rolling huskies design report r2

Elander 3.0

Design Report

Rolling Huskies 2012

Leaders: Albert Venegas, Danny Rodas.

Team Members: Alex Zaragoza, Juan Ayala, Eric Pierson,

Ruben Vielmas, Wenxuan Zhang, Wilkin Chan,

Michael Mariano, Donald Cristobal, Franco A. Salas,

Andrew Wong, Kelvin Chen, Tiffany Bermudez,

Melissa Godino

East Los Angeles College

1301 Avenida Cesar Chavez

Monterey Park, CA 91754

[email protected]

323-780-6831

mailto:[email protected]

Human Powered Vehicle Challenge

April 4, 2012

Page 1

Table of Contents

Abstract …………………………………………………………………………………..2

Justification ………………………………………………………………………………2

Weather in Tooele, Utah………………………………………….………………………3

Design……………………………………………………………………………………..3

Survey Monkey……………………………………………………………………………3

Drivetrain …………………………………………………………………………………4

Steering and suspension…………………………………………………………..……… 7

Kingpin inclination……………………………………………………….…………….… 8

Steering Dampener………………………………………………..……………………… 9

Seat weight reduction………………………………………….…….…………………… 9

Basket ……………………………………………………………….……………………10

Analysis………………………………………………………………………………...…11

Drag Force ……………………………………………………………...…...………...… 11

Diameter Bolt ………………………………………………………………………..……11

Braking System ………………………………………………………….………………..12

Pitman Arm……………………………………………………………………………. …12

Cost Estimate…………………………………………………………………….……..... 13

Steering Mechanics…………………………………………………………….…..…….. 15

Height of Steering Handle………………………………………………………………... 16

Angle of steering handle bar…………………………………………………………....… 17

Time Trial shifters…………………………………………………………..…………..…17

Wheel Guards……………………………………………………………….…………..…18

Bearing Selection………………………………………………………...……………….. 18

Testing ………………………………………………………………………………….…19

Seat Reference Point………………………………………………………...……………. 19

Back Bone Design………………………………………………………..………………. 21

Roll Center …………………………………………………………………..……………22

Brake Testing………………………………………………………………………………22

RPS Testing ……………………………………………………………………….………23

Safety………………………………………………………………………………………24

Team Safety………………………………………………………………………………. 24

Factor of safety…………………………………………………………………………….24

Aesthetics…………………………………………………………………………………..25


April 4, 2012

Page 2

Abstract The East Los Angeles College (ELAC) Rolling Huskies are student members of the American

Society of Mechanical Engineers (ASME) competing in the annual Human Powered Vehicle

Challenge (HPVC). The Rolling Huskies are a part of the engineering club. ASME members;

Los Angeles College is part of the California Community Colleges System. Students at ELAC

are encouraged to join the Engineering design team regardless of their academic level or major

of study. Student members are introduced to the engineering design process and given the

opportunity to apply classroom knowledge, research, and hands on experience.

The purpose of this report is to explain the engineering design process of the Elander 3.0, ELAC

Rolling Huskies human power vehicle (HPV). The Elander 3.0 is the third HPV built by the

design team. The vehicle was designed with the lessons learned from our two previous year’s

designs Elander 1.0 and Elander 2.0, in which they all share similar, chassis design and front

suspension. Last year’s design provided as a test vehicle for the team members to conduct lab

experiments and field testing to further improve their understanding and functionality of a human

power vehicle. This report describes the team’s approach to the research, design and analysis of

the drive train, brakes, wheels, suspension/steering, chassis, roll over protection (RPS), stress

FEA analysis, coefficient of drag, and ergonomics

Justification Society should make the change to alternative fuels as a means to power the transportation

system.There are many reasons why society should change the way energy are created. The first

most important reason is that crude oil is being depleted throughout the entire world. Once the

supply is gone majority of vehicles will become useless. The United States having one of the

higher percentages of vehicles in the world has become dependent on oil. The expense of

petroleum can be acceded to the high demand needed by the United States. The environment is

also affected by the vehicles that run on crude oil creating problems such as Greenhouse gases

are contributing to Global Warming. The pollution emitted also is risking person’s health.

Society has become consumed by the need of crude oil, there is need to keep energy

consumptions at a stable level. Compared to other countries, that need for larger energy

consumption in the United States became apparent as shown by B.K. Hodge “In 1950 petroleum

usage exceeded coal usage and natural gas usage was drastically increased.”[1] Crude oil

consumption has the biggest effect on the United States and they are many factors that can be

seen throughout history to show that the United States is currently the most dependent on cruel

oil then other countries. The area were crude oil is most consumed in the United States is in the

transportation system more specifically petroleum and Diesel because that is what most

transportation vehicles run on. A mostrecent survey conducted in 2007 shows “Transportation

account for 69 percent of the total petroleum usage in the U.S.”[2]. Over time petroleum has

become harder not only locate but extract causing prices for petroleum to shift dramatically. The

price of gasoline has risen in the United States significantly, on figure 1.11 shows the increase of

price from 1978-2007. Hodges a type of currency called nominal dollars, “whereas monomial

dollars represent the actual cost during a given year.”[3]


April 4, 2012

Page 3

Figure 1 Increase of Petroleum Prices from 1978-2007

Gasoline in the United States has steadily increased over the last three decades. One of the most

recent phenomenons that society has noticed about the constant burning of crude oil is how it

effects the environment. One example is how after burning crude oil for a long time it is causing

climate increase, which has been identified as the greenhouse effect which is defined by David

T. Allen and David R. Shonnard as [4]”The surface temperature of earth will rise until a

radiation equilibrium is achieved between the rate of solar radiation absorption and the rate of

inferred radiation emission.”[5].The United States also has a large increase of smog which is

explained in fig. [1][6] “Photochemical smog is an example of secondary pollution that is formed

from the emission of volatile organic compounds and nitrogen oxides, the primary

pollutions.”[7] Most smog is created through the emissions of petroleum powered combustion

engines which in that the vehicles on the road contribute to this pollution.

The solution is a human powered vehicle which gets its energy from the efforts of the person

riding it. They are many vehicles that run on human powered, but the one most familiar is the

bicycle. The United States has one of the largest percentages of people that are both overweight

and unhealthy as shown that, “the U.S. obesity prevalence increased from 13 percent to 32

percent between the 1960s and 2004, according to researchers at the Johns Hopkins Bloomberg

School of Public Health Center for Human Nutrition” [8]. Looking at these numbers makes the

idea of human powered vehicles a more appealing subject as a way to exercise. As a result,

people will begin to make healthier eating choices and cause a chain reaction around their

community. Children would become more health conscious while making choices that will

benefit them in the future like going out to exercise and play instead of watching television. This

may redefine a whole generation by simply changing their view and providing them with

knowledge of how important exercising is.

Weather in Tooele, Utah The purpose of this research is to acquire data of past weather activities in Toole, Utah. The

collected data could be utilized to design the Elander 3.0 to fit for that climate and region.

