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AUTOMATIC ARTIFICIAL FLOWER STEM CUTTER
A thesis submitted to the
Faculty of the Mechanical Engineering Technology Program
of the University of Cincinnati
in partial fulfillment of the
requirements for the degree of
Bachelor of Science
in Mechanical Engineering Technology
at the College of Engineering & Applied Science
By
ALAN VERHOFF
Bachelor of Science University of Cincinnati
May 2012
Faculty Advisor: Laura Caldwell
Automatic Artificial Flower Stem Cutter
ii
ACKNOWLEDGEMENTS
I would like to take this time to thank my parents. Without their constant support and
encouragement I would not be graduating from college, or be the person that I am today. I
would also like to thank my advisor, Professor Laura Caldwell, for helping and guiding me
through the process of completing this project; also the rest of the MET department for
sharing with me some of their knowledge, and for making these last five years worth my
time. My friends, Adam Dehne, Craig Davis, Nick Plataniotis, Frank Ricciardi, Shawn
Westerfield, and Jeremy Jacobs, it is safe to say that without these guys I would have lost my
mind long ago.
TABLE OF CONTENTS
AUTOMATIC ARTIFICIAL FLOWER STEM CUTTER ....................................................1
ACKNOWLEDGEMENTS .................................................................................................. II
TABLE OF CONTENTS ..................................................................................................... II
LIST OF FIGURES ............................................................................................................. III
LIST OF TABLES ............................................................................................................. IV
ABSTRACT ......................................................................................................................... V
PROBLEM DEFINTION AND RESEARCH ........................................................................1
PROBLEM DEFINITION AND BACKGROUND .................................................................................................... 1 RESEARCH—EXISTING PRODUCTS ............................................................................................................... 1 CUSTOMER NEEDS ....................................................................................................................................... 5 PRODUCT / ENGINEERING FEATURES ............................................................................................................ 6 PRODUCT OBJECTIVES ................................................................................................................................. 9
DESIGN .............................................................................................................................. 10
CONCEPT SKETCHES .................................................................................................................................. 10 3D MODELING—CUTTER ........................................................................................................................... 12 3D MODELING—FRAME ............................................................................................................................ 13 3D MODELING—CLAMPS .......................................................................................................................... 14 3D MODELING—GUARDS .......................................................................................................................... 15
FORCE CALCULATIONS ................................................................................................. 17
CALCULATIONS &ASSUMPTIONS ................................................................................................................ 17 FREE BODY DIAGRAMS .............................................................................................................................. 18 FINITE ELEMENT ANALYSIS ....................................................................................................................... 21
COMPONENT SELECTION .............................................................................................. 25
FABRICATION .................................................................................................................. 26
CUTTING STOCK TO NOMINAL LENGTH ...................................................................................................... 26 CLAMP MACHINING ................................................................................................................................... 28 WELDING .................................................................................................................................................. 29 ASSEMBLY, WIRING, PAINTING .................................................................................................................. 30 FINAL PRODUCT ........................................................................................................................................ 32
iii
PROJECT TESTING AND RESULTS................................................................................ 34
PROJECT MANAGMENT ................................................................................................. 35
SCHEDULE—PROPOSED VS. ACTUAL .......................................................................................................... 35 BUDGET—PROPOSED VS. ACTUAL .............................................................................................................. 36
RECCOMENDATIONS ..................................................................................................... 37
WORKS CITED.................................................................................................................. 38
APPENDIX A—RESEARCH ............................................................................................ A1
APPENDIX B—SURVEY ................................................................................................. B1
APPENDIX C—QFD ......................................................................................................... C1
APPENDIX D—SCHEDULE ............................................................................................ D1
APPENDIX E—BUDGET ................................................................................................. E1
APPENDIX F—FORCE CALCULATIONS ...................................................................... F1
SHEAR STRESS CALCULATION: ................................................................................................................... F1 BLADE FBD: ............................................................................................................................................. F1 ARM FBD: ................................................................................................................................................ F2
APPENDIX G—BILL OF MATERIALS ........................................................................... G1
APPENDIX H—PART DRAWINGS ................................................................................. H1
LIST OF FIGURES Figure 1--Live Flower Stem Cutter (3) ..................................................................................1
Figure 2--Live Flower Stem Cutter, Underwater (4) ..............................................................2
Figure 3-Hand Operated Single Stem Cutter (5) ....................................................................2
Figure 4—Side Cutters, Single Stem Cutter (6) .....................................................................3
Figure 5—Modified Bolt Cutter, Single Stem Cutter (7) ........................................................3
Figure 6—Automatic Copper Tube Cutter (8)........................................................................3
Figure 7—Hand Operated Sheet Metal Shears (9) .................................................................4
Figure 8—4 Bar Pull Concept Sketch .................................................................................. 11
Figure 9—4 Bar Push Concept Sketch ................................................................................. 11
Figure 10—Selected Cutter (5” blade) ................................................................................. 13
Figure 11—Modeled Cutter ................................................................................................. 13
Figure 12—Anchoring Frame .............................................................................................. 14
Figure 13—Stem Clamps .................................................................................................... 14
Figure 14—Clamps and Braces ........................................................................................... 15
Figure 15—Guards and Guard Framing ............................................................................... 16
Figure 16—Cutter Assembly ............................................................................................... 16
Figure 17—Location Call Outs ............................................................................................ 18
Figure 18—Blade Free Body Diagram................................................................................. 18
Figure 19—Blade Dimensions ............................................................................................. 19
Figure 20—Arm Free Body Diagram .................................................................................. 19
iv
Figure 21—Arm Dimensions ............................................................................................... 20
Figure 22—Loading Conditions for Frame Flexure ............................................................. 21
Figure 23—How the Frame Was Fixed................................................................................ 22
Figure 24—Frame Flexure FEA Results .............................................................................. 22
Figure 25—Close Up of Stressed Frame Region .................................................................. 23
Figure 26—Loading Conditions of the Arm......................................................................... 23
Figure 27—How the Arm was Fixed ................................................................................... 24
Figure 28—Arm FEA Results ............................................................................................. 24
Figure 29—Close Up of Stressed Arm Region..................................................................... 25
Figure 30—Metal Cutter ..................................................................................................... 25
Figure 31—Clamp Cylinders ............................................................................................... 26
Figure 32—Main Cylinder .................................................................................................. 26
Figure 33—Stock Cut to Length (Anchoring Frame) ........................................................... 27
Figure 34—Stock Cut to Length (Clamp Actuator Brackets) ............................................... 27
Figure 35—Sine Vise for Milling Clamp Pieces .................................................................. 28
Figure 36—2” Clamp Pieces with Milled Angles ................................................................ 28
Figure 37—3” Clamp Pieces with Milled Angles ................................................................ 28
Figure 38—Welded Clamps ................................................................................................ 29
Figure 39—Welded Anchoring Frame ................................................................................. 29
Figure 40—Machining Upper Clevis ................................................................................... 29
Figure 41—Welded Assembly ............................................................................................. 30
Figure 42—Sand-Blasted Assembly .................................................................................... 31
Figure 43—Electrical Switch ............................................................................................... 31
Figure 44—Final Assembly (Side View) ............................................................................. 32
Figure 45—Final Assembly (Front View) ............................................................................ 33
Figure 46—Final Assembly (Close-Up) .............................................................................. 33
Figure 47—Automatic vs Manual Cutting of Small Stems ................................................... 34
Figure 48—Automatic vs Manual Cutting of Large Stems ................................................... 35
LIST OF TABLES Table 1—Importance Survey Results 5
Table 2—Satisfaction Survey Results 6
Table 3—Engineering Characteristics with Relative Importance 7
Table 4—Designer Multiplier 7
Table 5—Planned Satisfaction 8
Table 6—Relative Weight % 8
Table 7—Weight Rates 12
Table 8—Schedule 36
Table 9—Budget 37
v
ABSTRACT
This report is the process taken to create a device that solves a real world problem. In
this case, the problem is fatigue in the hands after repeatedly cutting artificial flowers by
manual means; the solution to this problem is to develop a prototype that will shear these
artificial flower stems automatically. The entire process from surveying potential customers
to designing and manufacturing the product is covered in detail throughout this report. The
completion of this report is partial fulfillment of the curriculum for a bachelor’s degree in
MET at The University of Cincinnati.
