R.I.T. 175th Anniversary Chopper Senior Design Team
(Project Number 05912)
Diverse Team Members• Advisors
– Dr. James Taylor (ISE Associate Professor)– John Bonzo (Brinkman Lab Facilities Manager)
• Mechanical Engineering– Jonathan Howard– Alexandra (Alli) Collier– Lee Gagne
• Industrial Engineering– Jeremy Rank– John Johnson– Anthony Rounding
• Electrical Engineering– Curtis Vana
• Industrial Design– Scott Janis– Devin Connolly– Tim Houck
Agenda
• Needs Assessment
• Concept Development
• Feasibility Assessment
• Specifications
• Analysis and Synthesis
175th Anniversary Chopper Project Description / Desired Outcomes
• Convert stock 883 Harley-Davidson Sportster into custom chopper prototype
• Create customization kit for aftermarket sales – Conversion components must be bolt on
– No significant modifications can be made to the frame
• Rochester Institute of Technology • Senior Design Team• Santa Cruz Harley-Davidson
– Primary stakeholder for conversion kit
• Conversion Kit Customers– Approximately 500 Sportsters are manufactured daily
Stakeholders
Needs Assessment
• Team researched chopper motorcycles
• Talk with Mike James and Bob Davis of Santa Cruz Harley-Davidson
• Team developed a list of order qualifiers:– Rear end of the bike shall change
– Front end of the bike shall change
– Sheet metal on the bike shall change
– Electronics on the bike shall change
– Ride height shall change
– Paint on the bike shall change
– Seat on the bike shall change
– Custom parts must be bolt on
– Bike must be operable
Needs Assessment
• System changes to meet order qualifiers:– Fuel Tank
– Handlebars / Controls
– Ride Height
– Wheel Design
– Tire
– Drive System
Concept Development
– Wheel Hubs
– Headlight
– Electrical
– Exhaust
– Seat
– Conversion Kit
– Methods Used• Pros & Cons• Pugh’s Method• Weighted Concept Evaluation• Expert input / discussion
Feasibility Analysis
Electronics Specifications
• Increase Lighting – Hurt Motorcycle Accident Study
• ½ of all motorcycle accidents involve a motor vehicle (automobile) violating the motorcycle right-of-way
• Failure to recognize and detect motorcycles in traffic was the predominating cause of motorcycle accident
– Freedman and Ketron Lighting Study
• Found that the adding lights to the motorcycles rear and sides improved conspicuity
Electronics Specifications
Digital Control
Unit
RPM signal
User Interface
12VDC Battery
LED Driver
Accent Lighting( LEDs)
Accent Lighting System General Layout
•System Schematic
•Cost Analysis
Triple Clamp Specifications
• Design Constraints– Safety
– Machinability
– 7 Degree Rake Angle
– Forks
– Steering stem
– Mid-Glide front end
– Handlebars
– Style
Top Triple Clamp Analysis
Top Triple Clamp with 7G Horizontal Impact Loading
Top Triple Clamp with 3G Vertical Impact Loading
Max Stress 29,000 psi
Max Stress 9,300 psi
Lower Triple Clamp Analysis
Lower Triple Clamp with 7G Horizontal Impact Loading
Lower Triple Clamp with 3G Vertical Impact Loading
Max Stress 9,000 psi
Max Stress 37,000 psi
Front Wheel Specifications
• Design Constraints– Safety
– Manufacturability
– Style
– New Front End Design
Rear Wheel
Front Wheel Concepts
• Preliminary Design Issues– Manufacturability
– Safety
Front Wheel Analysis
• Impact Load• Torsion Test
6 G Load
Max Stress 8,123 psi
3,500 lb Load
Max Stress
20,071 psi
Front Hub Analysis
• Impact Load• Torsion Test
6 G Load
Max Stress 2,264 psi
3,500 lb Load
Max Stress
8,100 psi
Kit ContentsCustom Parts Designed and Manufactured
• Front Wheel
• Front Hub
• Front Axle
• Rear Wheel
• Rear Hub
• Rear Axle
• Triple Clamps
– Top and Bottom
• Steering Stem Shaft
• Steering Stops