Tooele, Utah is located in the southwest region of Utah. It has an elevation of 4446 ft. The

average high temperature in May is 69⁰F, the average low is 46⁰F. According to the Weather

Underground website’s almanac; the weather from May 3rd

to May 7th

has a 0% chance of

precipitation.There is a 65% chance of a warm day occurring in which temperatures may exceed

60⁰F, and a 20% chance of a freezing day in which temperatures may drop below 33⁰F. The

daily average wind speed is 17mph. The chance of a windy day, in which wind speeds reach over

22mph, is 7% [9]. It is recommended that a fairing be put in place on the vehicle in the event of a

storm.


April 4, 2012

Page 4

Survey Monkey Survey Monkey is a method created by the team using experiences from previous vehicle designs

and incidents to help the team rate the vehicle during competition, team performance, and

vehicle performance. Using a 1 to 10 scale (10 being very positive) team members rated the

Elander 2.0 from safety to controllability. These questions helped the team improve features that

were below average or of concern to the riders. For instance the lowest rating for riders after

2011’s HPVC was the ability to exit the vehicle; the main cause of this was due to the routing of

the cables and low sitting seat, which after the c-brackets were installed to raise the seat 2 inches.

Overall Survey Monkey ensures that we address critical areas that could potentially improve our

performance as a whole for future competitions and events. The survey monkey was a really

good tool to indicate where the vehicle is failing and where it out performs. This method of

receiving feedback from the people has proven successful when seeking where the vehicle needs

improvement.

Drivetrain Having participated in the previous two ASME HPV competitions, the Elander 2.0 drive train

evolved from a fixed seat and crank position. The mechanical boom met the requirement to allow

riders of different heights to ride the vehicle, but the chain slack created when the boom was

fully retracted required a second process to be mechanically adjusted. As a result, when

switching riders, a tedious process of removing several hardware components to adjust the

telescopic boom to a new rider’s height along with physically releasing or tightening chain slack

had to be performed. In addition, the drive train selected and installation by the previous team

was done with not enough understanding of how bicycle components function, so the 2012 drive

train team focused in designing a drive train that incorporates a telescopic boom that allows an

infinite amount of adjustments, and hands free self-adjusting chain slack tensioner. The team

utilized the feedback from the survey monkey to better design this component.

Table 6: Online Survey Monkey Questioner.

Part

1:

http://www.surveymonkey.com/s/2DZH9HK

Part

2:

http://www.surveymonkey.com/s/Q667JBV

The drivetrain team was divided into two different groups, and each group developed design

alternatives. The idea behind having two groups create their own designs alternatives was to give

the team a better designs selection and preventing the team from selecting a design that may have

been created with a bias idea.

The team approached the drivetrain research by first inventorying the Elander 2.0, the vehicle

used during the 2011 HPVC, drivetrain components.In addition, the Elander 2.0 was used as a

test vehicle during the testing of drivetrain modifications, rider’s general feedback, and prototype

testing of future components.

Completing the drivetrain inventory, each part was tagged with a brand name, model, and part

number. It was discovered that the rear cassettes were not compatible with the rest of the

http://www.surveymonkey.com/s/2DZH9HK

http://www.surveymonkey.com/s/Q667JBV


April 4, 2012

Page 5

drivetrain. According to Shimano [10] manufactures technical specifications the Sora RD-3400-

GS rear derailleur is not compatible with the 27-tooth cassette installed on the vehicle. In

addition, ParkTool Big Blue Book of Bicycle Repair [11] explains the sizing of a derailleur by

finding the teeth spread for the front chain ring by subtracting the tooth count from the small

chain from the large chain ring. The rear cassette tooth spread is calculated by repeating the same

procedure for the front chain ring.When both front and rear tooth have been calculated, they are

added together and the final number is the derailleur maximum cassette size. For example, Sora

RD-3400-GS derailleur small cog has a count of 11T and the largest cog has a count of 34T, so

the subtracting 11 from 34 equals 23. The front chain rings large tooth count is 52 and

subtracting 39 results in 13. Adding, 23 for the rear cassettes and 13 for the front chain ring gives

a final count of 36, so the rear derailleur needed is one with a minimum 36T capacity.

Additionally, when sizing a derailleur the sized of the body cage, where both the guide pulley

and chain pulley are attached, is taken into consideration. According to United Bicycle Institute

(UBI) [12] handbook, a derailleur for a 36-tooth total capacity and a 34T maximum cog requires

a medium size derailleur cage. Shimano [13] technical service for the Sora RD-3400 derailleur

shows the maximum cassette to be 27T while the largest cassette cog is 34T, so the Elander 2.0

had been driving with an improperly match rear derailleur. Table 5 and 6 shows the comparison

of both the Sora RD-4300 and Deore RD-M510 derailleur total capacity and maximum sprocket

size.

Having proved the derailleur was not matched correctly to the rest of the drive train system, the

team scheduled a testing session to further investigate the derailleur performance.Testing the

Sora derailleur, the team was able to pinpoint the vehicle poor shifting performance to the

derailleur. The cage on the derailleur was not large enough to take up the chain slack with the

15T cog and the front 39T gear combination; resulting in a bouncing chain that would eventually

derail.ParkTool [14]further explains the capacities of rear derailleurs are depended on their body

size. For a maximum rear cog of 33T, a medium capacity cage is required, and a 45T cog would

require a large cage. Because the largest rear cassette cog measures 37T, a derailleur sizewith a

large cage body is required. Elander 1.0 (the vehicle used during the 2010 HPVC) rear derailleur

model is a Shimano Deore RD-M510, and According to Shimano technical service instructions

[15] the derailleur is design for a total capacity of 43T with a maximum sprocket of 34T;

additionally, ParktTool [16] reference the Shimano Deore RD-M510 as a large body cage.

Replacing the Shimano Sora with the Shimano Deore rear derailleur the team scheduled a second

test drive. Testing the replacement rear derailleur, the vehicle shifting was consistent when both

downshifting and up shifting; additionally, the derailleur was capable of eliminating the

unwanted chain slack with the 15T rear cog and 39Tchain ring combination. Table 7 and 8

display the specifications of the Sora and Deore derailleur total capacity and largest sprocket

sizing.

Table 7: Shimano Sora RD-3400 Table 8: Shimano Deore RD-M510 Rear Derailleur


April 4, 2012

Page 6

Technical Service Specifications. Technical Service Specifications.

The Elander 2.0 telescopic boom is designed to extend and retract to different rider’s leg

extension, but the design has a flaw which only allows the boom to extended or retracted at

increments of 31.100mm (1.5in).Consequently, riders can not adjust the telescopic boom to their

specific height and must settle to an adjustment that is either to short or long for their leg reach

while seated. The flaw by the telescopic boom was addressed by the developing an alternative

design that did not deviate from the current design, but instead developed an alternative design

that would have an infinite number of adjustments. Table 9 is the functional chart created for the

telescopic boom requirements. Developing an alternative design to the telescopic boom, the team

created a chart listing both the boom functions and means.