Automatic Silk Flower Stem Cutter Alan Verhoff
1
PROBLEM DEFINTION AND RESEARCH
PROBLEM DEFINITION AND BACKGROUND
The purpose of this project is to design and build an automatic silk (artificial) flower
stem cutter for floral hobbyists and small town flower shops. This idea came about from
Dorothy Verhoff (1) who is a floral hobbyist. She was having pain in her hands and wrists
after hours of constantly cutting the stems of the silk flowers to fit the lengths needed for the
flower arrangements. After finding no such product on the internet or specialty stores, she
asked for something that would do the cutting for her, so that she would no longer have to
deal with the pain of cutting the stems, while still being able to do what she enjoys, making
flower arrangements.
In addition to helping Dorothy with her hobbyist flower stem cutting needs, this product
will also fit the needs of a small town flower shop. Mike Ellerbrock (2) is the part owner of
Town and County Flower of Ottawa Ohio. This company has three separate locations and
they deal with live and silk flowers every day. He, and his employees, were also tired of the
pain in their hands and wrists, and thought that a product of this nature would be very
beneficial.
In order to help Dorothy and Mike with their needs, research into some of the existing
products was conducted. This research was conducted in order to see how some of the
problems with cutting these stems by hand were solved.
RESEARCH—EXISTING PRODUCTS
Figures 1 and 2 are good examples of how many floral professionals and hobbyists
would cut live flowers. Since the stems of the live flowers are easy to cut, these mechanisms
do not have the need to be automatic.
Figure 1--Live Flower Stem Cutter (3)
Figure 1 shows multiple live flowers being cut at once. This is a very good idea,
Automatic Silk Flower Stem Cutter Alan Verhoff
2
however silk flowers will be much more difficult to cut than their live counterparts, so the
mechanism that is to be designed will have to be much more robust, and be capable of cutting
multiple silk flowers stems. Because live flowers are much easier to cut, figure 1 is powered
only by the force being applied by its human operator, and there is little fatigue in the hands
and wrists after using this product. However, when cutting silk flower stems with a
mechanism like this, there will be significant fatigue in the hands and wrists, because of the
extensive force needed to cut multiple silk flowers stems with a single cut.
Figure 2--Live Flower Stem Cutter, Underwater (4)
Figure 2 is a much more refined version of figure 1. This mechanism has a similar way
of cutting the live flower stems, but adds the ability to cut the live stems underwater. This
underwater feature is added to keep the live flowers fresh for longer. When cut, the live
flowers will immediately absorb some of the water, allowing them to stay fresh for a longer
time than if they were cut with the mechanism in figure 1. This mechanism also lacks the
feature to cut the stems automatically, which is not an issue when cutting live flowers.
Figures 3, 4, and 5 are all examples of hand operated silk stem cutters. All of these
cutters are designed to cut a single silk flower stem, but they are not automatic.
Figure 3-Hand Operated Single Stem Cutter (5)
Automatic Silk Flower Stem Cutter Alan Verhoff
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Figure 4—Side Cutters, Single Stem Cutter (6)
Figures 3 and 4 show silk flower stem cutters that are capable of cutting only one stem at
a time. Because these designs are hand powered, and you can only cut one stem at a time,
these cutters will lead to fatigue in the hands and wrists, and require extended time to cut a
bush of stems to length. In
Figure 5 is a modified bolt cutter that is used to cut one silk flower stem at a time. This
design is hand powered, and cuts the stem with one cut.
Figure 5—Modified Bolt Cutter, Single Stem Cutter (7)
This design is good for very thick stems, because the operator is able to apply some of
his/her body weight to the lever, increasing the cutting force. This is a good design because;
the addition of the lever creates a mechanical advantage, therefore making it easier to cut
through the thick stems. However, even with this mechanism, the operator is likely to
experience fatigue in the hands and wrists from repeatedly pushing the lever down.
Figure 6 is a product by Milwaukee, which is a hand-held, automatic copper tubing
cutter. This product is designed to cut a single piece of copper tubing ranging from 3/8”—1”
in diameter.
Figure 6—Automatic Copper Tube Cutter (8)
Automatic Silk Flower Stem Cutter Alan Verhoff
4
This product is very efficient at cutting round copper tubing, and is easily maneuvered to
different positions and orientations. However, the center of a silk flower stem in made of
copper, and this product may not be able to cut a harder material such as steel. Also, this
product has a minimum size of 3/8”, which will not work for flower stem because of the need
to cut the entire way through the stem.
Figure 7 is product made by JET. This product is used to cut sheet metal, and metal rods.
See Appendix—A for additional products that operate in a similar fashion, and are used for
similar purposes.
Figure 7—Hand Operated Sheet Metal Shears (9)
This product could be very affective at cutting silk flower stems. In the product
description it says that this mechanisms, and mechanisms like it, are capable of cutting up to
½” diameter steel rod. This would be ideal for a flower stem cutter, because the stem of the
flower are made of steel rod that is coated in plastic to give it a realistic look. Also, none of
the flower stems that Dorothy or Mike has ever encountered have had steel rods that were
larger than ½” in diameter.
On September 25, 2011, an interview was conducted with Dorothy Verhoff. Dorothy is a
floral hobbyist that makes arrangements for her own home and for her friends and families’
homes. During this interview, she discussed the fact that she enjoys working with flowers,
but the pain in her hands and wrists, from manually cutting the flower stems, make it very
difficult for her to make arrangements. She says, ‘Sometimes, after I have been cutting the
flower stems for long periods of time, my hands begin to hurt and it becomes very difficult
and painful for me to cut any more stems. When this happens I usually ask my husband or
my son to cut the flowers for me’. When asked if she would be interested in and automatic
flower stem cutter, Dorothy responded saying, ‘Yes, very much. That would just be the
greatest thing ever.’ (1)
On September 25, 2011, an interview was conducted with Mike Ellerbrock. Mike is the
owner of a small town flower shop called Town and Country Flowers. This business has
Automatic Silk Flower Stem Cutter Alan Verhoff
5
three locations, and has built a reputation with the community of providing quality flowers.
Mike, and his employees, have similar problem to Dorothy when cutting the thick flower
stems. ‘At first you can just cut right through the stems, and then after awhile it just starts
wearing on you, and pretty soon you can barley squeeze the cutter enough to cut through the
stems. Especially some of my female employees, they are always asking if either I or one of
the other guys can cut through some of the really thick stems. Having an automatic flower
stem cutter would be a valuable piece of equipment to have. I can’t believe that someone
hasn’t thought of it already.’ (2)
After researching the existing products, and conducting the interviews, it was determined
that a product of this nature should be designed. It is clear that the main criterion of this
product is that it must reduce the fatigue in the hands and the wrist. The next section will
discuss how the main features of the product were developed, and which of these features
were the most important.
CUSTOMER NEEDS
In order to know what the customers of this product were looking for, a survey was sent
out to Dorothy, and to Town and Country Flowers. A total of 24 surveys were completed and
collected; these surveys were completed by business owners, employees that work with the
flowers on a daily basis, and an average floral hobbyist.
