old sample.
After using the optical microscope one can conclude that with a groove making technique
(ball on disk) there is a wide range of results between the same sample (comparing the two
tracks) and between the old and new material. In the tribometer tester a load is applied on the
sample, and after taking out the load there is an elastic recovery of the material. The ball is
forced to go down while measuring the depth, but after the test is done the ductile material
relaxes and deforms back. That makes the LVDT less accurate, and therefore unreliable. When
using metal and ceramic material as discs, volume data is more accurate. In addition, with the
ball on disk method, local temperature causes the material to melt and deform. Melting can
increase the contact area of the ball, and this causes the friction force to increase. This might be
the explanation for the uneven roughness surface depicts in Figure 47 when using the
Profiliometer.
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Paddle Maker Machine and Material Selection
7.4.2
Overall Machine Components and Design
In the current design simple threaded rods are used to aid the drilling and sawing stations
to move in the horizontal direction. In order to improve the travel distance and speed of the
assemblies a precision lead screw from Grainger catalog (Appendix P) with ½ inch travel pitch
will have to be purchased. The cost for two lead screws, one for the drill and one for the saw is
$320.
The maximum speed for the stepper motor in the current design is 950 RPM. Each
assembly has to travel a horizontal distance of approximately 45”. If a new lead screw, of 1”
pitch, is purchased, it will take 2.84 sec for the saw and drill to travel the 45”. Figure 49 shows
comparable calculations for the time it takes when the lead screw comes with 1” and ½” travel
distance per revolution.
Figure 49-Travel Time Using Precision Lead Screw
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Paddle Maker Machine and Material Selection
8. Design Considerations
8.1 Assembly and Disassembly
In every mechanical system where wear and tear exists, the design challenge brings the
concern of flexible and fast maintenance. It is a fact that at some point in the life cycle of any
machine, maintenance will have to be performed to its moving components; consequently the
gaining easy access to these components that require maintenance is a characteristic that
concerns every user. Easy access means less time spent maintenance is done to the machine,
therefore saving money and down time. The flexibility of replaceable parts is a key feature as
well, particularly for those parts in contact with the product being handled. For these reasons
most of the components of the machine were designed to be attached with bolts for easy
disassembly, replacement and assemble process. The only component of the machine that was
permanently welded is the table structure, which is expected to have lifetime durability under
normal operating conditions.
8.2 Safety and Maintenance Procedure
The Safety Information Manual is attached in Appendix G. It includes general safety
information for machine shop usage of such a machine. It is clearly stated in this manual that all
personal working with this machine must follow the safety rules explained therein. Failure to
follow instructions can result in severe injury or death. OSHA [25] code violations must be
followed. Also it is mentioned that only authorized trained personal should operate the machine.
The manual is divided into four sections:

The 1st section is general machine shop safety information.

The 2nd section includes conveyor safety information, operation and maintenance.
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Paddle Maker Machine and Material Selection

The 3rd section contains table saw safety information, operation and maintenance.

The 4th section includes drilling safety information, operation and maintenance.
In addition, the safety manual includes all warning and hazards signs to be displayed in
the shop to assure personal awareness.
8.3 Environmental Impact
An assessment of the possible environmental impact of chemical or hazardous materials
being used must be taken into account while constructing a machine. The impact can have
positive or negative social and economical aspects.
Grease will be used to lubricate the machines‟ components. In addition, drilling holes
through plastic sheets, and the scraping corners of the paddles will create a great deal of chips. It
is our responsibility as engineers to promote a clean environment by recycling the chips, and
ensuring the use of non hazardous lubricants that will not cause severe health problems.
EP-2 lubricating grease will be used to lubricate the components. The machine will need
to be lubricated every 250 operational hours. It is a petroleum based mineral oil, which can cause
slight irritation when in contact with skin. The major environmental impact to be considered
relates to oil waste. Grease should not be disposed into water. When it floats on water it
eliminates the oxygen from being transport into the water and hence causes death for fish and
other marine life. It is the user‟s responsibility to dispose the grease in according with state
regulations and use approved containers meeting OSHA requirements.
All plastic chips generated from the machining of the paddles will be recycled. Plastics
are a man made product, and therefore it can and must be reused. A recycling program from an
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Paddle Maker Machine and Material Selection
vendor specializing in this field should be employed by the user so the machine will not have a
negative impact on the environment.
8.4 Risk Assessment
In the United States, machine safety and healthful working conditions for employee are
regulated by Occupational Safety and Health Administration (OSHA). This administration
provides information on installation of machine safety and proper guarding. A few organizations
have their own regulation; however those must as be firm as OSHA standards. In addition to
OSHA, other organizations such as the American National Standards Institute (ANSI) provide
information on construction, care and use of machine tools. This information is published as B11
standards. Certain standards are developed for specific types of machine tools. Standards in the
B11 series that are related to this project include:
B11.1: Mechanical Power Presses
B11.8 Drilling, Milling and Boring Machines
B11.10 Metal Sawing Machines
Purchasing the “ANSI B11.XX Machine Tool safety Package” is expensive. Therefore a
Safety Manual, attached in Appendix G, includes safety information that was gathered using
OSHA website and related links. Also, FIU Machine shop safety manual was used as a reference.
Safety Information Manual for the Paddle Maker Machine is attached in appendix G. It
includes instruction for Installation, Operation and Maintenance on Conveyor, Drilling and
Sawing operations.
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Paddle Maker Machine and Material Selection
Conveyors are one of the best productivity tools available to warehouses, and industrial
facilities. However, employers are losing millions of dollars each year due to conveyor related
injuries. The United States Department of Labor Bureau of Labor Statistics reports around fifty
workplace fatalities a year where conveyors are the source of injury. In general, conveyors are
safer than other material handling alternatives if they are maintained and designed properly. To
address the concern of conveyor related injuries the safety information below must be considered
by the employers:
1. Since guards make up one the most common types of safety devices used for the
protection of conveyors, they have to be maintained regularly. In addition warning signs
must be readable.
2. Conveyors operate using power transmission. Items such as gears, shafts, and belts are
common to all conveyors; therefore they must be guarded from exposed power
equipments to prevent accidents.
Typical items to be guarded include:

Drive Guards for chain, v-belt, and gearing. Guards can be constructed of different
materials such as: expanded metal, solid sheet metal, and plastic. They must be securely
fastened to the conveyor framework.

