Project Proposal and Feasibility Study

Team 15: Swayspension

Meng Chen, Scott Kamp, Nate Konyndyk, Jacob VandeHaar

Engr339/340 Senior Design Project

Calvin College

2012-12-07

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© 2012, Team 15 and Calvin College

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Executive Summary This report outlines and describes the introduction and preliminary development of Team Swayspension’s

Vehicle Suspension Prototype. We explore the many engineering and non-engineering aspects of starting

and managing a sizable mechanical project. Our project is to design and fabricate a concept vehicle which incorporates a new, leaning suspension. This new suspension will reduce lateral acceleration felt while a

cornering, increase vehicle performance, and make driving more dynamic and exciting. Our research

shows that many similar vehicles achieve tilting by using active hydraulic actuation, which limits the spontaneity of the leaning action and puts additional parasitic losses on the engine. Instead, we will design

the vehicle to lean passively. The design and analysis presented in this report conclude that the project is

feasible, and will be constructed in the spring.

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Table of Contents

© 2012, Team 15 and Calvin College .............................................................................................. ii

Executive Summary.......................................................................................................................... iii

Table of Figures .................................................................................................................................. v

Table of Tables .................................................................................................................................. vi

1 Introduction ................................................................................................................................ 1 1.1 Team Members................................................................................................................................. 1

2 Problem Statement..................................................................................................................... 2

3 Task Specifications and Schedule ............................................................................................ 3

4 Design Norms ............................................................................................................................ 4

5 Design ........................................................................................................................................... 5 5.1 Frame ................................................................................................................................................. 5 5.2 Primary Suspension ......................................................................................................................... 6

5.2.1 Research ....................................................................................................................................................................3 5.2.2 Challenges ...............................................................................................................................................................4

5.3 Secondary Suspension ..................................................................................................................... 5 5.4 Steering .............................................................................................................................................. 5 5.5 Drivetrain......................................................................................................................................... 8

6 Simulation .................................................................................................................................. 9

7 Integration, Testing, and Debugging .................................................................................... 11

8 Business Plan ............................................................................................................................ 13 8.1 Marketing Study ............................................................................................................................ 13

8.1.1 Competition .......................................................................................................................................................... 13 8.1.2 Market Survey ..................................................................................................................................................... 13

8.2 Cost Estimate .................................................................................................................................. 14 8.2.1 Development ........................................................................................................................................................ 14

9 Conclusion ................................................................................................................................. 15

10 Acknowledgments .............................................................................................................. 16

11 References .............................................................................................................................. 17

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Table of Figures Figure 1. Outward leaning during cornering ............................................................................................. 2

Figure 2. Fall schedule............................................................................................................................. 3

Figure 3. Spring schedule ........................................................................................................................ 3

Figure 4. Wire frame ............................................................................................................................... 5

Figure 5. Solid frame ............................................................................................................................... 5

Figure 6. Primary suspension of EP1798081 ............................................................................................ 6

Figure 7. Suspension linkage variation ..................................................................................................... 7

Figure 8. Primary suspension tie-rod ........................................................................................................ 8

Figure 9. Center of gravity ....................................................................................................................... 8

Figure 10. Center of gravity height response ............................................................................................ 9

Figure 11. Coil spring design ................................................................................................................... 9

Figure 12. Leaf spring design .................................................................................................................. 9

Figure 13. Primary suspension current design .......................................................................................... 2

Figure 14. Primary suspension lower control arm stress analysis .............................................................. 3

Figure 15. Wesll 4 wheel leaning suspension ........................................................................................... 3

Figure 16. Can-Am Spyder ...................................................................................................................... 4

Figure 17. Mercedes Benz F300 Life Jet .................................................................................................. 4

Figure 18. Paralympics Trike ................................................................................................................... 4

Figure 19. Double Wishbone Suspension ................................................................................................. 5

Figure 20. Steering Sensitivity ................................................................................................................. 6

Figure 21. Steering Mechanism ............................................................................................................... 6

Figure 22. Steering Control Gear Rack .................................................................................................... 7

