FSAE Outboard Suspension

Progress Report- Winter 2012

Mechanical Engineering Design Team

Rick Rickert

Carole Gayley

Charles Larson

Efe Yıldırım

Jose Colin

Josh McCall

Industry Advisor

Evan Waymire

Academic Advisor

Dr. Lemmy Meekisho

Executive summary

The purpose of this project is to redesign the outboard suspension of the 2012 Viking

Motorsports (VMS) Formula SAE (FSAE) car to reduce the machine time, weight, and to

integrate a centerlock wheel retention system. The FSAE Outboard Suspension (OS) Team will

provide all required drawings and analysis used to produce the new system by June 2012. The

purpose of the following document is to update the reader on progress made in the design of

the hub and upright systems, as well as bearing and wheel retention selection.

The project began with the Product Design Specifications (PDS), where VMS provided the OS

Team with measureable areas of achievement. An external search was conducted to explore

pre-existing options for centerlock systems. This was followed by an internal search, which

involved brainstorming possible solutions, culminating in several designs. A project timeline

was organized to ensure the team stays on track towards a complete verifiable concept design.

Table of Content

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s

Executive summary.....................................................................................................................................2

Table of Contents........................................................................................................................................3

List of Figures...............................................................................................................................................4

I - Introduction and Background Information..............................................................................................5

II - Mission Statement..................................................................................................................................7

III - Project Plan...........................................................................................................................................7

IV - Final PDS Summary................................................................................................................................9

V - External Search.....................................................................................................................................10

VI - Internal Search....................................................................................................................................12

Wheel Nut.............................................................................................................................................12

Wheel Nut Retention.............................................................................................................................12

Brake Hat...............................................................................................................................................12

Wheel Bearings......................................................................................................................................13

Upright..................................................................................................................................................13

Wheel Speed Sensor..............................................................................................................................13

VII - Top-Level Design Evaluation and Selection........................................................................................14

Hub Material..........................................................................................................................................14

Brake Hats.............................................................................................................................................14

Uprights.................................................................................................................................................14

Wheel Bearings......................................................................................................................................14

Wheel Nut.............................................................................................................................................15

Clamp Force.......................................................................................................................................15

Installation Torque.............................................................................................................................15

Retention...........................................................................................................................................15

Drive Pins...............................................................................................................................................16

VIII - Progress on Detailed Design..............................................................................................................17

IX - Conclusion and Recommendations.....................................................................................................17

Conclusion.............................................................................................................................................17

Appendix A – PDS, House of Quality, Technical Risk Management...........................................................19

Product Design Specification.................................................................................................................19

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House of Quality....................................................................................................................................22

Technical Risk Management..................................................................................................................24

Risk Identification..................................................................................................................................24

Risk Assessment....................................................................................................................................24

Risk Mitigation.......................................................................................................................................24

Risk Monitoring.....................................................................................................................................24

Appendix B – Detailed Project Timeline....................................................................................................25

Appendix C - Design Criteria Checklist.......................................................................................................26

List of Figures

Figure 1.1: Model year 2011 hub, showing complicated geometry and raw material used........................5

Figure 1.2: 2011 upright requiring 5-axis machining...................................................................................5

Figure 1.3: Exploded view of centerlock hub/wheel system concept..........................................................6

Figure 5.1: Porsche centerlock hub and wheel assemblies..........................................................................9

Figure 5.2: F1 centerlock using splines to locate and drive the wheels.....................................................10

Figure 5.3: Taylor Racing upright/centerlock design for FSAE and D-Sports Racers..................................10

Figure 6.1: Castle nut and automotive spindle nut retention systems......................................................11

Figure 6.2: Floating rotor system comprised of a hat, bobbins, and rotor................................................12

Figure 7.1: Concept centerlock hub with drive pins..................................................................................15

Figure A1: House of Quality.......................................................................................................................22

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I - Introduction and Background Information

Viking Motorsports (VMS) is a Portland State University student operated team that competes in the

Formula Society of Automotive Engineers (FSAE) race car design competition. FSAE student members

design and fabricate a race car while adhering to regulations provided by the FSAE governing body.

More than 140 college and university teams compete each June in Design, Cost and Manufacturing,

Acceleration, Skid Pad, Autocross, Endurance, and Fuel Economy events.