Coupling Guards to be provided when they are used to connect shafts. They must be
assembled around the connections between motors and gearboxes.

End Shaft Guards – They must be assembled in order to prevent items from becoming
caught in shafts. In particular, the protruding ends of the rotating shafts are dangerous.
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Paddle Maker Machine and Material Selection
A table saw is one of the most dangerous pieces of equipment in a workshop. An
increased awareness for caution is needed while working with a saw blade. This sharp, multitoothed blade usually spins at high rpm therefore care is required when working near the blade.
According to the US Consumer Product Safety Commission there are approximately 60,000
injuries each year related to saw blades. Another cause of table saw accidents is what is called
„kickback‟. Kickback happens when the blade catches the material and throws it back towards
you. Kickback can be caused by a variety of different things including:
1. When the blade is pinched by an internal stress in the work piece.
2. The work piece moves up or sideways during a cut
3. The material is pinched between the rear of the blade and the fence.
4. Underpowered saw.
It is very important to minimize the potential saw blade injuries occurring. This can be
done by applying the safety rules when working with such a machine.
The Paddle maker machine includes an automated drilling operation, run by step motors
and using a drill bit. The drilling operation will allow us to drill a defined hole into or through an
UHMW-PE work piece in a very repeatable manner. However power drills can cause severe
injuries. According to U.S. Consumer Product Safety Commission data for year 2003,
approximately 4,100 people received hospital treatment for power drill related injuries.
A video named “E-061Saws/Grinder/Drill Press Instruction” is available from the ANR
Environmental Health and Safety Library at http://safety.ucanr.org. To avoid accidents, the
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Paddle Maker Machine and Material Selection
operational safety rules attached in Appendix G must be observed and understood by everyone
working on the Paddle Maker Machine.
9. Conclusions
The main objectives of this project were to design and construct a prototype of a machine
that will manufacture paddles for a specified application and to explore the properties of the
material being used to manufacture these paddles in the search for a material with better
performance. The theoretical design of the prototype was not very complex. With the assistance
of several computer software and the knowledge acquired in the course of our studies, the most
relevant engineering analyses were conducted and the results are presented in this report.
The final prototype was decided upon after analyzing all the alternatives discussed in the
Design Alternatives section. After considering all factors of interest, it was decided to build the
presented design, which was called “Paddle Maker”. This decision took into account aspects
such as: machine cost, production cost per paddle, design reliability, part availability,
construction time, environmental impact and safety.
After all the dedicated work by each member of the team was combined, the results can
be seen on a functional machine that performs the required tasks. The team realizes that there are
still several aspects of the project that can be improved such as changing the whole thread rods
by lead screws, and replacing the drill motor by a more suitable one. This would allow for
smoother running of the system and as a result the production time will be decreased and the
machine and motor life extended.
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Paddle Maker Machine and Material Selection
Further testing and optimization of both the paddle and the Paddle Maker are an ongoing
process, since there are a few suggestions that can be implemented as explained in the Future
Work section.
Several comments can be stated as well in relation to the material study. Although the
results were not as predicted, the test gave us in depth understanding of the behavior of polymers
and their wear properties. The ball on disk is a test widely used for metal and ceramics. In this
case of testing the UHMW-PE, several phenomena like melting and plastic deformation seems to
affect the wear volume which explains why the results are not as expected knowing tensile
strength property.
There is a need to confirm the results through other test method such as hardness and pin
on disk abrasive type. In addition, more statistical data is required.
A further search for better wear resistant materials such as study effect of radiation doses
on the wear property should be followed.
As a group of prospective engineers, extraordinary effort was taken by all members of the
team to finalize the design and construction of a functional machine within the time limit
presented in the Timeline chart, as well as to find a material with better performance than the
existing one.
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Paddle Maker Machine and Material Selection
10. Future Work
Even though the prototype has already been finished, and it is working, some parts can be
replaced to improve the overall efficiency, quality and performance of the machine.

The two whole thread rods moving the drill and saw assembly should be replaced with
lead screws (Appendix P) to improved accuracy, production time and lifespan of the
machine.

A round corner router needs to be added to the saw assembly so that the side angle can be
obtained; since it will be mounted in parallel to the saw, the same stepper motor will
move the whole assembly.

Most raw material suppliers provide sheets of up to 102 inches long; therefore the rolling
table could be extended to handle longer sheets of raw material.

The circular saw blade used in this prototype should be substituted with one especially
made for cutting soft plastics (Appendix F) that would provide a better finished cut .

The drill motor can be replaced with one that is more suitable for that task, as shown in
Appendix L, thus increasing the durability of the machine, yet rising its price.

A system that would allow for the collection of the produced paddles needs to be
developed so that production of many paddles can be achieved in an organized and fast
manner. The team proposes to built a slider mechanism that would attached to the end of
the machine where paddles are output, and through which the paddles will slide down to
a collection table.