Figure 23. Drivetrain using splined shafts and U-joints ............................................................................ 8

Figure 24. Neutral position ...................................................................................................................... 9

Figure 25. Cornering at 0.4 g ................................................................................................................... 9

Figure 26. Dynamic simulation of assembled model .............................................................................. 10

Figure 27. Income Age Distribution ....................................................................................................... 13

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Table of Tables Table 1. Primary suspension spring decision matrix ................................................................................. 2

Table 2. Steering decision matrix ............................................................................................................. 7

Table 3. Testing Parameters ................................................................................................................... 12

Table 4. Similar Vehicles....................................................................................................................... 13

Table 5. Material costs........................................................................................................................... 14

Table 6. Team budget ............................................................................................................................ 14

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1 Introduction

This document provides material relevant to Team 15’s senior design project, Swayspension.

Calvin College is a four year, liberal arts college in Grand Rapids, Michigan. The Calvin College engineering program offers students degrees in Bachelors of Science in Engineering, with concentrations

in Mechanical, Chemical, Electrical/Computer, and Civil/Environmental. Senior Design is the year-long

capstone course for the engineering program and is intended to provide a real world engineering

experience to the students. During the first semester of this course, teams of students begin the design and feasibility analysis.

1.1 Team Members

Team 15 is comprised of four senior students at Calvin College. All plan to graduate in May 2013 with a B.S.E., Mechanical Engineering concentration.

Meng Chen is an international student from China. He is a competition-driven and motivated engineer,

who has great passion for system design and research activities. He values ambition, diligence and

persistence in his work. Aside from engineering work, he has great interests in economics, astrophysics, psychology, soft management theory, free diving, sensational music, and anything that is fast and furious.

He desires to see and experience many extraordinary sceneries and activities before the age of 35. He

believes having a goal is essential in life and hopes to experience as much of the wonderful world and magnificent nature as possible.

Meng handles all CAD design and computer simulation.

Scott Kamp has been a hands-on enthusiast from a very young age. Starting with Legos and a few simple tools, he has been taking things apart and building small electromechanical projects since his fingers

worked. He really feels that mechanical engineering aligns with his passions. He has spent the past two

summers working in low volume custom manufacturing, and during his junior year he worked in high

volume manufacturing. He is looking forward to joining the workforce and hopefully ending up somewhere exotic, such as Alaska or overseas. In his free time he enjoys camping, woodcarving, satirical

writing, a variety of sports, and learning his guitar.

Scott will lead fabrication in the spring. He currently helps with prototyping and designing.

Nate Konyndyk is currently working part time at Best Metal Products where he has been an intern for

over a year. He has always had an interest in designing cars and is very excited to help design a new

suspension system for a vehicle. Nate enjoys sports, hanging out with friends, camping, fishing, and traveling the world. Upon graduating, Nate plans to work at an engineering company in the Greater Grand

Rapids area.

Nate is in charge of the team finances and coordinating budget decisions.

Jacob VandeHaar has held two internships, one doing academic research and one manufacturing in West Michigan. He enjoys fixing cameras, browsing Wikipedia, and trying to keep his car operable. He also

enjoys traveling, reading, making and viewing art, and various other non-discipline activities. Jacob plans

to find an entry-level engineering job.

Jacob acts as primary designer for the team. He will aid in fabrication in the spring.

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2 Problem Statement

When a car corners, inertia pushes the car and its occupants away from the inside of the corner. A typical car leans towards the outside of the turn, as illustrated in Figure 1.

Figure 1. Outward leaning during cornering

Outward leaning can be uncomfortable due to the lateral acceleration. Leaning into the curve, as

motorcycles do, helps negate this force. Therefore, we are attempting to bring this leaning motion into our

car design. When a motorcycle rider leans during cornering, the horizontal forces felt are much less because some of the forces are transferred into vertical forces down to the seat.

Every part of the vehicle design affects performance as a whole. For example, because the frame

constitutes a large fraction of the vehicle mass, its design may shift the center of gravity significantly.