The 2011 VMS race car was a clean sheet design, resulting in a car that greatly outperformed the 2010

model. The outboard suspension (OS) featured lighter uprights and a new hub. The 2011 OS consisted

of hubs, uprights, wheel speed sensors, wheel bearings, and installation hardware. The rear hubs

featured integrated CV joints.

VMS primarily wanted to simplify the hub and upright designs for the 2012 car. The 2011 hub’s

geometry required a complex machining process on a CNC lathe (Fig. 1.1).

Figure 1.1: Model year 2011 hub, showing complicated geometry and raw material used.

The 2011 upright required 5-axis CNC machining because of an angled suspension mount (Fig. 1.2).

Figure 1.2: 2011 upright requiring 5-axis machinin g.

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An outboard suspension redesign would reduce manufacturing resources during fabrication and provide

an opportunity to integrate a centerlock wheel retention system.

Figure 1.3 illustrates an early iteration of the centerlock hub and wheel design. The components from

left to right are: upright, hub, brake caliper, brake rotor, and wheel center. Not shown are the wheel

bearings, centerlock nut and retainer, brake rotor bobbins, brake caliper fasteners, and wheel shell.

Figure 1.3: Exploded view of centerlock hub/wheel system concept

In June 2012, the Viking Motorsports team, racecar and improved outboard suspension will go to

Nebraska for the FSAE competition.

II - Mission Statement

The FSAE Outboard Suspension (OS) Team will design, validate, and produce a new outboard suspension

system that will reduce part machining time, weigh less, and integrate a centerlock wheel retention

system. The FSAE-OS team will produce all required drawings and BOM’s along with a report of the

design decisions and FEA analysis used to produce the new system. Once the parts have been fabricated

and installed, the vehicle will be tested to verify proper functionality prior to June 2012.

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III - Project Plan

The OS-Team will complete the project in a few major stages. Each stage will have a strict timeline in

order to meet the necessary dates. The overall stages are as follows:

Stage 1: Develop the PDS document, complete external and internal searches for design ideas and have

a conceptual design for both the hub and upright by the end of February 2012.

Stage 2: Develop a detailed design and validate the design using engineering practices by the end of

March 2012.

Stage 3: Complete manufacturing, assembly, and installation, and begin testing by the end of April

2012.

A detailed timeline (Gantt chart) has been provided in Table 3.1.

Table 3.1: Detailed project timeline

30-Ja

n

8-Fe

b

15-F

eb

22-F

eb

12-M

ar

21-M

ar

11-A

pr

18-A

pr

25-A

pr

9-M

ay

16-M

ay

23-M

ay

1-Ju

n

6-Ju

n

20-Ju

n

PDS

PDS Presentation

Internal Search

External Search

Concept Selection

Detail Design

Progress Report

Progress Report Presentation

Machining

Heat Treating

Grinding

Assembly and Testing

Final Presentations

Final Report

International FSAE Competition

Com

plet

ed T

asks

Task

s in

Prog

ress

Futu

re T

asks

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IV - Final PDS Summary

Table 4. 1 outlines the most important design specifications used to design the outboard suspension. Full list of design specifications can be found in Appendix A.

Table 4.1: Important product design specifications necessary for a successful design.

Design Criteria

Priority Requirements Primary Customer Goal Metric Target Target Basis Verification

5 2011 & 2012 parts

interchangeable

FSAE Team Back-up system in case

of failure

N/A N/A Customer

defined

Prototype

5 Centerlock nut

retention with two

threads exposed

(FSAE rule)

Driver Keep the wheel on the

car

On/Off On Driver’s

Safety

Nut cannot be

removed in

one step

4 Hub Weight FSAE Team Decrease weight Pounds 2lb Customer

defined

Prototype

4 Ease manufacturing FSAE Team/

Manufacturing

Decrease complexity Machining

time (min)

80 minutes Customer

defined

Prototype

3 Hub Cost FSAE Team Lower Cost Dollars ($) $200 Hub Customer

defined

Machine Shop

invoice

2 Service Life FSAE Team/

Driver

Ensure sufficient

reliability

Operating

life (years)

5 year life Customer/

group

FEA/Prototype

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V - External Search

Three of the most relevant existing centerlock designs are chosen to present. Centerlock hubs are

primarily used in racing applications because tires can be changed faster and they weigh less than an

equivalent multi-lug hub. One disadvantage of a centerlock hub design is an increased risk of failure due

to improper installation.

