P13675 Bike Helmet Mirror System Detailed Design Review
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Transcript of P13675 Bike Helmet Mirror System Detailed Design Review
P13675Bike Helmet Mirror System
Detailed Design Review
Rob Fish (Industrial Designer) Zachary Kirsch (Mechanical Engineer, PM) Martin Savage (Mechanical Engineer) Olivia Scheibel (Mechanical Engineer) Henry Woltag (Industrial and Systems Engineer)
Team
Guide◦ Dr. Richard Lux
Customer Proxy◦ Dr. B. Brooks
Faculty Support◦ Dr. M. Gomes◦ Dr. M. Lam
Sponsor◦ RIT MSD Project Office
Guides, Advisor, Sponsor
Project Summary Design Objectives Proposed Design
◦ Optical System◦ Support System
Bill of Materials Test Plans Risk Assessment MSD II Schedule
Outline
Current rear view mirrors systems for bicycles are clumsy, unattractive, poor quality, too expensive, or have a small viewing range.
Our solution is to create a low cost alternative that requires no power to operate,
and attaches to any helmet.
Mission Statement
Issues regarding geometric optics◦ Size of mirrors◦ Range of Adjustability◦ Model head, neck, eye, helmet positions◦ Create system in SolidWorks
Team should focus more on shock than vibrations
Testing◦ Deflection analysis◦ Drop testing
Takeaways from Systems Design Review
Concerns:◦ Not enough analysis / data involved in concept
selection◦ Settling on Rob’s prototype vs. alternate designs◦ Need to determine range of adjustability
Takeaways from Systems Design Review
Design Objectives
Optical System ConceptsBased on sensitivity analysis, the 2 mirror system was determined to be advantageous to the 3 mirror system.
Three mirror optical system concept. Two mirror optical system concept.
Feasibility Tests Conducted Using Prototype Distance a human was recognizable
– 37ft Distance a van was recognizable –
177ft+ Distance a car was recognizable –
110ft
Optical System
Maximum Area of Dual Lock™
Maximum Allowable Break Away Force,
Tensile disengagement of Dual Lock (250 Black),
Support System Attachment
“3M™ Dual Lock™ Reclosable Fastener.” Online image. 2013. 3M. 2 Feb. 2013 <http://www.3m.com/product/information/Dual-Lock-Reclosable-Fastener.html>
Dual Lock™ is a reclosable fastener made of mushroom-shaped stems that snap together. Similar to Velcro®, Dual Lock ™ will allow users to easily attach and detach the bike helmet mirror system.
Support System Attachment
Technical drawings of rear support bracket.
Technical drawings of front support bracket.
One Solid Manufactured Piece ABS Material 3 mm diameter support legs Uses cylindrical snap-fits to
constrain degrees of freedom Mylar coating on underside to
create mirror surface
Front Support System
Standalone Bracket
Bracket with Attachments
Bracket with Gooseneck/Attachments
Front Support System – Attachment Methods
Cylindrical Snapfit – 1 degree of freedom: Cylindrical Insert with adhesive/Epoxy
Mass of MirrorVolume of Top Mirror:
Density of Top Mirror,
Mass of Top Mirror:
Rear Support System MaterialsAssumptions
Entire weight of top mirror acts as a point force on the end of two, six inch sections of “Gooseneck”
“Flexible Gooseneck Tube.” Online image. 2013. Leflexo. 14 Feb. 2013 <http://www.leflexo.com/new_section.php?sid=204>
Material Selection Each six inch section of Gooseneck
needs to support 1.44 oz. Size (O.D.) 0.142-H can support 3.2 oz at
six inches
Impact Analysis
Potential Energy:
Impact Force:
Size (O.D.)0.142-H Gooseneck can support 3.2 oz applied on 6 in.
Gooseneck Feasibility AnalysisAssumptions
Entire weight of top mirror acts as a point force on the end of two, six inch sections of “Gooseneck”
Energy of impact is unabsorbed by body, helmet, etc.
PE (J) s (m) FTotal (N) FOne Section (N)
0.02 0.001 20.432 10.2160.02 0.003 6.811 3.4050.02 0.005 4.086 2.0430.02 0.010 2.043 1.0220.02 0.020 1.022 0.511
0.02 0.025 0.817 0.409
0.02 0.038 (1.5 in) 0.536 0.268
0.02 0.051 0.401 0.200
Impact Analysis for s=1in
Results The gooseneck will deform 12 mm after
a 1 in drop.
Based on the results of the sensitivity analysis, the optical system will still remain functional
Thermal Expansion of GooseneckLinear Thermal Expansion,
Diameter of gooseneck,
Thermal Expansion Coefficient of Steel,
Initial Temperature (SATP),
Final Temperature,
Rear Support System Mirror AttachmentThe gooseneck will be secured with a metal to plastic, weatherproof adhesive.