All the electronics should be optimized by electrical engineer since it was designed using
elemental knowledge of circuitry and electricity. The main elements that need to be
looked at are the wire sizes, power supply selection and motor efficiency.
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Paddle Maker Machine and Material Selection
11. References
[1] Shirong Ge, Shibo Wang, Norm Gitis, Michael Vinogradov, Jun Xiao, Wear behavior and
wear debris distribution of UHMW-PE against Si3N4 ball in bi-directional sliding,
Journal of Polymer Wear Testing Vol 264, 571-578, 2008
[2] S.A.R. Hashmi, Somit Neogi, Anuradha Pandey, Navin Chan, Sliding wear of PP/UHMWPE blends: effect of blend composition, Journal of Polymer Wear Testing Vol 247, 9-14, 2001
[3] Shirong Ge, Qingliang Wang, Dekun Zhang, Hua Zhu, Dangsheng Xiong, Chuanhui Huang,
Xiaolong Huang, Friction and wear behavior of nitrogen ion implanted UHMW-PE against
ZrO2 ceramic, Wear Testing Vol 255, 1069-1075, 2003
[4] Shigley, Joseph, Mischke, Charles, Brown, Thomas H, Standard Handbook of Machine
Design, 3rd edition
[5] Richard G. Budynas, and Keith Nisbett, Mechanical Engineering Design, 8th edition,
McGraw Hill, New York, 2008
[6] ASM Handbook, Vol.8, Mechanical Testing and Evaluation, ASM International, Material
Park, OH, 2000
[7] JT.Black, Ronald A. Kohser, Materials and Processes in Manufacturing, 10th edition, John
Wiley & Son, USA, 2008
[8] Michael Bauccio, American Society for metals, ASM Metal reference Book, ASN
International, 1993
[9] ASHBY, M F. 'Materials Selection and Process in Mechanical Design.' Butterworth
Heinemann, Oxford, 1999 ISBN 0-7506-4357-9
[10] Ashby, Mike and Johnson, Kara Materials and Design, the Art and Science of Materials
Selection in Product Design Butterworth Heinemann, Oxford, 2002 ISBN 0-7506-5554-2
[11] Courtney, T.H, Mechanical Behavior of Materials, 2nd edition, MeGraw Hill Higher
Education, Burr Ridge, IL, 2000
[12] Cowie, J.M.G., Engineered Material handbook, Vol 2, Engineering Plastics, ASM
International, Material park, OH, 1988
[13] Raymond Gauvin , Investigating the Thermoform ability of Uhmw-Polyethylene, Journal of
Plastic Film and Sheeting, Vol. 3, No. 4, 312-324 (1987)
[14] http://www.thomasnet.com/products/plastic-machinery-equipment-supplies-597512061.html - ThomasNet, industrial resource for Plastic Machinery, Equipment & Supplies
103
Paddle Maker Machine and Material Selection
[15] http://www.polysort.com/linksdirectory/machinery.aspx - PolySort, Plastics & Rubber
Machinery & Equipment, (industry news and web design tips)
[16] http://www.americanplasticscorp.com/products/polyeth.html- American Plastic Corp.
[17] http://en.wikipedia.org/wiki/Ultra_high_molecular_weight_polyethylene- Wikipedia
[18 http://www.plasticrubbermachines.com/plastic-cutting-machine.html - Plastic and Rubber
Machinery Place
[19] http://www.nanovea.com/Tribometers.html- Nanovia company
[20] http://www.cisco-eagle.com/systems/conveyors/Conveyor-Safety/conveyor-safetymanual.pdf- Conveyor safety
[21] http://www.northerntool.com/downloads/manuals/1591806.pdf
Blade Safety
[22] http://www.ccohs.ca/oshanswers/safety_haz/metalworking/general.html
Drill Safety
[23] http://www.machinesafety.net/na_machine_safety_standards.html
Machine Shop Safety
[24] H:\RTZ\My Docs\EIN3390L Lab Manual\VII. Safety\FIU EMC Safety Manual.doc
FIU Machine Lab safety manual
[25] www.OSHA.gov
OSHA Guidelines
[26]www.technet.unsw.edu.au/tohss/web%20files/drillpress1.pdf
Drill Press Safety
[27]http://safety.ucanr.org
Video Saws/Grinder/Drill
[28] http://patft.uspto.gov/
US patent search website
[29] Grainger catalog
Purchase machine components
[30] http://www.kaltenbachusa.com/saws-and-equipment/structural-fabricating/KD-drillingmachines/default.html
104
Paddle Maker Machine and Material Selection
[31] Singiresu S. Rao, Mechanical Vibration, 3rd addition, Addison Wesley Publishing
Company, USA 1955
[32] Dewalt catalog
Saw specification
[33] http://www.machsupport.com/
Art Soft Mach 3 software
[34] Mcmaster catalog
Purchase components
105
Paddle Maker Machine and Material Selection
12. Appendices
Appendix A-Paddle Material Data Sheet
The two following data sheets were obtained from the user manual of the RBT.
106
Paddle Maker Machine and Material Selection
107
Paddle Maker Machine and Material Selection
Proposed material from the same vendor but with beter wear resistance.
108
Paddle Maker Machine and Material Selection
Appendix B-Data Sheets From Different Vendors
Vendor 1- Interstate Plastic
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Paddle Maker Machine and Material Selection
Vendor 2- RPlastic.com
110
Paddle Maker Machine and Material Selection
Appendix C-New vs. Damaged Paddle
Figure 50-New vs. Damaged Paddle
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Paddle Maker Machine and Material Selection
Appendix D-RBT Drag-A-Flight Conveyor
Figure 51-Drag a Flight Conveyor from RBT
112
Paddle Maker Machine and Material Selection
Appendix E-Water Jet Machining Illustration
Figure 52-Precise Cutting, Clean and Smooth Finish of Water Jet Machining
113
Paddle Maker Machine and Material Selection
Appendix F-Drill Bit and Saw Blade Description
114
Paddle Maker Machine and Material Selection
115
Paddle Maker Machine and Material Selection
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Paddle Maker Machine and Material Selection
Appendix G-Safety Manual
Safety Information Manual
IMPORTANT!
FAILURE TO FOLLOW THESE SAFETY
INSTRUCTIONS CAN RESULT IN SEVERE
INJURY OF DEATH
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Paddle Maker Machine and Material Selection
GENERAL:
ONLY TRAINED AND AUTHORIZED PERSONEL MAY OPERATE THE
MACHINE.
PROPER EYE PROTECTION MUST BE WORN BY OPERATOR AND ALL
OBSERVERS
1. No Smoking is permitted!
2. Clear Working Area: The area around loading and unloading points shall be kept clear
of obstructions which could endanger personnel.
3. Machine Service: Service machine with only authorized maintenance personnel.
4. Eye Protection: Approved eye protection must be worn at all times in the shop area.
5. Wear Proper Apparel: Appropriate clothing is required while operating the machine. It
is prohibited to wear shorts and open toed shows.
Wear protective hair covering to contain long hair to prevent becoming entangled in the
machines.
Do not wear gloves; do not hold rag while operating machinery. They can be easily
caught in the machines that are in motion, pulling the operator into the equipment.
6. Keep Hand Clear of Moving Parts: Hands are to be kept clear of moving parts while
equipment is in motion. Machines must be completely stopped before handling moving
parts or the work piece.
7. Keep Guards in Place: The safety guards are to be kept in place at all times, unless the
shop supervisor gives you permission to remove them.
8. Prevent Slippage: Spill fluid or cutting material found around work area must be clean
immediately to prevent slipping and injury.
9. Care of Hazardous Material: Only approved chemicals will be used. All hazardous
materials and their disposal must meet OSHA requirements.
Contact the Environmental Safety Office for disposal of all chemicals.
10. Turn Power Off: Never leave tools running unattended. Turn power off.
11. Turn the Motor Switch Off and unplug from the power source when not in operation