Table 1 is the results from the Importance section of the survey. In this section the
customers were asked to fill out how important each feature was in the design of an
automatic flower stem cutter. The frequencies of these results were then tallied and place into
this table, starting with the most important. (In this survey 5 is the maximum score)
Table 1—Importance Survey Results
From table 1 it is clear that there are many very important features that will drive the
design of this product. Safety, Reliability, Efficiency, Affordability, and No Fatigue in the
Hand all scored perfect fives, which means that the most emphasis will be placed on these
features when designing this product. This does not mean that the Speed of Operation,
Maneuverability, Size, and Noise level aren’t important; it simply means that more time and
Feature
Safety
Reliability
Efficiency
Affordability
No Fatigue in the Hand
Speed of Operation
Maneuverability
Size
Noise Level
5.0
5.0
4.6
4.5
4.3
4.3
Importance Results
Average Result
5.0
5.0
5.0
Automatic Silk Flower Stem Cutter Alan Verhoff
6
consideration will be put into ensuring that the features that scored a five will be fully
incorporated in the design of the automatic flower stem cutter.
Table 2 is the results from the Satisfaction section of the survey. In this section the
customers were asked to fill out how stratified they were with their current method of cutting
silk flower stems. The frequencies of these results were then tallied and place into this table,
starting with the most important. (In this survey 5 is the maximum score)
Table 2—Satisfaction Survey Results
From table 2, it is easy to see that there is much room for improvement from the
customer’s current manual way of cutting silk flower stems. The Size, Efficiency, No fatigue
in the hand, and Speed of operations, are all categories that need improvement if this product
is to compete with their current way of cutting the flower stems.
Along with these two main parts, the survey also asks the customers how much they
would expect this device to cost. Roughly 70% of the customers expect this device to be in
the range of $300--$500. The materials used to make this product will then be purchased
using this cost range as a guide. A full version of this survey appears in Appendix—B. Now
that the customer needs are known, a way to meet these needs must be thought of in order to
ensure that the customer is satisfied with the product.
After the surveys were collected and the results were tallied, a QFD was constructed
analyzing the same criteria that were on the survey. These criteria were evaluated using some
engineering characteristics that would satisfy these criteria.
PRODUCT / ENGINEERING FEATURES
Table 3 is a table of the engineering characteristics used to evaluate the customer
criteria. Each criterion is satisfied by at least one engineering characteristic.
Feature
Noise Level
Maneuverability
Safety
Reliability
Affordability
Size
Efficiency
No Fatigue in the Hand
Speed of Operation
4.0
3.8
3.5
3.3
3.0
Satisfaction Results
Average Result
4.6
4.5
4.2
4.0
Automatic Silk Flower Stem Cutter Alan Verhoff
7
Table 3—Engineering Characteristics with Relative Importance
Table 3 lists the engineering characteristics, with their relative importance, used to
satisfy the customer’s criteria for this product. These characteristics are features that can be
desigend into the product to satisfy the customer features. An example of how this works is
as follows: Guards can be designed into the product to satisfy some of the Safety criterion
requirement, however guards will aslo have an impact on the Affordability criterion as well.
These weights will be used when selecting components, and deciding which of the
characteristics are the most important.
Tables 4 and 5 are the first time that the designer of the product has a say in what the
product will do, and how it is expected to preform. Table 4 is the desingner mulitplier section
of the QFD, and table 5 is the planned satisfaction section of the QFD.
Table 4—Designer Multiplier
Table 4 is the results from the designer multiplier section of the QFD. In this section, the
customer importance weights, results of the survey, are listed. Next to these values, the
designer decides if the value will increase, decrease, unchange the values. From table 4, the
designer has only increased three of the weights by 10%, and has not decreased any of the
Engineering Characteristics Relative Importance %
Cutter spec sheet 22%
Motor/actuator spec sheet 18%
COSMOS used for factor of safety 10%
Cuts one bush at a time 10%
Footprint 8%
Lightweight 7%
Casters 5%
Clamps to hold the stems 5%
Separate switches for operators safety 4%
Guards 4%
Handles 4%
Noise of motor/actuator 3%
Customer Importance Designer's Multiplier
Safety 5.0 1.0
Reliability 5.0 1.0
Size 4.3 1.1
Efficiency 5.0 1.0
Speed of Operation 4.6 1.0
Affordability 5.0 1.0
No Fatigue in the Hand 5.0 1.0
Noise Level 4.3 1.1
Maneuverability 4.5 1.1
Automatic Silk Flower Stem Cutter Alan Verhoff
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weights. The designer increased these three criteria importance values to ensure that the
customer would be very satisifed with how the device prefomred and operated. Conversly,
the designer didn’t decrease any of the values because the customers wouldn’t be as satisfied
as what they were expecting.
Table 5—Planned Satisfaction
Table 5 if the results for the planned satisfaction section of the QFD. In this section, the
customers current satisfaction weights were either increased, decreased, or unchanged by the
designer. This process is done to set benchmarks for the designer to reach. All of the
satisfactions were increased by the designer, which means that if successful, the product will
exceed the customers current method of cutting silk flower stems.
Table 6 is the relative weights, which the QFD generated. These weights will be used to
rank the criteria in relative importance.
Table 6—Relative Weight %
The results of the QFD are listed in table 6. These results show which if the customer’s
criteria are the most important relative to each other. These weights will be used when
deciding how to design the product. All of these criteria are close to each other in terms of
importance, but more time will be put into the design of the heavier weights, such as No
Current Satisfaction Planned Satisfaction
Safety 4.3 4.8
Reliability 4.0 4.5
Size 3.8 4.7
Efficiency 3.5 5.0
Speed of Operation 3.0 4.5
Affordability 4.0 4.0
No Fatigue in the Hand 3.3 4.8
Noise Level 4.7 4.7
Maneuverability 4.5 4.5
Relative Weight %
No Fatigue in the Hand 14%
Speed of Operation 13%
Efficiency 13%
Safety 11%
Reliability 11%
Size 11%
Affordability 9%
Noise Level 9%
Maneuverability 9%
Automatic Silk Flower Stem Cutter Alan Verhoff
9
fatigue in the hand, Speed of operation, and Efficiency.
When the QFD was completed, these relative weights were produced. These weights
will make it easier when selecting components because the ones with the greater importance
will have the biggest individual impact on how the product will ultimately perform. From the
table, the Motor/actuator, and Cutter spec sheets will have the greatest impact on whether the
product will perform as desired, or whether it will fail.
PRODUCT OBJECTIVES
The following is a list of product objectives and how they will be obtained or measured
to ensure that the goal of the project was met. The product objectives will focus on cutting
one bush at a time. This number of stems was chosen because this will primarily be used to
cut the stems to length, and this is usually done one bush at a time.
No fatigue in the hand (14%)
1.) The cutter will reduce the number of manual cuts by at least 80%, therefore, reducing
the fatigue in the hands.
Speed of Operation (13%)
1.) From the time the cutter is started to the time the stem/bush is cut will be 3 seconds or
less.
Efficiency (13%)
1.) The cutter will be able to cut the stems with one attempt
Safety (11%)
1.) Safety guards covering pinch points and moving parts.
2.) Separate switches to ensure that the user’s fingers will not be cut.
3.) Clamps to hold the stems while being cut, to prevent the stem from jumping.
Reliability (11%)
1.) Reliability of the cutter measured by component life and proper design criteria
specified in the following spec sheets:
-Motor spec sheet
-Cutter spec sheet
2.) A factor of safety of will be provided by COSMOS to show that structural
components of the cutter will not fail.
3.) Mechanical assembly will follow allowable torques of mechanical fasteners and the
use of Loctite.
4.) All electrical connections will be soldered and then covered in heat wrap to ensure a
quality connection.