Also, each part must meet certain requirements for its function: the frame must be rigid enough to take dynamic loading and there should be no interference between suspension and main frame. For this reason,

many design decisions will be revised multiple times before finalizing. Thus time is an important

constraint for this project.

The project is also limited by a financial budget, which heavily influenced design decisions. For instance,

a design that may cost more to mass produce will be used in the prototype because compensation for labor

is not included in the budget. Nevertheless, the design can easily be optimized to accommodate for necessary cost reduction when mass produced.

Our primary goal is to prove if our concept of a double suspension works on a full scale vehicle.

Depending on the performance as well as potential for improvement, this concept model could serve as a

platform for further development. Knowledge and data gained through this research project can also form the foundation for later designs and improvements.

If the prototype meets performance specifications and is used as a platform for a production version, the

vehicle will be aimed at a very specific market segment: small performance car.

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3 Task Specifications and Schedule

The fall semester schedule is shown in Figure 2. A more detailed schedule for the spring semester highlighting the fabrication and testing of the design is shown in Figure 3.

Figure 2. Fall schedule

Figure 3. Spring schedule

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4 Design Norms

Innovation Swayspension is an innovative approach to solving issues associated with

driving. Innovation plays an essential part in our design and product definition,

differentiating our product from our competitors’.

Reliability Reliability is absolutely essential for our engineering design. Our suspension

must be reliable and trustworthy to handle all kinds of driving.

Precision We make the best efforts to ensure the quality and performance of our

suspension. Parts tolerance must be controlled strictly to ensure maximum performance and proper tilting operation.

Transparency Our suspension will provide clear feedback for driver. It will be responsive,

allowing the driver to feel the cornering conditions of the vehicle and make appropriate adjustments as needed.

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5 Design

5.1 Frame

As the most fundamental part of any vehicle, the frame needs to safely hold all components together.

Initially, the frame was drawn by plotting datum points in a CAD program. The points were connected to form the wire frame shown in Figure 4.

Figure 4. Wire frame

This initial model enabled us to see where everything needed to be attached, and how the layout would

work. The frame could then been idealized. Tubing size and form could quickly be defined for static

Finite Element Analysis (FEA). After optimizing the geometry of the wire frame model, drafts will be published as a reference for constructing a solid model (Figure 5). In the solid model, details regarding

the cutting angle and notch size will be determined for each tube.

Figure 5. Solid frame

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5.2 Primary Suspension

Our primary suspension is the main component that distinguishes our vehicle from all other designs. It is

what allows and simultaneously causes the vehicle to sway while cornering. It will give our vehicle a high center of gravity, to allow the swaying motion to occur passively. It is also the component with the two

most critical connections—one to the frame and the other to the secondary suspensions.

We found numerous prototypes which use the same chassis and wheel tilting concept. A good example of

this is European Patent EP1798081 (

Figure 6). However, none of the vehicles or patents researched use a passive-leaning linkage.

Figure 6. Primary suspension of EP1798081

The primary-suspension linkage geometry controls the relative angle between the body of the vehicle and

the wheels. The relative angle can be adjusted by changing the length of the vertical linkages. Three

clarifying examples are shown in Figure 7.

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Figure 7. Suspension linkage variation

One problem for our vehicle that is not an issue for the snowmobile in EP1798081 (Figure 6) is the slight widening of the track (the tire-tire distance for either front or rear wheels) under loading. Lateral tire

movement is deleterious to handling capability, causing under- or over-steer depending on the forces

involved. To stop track widening, a tie-bar was added to hold the two lower control arms fixed relative to each other (Figure 8).

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Figure 8. Primary suspension tie-rod

In order to lean while cornering, the center of gravity of the vehicle must be low enough relative to the

pivot point of the vehicle (Figure 89).

Figure 9. Center of gravity

The primary suspension linkages are designed to be substantially higher than the wheels so that the

vehicle’s center of gravity hangs below them. When the vehicle corners, the frame shifts away from the apex, thereby forcing the suspension to tilt towards the apex. The necessary linkages were constructed in

CAD to be simulated. Results from a sensitivity study show the height of the center of gravity at various

tilting positions (Figure 10).