The 2010 and 2011 Porsche 911s were equipped with centerlock hub and wheel assemblies (Fig 5.1).

The National Highway Traffic Safety Administration recalled 1702 various Porsche 911 models equipped

with race style center lock hub wheel assembly because of excessive wear on the locking hub section.

This wear loosens the centerlock nut during normal driving conditions which could result in the wheel

coming free from the vehicle and increased likelihood of an accident. From this, the OS-Team learned

that a centerlock nut retention system must be integrated into the final design.

Figure 5.1: Porsche centerlock hub and wheel assemblies.

A splined centerlock system was found on ScarbsF1 blog [1], shown in Fig. 5.2.

Figure 5.2: F1 centerlock using splines to locate and drive the wheels.

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Splined centerlocks allow easy wheel installation, however splines are expensive to machine.

Taylor Racing [2] sells a center lock that incorporates a stub axle, see Fig. 5.3, designed for FSAE and D-

Sports Racers. Positive features include a modular tulip housing and replaceable wheel bearings. This

centerlock system was designed for larger cars, so it unnecessarily heavy.

Figure 5.3: Taylor Racing upright/centerlock design for FSAE and D-Sports Racers .

VI - Internal Search

An internal search was conducted for each component in the OS system. While every component must

ultimately work together, initial design concepts were evaluated individually.

Wheel Nut

The largest change in the wheel hub from 2011 was the wheel nut, so it was the first area the team

addressed. During the external search, it was noted that there are two common types of centerlock

wheel nuts. Some systems use a large (~ 2”) aluminum tapered nut, while others use a smaller (1/2” –

1”) steel hex nut. Wheel nut retention was an important issue, so the team also considered producing

its own wheel nuts that would integrate a retention device.

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Wheel Nut Retention

The simplest form of wheel nut retention the team found was to use a cotter pin or similar to prevent

the nut from backing off. Simply placing a cotter pin at the end of the threaded portion of the

centerlock could indeed prevent the nut from falling off completely, but would not ensure that the nut

retained its designed clamp load. To prevent the nut from loosening, systems such as castle nuts and

automotive spindle nut retainers were considered. Figure 6.1 shows two example retention systems.

Figure 6.1: Castle nut and automotive spindle nut retention systems.

Brake Hat

The brake hat is the inner part of a floating rotor system (Fig. 6.2). The hat mounts to the hub, and the

rotor mounts to the hat via bobbins. The 2011 hub had an integrated brake hat (shown in Fig. 1.1). Any

peripheral systems integrated into the hub increases its machine time and cost, so alternatives were

discussed.

Figure 6.2: Floating rotor system comprised of a rotor, hat, and bobbins.

The team considered redesigning the integrated brake hat to be smaller, which would reduce the

required stock OD and reduce the amount of material removed during machining. The brake hat could

also be designed as a separate part that would have to be fixed to the hub during assembly.

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Wheel Bearings

VMS specifically requested that the 2011 and 2012 hubs and uprights be modular, meaning the new hub

should work with the old upright and vice versa. Since the wheel bearings mate the two components,

their dimensions must remain unchanged.

Upright

The upright design locates the tie rod and outer control arm pivot points. VMS wanted to retain the

2011 geometry. These critical points, as well as the wheel bearing location, must remain unchanged.

VMS requested that the OS-Team target reducing weight and machine time, while increasing rigidity.

The team focused on identifying small changes that would fulfill these goals.

The 2011 uprights were billet 6061-T6 aluminum. Welded sheet metal uprights were considered for

increased rigidity, but the OS-Team did not want to detract too far from the main goal of redesigning the

hubs. Designing for a major material change would be time consuming, with a high risk of weight gain.

Wheel Speed Sensor

The 2011 wheel speed sensor was taped onto the side of the upright. The tone ring used to generate

the speed signal was threaded onto the hub. This required threading the hub (increased machine time)

and manufacturing a custom tone ring to interface accordingly. The OS-Team discussed ways to provide

a secure mount for the sensor, as well as simpler methods to generate the necessary speed signal.

VII - Top-Level Design Evaluation and Selection

Top level design selection of each component was addressed individually in succession, while taking into

consideration the final integration.