Size (11%)
1.) The cutter will have a footprint similar to that of a standard printer.
Affordability (9%)
1.) The cutter will be priced for not only a flower shop, but also a flower hobbyist.
(vacuum cleaner)
Maneuverability (9%)
Automatic Silk Flower Stem Cutter Alan Verhoff
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1.) The cutter will be able to be maneuvered by one person, of average strength, to the
position required.
2.) The cutter will have casters to improve maneuverability.
Noise level (9%)
1.) The noise level will around the level of a paper shredder.
The criteria from the survey and the QFD appear in the product objectives; however the
order in which they appear has changed. Their new order is based on the results of the survey
with the most important criteria appearing first, and the least important criteria appearing
last. Along with the criteria, the product objectives also include how the designer plans on
incorporating them into the design. For example, the Efficiency criterion says, ‘The cutter
will be able to cut the stems with one attempt’. In order to ensure this, the designer will have
to pay close attention to the cutter and the motor spec sheets, to ensure that the particular
cutter and motor will be able to handle the loads associated with cutting the flower stems.
The same process is repeated throughout the product objectives, for every criterion.
DESIGN
CONCEPT SKETCHES
The design of the automatic silk stem flower stem started with the concept sketches.
These are hand drawn sketches of conceptual ideas that will be used to ensure that the idea of
the cutter is not destined for failure from the start.
The idea of using one of the throat-less metal shears, found during the research, was
chosen as the basis of the design. Figure 7 is similar to the cutter that was chosen; the chosen
cutter has a 5” cutting blade, is capable of cutting up to 0.5” steel rod, and whose physical
dimensions fit the size requirements of this project.
Figures 8 and 9 are a sketches of how a throat-less metal shear could be modified to fit
the needs of this project. By fixing the shear to a custom frame, and attaching an electric
actuator to the handle, enough force could be generated to cut through the flower stems. Both
configurations would include similar frames, similar casters, and similar circuitry. (2 separate
switches for operation)
Automatic Silk Flower Stem Cutter Alan Verhoff
11
Because these configurations are so close to each other in terms of design, a weighted
rates table (table 7) was constructed to determine which of the two configurations would
fulfill the customer needs the best.
Figure 8—4 Bar Pull Concept Sketch
Figure 9—4 Bar Push Concept Sketch
Automatic Silk Flower Stem Cutter Alan Verhoff
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By assigning a value (0-4) to each customer feature, based on how well each design
configuration would fulfill that feature, and comparing the two; the ‘better’ design was
chosen. For example; because of the geometry the cutter, the pull configuration would have a
bigger footprint, therefore receiving a lower value than the push configuration. The product
of the values and their relative weights was then summed, and the configuration with the
bigger total was the ‘best’ design.
3D MODELING—CUTTER
During the research for the automated cutter, a throat-less sheet metal cutter was found
that was capable of cutting up to 0.5” steel rod. Because the flower stems are made from steel
cores, and because these cores are not greater than 0.5” in diameter, this cutter fit the needs
of the design perfectly. Also, this model came in several blade sizes; because the size of the
blade affects the overall dimensions of the cutter, the cutter with the 5” blade was selected
instead of the cutters with the larger blades. Figure 10 is the cutter that was chosen.
0-4 Scale
4=Best 0=Worst
Act
uat
or-
-Pu
ll
We
igh
ted
Rat
es
Act
uat
or-
-Pu
sh
We
igh
ted
Rat
es
Product Objectivs Weights
Safety 0.11 4 0.44 4 0.44
Reliability 0.11 4 0.44 4 0.44
Size 0.11 2 0.22 4 0.44
Efficiency 0.13 4 0.52 4 0.52
Speed of Operation 0.13 4 0.52 3 0.39
Affordability 0.09 4 0.36 3 0.27
No Fatigue in the hand 0.14 4 0.56 4 0.56
Noise Level 0.09 4 0.36 4 0.36
Maneuverability 0.09 4 0.36 3 0.27
Total 3.78 3.69
PULL PUSH
Table 7—Weight Rates
Automatic Silk Flower Stem Cutter Alan Verhoff
13
Since there were no 3d or detail drawings available for the cutter, the modeling of this
cutter was done by hand. The dimensions of the cutter were scaled off of the figure 10, and
were modeled in AutoCAD Inventor (figure 11).
Figure 11 is a screen shot of the modeled cutter; the rest of the automated device will be
built around this modeled cutter.
3D MODELING—FRAME
Figure 10—Selected Cutter (5” blade)
Figure 11—Modeled Cutter
Automatic Silk Flower Stem Cutter Alan Verhoff
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After the cutter was modeled, a frame was designed. This frame (figure 12) is to support
the cutter, and allow for the attachment of the clamps, actuators, casters, and other essential
items. This frame was made using standard sizes of square tubing and angle iron.
3D MODELING—CLAMPS
The design continued with the modeling of the stem clamps. These clamps were place on
both sides of the cutter to maximize the safety of the operation. The clamps have a ‘V’ shape
to them, in order to constrain the stems into a bundle. This bundling will ensure that the
stems are cut; as opposed to just sliding across the blade, as would occur if the clamps were
simply flat and not ‘V’ shaped. Figure 13 shows these clamps in their correct orientation with
the cutter.
Figure 12—Anchoring Frame
Figure 13—Stem Clamps
Automatic Silk Flower Stem Cutter Alan Verhoff
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The next step of the design process was the addition of the electric cylinders, and the
associated bracing needed (figure 14). Just as frame was made from standard material sizes,
the braces for the clamp cylinders were made from standard sizes.
3D MODELING—GUARDS
The guards, and guard-frame were then designed (figure 15). The guards are made from
plexi-glass, the two side guards have cutouts to allow the stems to easily pass into the cutter.
The guard-frame is made from standard size angle iron, and will be welded to the anchoring
frame; each frame piece, and its correlating plexi-glass guard has periodic holes drilled in
them to allow them to be bolted together.
Figure 14—Clamps and Braces
Automatic Silk Flower Stem Cutter Alan Verhoff
16
The cutter assembly in shown in figure 16, this assembly is shown with casters to
improve the mobility of the device. The final assembly will include handles, also for
improved mobility, and wiring for all of the cylinders.
After the design was complete, force calculations needed to be solved for. These forces
will then later be applied to the design to verify that it will be robust enough to with stand the
Figure 15—Guards and Guard Framing
Figure 16—Cutter Assembly
Automatic Silk Flower Stem Cutter Alan Verhoff
17
forces seen while cutting the flower stems.
FORCE CALCULATIONS
CALCULATIONS &ASSUMPTIONS
In order to calculate the force needed to shear the flower stems, a few assumptions were
made:
The stem of the flower is made of a steel core, .1” diameter, and a rubber/plastic
coating, .3” in diameter.
The steel core is assumed to be 1020 Cold-Drawn, with a Tensile Strength of
61,000psi. (Machine Elements in Mechanical Design, 4th Edition, Mott).
The Shear Strength of the steel is 2/3 of the Tensile Strength.
Assume also, that the maximum number of stems cut at one time to be two. This is
from knowing how rods behave when they are stacked on top of each other.
With these assumptions in mind, the following calculations were made:
Area
Shear Stress
Force Needed to Cut Stems
Automatic Silk Flower Stem Cutter Alan Verhoff
18
After the force needed to cut through the stems were calculated, free body diagrams
were used to calculate how much force was needed by the cylinder.
FREE BODY DIAGRAMS
Below, is a diagram of the location call outs used during the force calculations (figure
17). The called out points are the important points of the cutter, and the distances between
these points were used for the calculations as well.