Telescopic Boom Function

Function Means

Crank Support Bolted Screwed C-Clip Welded Quick Release Strap

Prevent

Rotation

Square

Tubing

Round

Tubing

Brace Angle

Iron

Bolted Welded

Adjustability Pin Holes Clamp Fixed Friction

chain slack

adjustment

Manually springs friction hydraulic shocks pulleys

The current telescopic boom already achieved several of the functions by providing a threaded

BB shell to mount the crank and a 31.750mm (1.25in) post to support the vehicle front facing

light. Additionally, the current boom design composes a two piece round tubing; the receiver

tube is welded to the vehicle frame as a fixed item with two fixed pin holes. While the telescopic

boom, has a smaller tube diameter that slides into the receiver with a pin hole at a distance of

31.100 (1.5in) Figure 14 shows a SolidWorks CADD rendering of the telescopic boom on the

vehicle. The boom design fallows the same design of the previous vehicle with the exception of

the boom being made of round tubing versus square tubing.

. Figure 14a: Side view of Receiver and Telescopic Boom Design

Figure 14b: Top View of Receiver and Telescopic Boom


April 4, 2012

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Figure 14c: Isometric View of Receiver and Telescopic Boom

The decision to manufacture the telescopic boom out of square tubing was chosen because

previous team encountered difficulties cutting round tubing at the necessary angles which

resulted in machining the same part several times over. Additionally, during the set up and

welding of the round tubing on the vehicle, holes had to be drilled on both the receiver and boom

piece. Lacking the proper equipment to drill center holes along the telescopic boom, the team

created a defective part by miss aligning the center marks on the boom, so to prevent the team

from defecting vehicle parts and adding to the manufacturing cost. The decision was made to

switch to square tubing which Fig. 15 shows a detail assembly drawing of the receiver boom and

Fig. 16 is a detail assembly drawing of the telescopic boom.

Figure 15: Assembly Drawing of Receiver Boom. Figure 16: Assembly Drawing of Telescopic Boom

The team original design criteria were to design a receiver that would provide a location for the

telescopic boom to mount. Additionally, the receiver would have a friction base clamp

mechanism that would eliminate the 7 independent holes that measured 31.100mm (1.5in) of

separation. With the friction clamp, the team’s goal was to create an adjustable boom with

infinite adjustment, but the team ran into technical problems, for the dimensioning of the inside

dimensions of the receiver boom did not allow the necessary room for the telescopic boom to

slide in and out without binding when clamp together. The alternative solution was to design a

boom and receive with preset holes for preset adjustments.

Steering and Suspension The objective for the steering design team in 2012 is to have a smoother turning vehicle capable

of turning within 8-10 feet. During 2011 the standard HPVC 25 foot radius was met however the

team goal was to have a 8-10 feet turn radius, but when the vehicle was tested on campus during

rider conditioning, we could only achieve a 14 foot turn radius so the team researched methods

to decrease the turn radius without increasing the track width and wheelbase due to the added

weight that will contradict our goal for weight loss. The team goal for suspension is to keep our


April 4, 2012

Page 8

height low enough to clear obstacles during the competition and terrain while testing. Suspension

and steering was drawn on solid works last year but with minimal experience with equipment

that was our disposal. The team did not achieve some dimensions on the engineer drawings. The

team plan was to manufacture as precise as possible for HPVC 2012. The previous design had a

caster angle of the kingpin component was at zero degree, due to limited knowledge and time.

The zero caster reduced steering control during a high rate of speed in a straightaway which

caused our, “front wheels (to become) prone to shimmy, capacity of steering wheel automatic

return-to-center becomes weak”. The vehicle would lose stability during testing due to the zero

caster effect disabling the driver’s control moderately. As a result caster was changed negatively

by 6 degrees on the Elander 2.0 for preliminary testing on steering to eliminate the shimmy

during straightaways. The camber on our 2011 vehicle was 9 degrees negative. Through testing

we found that we could add more camber for better control which is a goal the team is set to

accomplish for HPVC 2012. The team noted that too much camber would cause mobility

problems through doorways. By calculating the modified angle, we found a maximum angle was

15 degrees on each wheel would give the vehicle an added 1.05” of track width. Once the new

caster and camber were added to the vehicle we had begun testing with the modified angles.

(Figure 1 C-Bracket )

Kingpin Inclination The King pin inclination was an issue that we did not have time to address before HPVC 2011.

Through further research, we found that we did not have to meet the kingpin inclination with the

tire contact patch, as we had negative camber instead of zero camber. Through the research the

team also found that positive king pin offset of 1.78in will help revert the tires back to a straight

line after coming out of a turn. By decreasing the Kingpin angle from 65 to 60 (Figure 1-1)

degrees we could increase our track width for a better turning radius. During the weight

reduction process we identified that our C-bracket component that connects our wheels and

steering arms was over engineered and as a result was too bulky. In reducing the length, width,

and thickness of the C-bracket we lost nearly 3 inches of track width length. Therefore the

reason for inclining the kingpin angle to 60 degrees allowed us lengthening of the track width

without introducing more weight.


April 4, 2012

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(Figure 1-1. 65 - 60 degree inclination)

Steering Dampener One issue with the vehicle was the shimmy of the front tires when traveling at high speed. The

team researched a method to addressing this issue. The team came up with the idea of using a

dampener to the steering. While experimenting with a damper for dirt bikes to give us “the

swivel [king] pin inclination has the effect of causing the vehicle to rise when the wheels are

turned and produces a noticeable self-centering effect for [king] pin inclinations.”[17] A

dampening setup helps our vehicle stay centered while undergoing uneven terrain. Dampening

proved to work with our design, given that we found a damper with the right amount of travel to

cooperate with the steering displacement while at maximum turning position.

Seat Weight Reduction The team’s objective is to reduce the overall weight of the vehicle through modifications of the

vehicle. The vehicle’s weight will go from 74lbs to 50lbs meeting the design criteria for

minimum weight of vehicle granting us optimum points. By establishing parameters for the

vehicle’s structural integrity we found that we could have parts made of lighter material.The

team decided to lose weight from the seat by changing the materials. The seat frame was

originally steel, but was changed to aluminum. It was physically tested and confirmed that the

frame would be able to hold a riders weight. In choosing lighter material weighed 4 lbs. less than

the original seat. (Figure 2-1)

Figure 2-1. (Aluminum seat brackets) Figure 2-2. (Steel seat brackets)

Head Rest

The head rest was made out of lighter material; it was made of carbon fiber pieces. (Figure 2-3)

Figure 2-4) the original material of the head rest weighed 1.27 lbs. With the composite brackets

the weight went from 1.27 lbs. to 0.847 lbs., nearly half a pound in weight decreased.


April 4, 2012

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Figure 2-3. Aluminum Head rest bracket) (Figure 2-4 Carbon fiber head rest bracket)

Basket Design For the competition this year, vehicle needs a basket to be able to transport packages during the

competition, so the Rolling Huskies design the basket to carry the packages. In the last year the

team decided upon a single carrier basket. The basket’s bracket must be strong enough to with

the mass of the objects to be transported that is more resistant against weight. The vehicle’s

cargo area is often consisting of a steel tube carrier, a box, and a bracket. There are many

different kinds of baskets, such as Bakfiets, Rear and Front baskets as shown in figure 11-1, 11-

2, 11-3. Here are three types of baskets

Figure 11.1 Rear Basket Figure11-2 Front Basket Figure 11-3 Bakfiest Basket

The team researched different types of baskets and chose the best basket to which would be light

and would have enough cargo capacity to carry everyday items. The basket must be able to carry

small packages and 1 gallon water that is about 3.7 kilograms of water which is a standard

recyclable milk jug. Therefore, the basket must have enough space and enough strength to

transport the cargo. For the design alternatives, the team considers the different types of basket,

including shape and material. At our disposal the team has two available baskets. The first is a

basket made of wicker, the second made of iron wire. The team narrowed the design to either

using the existing basket, or a new basket design which is a twin basket design. The reason why

the twin basket design was considered because of the increased cargo capacity to which it posses

compared to the existing design.