Hub Material

It was decided early on that the rear hubs would again integrate the CV joints. Doing so simplified axle

geometry, requiring less design work for VMS. Due to the high contact stresses in the CV joint, the rear

hubs have to be steel. In an effort to use aluminum for the hubs, a pressed in CV joint was considered,

but eliminated due to geometric constraints. The OS-Team wanted to keep the front and rear hubs

identical (apart from the rear CV’s) to reduce design time. The front hubs will be steel as well.

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The alloy 4340 was chosen for its through-hardenability and low cost compared to other high strength

alloys. Initial contact stress calculations suggested the CV joints would have to be heat treated, if not

the entire hub.

Brake Hats

Focusing on simplifying the hub, the OS-Team decided to design a separate brake hat that would

interface with the hub. The brake hat could be machined from plate stock, rather than being machined

onto the hub itself. This will open up different material possibilities for the brake hat, as well as

different designs. Parts made from plate stock can be manufactured by VMS which will reduce cost.

Uprights

Upright design will remain largely unchanged. Since geometry and bearings can’t change, the OS-Team

will focus on tweaking the current design to meet design goals. 6061-T6 was chosen for the uprights for

its relatively high strength and ductility. Stronger alloys are available, but OS-Team wanted to ensure

that the uprights would yield in the event of overloading, rather than fracture.

VMS recently discovered that the brake caliper mounting brackets were placed incorrectly on the 2011

models, causing the brake rotor to drag on the body of the caliper. Caliper mounting position will be

corrected.

Wheel Bearings

Per VMS, the 2011 wheel bearings must be used to facilitate modularity between 2011 and 2012

hubs/uprights. The bearings are sealed 85mm deep groove ball bearings with a 65mm bore. The 2011

team used SKF-61813RS bearings. Other bearings are available in the same dimensions with various

load ratings, both from SKF and other manufacturers. Final bearing selection will depend on cost and

required bearing life.

Wheel Nut

Two basic selections are commonly available: large (~2” ID) aluminum tapered seat wheel nuts; and

small (1/2” - 1” ID) steel hex nuts. The threads on an aluminum nut are easily galled and require

frequent replacement. Small steel hex nuts were chosen for their low cost and longer thread life.

Final wheel nut size will be driven by availability, clamp force requirements, and installation torque.

For a given clamp force, the nut size and installation torque are inversely proportional, so nut choice is a

compromise between the two.

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Clamp ForceWheel nut clamp force serves two distinct purposes:

The clamp force must be high enough that the wheel cannot separate from the hub under cornering

load.

The clamp force should prevent rotational slipping between the wheel and the hub during braking or

acceleration.

The second point is not necessarily a requirement (centerlock wheels are often driven by pins/splines).

VMS requested that wheel nut clamp force be sufficient to prevent slipping under any expected

loading. Given approximate hub/wheel geometry and materials, the clamp force to prevent slip is

more than three times higher than that to prevent separation during cornering. While a multi-lug

system can easily achieve high clamping forces, preventing slip is not trivial with a single fastener.

Installation Torque

Correct installation torque is critical to the performance of the wheel/hub system. Too low and the

wheel may slip or separate from the hub; too high and something may yield. Because the nut will be

installed by hand with a torque wrench, tool availability and student strength were taken into

consideration. It was decided that installation should require no more than 300lbf.ft torque.

Retention

FSAE rules and common sense dictate a locking mechanism to prevent the wheel nut from falling off

when using a single fastener. While a pin on the end of the centerlock would satisfy FSAE rules, the

OS-Team wanted to ensure that the wheel nut would not come loose during competition. Automotive

spindle nut retainers (Fig. 6.1) were chosen for their low cost and availability.

Drive Pins

In the event that the wheel nut does come loose, the loss in clamping force would allow the wheel to

slip on the hub. VMS wanted to ensure that the driver could safely stop the vehicle without damaging

the wheel. Three dowel pins will be pressed into the hubs, which will engage the brake hat and the

wheel. Figure 7.1 shows a concept hub with drive pins installed.

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Figure 7.1: Concept centerlock hub with drive pins.

Wheel Speed Sensor

The OS-Team decided to integrate the speed sensor into the brakes, rather than reading a separate tone

ring. The sensor will be threaded into the upright so that it can detect slots cut into the brake rotor.