Top Mirror
Mirror-Gooseneck Attachment
“Gooseneck”- Flexible Tubing
Towards Front of Helmet
Proposed Design – Solidworks Model
Bill of MaterialsPart # Part Name Quantity Material Weight (lb)
Manufacturing Cost ($)
1 Front Mirror 1 Mylar 0 0.004
2 Front Mirror Housing 1 ABS 0.012 0.014
3 Front Support 1 ABS 0.013 0.016
4 Front Support Bracket 2 ABS 0.003 0.003
5 Top Mirror 1 Mylar 0 0.041
6 Top Mirror Housing 1 ABS 0.184 0.217
7 Flexible Tube 1 Steel 0.044 3.317
8 Rear Support Bracket 2 ABS 0.002 0.003
9 Dual Lock 4 Dual Lock 0 0.278
10 Adhesive Beacon GM2OZ 0 0.000
Total 0.258 3.89
Approximate Sales Cost $15.56
Engineering Specification VerificationCustomer Needs Rating
Safe to wear 9 Break away force: 45 lbs X
Provides a wide angle view behind the cyclist 9 Rear image angle: 25 degrees Calculated image angle: 47 degrees X
Holds mirror orientation as set by user 9 Image oriented properly Yes X
Minimizes obstruction to the cyclist's forward field of vision 9 Lateral forward viewing
angle:170 degrees X
Attaches to a typical helmet without compromising the helmets integrity
9 X
Is lightweight and comfortable to wear 9 Marginal Weight: .775 lbs Estimated Weight: .258 lbs X
Is durable 9 Survives drop from: 3 feet Test
Provides a clear, correctly oriented image 9 Distance behind at which
vehicles are visable130 ft Test
Is adjustable to provide optimal view for the rider 9 X
Is inexpensive ($10-$20) for the consumer 3 Marginal Cost: $30.00 Estimated sale cost: $15.56 X
Detaches from the helmet 3 X
Can be adjusted without the use of tools 3 X
Requires no power input 3 X
Is aesthetically pleasing 3 Ongoing
Refrains from significantly increasing wind resistance 1 Survives wind speeds 45 mph Test
Is fabricated in an environmentaly friendly way 1 Recycleability of materials
used:100% Ongoing
Related to Specifications Product Design
Angle of front mirror will be adjusted via ball joint. Top concave mirror will be stationary.
Will receive input from Rob Fish
Front attachments fabricated from plastic, will break before penetrating Helmet. Rear attachements fabricated from gooseneck, will bend before penetrating helmet.
Ball joint will hold front mirror orientation
Depends on if film will be removable from rapid plastic body
Front mirror will not affect lateral view. Placed 2 inches above eye level (y direction).
Designed to attach to helmets via dual lock, does not compromise material integrity.
Will not require power
No tools are needed
Utilizes dual lock to attach / detach from helmet
Specification: The mirror system must be mountable to at least 3 distinctly different helmet styles Test: Mount the system to three different helmet styles
Test Plan: Specification S4
http://bertsbikes.com/product/giro-rift-154856-1.htm
How to test:◦ Acquire three
distinctly different helmets and mount the mirror system
◦ Go to the bike shop and mock mount the mirror system to three distinctly different helmets
Test Plan: Specification S4 Pass Criteria: Successfully mount to three helmets in either test Risks and
Mitigations:◦ No foreseen risk
Specification: Survive drop from height of 3 feet
Test: Release helmet at 3 feet in the following impact orientations
◦ Correct, inverted, nose, back, side
Test Plan: Specification S5
http://static6.depositphotos.com/1025312/628/i/950/depositphotos_6280277-Helmet-on-handlebar.jpg
How to test: Hold the helmet at a 3 foot height above a concrete surface. Release in the required orientations.
Test Plan: Specification S5 Pass Criteria: No part failures. System operable after impact. Risks and
Mitigations:◦ Part fails during test
All team members wear appropriate PPE while test in progress (eye protection, gloves)
Specification: Operate in wind speeds of 45 mph (marginal) and 60 mph (ideal) Test: Place helmet in proper orientation within wind tunnel and subject helmet to various wind speeds
Test Plan: Specification S7
20”
30”
* Helmet with mirror measures: 9”W x 8”H x 12.5”L
How to test: Create a mount to secure helmet within wind tunnel. Subject helmet to speed increments of 5 mph from 0 to 60 mph
Test Plan: Specification S7 Pass Criteria: Mirror position does not deform under wind loading Risks and
Mitigations:◦ No foreseen risk
Specification: Mirror mount needs to break away from helmet under a 45 lb applied load to meet NHTSA standards Test: Measure force required to remove mirror system from helmet
Test Plan: Specification S8
http://www.transducertechniques.com/images/hfg-series-force-gauge.gif
How to test: Attach force gauge to the front of the mirror mount system. Apply force until the mounting system is removed from the helmet
Test Plan: Specification S8 Pass Criteria: Force applied to remove the helmet does not exceed the 45 lb standard Risks and Mitigations:
◦ The mirror system could violently rip off the helmet All team members
wear appropriate PPE while test in progress (eye protection)
Specification: The rider must see a horizontal rear image encompassing 10 degrees (marginal) and 25 degrees (ideal) Test: Measure the rear viewing angle of a team member using the system
Test Plan: Specification S9
How to test: A team member wearing the helmet stands a measured distance from a white board. Another team member walks behind the one wearing the helmet and marks the extent of vision. This distance is measured and the angle calculated.