When the selection of the baskets was made, the overall mass of the basket itself, the cargo

capacity, and the ability to hold a 1 gallon jug were all taken into consideration as listed in the

table below Table 3 Morph chart of baskets

Mesh basket(lid) Wicker basket Wire basket Mesh basket


April 4, 2012

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It was decided to go with the wire mesh basket, based upon the weight of the basket, only minor

modifications were needed to make the basket lighter. The modification that was made to the

basket was changing the material that made up the basket lid. The reason for this was to make

the basket lighter in so making the vehicle lighter.

Drag Force The objective of this calculation is to obtain the theoretical maximum force going against the

vehicle when it is traveling at 40 mi/hr. The calculation used the resisting force formula for when

an object is constant speed. It is assumed the drag coefficient is of a square frontal area. In

conclusion the air drag force going against the object is about 265.92 N or 57.724 lb. It is

assumed that there is no wind, the cross sectional area is a square going against air friction. The

cross sectional area could change, which is why it is assumed, the air friction is at its highest.

The common density of air was used, but the drag coefficient was modified to of Utah.

Data:

A = Cross sectional area D = Drag coefficient

p = density of air v = velocity

(1) A = W * H (2) R = DpAv2 / 2

Mathematics:

W = 30.44 in (77.3 cm) H = 36 in (91.44 cm) A = 30.44 * 36 = 1095.84 in2 (7069 cm

2)

D = 1.52 p = 1.29 Kg/m3 v = 40 mi/hr. (17.88 m/s)

A = (1095.84 in2) * (2.54 cm

2 /1 in

2) * (1 m

2 / 100 cm

2) = 0.707 m

2

v = (40 mi/hr.) * (1 hr. / 3600 s) * (5280 ft. / 1 mi) * (12 in / 1ft) * (2.54 cm / 1 in) * (1 m /100

cm)

= 17.88 m / s

[R = (1/2)*(1.52)*(1.29 Kg/m3)*(0.707 m

2)*(17.88 m/s)

2 =221.6 N] = 265.92 N

Or [221.6 N * 0.2246 lb. / 1 N = 49.77 lb.] + [49.77lb * 0.2 = 9.954 lb.] = 59.724 lb.

Results:

The amount of force the air is going to exert on the vehicle is 265.92 N or 57.724 lb.

Diameter of the Bolt The purpose of the calculation was to find the minimum diameter bolt needed to be capable to

maintain stable against the forces exerting against it. Using the formula for the engineering stress

and analyzing the forces acting towards the bolt, the results are listed in the table below. Based

Mass 623.21g 325.5g Over 610g 594.7g

Ability to hold 1

gallon water

Yes No Yes Yes

Dimension 12”× 10” ×9.4” 13” × 12” × 9” 13” × 9” × 9.5” 12”× 10” ×9.4”


April 4, 2012

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on the results any of the bolt sizes would be sufficient to sustain the forces applied to it. The

choice of the bolt will be based on the cost of the bolts.

Data:

WV = Vehicle weight WR = Rider weight WC = Cargo weight

(3) F1exp = WV + WR + WC (4) F1 = WV + WR + WC + 20% factor

Foot = F1 +F2 F1 = F2 psi = lb. /in.2

σ = Ftot /A A= πd2 / 4 d = (Ftot /σ * 4/π)1/2

Mathematics:

WV = 80 lb.f. (356 N) WR = 300 lb.f. (1336 N) WC = 10 lb.f. (45 N)

F1exp = 80 lb. + 300 lb. + 10 lb. = 390 lb. (1737 N) 20% factor = 390 lb. * 0.2 = 78 lb. (347

N)

F1 = 80 lb. + 300 lb. + 10 lb. + 78 lb. = 468 lb. (2084 N) Ftot = 468 lb. + 468 lb. = 936 lb.

(4169)

Grade Min Strength (103) in (psi): Minimum Diameter in (in.); (d = (Ftot /σ * 4/π)1/2)

SAE Grade 1 36 (2.48 bar) 0.1819 (0.462 cm)

SAE Grade 2 57 (3.93 bar) 0.1446(0.367 cm)

36 (2.48 bar) 0.1819(0.462cm)

SAE Grade 4 100 (6.89 bar) 0.1091(0.277 cm)

SAE Grade 5 92 (6.34 bar) 0.1138 (0.289 cm)

SAE Grade 8 130 (8.96 bar) 0.0957(0.243 cm)

Braking System The brakes that were used last year were sufficient to meet the rules requirement of 25 foot

braking distance. The modification is that now the team will use a Mountain Bike FR5 Brake

Lever. The reason why the team that the brakes were changed was that the steering design was

modified, compared to the superseded part lighter, and also made adjustment of the brakes

easier.

Pitman arm and tie rod After hand calculations, the location of the pitman arm was determined. Once the location of the

pit man arm was located the length of the tie rod was also determined. The manner in which the

pit man arm location was determined making a triangle which used the length of the wheelbase

and the track width from one king pin to the other. By calculating the theta of B and by using the

property of alternate interior angles of parallel lines the Ackerman angle was determined. The

location of the tie rod was then determined, we know that the location of the tie rod could lie

anywhere the line that is projected. It was also determined that the further away the tie rod was

located the more travel the wheels have to make a turn. Kingpin to kingpin = 20.49in (lower

kingpin to lower kingpin AutoCAD)Wheelbase = 47in Ackerman Arm = 3.5in (2011 knuckle

from lower kingpin to middle hole)

(1). (5) Tan θ = (

)

= 0.218


April 4, 2012

Page 13

θ = tan-1

(0.218) = 12.298ο (Ackerman Angle)

Ackerman Arm Radius

(6) sin (12.3) = Y/3.5

Y = (sin12.3)* 3.5in = 0.75in

3)

BC is the length of tie rod

Dkc is the distance between kingpins center to center

Raa is the radius of the Ackerman Arm

BC = Dkc – 2* Raa * sin(12.3)

BC = 20.49in – 2*3.5 * sin12.3

BC = 18.998in

4) Assuming we turn to left 15ο

Ax = 3.5cos (12.3 +15) = 3.11

Ay = 3.5sin (12.3 + 15) = 1.605

5)DE = AD – AE

DE = 20.49in – 1.605in = 18.885in

6) (7) BD = √ = √ = 19.14in

Tank =

=

θk= tan-1

= 9.35

ο

= ( )

= θy = cos

-1( )