Figure 17—Location Call Outs
Figure 18—Blade Free Body Diagram
Automatic Silk Flower Stem Cutter Alan Verhoff
19
Using figures 18 and 19, the following calculation was made:
The 175 lb force was solved for, and will be transmitted to the blade from the arm.
Figure 19—Blade Dimensions
Figure 20—Arm Free Body Diagram
Automatic Silk Flower Stem Cutter Alan Verhoff
20
Using figures 20 and 21, the following calculation was made:
The 175 lb force that was solved for in the blade free body diagram shows up in this one
as well. Using a similar method as before, a force of 48 lbs was calculated. This 48 lbs is the
force that the cylinder will need to pull in order to cut the stems.
The 48 lbs needed to cut the stems is when the cutter is at the end of its stroke. In order
to ensure that the 643 lb shearing force is maintained throughout the entire stroke, and Excel
sheet was set up; using simple trig formulas, the force at the beginning of the stroke, which
happens to be the maximum force, is 82 lbs. Because no electric cylinder was found that
could pull with this force and was still is dimensionally small enough to fit in the designed
space, an electric cylinder of 150 lbs pulling force was found, and had the dimensions that
would fit into the design. So the new pulling force of the cylinder is 150 lbs, this will be used
for all of the stress analysis.
Figure 21—Arm Dimensions
Automatic Silk Flower Stem Cutter Alan Verhoff
21
FINITE ELEMENT ANALYSIS
After the calculations were completed, multiple stress analysis simulations were run on
the designed parts to ensure that they would be able to stand up to the loading conditions.
The first simulation was done on the anchoring frame. The goal of this simulation was to
measure the frame flexure; to verify that the frame would not bend is such a way as to cause
failure. Figure 22 shows the loading conditions of the frame; a force of 150 lbs was applied
to the frame. This 150 lb force was applied the exact same way as the cylinder would apply
it. Also included in this simulation is the force of gravity. Figure 23 shows how the frame
was fixed.
Figure 22—Loading Conditions for Frame Flexure
Automatic Silk Flower Stem Cutter Alan Verhoff
22
The results of the simulation are shown in figures 24, and 25. After the results of the first
simulation were verified to be within the acceptable range, a second simulation was run. This
second simulation had the exact same loading and constraining conditions, the only
difference was that the mesh size was reduced around the stressed regions. The results of the
second simulation were only a few percent different, so the simulations verified each other.
Figure 23—How the Frame Was Fixed
Figure 24—Frame Flexure FEA Results
Max Displacement: 0.008”
Automatic Silk Flower Stem Cutter Alan Verhoff
23
Because the cutter is commercially rated to cut up to 0.5” steel rod, no stress analysis
was done on it, except for the arm of the cutter. The arm will be modified, and a stress
analysis was done on this to ensure that the planned modifications would not jeopardize the
integrity of the arm. Figures 26 and 27 show how the arm was loaded, the same 150 lb load
in the exact direction that the cylinder would apply it, and how it was constrained
respectively.
Figure 25—Close Up of Stressed Frame Region
Figure 26—Loading Conditions
of the Arm
Max Stress: 6.9ksi
Safety Factor: 4.34
Automatic Silk Flower Stem Cutter Alan Verhoff
24
Figures 28 and 29 show the result of the simulation, and a close up of the stressed region
respectively. Just as before, the mesh size was reduced around the stressed region and the
simulation was re run; and just as before the second simulation yielded results that were just
a few percent different than the first. The results of the simulation are: Max Stress 6.6 ksi,
Max Displacement 0.0007”, and a Safety Factor of 4.58. All of these numbers are acceptable.
Figure 27—How the Arm was Fixed
Figure 28—Arm FEA
Results
Max Displacement: 0.0007”
Automatic Silk Flower Stem Cutter Alan Verhoff
25
Simulations were also run on the clamps for the stems. These forces were so low and the
material was size was so over designed that the forces and stresses were minimal. After the
FEA was completed, and the results analyzed, it was decided that the design would perform
as expected and the project moved from the design stage to the Component selection stage.
COMPONENT SELECTION
Only three components needed to be chosen for this project the metal cutter (figure 30),
the electric cylinders for the clamps (figure 31), and the main electric cylinder (figure 32).
Figure 29—Close Up of Stressed Arm Region
Figure 30—Metal Cutter
Max Stress: 6.6ksi
Safety Factor: 4.58
Automatic Silk Flower Stem Cutter Alan Verhoff
26
FABRICATION
CUTTING STOCK TO NOMINAL LENGTH
After all of the design work was completed, and all of the components were selected; the
fabrication of the flower cutter could begin. The fabrication started by contacting local metal
suppliers and purchasing the stock at standard lengths, to keep the price as low as possible.
Then, using the horizontal band saw, the standard lengths were cut to the nominal lengths per
the detail drawings located in Appendix H. Some examples of this are figures 33, and 34.
Figure 31—Clamp Cylinders
Figure 32—Main Cylinder
Automatic Silk Flower Stem Cutter Alan Verhoff
27
Figure 33—Stock Cut to Length
(Anchoring Frame)
Figure 34—Stock Cut to Length
(Clamp Actuator Brackets)
Automatic Silk Flower Stem Cutter Alan Verhoff
28
CLAMP MACHINING
The clamps were made by again using the horizontal band saw, and cutting 12-2”, and
12-3” pieces. These pieces then had the required angles milled into them using a sine vise
(figure 35). The completed clamp pieces can be seen in figures 36, and 37.
Figure 35—Sine Vise for Milling Clamp
Pieces
Figure 36—2” Clamp Pieces with
Milled Angles Figure 37—3” Clamp Pieces with
Milled Angles
Automatic Silk Flower Stem Cutter Alan Verhoff
29
WELDING
After the machining was completed on the cut pieces, they were then welded together.
The anchoring frame (figure 38) was welded using a MIG welder, while the clamps and
clamp actuator brackets (figure 39) were welded using a TIG welder.
Bothe clevises were machined out of solid pieces of steel (figure 40).
Figure 39—Welded Anchoring Frame Figure 38—Welded Clamps
Figure 40—Machining Upper Clevis
Automatic Silk Flower Stem Cutter Alan Verhoff
30
ASSEMBLY, WIRING, PAINTING
After all of the sub-assemblies were completed, everything was clamped onto the
anchoring frame. Then, the main actuator was then put into place, and electricity was applied
to the actuator to make it both extend and retract. This was done several times in order to
ensure that the alignment of the sub assemblies were in their correct orientation and position.
The clamps were tightened down, and the main actuator was removed from the assembly so
the sub-assemblies could be welded to the anchoring frame, without endangering the
electrically sensitive actuator. Figure 41 is a picture of the welded assembly.
The next steps were sand-blasting, painting, and wiring. The blades were removed from the
cutter, and the entire assembly was sand-blasted (figure 42). The assembly was then painted,
and while the paint was drying, the wiring was completed. The wires were soldered to the
switches, and heat shrink and electrical tape were wrapped around the switches and wires for
added protection (figure 43).
Figure 41—Welded Assembly
Automatic Silk Flower Stem Cutter Alan Verhoff
31
Figure 42—Sand-Blasted
Assembly
Figure 43—Electrical Switch
Solder
Heat-Shrink
Automatic Silk Flower Stem Cutter Alan Verhoff
32
FINAL PRODUCT
The blades were then bolted back onto the cutter, the actuators and wiring were then put
into place, and the Plexi-Glass guards were bolted onto the guard frame. Pictures of the
completed assembly are below (figures 44, 45, 46).