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Figure 10. Center of gravity height response

Because the center of gravity stays within 0.1 mm, a spring is sufficient to control tilting and return the frame to neutral when driving straight. The spring mechanism is adjustable to accommodate varying

driving conditions. Two spring mechanisms were proposed to regulate frame tilting: a coil spring design

(Figure 11) and a leaf spring design (Figure 12).

Figure 11. Coil spring design

Figure 12. Leaf spring design

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Table 1. Primary suspension spring decision matrix

Design Weight Coil spring

Leaf spring

Cost 8 2 8

Time 6 5 5

Adjustability 9 7 8

Effect on CG 10 1 6

Ease of Fabrication 6 5 5

Total 149 256

The leaf spring design is the best option. The spring rate can be changed by inserting or removing separate layers. The current primary suspension, using a leaf spring, is shown in Figure 13.

Figure 13. Primary suspension current design

FEA analysis was performed on the lower control arm (Figure 14). The analysis indicated that a 500-lb

load would be required to stress a single primary lower control arm to the yield point. The current sprung

mass (including operator) is 650 lbs, distributed over four control arms. Therefore the control arm has a safety factor of 3.

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Figure 14. Primary suspension lower control arm stress analysis

5.2.1 Research

We found many designs of vehicles that lean into turns through two suspensions. However, what makes our design different is all those designs have an active suspension system, meaning something actuates

the leaning. This actuation is caused from hydraulics, linkages, or the driver leaning his or her body to

one side or the other. In our design, we would use a passive system that requires outside forces to cause the leaning. The outside force we are using is the lateral acceleration caused from inertia when the

steering is to one side of the other. The force of inertia causes the vehicle to want to continue driving

straight and we are going to take advantage of this inertia and sway the vehicle.

One of the many designs we looked at that were similar to our project was the Wesll 4 Wheel Leaning Suspension System (Figure 15).

Figure 15. Wesll 4 wheel leaning suspension

This system is similar to our design except this is an active system. A system of linkages controls the

leaning of the vehicle whereas we use inertia to control our leaning. Another design we looked into was the Can-Am Spyder (Figure 16) and the Mercedes Benz Fascination F300 Life Jet (Figure 17). Once

again, both of these suspension systems are active. The Mercedes Benz F300 Life Jet has an active system

where hydraulic pumps control the leaning of the vehicle as a function of the speed taken around a turn.

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Figure 16. Can-Am Spyder

Figure 17. Mercedes Benz F300 Life Jet

A fourth concept we discovered that is similar to our project is a trike used in the Paralympics (see Figure

18). This design uses bicycle tires and is similar to our project. The primary issue with this design is that it has three wheels where we would like to use a four-wheel design to better show our double suspension

system.

Figure 18. Paralympics Trike

5.2.2 Challenges

One of the major challenges of the secondary suspension system is the ability to also accommodate a

steering mechanism in the front and a rear drivetrain. The suspension system must be designed around the addition of the steering mechanism in the front by allowing the push/pull rod which connects to the hub

of the wheel which turns the front wheels left or right. The challenge of the rear secondary suspension is

to allow rear axles to connect to each wheel. These axles are powered by an engine which in turn rotates

the wheels ultimately causing the vehicle to move. Despite currently not including a drivetrain in our design, we are still designing individual components of the vehicle to have the option of including a

drivetrain later in the year. With this said, the rear secondary suspension must be designed to include the

possibility of a drivetrain also being connected to the wheel. Due to differing functions of a steering mechanism and the drivetrain, the front and rear secondary suspensions will differ slightly.

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5.3 Secondary Suspension

The secondary suspension absorbs bumps involved in everyday driving, like the suspension system on

typical vehicles. The reason to have two separate suspension systems is because one suspension cannot do both functions. With both systems, the driver experiences the most comfort, by the smooth ride and the

decreased lateral acceleration. One of the approaches to designing the secondary system is to use a

standard double wishbone design with a shock between each arm, all of which connects to the wheel hub.