7) (8) cosθ

θy = 80.65ο

Steering angle = θk + θy + AA - 90ο

Steering Angle = 9.35ο + 80.65

ο + 12.3

ο – 90

ο

Steering Angle = 12.3ο

Cost Analysis Tools = $6326.79 + Materials = 4265.50 Labor/Month = $20,832

$ 10592.20 Sub-Total Bikes/Month = $634.8 6042 - 44 E Whittier Blvd

Loopnet.com

Current Property Value = $ 749,000

Monthly Payment = 3800


April 4, 2012

Page 14

1. Vehicle Cost as Presented in Competition

= $ 4265.40

2. 10 Bikes/Month = $63486.00 (Material + Labor)

+

$6,326.79 (Tools)

$ 69,812.79

Utilities (Electricity, Heater, Water) = $200.00

Location: 6092-44 E. Whittier Blvd =

$3900 Monthly Payment

Total Property Value = $749, 000

Fist Month

Location Materials/Parts

(x10)

Tools Labor Office

Equipment

Utilities

Costs $ 749,000.00 $ 45,654.00 $ 6,326.79 $ 20,832.00 $ 9293.56 $ 200.00

“First Month” + “Every Month After” (x35) = 3 years

$ 831,106.35 + $66,486.00 = $897,592.35

New Total Value in 3 Years= $1,660,421.00

Capital Investments = $831,306.00

Tools = $6,326.79

Bike Cost at $10,000 = $386,550 Profit in 3 Years

Table 5 Cost of Every Month after First Month

Desks Chairs Laptops Printer USB

Mouse

Paper Pens Cabinets Staples Gas Water

Heater

Name

of item

(3)Bushview

(1)Linea

Italia Trento

L Shaped

OfficeMax

Crawley

Highback

Executive

HP Polio

I3-

10200S

Brother

HL-

4150

CDN

Color

Laser

Printer

Microsoft

Touch

8.5”×11”

500

Sheet

Pack

BIC

Roundstick

Grip 12

PK

HON

700

Series

Drawer

Cabinet

Swingline

Number

of items

4 4 4 1 4 50 50 2 4

Cost for

one

item

$ 329.99

$ 299.99

$ 59.99 $ 949.99 $

399.99

$ 79.99 $ 14.99 $ 2.49 $ 899.99 $ 9.49 $10/Month

$ 60

Electric

Month

$ 80 Water/

Month

Total

Price

$989.97 +

$299.99

$1289.96

$ 239.96 $3799.96 $399.99 $ 319.96 $ 749.50 $ 124.50 $1799.98

+

$329.99

$2129.97

$ 39.76 $150/Month

Place of

Buying

OfficeMax

.com


April 4, 2012

Page 15

Total Cost for month after first month (excluding utilities) = $ 66,486.00

Total Cost for month after first month (excluding utilities) = $ 66686.00

Total Cost before Utilities: $83,1106.35

Total Cost with Utility Costs: $83,1306.35

Average Inflation Rate over Time

Calculating the amount of building our vehicles after three years using a differential inflation

equation gave us the true cost after three years. The P is the first year cost of building our

vehicles, f is the assumed 2% inflation rate, and the n is the number of years we expect to

forecast to the nth power. This equation allows us to predict a realistic value for cost in the

future by including the assumed inflation rate.

(5) F = P( 1 + f )n

First Year Second Year Third Year

Cost $ 1,595,945.00 $ 1,627,863.00 (including 2% increase)

$ 1,660,421.00 (including 2% increase)

Steering Mechanics The team had to find the optimal position that of the steering mechanism was located to the sides

of the driver’s hip area. Since the handles are located between the wheels and seat, the team had

to find the maximum arc to decrease turn radius for both directional sides. We find that by

turning the handlebars more towards the outside of the vehicle, we are able to get our maximum

arc without any interference.

Also, by having the steering handles perpendicular to your lower part of your arm we have an

equal amount of force that is distributed throughout the entire arm length. We can achieve this by

having our arm at an angle of a 90 degree position with respect to the floor. Additionally, design

incorporates time trial shifters so the shifting will be more precise.

Using simple geometrical terms, the steering arm travel arc was determined. [D] We find the

arch’s area by using the formula S=ѲR. This formula represents the Arch area is equal to the

radius times the degree that it was given in which should be converted to radian before being

inputted. So, by getting our average radius due to the length of 12.6 the average person’s length

from the fist and elbow from our handle to the end to where it connects near to the king pin. The

maximum degree of displacement was calculated by letting the wheels face in a straight line with

respect to the vehicle. We then turn the wheels either to the left or right as far as possible and we

find that the maximum angle displacement with respect to its initial position. So now by applying

the formula we get:

(5)S=ѲR =>S= (20°)(12.6) =>S=4.3 in.

Materials/Parts (x10) Labor Utilities

Cost $ 45,654.00 $ 20,832.00 200.00


April 4, 2012

Page 16

The travel of the steering arm was 4.3 in. [B] This is implying that due to our inertia wanting to

go in a straight path, but by changing the directional force to a displacement of 20 degrees to

either the right or left we are given that our turn radius has the be greater to complete a full 180ᵒ turn. By modifying our handle bars by displacing them 4ᵒ outward from their origin we are able

to get the maximum turn radius we can from this vehicle due to the fact that stoker is further

away from the wheels and seat. Now by reapplying the formula for arch area we are given:

(6)S=ӨR => S=(24ᵒ)(12.6in) =>S=5.2 in.

Now we see based on our second area we are now given a much sufficient turn radius than what

we initially began with. This will allow the vehicle to acquire a greater turn radius without

making up a wide turn.

Height of Steering Handle process The comfortable arm position to be at a comfortable position we have to find a way that the

normal force that is acting on our body is distributed throughout the arms. We begin by initially

acquiring the angles and height of the previous design. The initial height of the handle bar to be 9

inches of the ground. Looking at this from a side view we see that the angle that the body

mechanics of the driver to hold the steering handles to be from 127ᵒ with respect to your

elbow.[19] This is an awkward position for your body mechanics to be in a resting position

because of the forces that are acting on your brachioradialis and your Palmaris longus. This

causes that you feel discomfort when traveling for long distances.

To minimize the stress that is implemented on the driver’s brachioradialis and Palmaris longus

we have to do some adjustments to the angle that is formed from his/her deltoids and wrist. As

we see in figure 4

Figure 4 Newton’s second law of motion [D]

Our arm is related to this figure when you are moving to a new directional force. These are the

forces that are acting on your arms when you are holding the handle to control the steering. At

still position we are given that the angle that is formed from the handle bar to your elbow with

respect to the ground we have 37ᵒ that is formed. We also give that gravity is 32 ft/ and the

mass varies between drivers. So now we have two forces that are acting on your arm. Now we

apply the summation of forces for your horizontal and vertical forces.

(9) ∑ = m(32) =ma

(10) ∑ = N- mg =0

For this part of the redesign of the vehicle we need to minimize the strain in the driver’s body

mechanics. On doing so, we have to decrease one force that is acting on the arms. To accomplish

our goal we have to decrease the force that the body is dealing with in the vertical direction. By

doing so we raised the handle bar to have a 45° from where it is going to be mounded on so we


April 4, 2012

Page 17

decrease the angle to 90 degrees from the shoulder to the wrist. This will cancel out the extra

force that was being acted on the horizontal direction. This will minimize the forces that are

going to be acted on the brachioradialis and your Palmaris longus.