12. Reduce the Risk of Unintentional Starting. Make sure switch is in off position before
plugging in.
13. Never stand on tools.
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Paddle Maker Machine and Material Selection
14. Plug in the Tool: Using a power source with voltage less than the nameplate rating is
harmful to the motor.
15. Extension Cord: Make sure your extension cord is in good condition. When using an
extension cord, be sure to use one heavy enough to carry the current your product will
draw. An under sized cord will cause a drop in line voltage resulting in loss of power and
overheating.
16. Manager must be notified immediately if broken tools are found or if the machine
is not operating correctly.
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Paddle Maker Machine and Material Selection
Conveyor
Safety
SAFTEY INFORMATION
 INSTALLATION
1. Interfacing of Equipment. When two or more pieces of equipment are interfaced,
special attention shall be given to the interfaced area to insure the presence of adequate
guarding and safety devices.
2. Guarded by Location or Position. Where necessary for the protection of employees
from hazards, all exposed moving machinery parts that present a hazard to employees at
their work station shall be mechanically or electrically guarded, or guarded by location or
position.
When a conveyor passes over a walkway, or work station, it is consider guarded solely
by location or position if all moving parts are at least 8 ft. (2.44 m) above the floor or
walking surface or are otherwise located so that the employee cannot inadvertently come
in contact with hazardous moving parts.
 OPERATION
1. Do Not Ride, Step, Sit or Climb on Conveyor.
2. A conveyor shall be used to transport only material it is capable of handling safely.
3. The work piece must be securely clamped before turning machine ON
4. Don't perform service on conveyor until motor disconnect is Locked Out!
5. Inspections and preventive and corrective maintenance programs shall be conducted to
insure that all safety features and machine parts are functioning properly.
6. Keep clothing, fingers, hair, and other parts of the body away from conveyor!
7. Don't load conveyor outside of the design limits.
8. Don't remove or alter conveyor guards or safety divides.
9. Know location and function of stop/start push button.
10. Keep all stopping/starting control devices free from obstructions.
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Paddle Maker Machine and Material Selection
11. Ensure all personnel be clear of conveyor before starting.
12. Report all unsafe practices and machine parts to your manager.
 MAINTENANCE
1. Maintenance, such as lubrication and adjustments, shall be performed only by qualified
and trained personnel.
2. It is important that a maintenance program be established to insure that all conveyor
components are maintained in a condition which does not constitute a hazard to
personnel.
3. When a conveyor is stopped for maintenance purposes, starting devices or powered
accessories shall be locked or tagged out in accordance with a formalized procedure,
designed to protect all person or groups involved with the conveyor against an
unexpected start.
4. DO NOT lubricate conveyors while they are in motion. Only trained personnel who are
aware of the hazard of the conveyor in motion shall be allowed to lubricate.
5. Maintain all guards and safety devices IN POSITION and IN SAFE REPAIR
6. Maintain all warning signs in a legible condition and obey all warnings.
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Paddle Maker Machine and Material Selection
Saw Blade
Safety
SAFETY INFORMATION
 INSTALLATION
A new saw blade and blade guard are not in the installed condition. Assemble as follows:
CAUTION:
Always unplug the tool before assembly.
1. Installing a new saw blade: Uninstall the circular saw blade by loosening the screws
holding the blade. Always make sure that while dismantling, your arms or body is not
directly in front of the saw.
Assemble the new blade making sure that the blade‟s teeth are pointing down at the tip of
the roller table and aligned in the direction of cutting.
CAUTION: Avoid having dust or dirt on the flange, as this could provoke slippage of the
blade.
Securely adjust the new saw blade to the assembly with a wrench, using a glove if
necessary
Installing blade guard
CAUTION: Before installing the blade guard, adjust the depth of cut to its maximum
elevation. Insert the spreader between the blade guard mounting portion (stay) and the pressure
plate.
Tighten the hex bolts (A) with the offset wrench. The spreader installing location is
factory-adjusted so that the blade and spreader will be in a straight line. However, if they are not
in a straight line, loosen the hex bolts (B) and adjust the blade
guard mounting portion
(stay) so that the spreader is aligned directly behind the blade. Then tighten the hex bolts (B) to
secure the stay.
CAUTION: Always grasp the striped portion of the offset wrench when tightening the
hex bolts. If you tighten the hex bolts while grasping the offset wrench further than the striped
portion, the hex bolts may be damaged and/or an injury to your hand may result. If the blade and
spreader are not aligned properly, a dangerous pinching condition may result during operation.
Make sure they are properly aligned. You could suffer serious personal injury while using
the tool without a properly aligned spreader.
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Paddle Maker Machine and Material Selection
NEVER make any adjustments while tool is running. Disconnect the tool before making
any adjustments.
There must be a clearance of about 4 - 5 mm (5/32” - 13/64”) between the spreader and
the blade teeth. Adjust the spreader accordingly and tighten the hex bolts (A) securely. Attach
the table insert on the table, then check to see that the blade guard works smoothly before
cutting.
2. Adjusting depth of cut The depth of cut may be adjusted by turning the handle. Turn the
handle clockwise to raise the blade or counterclockwise to lower it.
NOTE: Use a shallow depth setting when cutting thin materials in order to obtain a
cleaner cut.
3. Adjusting bevel angle Loosen the lock lever counterclockwise and turn the hand wheel
until the desired angle (0° - 45°) is obtained. The bevel angle is indicated by the arrow
pointer. After obtaining the desired angle, tighten the lock lever clockwise to secure the
adjustment.
CAUTION: After adjusting the bevel, be sure to tighten the lock lever securely.
4. Adjusting positive stops The tool is equipped with positive stops at 90° and 45° to the
table surface. To check and adjust the positive stops, proceed as follows: Move the hand
wheel as far as possible by turning it. Place a triangular rule on the table and check to see
if the blade is at 90° or 45° to the
table surface. If the blade is at an angle shown in
Fig. A, turn the adjusting screws clockwise; if it is at an angle shown in Fig. B, turn the
adjusting screws counterclockwise to adjust the positive stops.
5. Switch action This tool is equipped with a special type of switch to prevent unintentional
starting. To start the tool, first depress the switch lever. While keeping it depressed, pull
its lower portion toward you. To stop the tool, press the lower portion of the switch lever
CAUTION: Always use “work helpers” such as push sticks and push blocks when
