

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Rob Fish (Industrial Designer)
Zachary Kirsch (Mechanical Engineer, PM)
Martin Savage (Mechanical Engineer)
Olivia Scheibel (Mechanical Engineer)
Henry Woltag (Industrial and Systems Engineer)

Guide
◦ Dr. Richard Lux

Customer Proxy
◦ Dr. B. Brooks

Faculty Support
◦ Dr. M. Gomes
◦ Dr. M. Lam

Sponsor
◦ RIT MSD Project Office

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
Project Summary
Design Objectives
Proposed Design
◦ Optical System
◦ Support System




Bill of Materials
Test Plans
Risk Assessment
MSD II Schedule
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.

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

Concerns:
◦ Not enough analysis / data involved in concept
selection
◦ Settling on Rob’s prototype vs. alternate designs
◦ Need to determine range of adjustability
Based 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
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.
Maximum Area of Dual Lock™
Maximum Allowable Break Away Force,
𝐹𝐵 = 45 𝑙𝑏
Tensile disengagement of Dual Lock (250
𝑙𝑏
Black), 30 2
𝑖𝑛
𝐴𝑚𝑎𝑥 =
45 𝑙𝑏
𝑙𝑏
30 2
𝑖𝑛
𝐴𝑚𝑎𝑥 = 1.5 𝑖𝑛2
“3M™ Dual Lock™ Reclosable Fastener.” Online image. 2013. 3M. 2 Feb. 2013 <http://www.3m.com/product/information/Dual-LockReclosable-Fastener.html>
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
Bracket with Attachments
Standalone Bracket
Bracket with Gooseneck/Attachments
Cylindrical Snapfit –
1 degree of freedom:
Cylindrical Insert with adhesive/Epoxy
Mass of Mirror
Volume of Top Mirror: 𝑉𝑚 ≈
(13.10𝑐𝑚)(10.16𝑐𝑚)(0.60𝑐𝑚) = 79.85𝑐𝑚3 ≈ 80𝑐𝑚3
Assumptions

Entire weight of top mirror acts as
a point force on the end of two, six
inch sections of “Gooseneck”
Density of Top Mirror, 𝜌𝑚 = 1.024 𝑔/𝑐𝑚3
Mass of Top Mirror: 𝑚𝑚 = 𝑉𝑚 𝜌𝑚 ≈ 82𝑔 ≈ 2.89 𝑜𝑧
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
“Flexible Gooseneck Tube.” Online image. 2013. Leflexo. 14 Feb. 2013 <http://www.leflexo.com/new_section.php?sid=204>
Impact Analysis
Assumptions

Potential Energy: 𝑃𝐸 = 𝑚𝑔ℎ

Impact Force: 𝐹 = 𝑃𝐸/𝑠
Size (O.D.)0.142-H Gooseneck can
support 3.2 oz applied on 6 in.
3.2𝑜𝑧 = 0.0907𝑘𝑔
PE (J)
𝑚
𝑠2
s (m)
FTotal (N) FOne Section (N)
0.001
0.003
20.432
6.811
10.216
3.405
0.02
0.02
0.02
0.005
0.010
0.020
4.086
2.043
1.022
2.043
1.022
0.511
The gooseneck will deform 12 mm after a
1 in drop.
0.02
0.025
0.817
0.409
0.02
0.038 (1.5 in)
0.536
0.268
Based on the results of the sensitivity
analysis, the optical system will still
remain functional
0.02
0.051
0.401
0.200
𝐹𝑎𝑙𝑙𝑜𝑤𝑒𝑑 = 0.89𝑁
Results