• Modified Purchased Front Sprocket
• Modified Purchased Rear Sprocket
• Tank Mounts
• Seat Mounts
• Seat Pan
• Ignition / Key Casing
• Converted To Hydraulic Clutch
• Exhaust• Paint Scheme and
Implementation– Gas Tank– Rear Fender– Oil Cover– Electronics Cover– Frame
• Engraved Designs On The Air Intake and Engine Casing
• Cutting Fender Struts and Remanufacturing Chrome Covers
• Brake Light• LED Lighting System
• 11inch Eye-To-Eye Shocks
• Inverted Forks
• Handlebars
• Front and Rear Tires
• Chain
• Air Intake Filter
• Chrome Engine Covers
• Single Rider Seat
• Chrome Swing Arm
• Headlight
• Slave Cylinder
Kit ContentsAftermarket Parts Purchased and Implemented
Lessons Learned
• Always have a predetermined contingency – In the feasibility analysis, we only decided upon the
optimal solution• Fender attachment
• Critical path – reconstructing the critical path to make difficult tasks non-sequential
Questions
Shoulder Moment Reduction
• Original designM (shoulder) = (18.62N*.170m) + (10.78N*.480m)
M (shoulder) = 8.34 Nm
• New DesignM (shoulder) = (18.62N*.120m) + (10.78N*.340m)
M (shoulder) = 5.89 Nm
• Moment Reduction – 29%
Back
Algorithm
Back
Check State of
Comparator Interrupt
Flag
Peak Check
Is Peak? Increment Counter
Have 45 peaks been counted?
Toggle Output
Begin
Reset Counter
General outline of lighting control algorithm
•Comparator state check
•Increment
•Toggle Output
Lighting Control System
Back
R 1
1 0 k
R 21 k
I N1
O U T2
CO
MM
ON
3
U 1
U A 7 8 0 5 / TE M PM o t o rc y c le B a t t e ry
1 2 V d c C 11 n
5Vdc
12Vdc
C 21 n
PIC12F675
C ra n k P o s it io n S e n s o rC 31 n
D 1D 1 N 4 0 0 4
D 2D 1 N 4 0 0 4
Pin6
Pin1
Pin8
Pin3
0
L E DLED (Accent Lighting) Load
0
PVDZ172N
R 31 k
Power Conditioning Circuit
Signal Conditioning Circuit
R 41 8 k
R 52 2 k
•Power conditioning circuit
•Signal conditioning circuit
•Processing
Cost Analysis
Pugh’s Method Comparison
Back
Final Parts UA7805C PIC12F675
PVDZ172N PCB Terminals
Project Enclosure
Manufacturer
Texas Instruments
Microchip International Rectifier
Radio Shack Radio Shack
Function Voltage Regulator
Signal Processor
Solid State Relay
Terminals Enclosure
Quantity 2 2 2 8 (2 sets of 4)
2
Price per .52 2.15 8.50 2.29 3.99
Price for 2 sets
1.04 4.3 17 4.58 7.98
Total Project Price
$34.90
Final Parts
UA7805C PIC12F675
PVDZ172N PCB Terminals
Project Enclosure
Manufacturer
Texas Instruments
Microchip International Rectifier
Radio Shack
Radio Shack
Function Voltage Regulator
Signal Processor
Solid State Relay
Terminals Enclosure
Quantity 2 2 2 8 (2 sets of 4)
2
Price per .52 2.15 8.50 2.29 3.99
Price for 2 sets
1.04 4.3 17 4.58 7.98
Total Project Price
$34.90
Digital Control Unit
DIGITAL CONTROLLER COMPARISON PIC-12F629 Z8F011AHH020EC CY8C22113-24PIManufacturer Microchip Zilog CypressMemory Size (FLASH) 1024Kx14 words FLASH 1K 2KRAM 64bytes 256bytes 256bytesEEPROM 128bytesNVDS 16bytesVDD 6.5V Operating Voltage 2V - 5.5V 2.7-3.6I/O Lines 6 17 6UART 1Serial Lines yes noA/D 4 3CLK Speed 20MHz 20MHz 24MHzPower Dissipation 800mWPrice 1.68 3.18 2.50
Device Comparison
Algorithm Back
Rear Wheel and Hub
Back
– Clean up controls – sleeker look
– Hide control cables within handlebar
– Change handlebar shape / geometry• Biomechanics
– Use twist-grip clutch
– Suicide Shift
– Custom foot controls
Handlebar Control Concepts
Back
– Lower ride height – rear end
– Shorten shocks
– Rigid Hard-tail design
– Redesign rear suspension geometry
Ride Height Concepts
Back
– Three claw design• 3-dimensional
• 2-dimensional
– Solid Wheel Design • Spoke Appearance
– Incorporate tiger image into design
– Fabricate wheels in-house (Brinkman Lab)
– Outsource wheel fabrication