Angle of the steering handle bar To improve the handle bar that is going to control the vehicle’s direction we initially begin by

acquiring the measurements of the previous design. We are set with an initial angle from the bar

that connects from next to the king pin to the handle bar with respect to the grounds

perpendicular axes. We get that the angle is 68°. We are also given that the average length from

the handle bar and the center of the wheels is 12.6 inches. Also known is the average length

between the team’s elbow and knuckles is 14.5 inches [22]. These known values are the leading

causes for the uncomfortable position faced by drivers.

o improve the handle bar the team set the bar 78.8 degrees from the vertical axis because the

average angle that a hand makes when it is holding an object that is vertically incline to a

horizontal plane is 7.8 degrees from a vertical displacement. This allows the arm of the driver to

be horizontal to respect to the ground [23].

Time Trial Shifters In the previous year we’ve used the Shimano Tiagra Road shifters which were unable to

accommodate what leave you are on the shifting lever. The downfall of these shifters was the

sensitivity of the shifters to braking. [24].

The reason for applying time trial shifters instead of last year’s shifters is because we have more

benefits when regarding accuracy. We applied this function on top of the handle bar so we can

control be able to control it with our thumb. The benefits that vehicle will have by switching to

time trial shifters are:


April 4, 2012

Page 18

Table 2 Features and benefits of time trial shifters

Features Benefits

Back To Zero To optimize the aerodynamics position and

ergonomics

Adjustable Starting Position Maximum ergonomics in respect to the shape

of the handle bars and the personal position of

the hands.

New Internal Mechanism Reduction of the required load for up shifting

and down-shifting and positive indexed

feeling

Multiple Shifting Shifts up and down up to 3 sprockets at a time

with one swing of the lever.

Micro index adjustment of the front

derailleur

Allows small adjustments to the position of

the front derailleur to keep it in an optimal

position with respect to the chain line

“Double Shape” levers Optimal ergonomics reduces t efforts to

activate the levers to a minimum and maintain

an aerodynamics position

External Cable Routing Special cable routing allows for fitting the

cables with no need to remove the cable

housing with no need to remove the cable

housing easing assembly and maintenance

By these new applications from the time trial shifter the driver is able to be more accurate when

changing gears and having a less lag-time when changing gears.

Wheel Guards The Elander 2.0 had fully exposed front wheels, rather than have this be a serious problem in the

future the team proposed a solution. The manner in which the team addresses this problem is by

implementing wheel guards for the front wheels. Not only do the wheel guards keep the stoker

hands safe and away from harm, the wheel guards also protect the stoker when driving wet road

conditions by keeping the water or mud by being blocked with the wheel guards.

Bearing selection The goal of this design was to make the vehicle easier to service while keeping it light. The

design was to replace the original bearing that was set in place for the front suspension. The

criteria meant that the bearings should be able to handle the load they would be subjected to. The

bearings will be subjected to the weight of the vehicle and components and weight of the rider.

The research that was conducted had taken into consideration the bearings capabilities and

limitations.


April 4, 2012

Page 19

Figure 12 the larger α, the higher the axial load carrying capacity. Figure 13 Angular contact ball bearings

Angular contact ball bearings – This type of bearing is design specially to handle combined

loads. Instead of having the bearing race should being an equal height the thrust sides of the

Angular contact bearing is higher to support the combined load. This bearing can handle the

combined load applied opposite side to higher shoulder of the bearing race, seen in figure 13

(Corporation) This system is used in bicycle fork headsets, crank set bottom bracket bearing.

(Institute)

Due to the budget constrain of the team size of the new bearing must fit the aluminum tubing

stock the team have in stock. This restrict the bearing use for the new design to a maximum

outer diameter 1.4 inch but larger than 1.25 to allow a snug fit inside the 1.5 tube with a ¼ inch

wall thickness. A market research was done by searching popular online dealers such as

McMaster Carr, Amazon, VXB, and bearing manufactures such as Timken Inc. to find out what

bearings that meet our criteria was readily available. Two different bearings system from two

different manufactures were considered as a possible solution due to their type, size and

availability. The first system is the taper roller bearing from Timken and the other was an

angular contact bearing from VXB bearing. Out of the bearings available from the online vender

the taper roller from Timken (parts #A4059 A 4138) type bearing has one of the highest loads

handling rating according to the bearing application chart in the Timken product catalog. This

style of bearing will provide the greatest stability (due to contact surface) and installation

complexity can reduce with this design since the bearing cage will provide a direct mounting

service to the knuckle. The only drawback is the only bearing found that fit the design criteria

was found to be too heavy duty for our application. The originally design of the bearing was

originally design as an automotive wheel bearings design to handle the loads of a 5000 + pound

car.

The second bearing system considered is the angular contact bearing used in the bicycle industry.

The second type is the angular contact ball bearing. This system is used in the cycle industry as

well as in the automotive industry to handle combine loads. The dealer that carried the bearings

is local and it was a regular stocked item. The pricing of the selected bearing is also much more

favorable comparing to the wheel angular tapered bearing that would fit our application. The

bearings we selected cost $80 for 8 bearings (2 sets left and right).

Seat reference points The ergonomics’ of the geometrical incline of the seating position purpose is to maximize the

output force of the vehicle. By applying the “Trunk-Limb” [25] measurement the team can

average out the best output of comfort and visibility as you sit in the vehicle [26]. To maximize

the best output force from our inclined posture we have round of the best efficient posture for

this vehicle is the “kyphotic posture” [25]. The ergonomics purpose is to find a “better fit


April 4, 2012

Page 20

between people and the things they do” [26], the objects they use, and the environmental in

which they work. By increasing the seat angle by 60 degrees we are able to acquire the

maximum output of your (primary) muscles: quadriceps and your (secondary) muscles: Gluts,

Hamstrings, Calves and Lower Back. By having this inclination as shown in the image in the left

it gives the driver a c curved back that allows him to fix his/her tilt to prevent deformation from

their back [27]. A kyphosis posture is known for giving the sitting person a c-curve [28]. By

having a kyphosis posture when you are sitting on the vehicle, it enhances a horizontal optical

view of your surroundings while riding. The way to acquire this sitting position is to increase

from a 0 degree posture to a 95-100 degree posture to give you that c-curve back shape in the

vehicle.

Figure 3 Kyphosis C-Curve Figure 2 show a 60 degrees inclined sitting posture

Table 1 Body Measurements of Team Members

NAM

E

HT

[IN]

Shoul

der

to

Finge

r

[IN]:

Shoul

der

to

Elbow

[IN]:

Shoulder

to

Head

[IN]:

Should

er

to

Hip

[IN]:

Hip

to

Knee

[IN]:

knee

to

ankle

[IN]:

Inseem

to

Heel

[IN]:

Hea

d

[IN]

:

weig

ht

[lb]

1 Erik

Orellana

68 28/30.

5

14 13/12 21/21 20/22 15.5/1

7.5

30/30 6 230

2 Juan

Ayala

63 28/29 12/13 13/11 15/16 18/20 16/17 28/30 6 150

3 Alex

Zaragoza

70.5 31/30 15.5/1

4

12.5/13 21.5/19 20/18.

5

18/18.

5

32.5/33.

5

6 169

4 Scott

Wong

67 30/30.