there is a danger that your hands or fingers will come close to the blade.
Always hold the work piece firmly with the table and the rip fence or miter gauge. Do not
bend or twist it while feeding. If the work piece is bent or twisted, dangerous
kickbacks may occur.
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Paddle Maker Machine and Material Selection
NEVER withdraw the work piece while the blade is running. If you must withdraw the
work piece before completing a cut, first switch the tool off while holding the work piece
firmly. Wait until the blade has come to a complete stop before withdrawing the work
piece. Failure to do so may cause dangerous kickbacks.
NEVER remove cut-off material while the blade is running.
NEVER place your hands or fingers in the path of the saw blade. Be especially careful
with bevel cuts.
Always secure the rip fence firmly, or dangerous kickbacks may occur.
Always use “work helpers” such as push sticks and push blocks when cutting small or
narrow work pieces, or when the dado head is hidden from view while cutting.
6. Work helpers Push sticks, push blocks or auxiliary fence are types of “work helpers”.
Use them to make safe, sure cuts without the need for the operator to contact the blade
with any part of the body.
 OPERATION
CAUTION:
1. NEVER remove cut-off material while the blade is running
2. NEVER place your hands or fingers in the path of the saw blade. Be especially careful
with bevel cuts
3. NEVER stand or permit anyone else to stand in line with the path of the saw blade.
4. Read the Manual: Read all warning labels and the owner‟s manual before operating the
saw.
5. Direction of Feed: Feed work into a blade or cutter against the direction of rotation of
the blade or cutter
6. Check for damaged Blade before operation. Ask a technician to replace cracked or
damaged blade immediately.
7. Watch for Vibration: that could indicate poor installation.
8. Use blade guards
9. Minimize the blade height. Ensure the height is ¼” to ½” below the gullet.
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Paddle Maker Machine and Material Selection
10. Do not wear gloves Gloves cause a loss to your sense of touch as well as a possible loss
of gripping power.
11. Lower Blade When Work is Done: After finishing your work the saw blade should be
lowered below the table
12. Use a sharp, clean blade.
13. Never „freehand‟ a cut
14. Stop Button: Ensure that the stop button is easily accessible.
15. Turn off the saw before removing small cut off pieces
16. Use eye and ear protection
17. Do not reach over the saw blade when it is running. This puts you off balance and you
could slip into the blade
 MAINTENANCE
CAUTION: Always be sure that the tool is switched off and unplugged before attempting
to perform inspection or maintenance.
1. Cleaning: Clean out chips from time to time.
2. Lubrication: Keep the saw in running condition at all time to assure maximum service
life
3. Lubrication places:
-Threaded shaft to elevate the blade
-Elevation guide shafts on motor
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Paddle Maker Machine and Material Selection
Electric Drill
Safety
SAFETY INFORMATION
 INSTALLATION
1. Ensure that the drill machine has a start/stop button within easy reach of the operator.
Further details will be added as the machine is completed.
 OPERATION
CAUTION: THE MACHINE IS RUNNING AUTOMATICALLY WHEN
SWITCH TURNED ON
1.
Prior to or before operating this machinery operator must ensure that he/she understood
the owner‟s operator‟s manual.
2.
Learn the machine's applications and limitations, as well as the specific potential
hazards peculiar to this machine. Follow available operating instructions and safety
rules carefully.
Do not allow hands to come in contact with the drills bit while it is in motion
3.
The work piece must be securely clamped
4.
Use a vacuum, brush or rake to remove cuttings
5.
Remove burrs and chips from a drilled hole
6.
Keep drill bits clean and sharp. Dull drills are a common cause of breakage.
7.
Keep floor around the drill machine free of oil and grease.
8.
Keep guards in place and in good working order
9.
Do not remove cuttings by hand. Wait until the machine has stopped running to clear
cuttings with a vacuum, brush or rake
10. Do not leave machines running unattended. Turn power off
11. Be sure the power is shut off before changing drill bits
12. Be sure drill bit or cutting tool is securely locked in the chuck
Inform the technician if the tool seems to be malfunctioning or is damaged.
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Paddle Maker Machine and Material Selection
Appendix H-Paddle Maker‟s User Manual
Paddle Maker’s User Manual
In the following document the steps necessary for the user to effectively operate the
Paddle Maker Machine are named and explained.
Figure 53-Paddle Maker Prototype
Be advised that using this machine may cause harm if safety precautions and instructions in this
manual are not followed. Please refer to the Safety Manual also attached in this report for further
details. Also note that for an accurate cut, given the nature of UHMWPE that this machinery
should be inside a closed facility, kept at room temperature, to avoid deflection and dust in the
work piece. In between paddles have an employee dust the work piece with a pressure air hose.
It is of great importance to know beforehand, the direction and purpose of each axes. For this
refer to the table below:
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Paddle Maker Machine and Material Selection
Table 8-Axis Function and Direction
Axis
X
Y
Z
A
Function
drill horizontal movement
Saw horizontal movement
drill vertical movement
sheet mover
+ Direction
to the rigth
to the rigth
up
clockwise
Operation Routine
1. Do not Turn Power On.
2. Check that the sheet of UHMWPE is in the starting position by the end of the roller table,
being pressed by the rubber wheels of the table mover mechanism.
3. Assure that the screw connections between the computer and the driver in the hardware
box are not loose.
4. Verify that the saw‟s blade is in good condition and well adjusted.
5. Check that the drill bit in the drilling assembly is operable.
6. Connect both the machine and computer plugs to the outlets.
7. Turn on the computer and open Mach 3 Loader.
8. Load the G-code attached in section 7.1.2 of this report.
9. Make sure that the four axes; X, Y, Z, A are in their respective home positions.
NOTE: If axes are not at home position then follow the section: Moving the
axis to home position below.
10. Turn the saw and drill SWITCHES ON.
11. On The Monitor click Start Cycle on Mach 3.
12. Carefully supervised that the machine is functioning adequately, and that the final
product (paddle) quality is good.
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Paddle Maker Machine and Material Selection
ATTENTION: If needed, STOP the cycle using the ESC button on the keyboard,
or STOP icon in the Mach3 interface, or by pressing the
EMERGENCY BUTTON in the electronic box at the right side of
the machine.
13. When there is not enough material left to do one more paddle, the machine should be
stopped and a new sheet of material will be replaced
14. Repeat steps 1-13.
Moving the axis to home position
If moving an axis to his home position is required then the following steps are to be followed.