VIII - Conclusion and Recommendations

Following the internal and external searches, the concept design was formulated. The hub will be made

from 4340 steel, while the upright will be made from 6061–T6 Aluminum. A separate brake hat will

interface with the hub, rather than being machined onto it. Critical wheel bearing and upright

dimensions will remain unchanged, allowing 2011 and 2012 OS parts to be interchangeable. The wheel

will be secured using a steel hex nut with an automotive spindle nut retainer. Three dowel pins will

transmit brake torque in the event of wheel nut loosening. CV joints will be integrated into the rear

hubs. Parts will be sized such that nut installation torque will be less than 300lbf.ft.

Project progress is on schedule. Based on the product design specifications, a conceptual design has

been selected. The team is currently working on detail hub and upright design. This includes selecting

appropriate hub and upright dimension based on assumed input loads. Rotational bending stresses in

the hub will require fatigue analysis. Heat transfer from the brakes and variations in thermal expansion

between the materials complicate the bearing press fit calculations. These challenges will be overcome

using knowledge gained through the mechanical engineering curriculum and advise of experienced

professionals. An FEA validation of the design is necessary before the parts are machined. Final

assembly and testing will be completed by June 1, 2012.

Currently the conceptual outboard suspension design meets all of the customer needs identified in the

PDS report. No PDS changes are foreseen at this time.

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References

[1] ScarbsF1. “Force India: Closer look at their splined wheel mounting.” Posted February 27, 2010,

accessed March 03, 2012. http://scarbsf1.wordpress.com/2010/02/27/force-india-closer-look-at-

their-splined-wheel-mounting/

[2] Taylor Race Engineering Inc. “Taylor Race FSAE and DSR Generic upright with center-lock stub axle.”

Last modified March 03, 2012, accessed March 03, 2012. http://www.taylor-race.com

/pdf/ACFD06.pdf

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Appendix A – Product Design Specifications

Performance

Priority Requirements Primary Customer

Goal Metric Target Target Basis

Verification

4 Hub weight FSAE Team Decrease weight

Pounds 2lb Customer defined

Prototype

3 Rolling resistance

FSAE Team Decrease Resistance

In*lb <1in*lb Customer defined

Prototype

4 Load capacity FSAE Team Withstand racing conditions

G 2 G lat/long 5G vertical

Customer defined

Prototype

ManufacturingPriority Requirements Primary

CustomerGoal Metric Target Target Basis Verifi-cation

4 Ease of hub manufacturing

FSAE Team / manufacturing

Decrease complexity

Machining time (min)

80 minutes

Customer defined

Proto-type

Life in ServicePriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

2 Service life FSAE Team / driver

Ensure sufficient reliability

Operating life (years)

Minimum 5 year life

Customer / group

FEA / prototype

SafetyPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

5 Centerlock nut retention

Driver Keep the wheel on the car

On/Off On Driver’s safety

Nut cannot be removed by using cotter pin

5 Factor of safety

FSAE Team Safe operating range

N/A 1.5 Driver’s safety

FEA

EnvironmentPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

4 Operating temperature range

FSAE Team Operate within operating temperature

°F 600°F Driver’s safety

FEA/ prototype

3 Operating environment

FSAE Team Operating in dust/water

N/A N/A Customer defined

Prototype

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Maintenance and PartsPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

3 Wheel bearing

Mechanic Ease of assembly

Time and tools required

No specialized tools/fixtures

Mechanic crew

Assembly

InstallationPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

5 Suspension link connecting points

FSAE Team

Must provide same geometry as 2011

N/A N/A Customer defined

Prototype

5 Must interface with 2012 wheels

FSAE Team

Must be able to mount 2012 wheel to the hub

N/A N/A Customer defined

Prototype

5 Drive axle FSAE Team

Integration with existing equipment

N/A N/A Customer defined

Prototype

5 Floating Rotor FSAE Team

Floating N/A N/A Customer defined

Prototype

3 Hub/wheel assembly

FSAE Team

Easy to assemble

Assembly time

Hub: <50minWheel: <1min

Customer defined

Prototype

CostPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

3 Hub Cost FSAE Team Lower cost

Dollars ($)

$200/Hub Customer Defined

Machine Shop Invoice

Production QuantityPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

4 Assembly Quantity

FSAE Team

Sufficient Part Quantity

Quantity of assemblies

3 front and 3 rear assemblies

Customer Defined

Delivery Receipt

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MaterialsPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