An example of the double wishbone design is shown in Figure 19 below.

Figure 19. Double Wishbone Suspension

With this type of suspension, when the wheel hits a bump, the wheel will bounce up or down causing the

spring and the shock to extend or retract, hence absorbing much of the energy of the disturbance.

The front suspension will be designed around the steering mechanism which turns the front wheels left or

right.

The design of this suspension is especially difficult because it must work flawlessly with the upper and lower arms, connecting shocks, and the wheels. Due to differences in weights of drivers and the desire of

performance, the shocks can be adjusted by moving the location of the upper connector for the shock

either further or closer to the wheel. This is done by moving where the pin connector is inserted into the upper arm. There are several pinholes on the upper arm where the shock is attached.

5.4 Steering

Our steering mechanism must be reliable, responsive and user-friendly. Reliable steering control is,

perhaps, the most important safety aspect for a vehicle. Vehicles must be controllable at all times;

therefore, the steering system needs to be designed with redundancy to ensure the linkages and joint integrity during the operation.

Responsiveness aspect of the steering relates to the steering angle sensitivity curve, the rate of wheel

angle changes to the rate of steering wheel angle changes. Ideally, the steering is less sensitive during the

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first half rotation of the steering wheel and becomes increasingly sensitive as the rotation of the steering

wheel increases like illustrated in Figure 20 below.

Figure 20. Steering Sensitivity

Also, the steering control must be user friendly. The steering wheel response from the vehicle tilting must

be minimized, preferably eliminated completely. So, the wheel steering angle does not change with the

frame tilting.

Challenges for the steering mechanism design are mostly brought by the vehicle tilting motion. The

frame’s relative position to the wheel changes significantly when the vehicle is tilted in a corner. This

means, conventional type of steering mechanism design would not be able provide precise control to the

wheel.

To solve the issue, two solutions were considered. The first solution involves either hydraulic or electrical

actuation. Instead of connected by physical linkages, the vehicle adopts a drive-by-wire type of control.

There are multiple advantages for this system: the sensitivity curve for steering can be easily achieved by programing method, there are a lot more flexibility to fine tune the steering and handling. However, the

major flaw of the system is the reliability. Because the wheel is no longer physically connected to the

steering, the vehicle will become uncontrollable in the case of electronic failure. Also, the cost for adopting such a system is much higher than our alternative proposal, series push-rod design.

Figure 21. Steering Mechanism

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The alternative design utilizes the parallelism of the primary and secondary suspension and positions the

linkage joints deliberately in-line with the primary and secondary suspension, so that the distance between two joints stays the same regardless the tilting position of the vehicle. This is shown in Figure 21 above.

Hence, the steering wheel angle relative to the frame is the only determining factor for the wheel angle.

Also, the design offers directly linkage between the steering wheel and front wheel of the vehicle, thus,

improve the reliability. The linkage system is easy to fabricate and much less expensive. A series push-rod system was selected using a decision matrix (Table 2).

Table 2. Steering decision matrix

Weight Electronic actuation

Series push-rod

Reliability 10 3 10

Design flexibility 5 8 4

Cost 10 2 7

Fabrication difficulty 5 2 3

Time 10 6 3

Total 160 235

After the design decision was made, a more detailed version of the design has been updated to the series

push-rod mechanism. The steering wheel will control the rotation of a pinion gear, which in turn, shift the gear rack left and right to actuate the push-rod connections. Currently, the 4 inches of shifting range from

the left most position to the right most position is required to achieve desired steering wheel angle. Two

rotations on the steering wheel are required to reach the steering limit. Therefore, the pitch diameter for our pinion gear was determined to be 1 in. Compatible parts were found online, McMaster Carr, which

has pitch diameter of 1” and pitch 24 with the meshing gear rack. A model of the steering control gear

rack is shown in Figure 22.

Figure 22. Steering Control Gear Rack

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5.5 Drivetrain

After discussing the scale of the project with our industrial consultant, we determined to scale back our

design. To scale back the project, the drivetrain has been deferred at this stage of design. One possible design is illustrated in Figure 23 below.