Go to MDI tab in the Mach3 interface

In the input line write: G0 x0 y0 z0 a0, all axis should move to their initials positions

If they are not, then you need to input G0 followed by the axis and the distance wished to
be moved; until the zero initial position is reached namely the first hole.

Then go to the Reference All Home section, and click on the axis you just moved to the
desired initial position.

You have just set your starting point for that axis. Same process can be repeated for all
other axes.

Notice that when using this procedure, the system of coordinate being used is absolute.
Example: if you need to move the x axis 2 inches to the right, then input: G0 X2, supposing that
the position you are moving in from is the zero position. Let‟s say that the actual position shown
in the Mach3 CNC Controller under this axis is not zero but x40, and you want to move to the
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Paddle Maker Machine and Material Selection
right 2 inches then you would need to input: G0 X42. Similarly if moving the z axis 3 inches
down, from the zero position, then inputting: G0 Z-3 would accomplish that.
For further details on using G-code and M-codes click on the bottoms found in left hand corner
of the Mach3 interface.
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Paddle Maker Machine and Material Selection
Appendix I-Linear Stage Specifications
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Paddle Maker Machine and Material Selection
Appendix J-Torques Calculation
1 of 2
132
Paddle Maker Machine and Material Selection
2 of 2
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Paddle Maker Machine and Material Selection
Appendix K-Deflection Analysis of Linear Shaft
The following data was the input parameters and the corresponding results obtained from
Beam 2D
BEAM LENGTH = 40.0 in
MAXIMUM BENDING MOMENT ***
MATERIAL PROPERTIES
-50.0 lb-in at
0.0 in
Steel AISI 4140 N:
-50.0 lb-in at
40.0 in
Modulus of elasticity = 29000000.0 lb/in²
50.0 lb-in at
20.0 in
Stress limit = 95000.0 lb/in²
MAXIMUM SHEAR FORCE ***
CROSS-SECTION PROPERTIES
5.0 lb from 0.0 in to 20.0 in
Moment of inertia = 0.003067962 in^4
-5.0 lb from 20.0 in to 40.0 in
Top height = 0.25 in
Bottom height = 0.25 in
MAXIMUM STRESS ***
Area = 0.1963495 in²
Tensile
= 4074.366 lb/in² No Limit
specified
EXTERNAL CONCENTRATED FORCES
Compressive = 4074.366 lb/in² No Limit
10.0 lb at 20.0 in
specified
Shear (Avg) = 25.4648 lb/in²
SUPPORT REACTIONS ***
No Limit
specified
Fixed at 0.0 in
Reaction Force =-5.0 lb
ANALYSIS AT SPECIFIED LOCATIONS ***
Reaction Moment =-50.0 lb-in
Location
Fixed at 40.0 in
= 20.0 in
Deflection = 0.03746543 in
Reaction Force =-5.0 lb
Slope
Reaction Moment = 50.0 lb-in
= 0.00000000000000008 deg
Moment
= 50.0 lb-in
Shear force = 5.0 lb
MAXIMUM DEFLECTION ***
Tensile
= 4074.366 lb/in²
0.03746543 in at 20.0 in
Compressive = 4074.366 lb/in²
No Limit specified
Shear stress = 25.4648 lb/in²
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Paddle Maker Machine and Material Selection
Appendix L-Drill Motor Options
Company: Bodine Electric Company
Company: Sinotech
140 Watt 100mm AC Gear motors
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Paddle Maker Machine and Material Selection
Characteristics of Motors Used In Gearmotors
Model
Motor
6IK140A-AF
induction motor
6IK140A-CF
induction motor
6IK140A-SF
induction motor
6IK140A-S3F
induction motor
Out-
Motor with gear
shaft
put
W
Rated
Volt
Freq Poles
Duty
V
Start
Spd Curr Torq torq
rpm
A
N.m N.m
Capacitance
Hz
P
μF/VAC
140 1ph110
50
4
CONT 1350 2.00 0.99 0.90 30.0/250
140 1ph220
50
4
CONT 1350 1.13 0.99 0.90 10.0/450
140 3ph220
50
4
CONT 1350 0.95 0.99 3.50
/
140 3ph380
50
4
CONT 1350 0.55 0.99 3.50
/
140 1ph220
50
2
CONT 2800 0.88 0.45 0.44 10.0/450
140 3ph220
50
2
CONT 2800 1.25 0.48 3.33
/
140 3ph380
50
2
CONT 2800 0.42 0.48 3.33
/
6IK140GU-AF
gear motor gear
motor
6IK140GU-CF
gear motor gear
motor
6IK140GU-SF
gear motor gear
motor
6IK140GU-S3F
gear motor gear
motor
6IK140A-DF
induction motor
6IK140A-TF
induction motor
6IK140A-T3F
induction motor
The required capacitor value will vary depending on operating voltage. A correct capacitor is required to
match the applied voltage.
General Motor Characteristics
Insulation Resistance: 100MΩ at 500V between motor winding and shell
Insulation Voltage:1500V 50/60Hz @1min between motor winding and shell
Temperature Rise: Max 80oC
Insulation Class: Class B (130oC)
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Paddle Maker Machine and Material Selection
Operating Temperature: -10oC to +40oC (Three phase -10oC to +50oC)
Humidity: 85% max.
Adjustable Speed Motors- Heavy Duty
140 Watt 100mm
(with fan)
The value in the ( ) is the value for the small gear shaft motor
Characteristics of Motors Used In Gearmotors
Allowable
Model
Output
Motor
Volt
Freq Poles
Speed
Duty
Motor with gear
shaft
6IK140RA-
6IK140
AF
RGU-AF