Wheel Design Concepts
Back
– Increase rear tire width• Size Range – 180mm – 220mm
– Change front tire to match new rear tire
– Find similar front & rear tire pattern
Tire Concepts
Back
– Switch from belt to chain drive
– Switch to narrower belt
– Use current belt• Drive extension / spacer to accommodate new rear tire
• Widen swing arm
– Replace existing drive covers• Chrome
• Powder coat
• Aftermarket color
Drive System Concepts
Back
– Fabricate all components of kit
– Purchase all components (aftermarket)
– Combination of purchase / fabrication
– Final Kit delivery• All components – 1 set
• Documentation
– “Bolt on” components
Conversion Kit Concepts
Back
– Design hubs to fit custom wheel
– Purchase aftermarket hubs• Requires wheel design to conform
Wheel Hub Concepts
Back
– In-house custom fabrication
– Purchase aftermarket headlight
– Remove headlight from design
– Reuse stock headlight
Headlight Concepts
Back
– Left exit exhaust
– Converging exhaust pipes (two into one)
– Shortened straight pipes
– Street sweeper pipes
– Purchase aftermarket pipes
– Fabricate exhaust in-house
Exhaust Concepts
Back
– Replace stock two-up seat
– Single seat• Fabricate in-house
• Purchase aftermarket
– Redesigned two-up seat• Fabricate in-house
• Purchase aftermarket
– Sissy bar• Fabricate in-house
• Purchase aftermarket
– Incorporate Logo into seat design• RIT 175th anniversary
• Sponsor Logo
Seat Concepts
Back
– Pugh’s Method
Electrical Feasibility
Back
GENERAL SYSTEM COMPARISON Digital Controller-LED Driver Digital Controller Analog CircuitDesign Complexity 3 3 2Sufficient Equipment 5 5 5Cost of Total Materials 3 4 2Availability of Components 5 5 5Versatility of Design 5 3 1Power Efficiency 5 4 3Mean Score 4.33 4 3
– Integrate rear lights into rear fender
– Develop proximity sensors
– Develop variable intensity lighting
– Accent lighting for engine
– Custom turn signals
– Ignition• Access code
• Toggle switch
Electrical Concepts
Back
– Variable intensity lighting• Pro:
– Safety (increase visibility)
– Aesthetically pleasing
• Con:– Not visible during the daytime
– Proximity sensor system• Pro:
– Safety (visibility)
• Con:– Cost
– Time required to implement
– Resources (people)
Electrical Feasibility
Back
• Custom designed tank• Cons:
• Team lacks expertise in metalworking
• Cost to outsource fabrication of in-house design ~ $2000 per tank
• Pros:
• Radical one of a kind
• Does not compromise the Industrial Designer’s design
• Commercially available tank• Cons:
• Compromises the Industrial Designer’s design
• Not a radical design
• Pros:
• Cost: ~$600 per tank
Fuel Tank Feasibility
Back
• Weighted concepts
Fuel Tank Feasibility
Back
Attributes 1 2 3 4 5 TOTAL Weights
1. Price X 3 0 3 0.27
2. Uniqueness X X 0.5 0 0.5 0.05
3. Design concept X X X 0 0.5 0.5 0.05
4. Ease of manufacture X X X X 0 2 2 0.18
5. Fullfills project goals X X X X X 0 5 5 0.450 0 0.5 2 5 11 1
• Pugh’s method
Fuel Tank Feasibility
Back
Evaluate each additional concept against the baseline, score each attribute as: 1 = much worse than baseline concept 2 =
worse than baseline 3 = same as baseline 4 = better than baseline 5= much better
than baseline
Purchase Custom Tank
Fabricate Tank
Purchase Aftermarket
Tank
Sufficient Student Skills 3 2 3Sufficient Shop Equipment 3 2 3Economic Feasibility 3 4 5Cost of Materials 3 4 5Cost of Purchased Components 3 4 5Schedule Feasibility 3 1 3Task Time 3 1 3End user satisfaction 3 3 1Technology Feasibility 3 2 3Meets intermediate milestones 3 3 3Meets PDR requirements 3 3 3Meets CDR requirements 3 3 3
Mean Score 3 2.67 3.33
Normalized Score 0.9 0.8 1
• Custom built handlebars