Figure 23. Drivetrain using splined shafts and U-joints

If the main suspension designs, fabrication and testing were to be accomplished ahead of schedule in

April, then the drivetrain design will be revived and added as an extra feature for our prototype.

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6 Simulation

The concept of a primary and secondary suspension system was tested through two simplified models, one being a Lego® model and the other an aluminum model which uses rubber bands and a string to

demonstrate the shocks.

Software was used to obtain more accurate system response for our specific design. Mechanism simulation was also conducted in Pro/E to determine the system response to various driving patterns.

Gravity condition in CAD program would easily be manipulated to simulate the vehicle driving straight,

accelerated, decelerate and pass corner as various speeds. For simplification and fluidity of the process,

initial simulation was only performed on a single suspension. The center of gravity of the total assembly was estimated and represented by a force load pointing towards the direction of gravitation.

Figure 24. Neutral position

Figure 25. Cornering at 0.4 g

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Sensitivity analysis was performed to determine the optimal center of gravity position and the threshold

position to achieve tilting. After obtaining the desired center of gravity range for the top-level assembly, connections between the frame and primary suspension could be determined in more details.

Figure 26. Dynamic simulation of assembled model

The complete vehicle was dynamically simulated to verify the design. Light-weight, complex components

such as the wheels and steering assemblies were excluded from this simulation to improve simulation capability. Several major concerns emerged from the simulation results:

Vehicle demonstrates minimal tilting without adding driver weight to the simulation. This means

our vehicle response might be too reliant on driver weight, physique and some other factor which

we cannot control.

To solve the issue of tilting sensitivity to driver condition, we could shift the center of gravity of

the frame down relative to the suspension. However, this causes clearance issue to the ground and

bigger wheels will be needed to compensate the clearance loss. Nevertheless, engine or battery

weight was not considered in this simulation either. If placed properly, it would shift the center of

gravity down significantly.

Current conditions suggest that there might be a lateral-acceleration tilting activation threshold.

At 0.4-g lateral acceleration without a driver, the tilting was small. However, at 0.7-g lateral

acceleration the system achieved significant tilting.

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7 Integration, Testing, and Debugging

One of the main goals of the project is to reduce the lateral acceleration the driver experiences while the vehicle is cornering. Modern accelerometers, especially when paired with the power of smartphones, are

very capable and adaptable tools. We have already found an app that records acceleration data in all three

dimensions. We plan to mount the smartphone to a fixed part within the frame as we are testing it, in order to take data while the car is moving. This data will be able to tell us if our objectives have been

met.

We have two methods by which we plan to test the vehicle while it is moving, and because a drivetrain is

beyond the scope of our project, we have determined alternate methods. The first will be with gravity, as we plan to drive it repeatedly down the hill on the east side of campus. The second is to pull the vehicle

with a golf cart, at a constant speed, going around a fixed course. This will enable us to keep the testing

repeatable.

The dynamic response of the frame at rest will be relatively simple. We will place the vehicle on a level

surface, and with two people, manually tilting the frame. When the individuals holding the frame let go, it should return very close to the upright position, and in a relatively short time.

The individual components and subsystems will also be tested individually. A brief description and the

goals are shown below in Table 3.