adjustable
adjustable speed
speed
motor w/gear
motor
shaft
5IK140RA-
6IK140
CF
RGU-CF
adjustable
adjustable speed
speed
motor w/gear
motor
shaft
W
V
rpm
Torque
1200r
90r
N.m
N.m
Start
Capaci-
Torq
tance
N.m
μF/VAC
Hz
P
140 1ph110
50
4
CONT 90~1350
0.85
0.45 0.62 30.0/250
140 1ph220
50
4
CONT 90~1350
0.85
0.45 0.68 10.0/450
The required capacitor value will vary depending on operating voltage. A correct capacitor is required to
match the applied voltage.
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Paddle Maker Machine and Material Selection
General Motor Characteristics
Insulation Resistance: 100MΩ at 500V between motor winding and shell
Insulation Voltage:1500V 50/60Hz @1min between motor winding and shell
Temperature Rise: Max 80oC
Insulation Class: Class B (130oC)
Operating Temperature: -10oC to +40oC (Three phase -10oC to +50oC)
Humidity: 85% max.
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Paddle Maker Machine and Material Selection
Appendix M- Material Lab Notes
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Paddle Maker Machine and Material Selection
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Paddle Maker Machine and Material Selection
Appendix N-Material Testing Data Samples
Time(min)
0.0091000
0.0098833
0.0109333
0.0117167
0.0125000
0.0135333
0.0143167
0.0153500
0.0161333
0.0169167
0.0179667
0.0187500
0.0195167
0.0205667
0.0216000
0.0223833
0.0231667
0.0242167
0.0250000
0.0260333
0.0268167
0.0276000
0.0286333
0.0294167
0.0302000
0.0312500
0.0320167
0.0330667
0.0338500
0.0346333
0.0356667
0.0364500
0.0372333
0.0382667
0.0390500
0.0401000
0.0408833
0.0416667
0.0427000
0.0434833
0.0442667
0.0453000
0.0460833
0.0471333
0.0479167
0.0486833
0.0497333
0.0507667
0.0515500
Distance(meters)
0.085722
0.093101
0.102992
0.110371
0.11775
0.127484
0.134863
0.144597
0.151976
0.159355
0.169246
0.176625
0.183847
0.193738
0.203472
0.210851
0.21823
0.228121
0.2355
0.245234
0.252613
0.259992
0.269726
0.277105
0.284484
0.294375
0.301597
0.311488
0.318867
0.326246
0.33598
0.343359
0.350738
0.360472
0.367851
0.377742
0.385121
0.3925
0.402234
0.409613
0.416992
0.426726
0.434105
0.443996
0.451375
0.458597
0.468488
0.478222
0.485601
Coefficient of Friction
0.137471362
0.133930433
0.14455322
0.141428871
0.1449698
0.141012291
0.14351177
0.138929391
0.147469279
0.152259948
0.149760468
0.137887942
0.14392835
0.157467196
0.156634036
0.157467196
0.149552178
0.157467196
0.162882735
0.157467196
0.150801918
0.155800877
0.162882735
0.167256823
0.162257865
0.155384297
0.162466155
0.169964593
0.166007084
0.166215374
0.161216415
0.168089983
0.174963551
0.172672362
0.169548013
0.164549054
0.173297232
0.17912935
0.17787961
0.166631954
0.171422622
0.1780879
0.174963551
0.165590504
0.169756303
0.176421581
0.183086859
0.182461989
0.169756303
Table 9- Tribometer Data Sample
141
LVDT(mm)
0.586952367
0.590283882
0.591192477
0.594221127
0.596038317
0.599369831
0.599369831
0.598461237
0.598461237
0.599975561
0.599975561
0.598764102
0.599066966
0.601489886
0.602095616
0.599975561
0.599369831
0.600278426
0.601187021
0.601489886
0.600581291
0.600581291
0.603912806
0.604821401
0.603004211
0.602095616
0.602398481
0.603307076
0.603307076
0.601489886
0.600278426
0.602095616
0.604215671
0.604215671
0.601792751
0.601792751
0.604821401
0.605124266
0.603307076
0.602701346
0.604518536
0.605729996
0.605729996
0.604821401
0.605124266
0.606335726
0.606638591
0.605427131
0.603609941
Paddle Maker Machine and Material Selection
Appendix O-Bearings, Gears and Belt Specification
Drilling Stage
TWA-W Type: Slide Unit, Pillow Block
Made in Japan: NB Linear Systems
Nippon Bearing Linear Systems
major dimensions
inch
basic load
rating
Shaft
Part
mas
diamete
dynami stati
Numbe
s
T
S
r
h
E
W
L
F
G M
B
C
c
c
r
lbs
inc
inc
inch inch inch inch inch inch
inch inch inch inch
C
Co
h
h
lbf
lbf
TWA
.687 1.00 2.00 3.50 1.25 .25 1.12 1.37 1.68 2.50 .15
1/2
370 580 .510
8WUU
0
0
0
0
0
0
5
5
8
0
6
142
mounting
dimensions
Paddle Maker Machine and Material Selection
Sawing Stage Bearing
TWA Type: Slide Unit, Pillow Block
Made in Japan: NB Linear Systems
Nippon Bearing Linear Systems
major dimensions
mounting
basic load
inch
dimensions
rating
Shaft
mas
Part diamete
dynami stati
s
T
S
Number
r
h
E
W
L
F
G M B
C
c
c
lbs
inc
inc
inch inch inch inch inch inch
inch inch inch inch
C
Co
h
h
lbf
lbf
TWA8U
.687 1.000 2.000 1.68 1.25 .25 1.12 1.37 1.68 1.00 .15
1/2
230 290 .248
U
0
0
0
8
0 0 5
5
8
0 6
1/2" Slide Unit Pillow Block (Inch Series), inner diameter(bore)= 1/2"
(.500") inch dimensions with steel retainer, high accuracy grade
linear bushings, series mainly used in the USA, NB brand (Nippon
Bearing Linear Systems), made in Japan.
143
Paddle Maker Machine and Material Selection
Ball and Roller Bearings
This product matches all of your selections.
Part Number: 6384K363
Type
Ball Bearing Style
Ball Bearing Type
System of Measurement
For Shaft Diameter
Outside Diameter
Width