4 Hub Material FSAE Team Must be steel

ANSI Grade

4340 Steel or similar

Customer Defined

Prototype

4 Upright Material

FSAE Team Must be aluminum

ANSI Grade

6061-T6 Aluminum or similar

Customer Defined

Prototype

DocumentationPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

4 Full Engineering Documentation

FSAE Team Project must be fully documented

N/A N/A Customer Defined

SolidWorks CAD files

3 Installation Instructions

Mechanic Full assembly instructions

N/A N/A Customer Defined

Word Document

Rules and RegulationsPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

5 Must adhere to all FSAE rules and regulations

FSAE Rule Book

Must pass tech inspection

N/A N/A Customer Defined

Prototype

Legal (Patents, Product Liability)Priority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

4 Minimize product liability issues

Design Team

Avoid legal ramifications

N/A Use practices to minimize catastrophic failure

Design Team

Prototype

4 No patent infringement

Design Team

Avoid legal ramifications

N/A Design must be unique

Design Team

Patent Search

AestheticsPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

2 Aesthetically pleasing

FSAE Team Must look well engineered

N/A N/A Customer Defined

Prototype

DisposalPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

1 Recyclable Material

FSAE Team Minimize Disposal Cost

N/A N/A Customer Defined

MSDS

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TestingPriority Requirements Primary

CustomerGoal Metric Target Target

BasisVerification

5 Must complete testing sequence before first use

FSAE Team Verify assembly integrity

Hour 4 Design Team

Complete Testing Check-sheet

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Appendix B: House of QualityCritical design parameters were identified and targets set through benchmarking against other outboard

suspension designs. A summary of these comparisons is shown in the Table A1.

Table A1: House of Quality

Customer Needs

Hub

Cost

($)

Hub

Mac

hini

ng

Tim

e (m

in.)

Hub

Wei

ght (

lbs)

Asse

mbl

y Ti

me

(min

)

Num

ber o

f Lug

s

Life

(yea

rs)

2011

PSU

FSA

E O

utbo

ard

Susp

ensio

n

2010

PSU

FSA

E O

utbo

ard

Susp

ensio

n

Tayl

or R

acin

g O

utbo

ard

Susp

ensio

n

1. Performance Driver Handling2. Ease of Manufacturing FSAE Team 2 **** ** * ** ****3. Ease of Assembly FSAE Team 1 * **** * ** ***4. Ease of Use Speed of Tire Changes5. Production Cost FSAE Team 1.5 **** ** * * ** **6. Life In Service FSAE Team 0.5 **** **** **** ***

7. SafetyDriver, FSAE Team 2 *** *** ****

200 120 3.1 60 4 5

35 0 4 40 4 10389 0 4 30 1 5200 80 2 50 1 5

Invoice Test Test Test Inspection Test

**** - Strong Correlation* - Weak Correlation

FSAE Outboard Suspension: House of Quality

Market Competition2011 PSU FSAE Outboard Suspension

2010 PSU FSAE Outboard SuspensionTaylor Racing Outboard Suspension

Target

* * *

** ****

End

Use

r

Impo

rtan

ce

Engineering Criteria Market Competition

**

Defined by Competion Rules

Verification

** ** *

****FSAE Team

2

1

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Appendix C: Technical Risk Management

Frequent Likely Possible Unlikely RareCatastrophic Extreme Extreme High High ModerateSevere Extreme High High Moderate LowMarginal High Moderate Moderate Low LowNegligible Moderate Low Low Low Low

Missed delivery date Parts undersizedParts cost too high

Risk Identification

The parts cost too much

The team is unable to deliver parts on time

The parts are improperly sized

Risk Assessment

Frequently manufacturing costs are higher than first estimated, but the consequence is

marginal. The team can rearrange the budget.

The probability of not meeting deadlines is likely and the consequence is severe. Without parts,

the team can’t compete.

The probability of the parts being undersized is possible and the consequence would be

catastrophic. Driver injury could result.

Risk Mitigation

The parts will be designed with simplicity in mind. The team will review the parts before being

machined and get quotes in writing.

The team will follow tight timelines using the Gantt chart found in Appendix A.

Interchangeability with previous models is maintained.

Detailed FEA and extensive on vehicle testing will be done before the car is released for use.

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Risk Monitoring

By watching timelines, getting written quotes and performing careful testing of the car, we expect to

maintain a reasonable level of risk during our project.

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