• Cons:
• No member of the team has experience designing handlebars
• Pros:
• Conceal controls
• Change look of bike from dirt bike to a chopper
• Purchase handlebars
• Cons:
• Cost: ~ $3000 per set
• Pros:
• Built by manufacturers with experience
• Conceal controls
• Changes look of bike from dirt bike to chopper
Handlebars Feasibility
Back
• Remove shocks• Cons:
• Turns bike into rigid, decreasing the ride ability of the bike
• Pros:
• Gives bike a sleeker look by removing the shocks
• Shorten shocks• Cons:
• May result in possible problems with concerning clearance, ground clearance and handling
• Cost of new shocks $281 per set
• Pros:
• Gives the bike a squatter stance
• As compared to the rigid, the bike is easier to ride (comfort)
Ride Height Feasibility
Back
– 3D design• Cons:
– Requires adding material to the wheel blank
– Safety concerns (excess weight)
– Machinability
• Pros:– Radical custom look
– 2D design• Cons:
– Not as custom
• Pros:– Machinable
– Safer
Wheel Design Feasibility
Back
Tire Feasibility
– Width over 190mm• Cons:
– Rear wheel in excess of 190mm will result in a redesign of the XL swing arm
• Pros:– Will give bike the massive back wheel look of a chopper
– Width equal to or less then 190mm• Cons:
– Rear wheel may appear to be stock
• Pros:– 190mm is a proven good look on an XL– No swing arm of drive redesign is needed
Back
Drive System Design Feasibility
– Pugh’s methodEvaluate each additional concept against the baseline, score each attribute as: 1 = much worse than baseline concept 2 =
worse than baseline 3 = same as baseline 4 = better than baseline 5= much better than
baselineExisting belt drive Smaller belt drive Chain drive
Sufficient Student Skills 3 3 3Sufficient Shop Equipment 3 3 3Economic Feasibility 3 2 4Cost of Materials 3 2 2Cost of Purchased Components 3 2 5Schedule Feasibility 3 2 4Task Time 3 2 4End user satisfaction 3 3 2Technology Feasibility 3 3 5Meets intermediate milestones 3 3 4Meets PDR requirements 3 3 4Meets CDR requirements 3 3 4
Mean Score 3 2.58 3.67
Normalized Score 0.82 0.70 1
Back
Exhaust Design Feasibility
– Right hand exhaust• Cons:
– Looks like the majority of bikes on the market
• Pros:– XL 883C is built with and for right hand exhaust– Proper flow of exhaust
– Left hand exhaust• Cons:
– Proper flow of exhaust may be difficult to obtain on XL– XL 883C is not built for left hand exhaust
• Pros:– Left hand exhaust is not norm, creating custom and radical look
Back
Fuel Tank Concepts• Custom designed tank
– Incorporate RIT Tiger into tank
• Custom fabricate
• Custom paint
• Commercially available tank
Back
– Feasibility Methods Used• Pros and Cons
• Pugh’s Method
• Weighted Concept Evaluation
– Specifications• Purchase aftermarket tank
Fuel Tank
– Feasibility Methods Used• Pros and Cons
– Specifications• Have custom handlebars with integrated controls
manufactured
Handlebars / Controls
– Feasibility Methods Used• Pros and Cons
– Specifications• Lower ride height by 1”
Ride Height
– Feasibility Methods Used• Pros and Cons
– Specifications• 2-dimensional design
• In-house fabrication
Wheel Design
– Feasibility Methods Used• Pros and Cons
– Specifications• 190mm rear tire
• Purchase front tire with matching
tread pattern
Tires
– Feasibility Methods Used• Pugh’s Method
– Specifications• Chain drive
Drive System Design
– Feasibility Methods Used• Pro & Con
• Pugh’s Method
– Specifications• Accent lighting - safety
• Blinking frequency dependant
on RPM
Electrical Design
– Feasibility Methods Used• Pros and Cons
– Specifications• Right Exit Exhaust
Exhaust Design
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