Flange Outside Diameter
Flange Thickness
ABEC Precision Bearing Rating
Dynamic Radial Load Capacity, lbs.
Dynamic Radial Load Capacity Range,
lbs.
Maximum rpm
Maximum rpm Range
Temperature Range
Bearing Material
Seal Material
Specifications Met
Note
Ball Bearings
Flanged Double Sealed
General Purpose
Inch
1/2"
1-3/8"
1/2"
1-1/2"
1/16"
Not Rated
450
251 to 500 lbs.
1,000
250 to 3,000
-20° to +250° F
Steel
Plastic
Not Rated
Bearing comes greased.
Mounted Bearings
This product matches all of your selections.
Part Number: 7208K51
Mounting Style
Flange Mount Type
Type
Bearing Style
For Shaft Diameter
Dynamic Radial Load
Capacity, lbs.
Maximum rpm
ABEC Precision Bearing
Rating
Housing Material
Steel Housing Material
Bearing Material
Temperature Range
Bearing Construction
Secures/Attaches With
Note
144
Flange Mount
Standard
General Purpose
Ball
3/8"
580
3,000
Not Rated
Steel
Plain Steel
Steel
Up to +250° F
Double Sealed
Double Set Screw
Sets screws included.
Paddle Maker Machine and Material Selection
Pulleys for Belts
This product matches all of your selections.
Part Number: 57105K22
Pulley Type
For Belt Type
Timing Belt Series
Number of Teeth on Pulley
Pulley Design
System of Measurement
For Timing Belt Width
Outside Diameter
Bore Type
Finished Bore Pulley Style
Bore Size (ID)
W-Dimension
X-Dimension
Y-Dimension
Z-Dimension
V-Dimension (Pitch Dia.)
Pitch
Pulley Material
Note
Drive Pulleys
Timing Belt Pulleys
XL Series
24
Solid
Inch
1/4", 3/8"
1-3/4"
Finished Bore
Standard
5/16"
1/2"
5/8"
7/8"
7/8"
1.528"
.2"
Acetal Plastic with Aluminum Hub
Includes set screws.
Pulleys for Belts
This product matches all of your selections.
Part Number: 6495K733
Pulley Type
For Belt Type
Timing Belt Series
Number of Teeth on Pulley
Pulley Design
System of Measurement
For Timing Belt Width
Outside Diameter
Bore Type
Finished Bore Pulley Style
Bore Size (ID)
W-Dimension
X-Dimension
Y-Dimension
Z-Dimension
V-Dimension (Pitch Dia.)
Pitch
Pulley Material
Note
145
Drive Pulleys
Timing Belt Pulleys
XL Series
72
Solid
Inch
1/4", 3/8"
4.564"
Finished Bore
Standard
3/8"
9/16"
9/16"
1"
1-1/2"
4.584"
.2"
Steel
Not flanged. Includes set screws.
Paddle Maker Machine and Material Selection
Belts
This product matches all of your selections.
Part Number: 6484K228
Form
Type
Timing Belt Type
Material
Cord Material
Number of Teeth
Outer Circle
Belt Width
Timing Belt Series
Pitch
Trade Size
Color
Specifications Met
146
Belts
Timing Belts
Single-Sided with Trapezoidal Teeth
Rubber
Polyester
90
18"
3/8"
XL Series
.2"
180XL
Black
Not Rated
Paddle Maker Machine and Material Selection
Appendix P-Lead Screws and Linear Shaft
147
Paddle Maker Machine and Material Selection
Precision Shafts
This product matches all of your selections.
Part Number: 6061K73
Application
Type
Shaft Type
System of Measurement
Material
Steel Type
Finish
Surface Finish
Hardness
Minimum Hardness Depth
Rockwell/Brinell Hardness
Outside Diameter
Outside Diameter Tolerance
Straightness Tolerance
Overall Length
Ends
Specifications Met
Note
Linear Motion Shafts
Shafts
Shafts
Inch
Steel
AISI 1566 Steel
Plain
12 rms
Case Hardened
0.04"
Rockwell C60
1/2"
-0.0005" to -0.001"
0.002" per foot
48"
Chamfered
American Iron and Steel Institute (AISI)
Are precision ground for exacting diameter and
straightness tolerances.
Precision Shafts
This product matches all of your selections.
Part Number: 6061K636
Application
Type
Shaft Type
System of Measurement
Material
Steel Type
Finish
Surface Finish
Hardness
Minimum Hardness Depth
Rockwell/Brinell Hardness
Outside Diameter
Outside Diameter Tolerance
Straightness Tolerance
Overall Length
Ends
Linear Motion Shafts
Shafts
Shafts
Inch
Steel
AISI 1566 Steel
Plain
12 rms
Case Hardened
0.04"
Rockwell C60
1/2"
-0.0005" to -0.001"
0.002" per foot
42"
Chamfered
Specifications Met American Iron and Steel Institute (AISI)
Note Are precision ground for exacting diameter and
straightness tolerances.
148
Paddle Maker Machine and Material Selection
Compatible Nut
Compatible Nut
149
Paddle Maker Machine and Material Selection
Appendix Q-Vibration Analysis
1 of 3
150
Paddle Maker Machine and Material Selection
2 of 3
151
Paddle Maker Machine and Material Selection
3 of 3
152
Paddle Maker Machine and Material Selection
Appendix R-Rockcliff Pin Assignment
153
Paddle Maker Machine and Material Selection
Appendix S-Machine Shop and Field Snapshots
154
Paddle Maker Machine and Material Selection
155
Paddle Maker Machine and Material Selection
156
Paddle Maker Machine and Material Selection
157
Paddle Maker Machine and Material Selection
Appendix T-Snapshots Visit to Grainman Corporation
158
Paddle Maker Machine and Material Selection
159
Paddle Maker Machine and Material Selection
Appendix U-Electronics Set Up
Figure 54-Electronic Controls
160
Paddle Maker Machine and Material Selection
Figure 55-Power Supplies
Figure 56-Emergency Stop and Controlling
161
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