Impact Analysis for s=1in
0.02
0.02
𝐹𝑎𝑙𝑙𝑜𝑤𝑒𝑑 = 0.0907𝑘𝑔 ∗ 9.81

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.
The gooseneck will be secured with a metal to plastic, weatherproof adhesive.
Towards Front of
Helmet
Thermal Expansion of Gooseneck
Top Mirror
Linear Thermal Expansion, Δ𝐿 = 𝐿0 𝛼(𝑇1 − 𝑇0 )
Diameter of gooseneck, 𝐿0 = 0.142 𝑖𝑛
Thermal Expansion Coefficient of Steel, 𝛼 = 13.0 ∗
10−6
Mirror-Gooseneck
Attachment
“Gooseneck”Flexible Tubing
𝑖𝑛
𝑖𝑛 °𝐹
Initial Temperature (SATP), 𝑇0 = 77°𝐹
Final Temperature, 𝑇1 = 18°𝐹
Δ𝐿 = −11 ∗ 10−5 𝑖𝑛
Quantity Material Weight (lb)
Manufacturing
Cost ($)
Part #
Part Name
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
0
0.278
10
Adhesive
0
0.000
0.258
3.89
Total
Approximate Sales Cost
Dual
Lock
Beacon
GM2OZ
$15.56
Customer Needs
Rating
Related to Specifications
Safe to wear
9
Break away force:
45 lbs
Provides a wide angle view
behind the cyclist
Holds mirror orientation as set
by user
Minimizes obstruction to the
cyclist's forward field of vision
Attaches to a typical helmet
without compromising the
helmets integrity
Is lightweight and comfortable
to wear
9
9
9
Rear image angle:
25 degrees
Is durable
Provides a clear, correctly
oriented image
Is adjustable to provide optimal
view for the rider
Is inexpensive ($10-$20) for the
consumer
Image oriented properly
Yes
Lateral forward viewing
angle:
170 degrees
9
9
9
9
9
3
Marginal Weight:
.775 lbs
Product Design
Front attachments fabricated from plastic, will
break before penetrating Helmet. Rear
attachements fabricated from gooseneck, will
bend before penetrating helmet.
X
Calculated image angle:
X
47 degrees
Ball joint will hold front mirror orientation
X
Front mirror will not affect lateral view. Placed 2
inches above eye level (y direction).
X
Designed to attach to helmets via dual lock, does
not compromise material integrity.
X
Estimated Weight:
X
.258 lbs
Survives drop from:
3 feet
Test
Distance behind at which
vehicles are visable
130 ft
Test
Marginal Cost:
$30.00
Angle of front mirror will be adjusted via ball
joint. Top concave mirror will be stationary.
X
Estimated sale cost:
X
$15.56
Detaches from the helmet
3
Utilizes dual lock to attach / detach from helmet
X
Can be adjusted without the use
of tools
3
3
3
1
1
No tools are needed
X
Will not require power
X
Requires no power input
Is aesthetically pleasing
Refrains from significantly
increasing wind resistance
Is fabricated in an
environmentaly friendly way
Will receive input from Rob Fish
Survives wind speeds
Recycleability of materials
used:
45 mph
100%
Ongoing
Test
Depends on if film will be removable from rapid
plastic body
Ongoing
Specification:
The mirror system must
be mountable to at least
3 distinctly different
helmet styles
 Test:
Mount the system to
three different helmet
styles

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
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
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.
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

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
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

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

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


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.
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

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
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
Likelihood
Severity
Importance
2
3
6
Test image quality as early as
possible and prepare
contingencies.
Olivia Scheibel
Cost of materials
Team will run out
Exceeding the
to build system
2
of funds to build
designated budget.
and/or number of
working prototype.
redesigns
2
3
6
Ensure all costs are
documented before any
purchasing.
Zachary Kirsch
Parts and materials Prototype cannot
3 do not arrive on
be completed on
time
schedule
2
2
4
Accurately identify lead times
of materials.
Zachary Kirsch
4
Consistent communication
among team members. Each
team member will complete
individual responsibilities to
expected quality and on time.
Zachary Kirsch
ID
Risk Item
Effect
Reflective film does
not display image Reflective film is
1
to meet
unaccepatable
specifications
Cause
Does not pass rear
viewing distance
tests
Item lead times do
not match
anticipated values.
Lack of
communication
and poor
Group does not
compromising.
4 Group dysfunction work as efficiently
Group members
as possible.
do not contribute
equally to the
project.
2
2
Action to Minimize Risk
Owner
Cause
Aesthetics were not
Final product is not
Product will not be considered during
5 aesthetically
marketable.
design and/or
pleasing
manufacturing.
Poor
6
documentation
Disorganization of
team. Follow up Inconsistent
projects lack
documentation.
foundation.
Improper design
provided to rapid
8
prototyping
machine
Action to Minimize Risk
Owner
2
2
4
Coordinating with Rob to
ensure the design meets his
product vision.
3
1
3
Update EDGE weekly with
meeting minutes, notes, and
other important information.
Henry Woltag
3
3
Prepare contingencies.
Olivia Scheibel
3
Contact professors involved
with rapid prototyping and
obtain information regarding
necessary machine inputs.
Martin Savage
System is heavier or
Dual Lock™ is not as
1
strong as
anticipated.
Improper
Prototype can not formatting, not
be created on
understanding
1
schedule
needs of rapid
prototyping system
Dual Lock ™ does Redesign is
7
not support system needed.
Importance
Effect
Severity
Risk Item
Likelihood
ID
3
Henry Woltag
Week 1
Su M T W R F
Week 2
S Su M T W R F
Week 3
S Su M T W R F
Week 4
S Su M T W R F
Week 5
S Su M T W R F
S
Assess Risks
Upload Documents to EDGE
Reevaluate Detailed Design
Finalize Test Plans
Order Materials
Rapid Prototype Support System Components
Assemble Support System
Assemble Mirror System
Mount Entire Assembly
Test For Failures
Implement Modifications as Needed
Documentation of Assembly, Tests, Etc.
Prepare Poster
Prepare Final Technical Paper
Week 6
Week 7
Week 8
Week 9
Week 10
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 S
Assess Risks
Upload Documents to EDGE
Reevaluate Detailed Design
Finalize Test Plans
Order Materials
Rapid Prototype Support System Components
Assemble Support System
Assemble Mirror System
Mount Entire Assembly
Test For Failures
Implement Modifications as Needed
Documentation of Assembly, Tests, Etc.
Prepare Poster
Prepare Final Technical Paper