Figure 44—Final Assembly (Side View)
Automatic Silk Flower Stem Cutter Alan Verhoff
33
Figure 45—Final Assembly (Front View)
Figure 46—Final Assembly (Close-Up)
Automatic Silk Flower Stem Cutter Alan Verhoff
34
PROJECT TESTING AND RESULTS
In the project objectives it states that the cutter will reduce the number of manual cuts by
at least 80%. In order to test this at least 6 stems need to be cut at a time. In the demo for
Professor Caldwell the cutter cut through 7 stems. These 7 stems were comprised of an
assortment of different sized stems, and the cutter was able to cut shear all 7 of them in the
first attempt. The cutter was also tested by cutting through an average bush of flowers. This
bush was comprised of 18 stems of small diameter, and like the previous test, it cut right
through the stems.
Figures 47 and 48 are pictures of graphs that were made to demonstrate the increased
efficiency of the automated flower cutter. From figure 47 it is clear that after 11 small stems
it is more efficient to use the automated cutter, as opposed to the manual cutter. And the
efficiency increases even more, starting at 7 stems, when you are cutting larger stems as you
can see from figure 48.
Figure 47—Automatic vs Manual Cutting of Small Stems
Automatic Silk Flower Stem Cutter Alan Verhoff
35
PROJECT MANAGMENT
SCHEDULE—PROPOSED VS. ACTUAL
In order to ensure that the project would be completed by the required date, a schedule
was developed. The expected completion dates are in blue, and the actual completion dates
are in red if they were completed behind schedule and green if they were completed either
before or on schedule. Table 8 is a compressed version of the schedule.
Figure 48—Automatic vs Manual Cutting of Large Stems
Automatic Silk Flower Stem Cutter Alan Verhoff
36
For a copy of the Schedule, refer to Appendix—D Schedule.
BUDGET—PROPOSED VS. ACTUAL
Because this project will be funded the designer, it is important to have a proposed
budget. This budget is just a rough estimate, and will be refined after the parts have been
purchased and the project has been completed. Table 9 is a copy of this budget.
Table 8—Schedule
Expected Actual
5-May 11-May
17-May 17-May
1-Jun 21-May
4-Feb 4-Feb
28-Feb 28-Feb
28-Apr 4-May
Completion
24-Dec 28-Dec
28-Jan 1-Feb
May 6 - May 18
May 19 - June 1
3D Modeling of Entire Device
Calculations, Shop Drawings, Component Selection
Design Freeze
Begin Fab, Work on Winter Report/Oral
Electrical Research, Complete Fab
Test/ Fine Tuning
Demo to Advisor/Faculty
Spring Report/Oral
Nov 27 - Dec 24
Dec 25 - Jan 28
Jan 29 - Feb 4
Feb 5 - Mar 9
Mar 10 - Apr 28
Apr 29 - May 5
Automatic Silk Flower Stem Cutter Alan Verhoff
37
Proposed Budget Actual
Component Description Cost Cost
Frame
Links/Braces Steel $50 $45
Casters $20 $18
Clamps Steel $20 $20
Guards Plexi Glass $30 $50
Drivers/Cutter
Drivers/Cutter Actuators $200 $335
Cutter Metal Cutter $175 $100
Electrical
DC Power
Supply AC-DC $50 $60
Wiring/Switches $25 $20
Miscellaneous Bolts/Nuts/Paint $40 $20
Total $610 $668
From table 9, the projected budget is $610. After the project was completed the final cost
was $668. This is over budget, but because this was a prototype, the amount spent on the
project is an acceptable number. A full version of the proposed budget can be found in
Appendix—E Budget.
RECCOMENDATIONS
Although the project was finished on time and completes the task that it was designed to
do, there are a few things that should be modified in order to make the product better as a
whole.
Using only one actuator to move the clamps. This would reduce the cost by roughly
$100, which would keep the cost at a more reasonable level.
Using aluminum instead of steel for the anchoring frame the guard frame and the
clamps. This would make the cutter much lighter and easier to move.
Account for the power supply in the design of the cutter. As it works now, the power
supply sits next to the cutter, and must be moved independently of the cutter. The
best thing to do is raise the cutter up by using larger diameter casters, allowing the
power supply to fit under the cutter. Then securing the power supply to the cutter so
that they will move together.
Table 9—Budget
Automatic Silk Flower Stem Cutter Alan Verhoff
38
WORKS CITED 1. Verhoff, Dorothy. Floral Hobbyist. 17460 Road K Ottawa, Ohio, 45875, 9 25, 2011.
2. Ellerbrock, Mike. Owner of Flower shop. 15800 Road Z Columbus Grove, Ohio, 45830,
9 25, 2011.
3. Flower Stem Cutter. wholesalefloral.com. [Online] [Cited: 9 22, 2011.]
http://www.wholesalefloral.com/Flower_Stem_Cutter_p/stemcutter.htm?Click=3793&gclid=
CMLgxeuCsasCFUTBKgodMHihhg.
4. High-capacityFloor model Underwater Stem Cutter. floralsupply.com. [Online] [Cited: 9
22, 2011.] http://www.floralsupply.com/cooler-buckets-flower-prep-items/stemcutter/1211-
unifuse1-flower-stem-cutter.htm.
5. Floral Stem Cutter 12.6-Inch. amazon.com. [Online] [Cited: 9 23, 2011.]
http://www.amazon.com/Fiskars-01004726-Floral-Cutter-12-6-
Inch/dp/B002IPH602/ref=sr_1_1?ie=UTF8&qid=1316701477&sr=8-1.
6. 7 1/2" Heavy-Duty Floral Stem. tooltron.com. [Online] [Cited: 9 22, 2011.]
http://www.tooltron.com/products/7-1%7B47%7D2%22-Heavy%252dDuty-Floral-Stem-
Cutter.html.
7. How to cut silk flower stems for floral arrangments. wonderhowto.com. [Online] [Cited: 9
23, 2011.] http://www.wonderhowto.com/how-to-cut-silk-flower-stems-for-floral-
arrangements-273769/.
8. Milwaukee 2471-21 12-Volt Copper Tubing Cutter Kit. amazon.com. [Online] [Cited: 9
27, 2011.] http://www.amazon.com/Milwaukee-2471-21-12-Volt-Copper-
Tubing/dp/B001FB64N0/ref=sr_1_1?ie=UTF8&qid=1317140163&sr=8-1.
9. Vansantent.com. [Online] JET. [Cited: 10 27, 2011.]
http://vansantent.com/sheet_metal_machines/slitting_shear.htm.
Appendix A1
APPENDIX A—RESEARCH
Don't get stuck with a short flower stem
cutter that cut a full bunch try this 22.5" long
stainless steel fresh flower stem cutter. Can
be used underwater. Mounting brackets are
attached. Easy grip padded wooden handle.
Not for cutting silk flower wired stems.
Measure 22.5" long x 6". 13". Stainless steel
blade is 12.5" long.
Easily moved.
Good design for real flowers.
Would not be able to cut silk (fake) flower
stems.
Not automatic.
Hands may get fatigued after hours of use.
http://www.wholesalefloral.com/
Flower_Stem_Cutter_p/stemcutte
r.htm?Click=3793&gclid=CMLg
xeuCsasCFUTBKgodMHihhg
Flower Stem Cutter
wholesalefloral.com 9/22/2011
Appendix A2
This new product provides a complete
maintenance free underwater stem cutting system
for florists and floral departments.Allows
submerged trimming which prevents air bubbles
from choking the bloom.The 25-gallon tub
secures the cutter and is small enough for
portability and easy trim removal.The fitted
plastic spigot allows for quick draining. Easy to
clean polyethylene is USDA/FDA approved and
will not rust, chip or crack. The stainless
mechanism is maintenance free and allows safe
changing of the cutting blade.Uses the Same
blades as the Watercut II machine.The product
measures 20î x 29î x 14î h making it small
enough to be used on a table top or increase the
standing height to 29î with our elevated
dolly.This is THE finest underwater flower cutter
made!SHIPPING NOTE:Comes ion two cartons.