Test Plan: Specification S9 Pass Criteria: The calculated angle meets or exceeds the angle specified Risks and
Mitigations:◦ No foreseen risk
Specification: Vehicles behind cyclist must be visible at 130 ft (marginal) and 200 ft (ideal) Test: Team member wearing helmet attempt to identify objects at these distances
Test Plan: Specification S14
http://turningplace.files.wordpress.com/2013/01/aaaa.jpg
How to test:◦ Team member wearing
helmet stands on end zone line of football field and attempts to identify another team member standing 130 and 200 ft away
◦ Team member wearing helmet stands along the edge of the road and attempts to identify a vehicle driven by another team member at 130 and 200 ft away
Test Plan: Specification S14
Pass Criteria: Person visible at given distances or car visible at given distances Risks and
Mitigation:◦ Safety concern with
team members being on the road for testing Look into traffic control
options
Risk AssessmentID Risk Item Effect Cause
Likelihood
Severity
Importance Action to Minimize Risk Owner
1Reflective film does not display image to meet specifications
Reflective film is unaccepatable
Does not pass rear viewing distance tests
2 3 6Test image quality as early as possible and prepare contingencies.
Olivia Scheibel
2Exceeding the designated budget.
Team will run out of funds to build working prototype.
Cost of materials to build system and/or number of redesigns
2 3 6Ensure all costs are documented before any purchasing.
Zachary Kirsch
3Parts and materials do not arrive on time
Prototype cannot be completed on schedule
Item lead times do not match anticipated values.
2 2 4 Accurately identify lead times of materials.
Zachary Kirsch
4 Group dysfunction
Group does not work as efficiently as possible.
Lack of communication and poor compromising. Group members do not contribute equally to the project.
2 2 4
Consistent communication among team members. Each team member will complete individual responsibilities to expected quality and on time.
Zachary Kirsch
Risk Assessment
ID Risk Item Effect Cause
Likelihood
Severity
Importance Action to Minimize Risk Owner
5Final product is not aesthetically pleasing
Product will not be marketable.
Aesthetics were not considered during design and/or manufacturing.
2 2 4Coordinating with Rob to ensure the design meets his product vision.
Henry Woltag
6 Poor documentation
Disorganization of team. Follow up projects lack foundation.
Inconsistent documentation. 3 1 3
Update EDGE weekly with meeting minutes, notes, and other important information.
Henry Woltag
7Dual Lock ™ does not support system
Redesign is needed.
System is heavier or Dual Lock™ is not as strong as anticipated.
1 3 3 Prepare contingencies. Olivia Scheibel
8
Improper design provided to rapid prototyping machine
Prototype can not be created on schedule
Improper formatting, not understanding needs of rapid prototyping system
1 3 3Contact professors involved with rapid prototyping and obtain information regarding necessary machine inputs.
Martin Savage
MSD II ScheduleSu M T W R F S Su M T W R F S Su M T W R F S Su M T W R F S Su M T W R F S
Assess RisksUpload Documents to EDGEReevaluate Detailed DesignFinalize Test PlansOrder MaterialsRapid Prototype Support System ComponentsAssemble Support SystemAssemble Mirror SystemMount Entire AssemblyTest For FailuresImplement Modifications as NeededDocumentation of Assembly, Tests, Etc.Prepare PosterPrepare Final Technical Paper
Week 1 Week 2 Week 3 Week 4 Week 5
Su M T W R F S Su M T W R F S Su M T W R F S Su M T W R F S Su M T W R F SAssess RisksUpload Documents to EDGEReevaluate Detailed DesignFinalize Test PlansOrder MaterialsRapid Prototype Support System ComponentsAssemble Support SystemAssemble Mirror SystemMount Entire AssemblyTest For FailuresImplement Modifications as NeededDocumentation of Assembly, Tests, Etc.Prepare PosterPrepare Final Technical Paper
Week 6 Week 7 Week 8 Week 9 Week 10
Thank you for your time and support.