25

13/14 13/12.5 19/19 19/21 19/18 31/31 6 160

5 Wilkin

Chan

66.5 26.5/2

9.5

14/14 13/13 17/19 20/21 19/17.

5

30/32 6 160

6 Erick A

Garcia

66 26/28 11/12.

5

12/11.5 20/20 18/17.

5

20.5/2

0.5

28/28.5 6 190

7 Michael

Mariano

69.5 29/29 13/14 13/13 20.5/20 19/20 16/21 27.5/28.

5

6 225

8 Danny 63 26.5/2 11/11. 12/11.5 20/19.5 16/17. 17.5/1 27.5/27. 6 145


April 4, 2012

Page 21

Rodas 7.5 5 2 9 75

9 Virginia

Sanchez

60.5 24.5/2

5

11/10.

4

10.8/9 17/15.4 15.5/1

5.5

26.5/26.

5

5.8 140

10 Jackson

Tu

68 26.3/2

6.6

11.5/1

1.3

11 */12 19.5/18 17.5/1

3.7

29.4/29.

6

6.1 220

11 Sarah V.

Sui

64.5 13.5/2

5.3

10.7/1

0.9

10/10.4 18.8/16

.8

15/15.

5

28/28 6

12 Elvira

Martinez

57.5 23.4/2

3.9

10.6/1

1

10.5/10.2 15/13.3 15/15 26.2/26 5.1 102

13 Eric

Pierson

67 28/32.

1

13/12.

8

12/12.6 16/17 19.2/1

8.7

33/31.5 5 142

14 Albert

Vengas

72 32.1/3

1.5

15.3/1

4

11/12.6 18/17.5 21.5/2

2

32.9/21.

5

6 226?

The “Trunk-Limb” measurements is the proper design of equipment which will facilitate most

efficient use by the human operator requires, among other factors other factors, information

concerning dimensions of all parts of the body, in various positions [29]. By applying these

measurements to our drivers we are able to find the average size that the vehicle has to exceed to.

The measurements in the left side of the columns are of the driver standing up; the ones on the

right are when the driver is on the vehicle.

Back Bone design This year’s team goal is to compete with a lighter vehicle. One option that was considered to

achieve this goal is to make the Back bone lighter. Last Year the Elander 2.0 weighed in at

almost 80 lbs., the weight includes all the vehicle components. The chassis of the vehicle was a

good place to lose weight but this would prove true until further research and simulation would

prove true. The objective for this design was to make the back bone lighter without the

compromise of strength properties. The chassis is the one component that holds all of the vehicle

components, so maintaining the strength properties of the back bone is something that must be

kept in consideration at all-time throughout the build.

There are many ways that the vehicle chassis can be made lighter. The methods of which to lose

weight on the chassis were quite simple. This could be done with a simple drill with a big

enough bits and the proper amount of torque. Another method in which the back bone could be

modified is by using an automated 5 axis CNC Machine to minimize error. The methods of

making the vehicle lighter were brainstormed thoroughly; the conclusion the team came to, was

to make holes on the chassis of the vehicle. The next item to be considered was the placement,

size and orientation of the wholes. The next item to be addressed is the forces that the desired

component will encounter. The Chassis of the Elander2.0 is a backbone chassis. The choice of

material is 6061 grade Aluminum, the dimension of which is 2x2 inch by 40.5 inches square

tubing.

Listed below are the different options in which the team were considering, the option are for the

solid beam back bone. The First test was the forces that is applied from the top, 300 lbs. The first

test was conducted on the current design as a control. The holes were ¾ inch holes and used a 3

pint bend test.


April 4, 2012

Page 22

Design Selection

Image Design Description Deflection Weight

Solid beam with an simulated

applied load of 300 lbs. with

fixed points at both ends

of the beam.

7.75x10^-3 in. 4.02 lbs


applied top load of 300 lbs.

with fixed points at both ends

of the beam. The beam has ¾

inch holes on

the side of the beam

9.11x10^-3 in. 3.55 lbs.




of the beam. The holes on

the top of the beam

1.12x10^-2 in.




of the beam. The holes on

all 4 sides of the beam

1.33x10^-2 in. 3.08 lbs.

A variety of different types of orientations for the holes on the chassis were considered. The

team decided to keep the design as simple as possible. The Diameter hole that was selected was

½ inch, and the orientation to be spaced out evenly throughout the entire beam. The stresses that

will be applied on the chassis were something that was highly taken into consideration. The

simulations were run using solid works, utilizing the fixed points at the end of the beam.

After the simulations were completed, the design in which the team will decide to go with is

having holes drilled on the side of the Back bone of the chassis. The vehicle has a significant loss

of weight but still maintained a decent amount of

Roll Center The Roll Center and instantaneous center of our vehicle is the limit at which our vehicle will roll

over if we exceeded the angle of the Roll Center. The team used the dimensions of the vehicle to

find the Roll Center and to draw lines from the contact patch of the tire., the center line of the

vehicle, and a horizontal line from the lower connections of the suspension C-bracket these lines

will generate a common intersection somewhere in real space defining our instantaneous center,

roll center position and angle. Using existing dimensions from AutoCAD (Figure1-2 Roll

Center) the front suspension from the Elander 3.0, it was found that our roll center is 1.23 inches

from ground level, and 14.98 inches from the tire contact patch to the center line of the vehicle.


April 4, 2012

Page 23

These points then gave us the slope with which we found the angle of the roll over limit to be 5

degrees. This means that if at any point of the Elander 3.0 turns sharply and the angle of roll

from horizontal exceeds 5 degrees the vehicle will roll over.

(Figure 1-2 Roll Center)

Brake Testing The objective for the brake testing was to come to a complete stop from an average of 20 ft. /sec.

within 15 feet ensuring that our vehicle will provide adequate braking power to meet HPVC

safety standard. Testing was carried out by four riders each doing three runs so that we could

average the brake distance from 12 runs total rather than 3. The average team speed was 22.3ft/s

from a 100 foot distance start to finish, the E-Lander’s disk brakes allowed us to stop within an

average of 13.9ft at this speed meeting the safety brake test. The data collected was compared to

an average speed and brake distance from two riders on a road bike using the same distance start

to finish. The road bike test accelerated faster giving us a higher final velocity but with less

breaking power than the Elander, it averaged a 24.15 foot brake distance. This established that if

the weight of the Elander is three times that of road bike then we would need extra brake power

which was clearly achieved by two disk brakes mounted to the front wheels, and for added

emergencies we incorporated a single rim brake on the rear wheel.