Freight on this item WEST of the Mississippi
River is high due to the cartons sizes.
Easily moved.
Good for real flowers.
Bad for silk flowers, (underwater not
needed).
Expensive ($899.95).
http://www.floralsupply.com/cool
er-buckets-flower-prep-
items/stemcutter/1211-unifuse1-
flower-stem-cutter.htm
High-capacity Floor model
Underwater Stem Cutter
floralsupply.com 9/22/2011
Appendix A3
Professional grade
Cuts stems up to 1/2-inch diameter
Tabletop design for more control
Cuts up to four times easier than standard
wire cutters
Good for both real and silk flowers.
1/2 –inch max. diameter.
Hand fatigue after much use.
Easy to use.
C-45 carbon steel. Foam grip handles. Ideal
For Stem Cutting Both Silk And Fresh
Flowers, PVC Dipped Handles Machine
Cutting Edges.
Good for both real and silk flowers.
Easy to use.
Not automatic.
Fatigue in the hands, after hours of use.
Difficult for thick stem silk flowers.
http://www.tooltron.com/product
s/7-1%7B47%7D2%22-
Heavy%252dDuty-Floral-Stem-
Cutter.html
7 1/2" Heavy-Duty Floral Stem
Cutter
tooltron.com 9/22/2011
http://www.amazon.com/Fiskars-
01004726-Floral-Cutter-12-6-
Inch/dp/B002IPH602/ref=sr_1_1
?ie=UTF8&qid=1316701477&sr
=8-1
Floral Stem Cutter 12.6-Inch
amazon.com 9/23/2011
Appendix A4
If you've worked with silks, you know that
sometimes stems are hard to cut. In this
video tutorial, Dana Plazyk of Flowers by
Design shows you some simple techniques
and special tools to get the job done! See
how to design and cut silk flower stems for
floral arrangements.
Easy to move.
Works good for silk flowers.
Not automatic.
http://www.wonderhowto.com/ho
w-to-cut-silk-flower-stems-for-
floral-arrangements-273769/
How to cut silk flower stems for
floral arrangements
wonderhowto.com
9/23/2011
Interview with Mom, September 25, 2011
Dorothy Verhoff, Floral Hobbyist, 17460 Road K, Ottawa, Ohio, 45875.
Assembles flower arrangements for family and friends
Fatigue in the hand after cutting thick silk flower stems
Interested in an automated stem cutter
Interview with Family friend, September 25, 2011
Mike Ellerbrock, Owner of a Flower shop, 15800 Road Z, Columbus
Grove, Ohio, 45830.
Owns a flower shop, with three different locations
Has a device that cuts the thick stems, but is interested in an automated
version
Appendix A5
12V LITHIUM-ION battery for
longer run-time
Close quarter rotating cutting head
cuts pipe in confined spaces
Automatic adjustment from 3/8” – 1”
tubing with Auto locking mechanism
and Water resistant metal cutter head
Ergonomic, compact, and lightweight
design for operator comfort and Ultra-
efficient drive mechanism delivers
over 200 cuts per charge
Battery Fuel Gauge displays
remaining run-time and Built-in LED
light illuminates work surface
Looks like a very promising device for silk
flower stem cutting
Need to figure out how to incorporate into
table top form
Easy to use
Needs to be able to cut smaller stems
http://www.amazon.com/Milwau
kee-2471-21-12-Volt-Copper-
Tubing/dp/B001FB64N0/ref=sr_
1_1?ie=UTF8&qid=1317140163
&sr=8-1
Milwaukee 2471-21 12-Volt
Copper Tubing Cutter Kit
amazon.com
Appendix A6
Capable of shearing sheet steel, steel
bars and rods plus many non-metallic
materials
Replaceable high quality stainless
steel blades are hardened and
tempered for maximum service life
An adjustable hold down clamp aids
in securing material
Compound leverage allows the
operator to easily perform work
within shears' rated capacity
Includes 35-1/2" handle
Round Capacity 1/2” (mild steel)
Good option for cutting the stems
Not sure if it’s able to cut multiple stems
Needs to be automatic
Modifications needed to fit my application
http://vansantent.com/sheet_meta
l_machines/slitting_shear.htm
Jet Hand Slitting Shears
Vansantent.com
10/27/2011
Appendix A7
Rack and pinion gearing, plus
extended handle, improve your
leverage
Tool steel blades slice thru 14-ga.
mild steel, 18-ga. Stainless
Throatless shear is crafted of rugged
cast iron
Good for cutting sheet metal
Modifications needed to the mechanism to fit
my needs
Needs to be automatic
http://www.eastwood.com/throatl
ess-shear.html
Economy Throatless Shear
Eastwood.com
10/27/2011
Appendix A8
Cuts up to 3/16" mild steel
Will also cut up to 5/16" round bars
8" High speed steel blades
Adjustable material hold down
Spring return handle
Cuts thick round bar
Needs to be automatic
Modifications needed to fit my application
http://www.ebay.com/itm/Throatl
ess-sheet-metal-hand-shear-3-16-
mild-steel-capacity-Woodward-
Fab-
/350499003126?pt=Motors_Auto
motive_Tools&vxp=mtr&hash=it
em519b5e5af6#ht_656wt_1185
Throatless sheet metal hand shear
3/16" mild steel capacity
Ebay.com
10/27/2011
Appendix A9
Super Heavy Duty steel frame and
hardened high carbon steel blade
Carbon steel blade is easily
replaceable. Replacement blades are
available from us
Blade length: 8"
Mild steel cut thickness: 3/16"
Stainless steel cut thickness: 1/8"
Steel rod cut thickness: 1/2"
Aluminum cut thickness: 1/4"
Copper cut thickness: 3/16”
We stock replacement blades for this
shear!
Able to cut the stems (1/2” steel round bar)
Needs modifications to make it automatic
Good price ($134)
http://www.ebay.com/itm/8-
Sheet-Metal-Shear-Steel-
Aluminum-Copper-Hand-Cutter-
/350502153852?pt=LH_DefaultD
omain_0&hash=item519b8e6e7c
#ht_1946wt_1185
8" Sheet Metal Shear Steel
Aluminum Copper Hand Cutter
Ebay.com 10/27/2011
Appendix B1
APPENDIX B—SURVEY
AUTOMATIC SILK FLOWER STEM CUTTER
CUSTOMER SURVEY
Using a hand powered silk stem flower cutter, is known to cause fatigue in your hands
after extended use. As my senior design project I have chosen to create a solution to this
problem. If you could please fill out this survey, your opinions will be used to drive the
design process to ensure that the product is the best that it can be.
How important to you is each feature for the design of an automatic silk flower stem
cutter?
Please circle the appropriate answer. 1 = low importance 5 = high importance
Avg.
Safety 1 2 3 4 5 (24) N/A 5
Reliability 1 2 3 4 5 (24) N/A 5
Size 1 2 3 (4) 4 (8) 5 (12) N/A 4.3
Efficiency 1 2 3 4 5 (24) N/A 5
Speed of Operation 1 2 3 4 (8) 5 (16) N/A 4.6
Affordability 1 2 3 4 5 (24) N/A 5
No fatigue in the hand 1 2 3 4 5 (24) N/A 5
Noise level 1 2 3 4 (16) 5 (8) N/A 4.3
Maneuverability 1 2 3 4 (12) 5 (12) N/A 4.5
How satisfied are you with your current silk flower stem cutting device?
Please circle the appropriate answer. 1 = very UNsatisfied 5 = very satisfied Avg.