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Table 3. Testing Parameters

Test Testing Order

Testing Subjects

Testing Goals Testing Purposes

Frame Static

Loading Test

1 Frame Frame can take 650 lbs static

Load

Ensure overall rigidity of the

frame

Leaf Spring

Strain Test

2 Primary Susp.

Leaf Spring

Leaf Spring can reach

required strain without

deform permanently

Verify the performance of

leaf spring design

Suspension

Settle Test

3 Secondary

Suspension

There are at least 3 inch of

travel left in the spring

Check the amount of spring

settle on the secondary

suspension Stationary

Steering Test

4 Steering

Assembly

Can control the wheel angle

from Steering wheel

Test the steering response and

functionality

Rolling Test 5 whole vehicle Vehicle can roll forward

straight without controlled

from Steering Wheel

The connection between

suspension and wheel

Braking Test 6 Braking

Assembly

Vehicle should be stopped

from 25 mph to stop in 30 ft at most without skidding

Determine the appropriate

braking force to stop fast while avoid skidding

Dynamic

Steering Test

7 Steering

Assembly

The effect of frame tilting

should have minimum effect

on steering angle

Verify the reduced

countersteering induced by

frame tilting

Cornering

stability

8 whole vehicle Vehicle should remain stable

in a corner

Test the stability of the

leaning angle in a corner

Transient

Response

9 whole vehicle Vehicle retains its leaning

characteristic in a figure-8 driving test

Test the time for the frame to

settle in to positions

Lateral

Acceleration Reduction

10 whole vehicle Measured the maximum

lateral acceleration reduction should be no less than 20%

Test the maximum lateral

acceleration reduction

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8 Business Plan

8.1 Marketing Study

8.1.1 Competition

Similar sport vehicles with tilting suspensions were researched (Table 4). However, none of the vehicles found have passive leaning, a defining feature of Swayspension.

Table 4. Similar Vehicles

Make Model Wheel Layout

Leaning Method

Status Price

Mercedes-Benz F300 Life Jet Tadpole Active Concept Only

Carver Europe Carver One Trike Active Bankrupt € 30,000

GM Lean Machine Trike Active Concept Only N/A

8.1.2 Market Survey

Following demographical income graph illustrate the earning power of the 21 to 35 year-old age group.

This graph is shown in Figure 27.

Figure 27. Income Age Distribution

This particular group is less likely to be married compared with the age group of 35 to 40 and 45 to 54, while still having significant earning power. Our target market is likely to spend more income pursuing

excitement and new experience. This desire could be satisfied by our Swayspension. Market related to

sports car and track days is relative small and privileged. However, it is equally lucrative and rewarding if a company becomes successful.

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8.2 Cost Estimate

8.2.1 Development

The materials cost is shown in Table 5.

Table 5. Material costs

Parts Prototype Cost

($)

Steel tubing for frame (70 ft) 154

Bicycle wheels (4) 160

Suspension tube/rod 0

Steering ball joints (2) 20

Suspension ball joints (4) 60

Miscellaneous Steel 0

Steering Wheel 0

Steering Column 80

U-joints (8) 160

Brakes (4) 120

Pedals - gas/brake/clutch 15

Driver Seat 25

Brake/throttle cable (15ft) 15

Drive Train 0

Differential 0

dash/display/controls 10

Seat belt 0

Paint 30

20% Contingency 170

Total 1019

The total budget includes spare parts (as 20%) of the materials cost. No specialty software or tools need to

be purchased. The total budget is then $1,151 (Table 6).

Table 6. Team budget

Item Cost ($)

Prototype materials 1,019

Software 0

Tools 0

Spare parts 102

Printing costs 30

Testing parts 0

Total 1,151

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9 Conclusion

Current feasibility study indicates that the tilting action is highly sensitive to weight distribution. It will be important and challenging to design the vehicle such that all components coordinate to produce the

desired tilting effect.

Our design appears feasible but will require next semester to build and test the design. The final design report will address the testing results acquired if the design works.

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10 Acknowledgments

Team 15 appreciates the aid offered by

Ned Nielsen (Team Advisor)

Ren Tubergen (Industrial Consultant)

Phil Jasperse (Shop Manager)

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11 References

http://www.Alan927.com

http://www.jumpjet.info/Classic-Games/Windows/RCT/Facilities/Coasters/Suspended/Suspended.html

http://wendolonia.com/bm/hammock_car.jpg

http://thekneeslider.com/archives/2009/01/29/wesll-4-wheel-leaning-suspension-system/

http://motorcyclesspecification.blogspot.com/2012/04/2012-can-am-spyder-rt-s-review.html

http://www.cyclingnews.com/features/photos/sea-otter-2012-danny-hart-jared-graves-and-tara-llanes-race-bikes/220104