Rider time (s) distance

(ft)

average speed

(ft/s)

Brake Distance

(ft)

Scott 5.04 100 19.84 12.19

Scott 4.99 100 20.04 11.34

Scott 5.01 100 19.96 13.2

Mike 5.22 100 19.16 11.7

Mike 4.89 100 20.45 13.5

Mike 4.68 100 21.37 16.9

Eric 4.42 100 22.62 12.4

Eric 4.43 100 22.57 15.5

Eric 4.34 100 23.04 16.3

Danny 3.89 100 25.71 14.7

Danny 3.98 100 25.16 16.5

Danny 4.18 100 23.92 14.7

Danny 3.85 100 25.97 11.7

Average 22.29307692 13.89461538

Scott/Road Bike/700cc Wheels/Rim

brakes

3.26 100 30.67 20.4

Scott/Road Bike/700cc Wheels/Rim 3.29 100 30.39 26.5


April 4, 2012

Page 24

brakes


brakes

3.14 100 31.84 35.9


brakes

3.77 100 26.53 21.5


brakes

4.17 100 23.98 23.1

Mike/ Road Bike/700cc Wheels/Rim

breaks

3.82 100 26.18 24.7

Danny/Stock Bike 3.58 100 27.93 19.1

Danny/Stock Bike 4.01 100 24.94 22

Average 27.8075 24.15

Physical testing of RPS The physical testing that was conducted was to test the strength of the Roll over protection

system. The HPVC 2012 rules state that the Roll over protection system should be able to

withstand a top load of 600lbs. and a side load of 300 lbs of force. The way in which the physical

testing was conducted was by loading a Steel mesh cart with 12 cases of paper on top of it. The

cart loaded with the paper cases was loaded on the forklift then suspended over the vehicle. Each

cart was lowered and tested on both the top and side of the vehicle. There were cases of paper,

each of which weighed in about 53+ lbs. each the actual weight of the cart and paper cases were

approximately 781 lbs. Upon further inspection after the physical testing was there was no

measurable deflection, and no visible damage or deflection

Safety The vehicle is rather safe in that there are several safety systems in place that would prevent

harm to the driver as well as vehicles and people outside the vehicle. One of the systems

incorporated into the vehicle was the roll-over protection system in which prevents harm from

coming into the driver should the vehicle flip over or roll during a possible collision from other

vehicles. The system has been tested to simulate the situation in which should the vehicle flip

over, the driver’s head will not come in contact with the ground. Other systems incorporated into

the vehicle were the standard seatbelt in which is critical for all vehicles used in everyday life.

The seatbelt will keep the driver safe in many situations, an example would be that should the

vehicle come into a collision there is a chance the driver may fly out of the vehicle or fall

towards it. Should the driver fall out of the vehicle, chances are the driver’s head would come in

contact with the derailleur in which contains a lot of sharp metal teeth. Also should the scenario


April 4, 2012

Page 25

of the driver flying out of the vehicle then chances are that the flight will lead to serious injuries

or possible death in that should a collision happen and the driver was to fly out then the driver

may fly into the car in front of him. The last safety system that is available in the vehicle is the

brakes. These brakes will help provide the vehicle a complete stop so that it may prevent an

accident that may occur should a pedestrian walk in a crosswalk or trying to make a turn.

Team Safety When the vehicle was being modified and built the team always kept in mind safety when

operating moving machinery. Team members would ask each other if they have the proper safety

equipment before operating machinery. New members that recently joined the team were taught

and supervised when operating the machinery for cutting tools or just using it. When new

member join much of the common safety practices were being introduced. Each team member

was tested orally before operating on any machines as the advisor must be present at all times

when machines are being operated. Members of the Rolling Huskies always took patience in the

teaching of how the tools are to be used to novices. Before any new member was to work on a

something for the team, they would be advised on the process of how to work on a project. When

a team new team member worked on something improperly such as sawing a square metal tubing

with a hacksaw they were shown the correct process that way the equipment would not be

destroyed as well as a smoother process of cutting.

Factor of Safety Safety is the most important factor when driving the vehicle, so get the factor of safety is

important. To calculate the safety, the team used two methods. One method is using the formula

FS = Sal/σap[a]. Sal is the allowable strength, σapis the applied stress, and FS is the factor of

safety. The team used aluminum 6061 T-6 to make the main part of the vehicle. Its allowable

strength at 24°C is 276MPa[b]. The team only used 20% of yield strength. Therefore, the

allowable strength of the material is 55.2MPa.

(11) σ =

For Chassis:

σ =

=

( ) =4.497MPa

FS = Sal/σap = 55.2/4.497 = 12.3

For RPS:

σ =

=

( ) =4.521MPa

FS = Sal/σap= 55.2/4.521 = 12.2

The other method was using the classical rule-of-thumb factor of safety

It has a formula FS = FSmaterial × FSstress × FSgeometry× FSfailure analysis × FSreliability

If the properties are known from a handbook or are manufacturer’s values, the FSmaterial= 1.0

If the nature of the load is defined in an average manner, with overloads of 20 to 50 percent, and

the stress-analysis method may result in errors of less than 50 percent, the FSstress = 1.2 If the

dimensions are not closely held, the FSgeometry = 1.1If the failure analysis is not well developed,

such as with cumulative damage or multi-axial nonzero-mean fatigue stresses., the FSfailure analysis

= 1.4If the above reliability must be high, greater than 99 percent, FSreliability is 1.4. in conclusion

the force of FS is 2.578.


April 4, 2012

Page 26

Aesthetics Taking a vehicle such as the Elander3.0 to market for general consumer use would only require

slight additions for safety and comfort. A vehicle as low to the ground has to use additional

accessories to increase its visibility to other vehicles on the road. First and foremost, a bright

florescent colored flag on a rigid yet lightweight rod would be attached to the rear of the vehicle

reaching at least 5 feet in to the air. This would alert drivers of the vehicles presence to allow the

other vehicles of the road to give the vehicle safe distance. Other concerns in the same area of

visibility would be to increase the vehicle’s night time visibility. Every wheel will have the

standard spoke reflector on each wheel as will there be reflectors mounted on the front and rear

of the vehicle as well. Electric bicycle lights would also be implemented in addition to the

reflectors. Preferably a “see by” light as well as a “be seen light.” Ideally something as

revolutionary as the Revolights or Rimfire illumination systems would be used, but also readily

obtainable lighting systems such as X-Fire would be just as adequate and safe. Rear red blinking

lights would accompany rear reflectors on the vehicle to ensure maximum night time visibility.

The quickest, most inexpensive and most lightweight option we’ve found for also achieving

increased visibility would be adhesive reflective tape. Adhesive tape can be applied to the sides

of the vehicle wherever there is surface area that will allow it. One company that manufactures a

very good product for this application is Hillman Sign Center. Their product is made here in the

USA and exceeds US safety Standards and is readily available at most hardware stores or

building supply centers. Just as it is important for other vehicles to see the rider, it’s equally

important for the rider of an HPV to be aware of other vehicles on the road as well. Rearview

mirrors are essential to accomplish and aid in total road awareness and safety. Mirrors allow for

safe maneuvering ensuring that when you make a decision you know that you will not be causing

any unnecessary accidents that could happen from behind. HPVs are generally quieter than

anything else on the road, sometimes more quiet than a pedestrian walking. The addition of an

aural alerting device, such as bells or horns, is a great asset to a vehicles safety. Even if one

were to settle for the rubber ball clown horn, they would be better off than a rider without one.

For this particular vehicle using a horn like the Airzound compressed air, water bottle horn

system would be more appropriate. With a capability of being powered by up to 115psi of air

and delivering a 115 db. of sound, it will definitely get a rider the attention they need let people

know they’re on the road with the type of vehicles sharing the road becoming more and

diversified every year, the Elander3.0 can be a viable option for commuting, recreation or sport.


April 4, 2012

Page 27

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