Safety 1 2 3 (6) 4 (6) 5 (12) N/A 4.2
Reliability 1 2 3 (4) 4 (16) 5 (4) N/A 4
Size 1 2 (4) 3 (4) 4 (4) 5 (8) N/A 3.8
Efficiency 1 2 (4) 3 (4) 4 (16) 5 N/A 3.5
Speed of Operation 1 (4) 2 3 (12) 4 (8) 5 N/A 3
Affordability 1 2 3 (8) 4 (8) 5 (8) N/A 4
No fatigue in the hand 1 (4) 2 (4) 3 (4) 4(4) 5 (8) N/A 3.3
Noise level 1 2 3 4 (8) 5 (16) N/A 4.6
Maneuverability 1 2 3 (4) 4 (4) 5 (16) N/A 4.5
Is having an automatic silk flower stem cutter something that you would be interested in
having?
YES NO
How much would you be willing to pay for a device like this?
$50 $100, $100-$200 (4) $200-$500 (20) Other $ _______
Thank you for your time.
Appendix C1
APPENDIX C—QFD
G
uard
s
Separa
te s
witchs f
or
opera
tors
safe
ty
Cla
mps t
o h
old
the s
tem
s
Moto
r/actu
ato
r spec s
heet
Cutt
er
spec s
heet
CO
SM
OS
used f
or
facto
r of
safe
ty
Footp
rint
Handle
s
Nois
e o
f m
oto
r/actu
ato
r
Lig
htw
eig
ht
Caste
rs
Cuts
one b
ush a
t a t
ime
Custo
mer
import
ance
Desig
ner's M
ultip
lier
Curr
ent
Satisfa
ction
Pla
nned S
atisfa
ction
Impro
vem
ent
ratio
Modifie
d I
mport
ance
Rela
tive w
eig
ht
Rela
tive w
eig
ht
%
Safety 9 9 9 3 9 9 3 3 5.0 1.0 4.3 4.8 1.1 5.6 0.11 11%
Reliability 9 9 9 5.0 1.0 4.0 4.5 1.1 5.6 0.11 11%
Size 3 3 3 9 4.3 1.1 3.8 4.7 1.2 5.9 0.11 11%
Efficiency 1 9 9 9 5.0 1.0 3.5 5.0 1.4 7.1 0.13 13%
Speed of Operation 1 1 9 9 3 4.6 1.0 3.0 4.5 1.5 6.9 0.13 13%
Affordability 3 1 3 9 9 3 3 3 1 5.0 1.0 4.0 4.0 1.0 5.0 0.09 9%
No Fatigue in the Hand 3 1 3 1 9 5.0 1.0 3.3 4.8 1.5 7.3 0.14 14%
Noise Level 3 3 9 4.3 1.1 4.7 4.7 1.0 4.7 0.09 9%
Maneuverability 3 9 9 9 9 4.5 1.1 4.5 4.5 1.0 5.0 0.09 9%
Abs. importance 1.23 1.31 1.36 5.10 6.14 2.79 2.11 0.98 0.80 1.85 1.39 2.84 27.9 53.1 1.0
Rel. importance 0.04 0.05 0.05 0.18 0.22 0.10 0.08 0.04 0.03 0.07 0.05 0.10
Alan VerhoffAutomatic Silk Flower Stem Cutter
9 = Strong3 = Moderate1 = Weak
Appendix D1
APPENDIX D—SCHEDULE
TASKS No
v 2
0-2
6
No
v 2
7-
Dec
3
Dec
4 -
10
Dec
11
- 1
7
Dec
18
- 2
4D
ec 2
5 -
31
Jan
1 -
7
Jan
8 -
14
Jan
15
- 2
1
Jan
22
- 2
8
Jan
29
- F
eb 4
Feb
5 -
11
Feb
12
- 1
8
Feb
19
- 2
5
Feb
26
- M
ar 3
Mar
4 -
10
Mar
11
- 1
7
Mar
18
- 2
4
Mar
25
- 3
1A
pr
1 -
7
Ap
r 8
- 1
4
Ap
r 1
5 -
21
Ap
r 2
2 -
28
Ap
r 2
9 -
May
5
May
6 -
12
May
13
- 1
9
May
20
- 2
6
May
27
- J
un
2
Jun
3 -
9
Proof of Design to advisor 21
Concept sketches to advisor 23
3d modeling-frame 10
7
3d modeling-motor/actuator 17
7
3d modeling-electrical/assembly 24
7
Calculations based on simulations 7
14
Shop drawings, BOM, Purchase 14
14
Component selection 28
28
Design freeze 4
4
Fabrication-cut stock to length 18
7
Winter oral 17
17
Report 17
Research electrical circuitry 24
12
Fabrication-weld frame 31
14
Fabrication-Guards-casters 7
21
Finish Fab.-electrical-misc. 21
12
Demo to Adviser 14
14
Demo to Faculty 17
17
Spring Oral 21
21
Report 5
5
Alan VerhoffAutomatic Artificial Flower
Stem Cutter
Appendix E1
APPENDIX E—BUDGET
Actual
Component Description Cost Cost
Frame
Links/Braces Steel $50 $45
Casters $20 $18
Clamps Steel $20 $20
Guards Plexi Glass $30 $50
Drivers/Cutter
Drivers/Cutter Actuators $200 $335
Cutter Metal Cutter $175 $100
Electrical
DC Power Supply AC-DC $50 $60
Wiring/Switches $25 $20
Miscellaneous Bolts/Nuts/Paint $40 $20
Total $610 $668
Proposed Budget
Appendix F1
APPENDIX F—FORCE CALCULATIONS
SHEAR STRESS CALCULATION:
The stem of the flower is made of a steel core, .1” diameter, and a rubber/plastic
coating, .3” in diameter.
The steel core is assumed to be 1020 Cold-Drawn, with a Tensile Strength of
61,000psi. (Machine Elements in Mechanical Design, 4th Edition, Mott).
Assume also, that the maximum number of stems cut at one time to be two. This is
from knowing how rods behave when they are stacked on top of each other.
All distances were taken from the solid model.
BLADE FBD:
A
643 lbs
B
C
Appendix F2
ARM FBD:
Forces needed throughout the entire stroke of the cutter.
D
BC F req.
Degrees Force Needed (lbs)
59 54.95
60 54.39
61 53.85
62 53.34
63 52.86
64 52.40
65 51.97
66 51.56
67 51.17
68 50.80
69 50.45
70 50.12
71 49.81
72 49.52
73 49.25
74 49.00
75 48.76
76 48.54
77 48.34
78 48.15
79 47.98
80 47.83
81 47.69
82 47.56
Appendix G1
APPENDIX G—BILL OF MATERIALS
Description Specification Quantity
Frame Tube AISC 2"*2"*1/4" 30"
Frame Rails AISC L 2"*2"*5/16" 36"
Guard Frame AISC L 1"*1"*1/8" 72"
Flat Bar Steel AISC 1/2"*1/2" 145"
Clevis Mild Steel 2"*1" 8"
Plexi Glass Top 18"*9.5" 1
Plexi Glass Sides 15.5"*17.5" 2
Plexi Glass Backs 15.5"*9" 2
Metal Cutter 1/2" Steel Rod Cap. 1
Casters 2" Caters 4
Bolts 1/4-20 UNC * 0.75" 24
Nuts 1/4-20 Jam Nuts 24
Clevis Pins 1/4"-2" 2
Main Cylinder Electric Actuator 50lbs 1
Clamp Cylinders Electric Actuator 20lbs 2
Electrical Components Wires, Switches…. ???
Bill of Materials
Appendix H1
APPENDIX H—PART DRAWINGS
Appendix H2
Appendix H3
Appendix H4
Appendix H5
Appendix H6
Appendix H7
Appendix H8
Appendix H9
Appendix H10
Appendix H11
Appendix H12