2011 Human Power Vehicle Challenge Rolling Huskies

East Los Angeles College Student Design Report

2010 - 2011

Human Powered Vehicle Challenge 2011 2  Table  of  Contents  1.0  Abstract  ...................................................................................................................................................  3  

2.0  Design  ......................................................................................................................................................  3  

2.22  Chassis  Design  and  Material  Selection  ....................................................................................................  8  

2.23  Hardware  and  Fasteners  ......................................................................................................................  14  

2.24  Seat  Reference  Point  and  Bottom  Bracket  (Biomechanics)  ...................................................................  14  

2.25  Drive  Train,  Innovation,  and  Energy  Storage  Device  .............................................................................  16  

2.26  House  of  Quality  ..................................................................................................................................  18  

2.27  Robust  Design  ......................................................................................................................................  20  

3.1  Rollover  Protection  System  (RPS)  FEA  ....................................................................................................  21  

3.2  Vehicle  Fairing  and  Fluid  Flow  Analysis  ..................................................................................................  23  

4.0  Material  Testing  .....................................................................................................................................  24  

Appendix:  Cost  Analysis……………………………………………………………………………………………………………………………..27  

References  ...................................................................................................................................................  28    

Human Powered Vehicle Challenge 2011 3  

1.0  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 part of the engineering mother club (EMC) at East Los Angeles College and the team is composed of 18 active ASME student members; Los Angeles College is part of the California Community Colleges System. Students at ELAC are encouraged to join the HPVC regardless of their academic level or major of study. Student members are introduced to the engineer design process and given the opportunity apply classroom knowledge, research, and hands on experience. The team overall goal for 2011 ASME HPVC is clear, achieve a top 10 finish. The purpose of this report is to explain the engineering design process of the Elander 2.0, East Los Angeles College Rolling Huskies human power vehicle (HPV). The Elander 2.0 is the second HPV built by East Los Angeles College (ELAC) students. The vehicle was designed with the lessons learned from the Elander 1, the first HPV built in 2010, which shares similar chassis design and front suspension design. Elander 1 provided 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 approach to the research, design and analysis of the drive train, brakes, wheels, suspension/ steering, chassis, roll over protection (RPS), stress FEA analysis and coefficient of drag using SolidWorks, manufacturing cost, biomechanics, tool/ hardware and innovation design.

2.0  Design  

Before the team could begin researching, designing, and building their 2011 HPV they set a clear goal with objectives that would guide them through the engineer design process, so the Rolling Huskies approach the 2011 ASME HPV challenge by first setting a clear understanding of their goals and objectives. Establishing the goal of ranking top 10 at the 2011 HPVC the team was able to created a list of objectives that will help them reach that goal. The goals and objectives are firm, but the methods to achieve these goals are flexible only when they strive to meet the stated overall direction of the Rolling Huskies. 2.1 Goal and Objectives: The team’s goal is to place within the top ten at the HPVC 2011. Objective 1: Speed: vehicle will have the best combination of gear ratio to achieve a fast take off from 0 MPH, acceleration to pass other vehicles, and achieve a minimum cruise speed of 25 mph. Objective 2: Steering: the steering system will allow the vehicle to turn in less than 8-10ft and allow the vehicle to steer straight for 100ft. The systems will also incorporate the attachment for the breaking system. Objective 3: Suspension: the suspension system suspends the vehicle and rider weight at a ride height high enough to meet the requirement to participate in the unrestricted class and to overcome the obstacles in the utility event. Objective 4: Roll over protection: the vehicle RPS will be fabricating using the lightest material possible, clear the tallest rider’s head, the widest rider’s shoulder, and withstand a 600lb top load (with less than 2 inch of elastic deformation and not come in contact with the rider) and 300lb side load (with less than 1.5 inch of elastic deformation and not come in contact with the rider); in addition, neither the RPS or frame attachment points should experience any permanent structural damage or delamination.

Human Powered Vehicle Challenge 2011 4  Objective 5: Report: The report will have a maximum of 30 pages including stress analysis, formula calculations, figures and necessary supporting information and references. Also, the report will follow the outline structure described in ASME rules book and judges criteria form. Objective 6: Fairing: the vehicle fairing will provide a location to place a team name ASME and sponsorship logo while reducing drag coefficient, and protect the rider from debris and weather elements. Objective 7: Braking: the vehicle will come to a complete stop within 2-5 ft. after reaching minimum speed of 15MPH.

2.2 Design Features

2.21 Suspension and Steering Objective

To research and experiment with various steering & suspension systems and to find the optimal features that will be incorporated into the new vehicle. With the experience gain from the previous year HPVC and new research conducted in 2011 the team will design and select an alternative suspension and steering system. Design Goals

• Vehicle must be able to drive in a straight heading for a minimum of 100 ft. • Vehicle must be able to turn within a maximum radius of 8-10 feet. • Provide attachments points for steering components. • Provide vehicle clearance while riding over speed bumps. • Provide minimum rolling resistance in every direction. • Provide damping control over bumps and uneven terrain. • Provide the correct turn radius according to Ackermann Geometry. • Suspend the vehicle while supporting the driver weight.

Meet minimum height requirements to clear speed bumps. Suspension Design

Research was done on different suspensions found on cars, trucks, and bicycles. Through this research the team was able to compare advantages and disadvantages of various suspension types. The suspensions researched include the unequal/ equal length double a-arm, McPherson strut, trailing link, and beam axle suspensions. Understanding the different suspension and objectives, the team was able critique and analysis various suspension combinations and ranks them according to how well they met the overall team goal.

A morphological chart, was created with the function placed on rows and the means placed on the column providing the team a view of the different suspension combinations (figure 1). In the grading system various constraints were taken into account that would limit the team in designing and building an effective suspension system. Every suspension was rated on a scale from 1 to 5 with 1 being the least and 5 being the highest score possible. Each suspension design was ranked according to how well they met the overall team goals and objectives. The ranking of different suspension provided the team with an unbiased selection process.

The beam axle is a very durable and rigid type of suspension with minimal components, which is great for minimal maintenance (Adams 38). Another advantage of the solid beam axle suspension is that the camber is preset so no matter what terrain the driver encounters the camber angle will not be affected (Adams 38). A trailing link was the system that best fit a single wheel in the rear end. The

Human Powered Vehicle Challenge 2011 5  trailing link has its disadvantages such as bending while encountering hard cornering. To over come these defects we must reinforce the mounting point on the frame for minimal movement of the trailing link. Although there are minor disadvantages we found the most beneficial of having a trailing link is there is greater comfort for the driver of the vehicle (Adams 40).

Table 1: Morphological charts showing the functions and means for every suspension setup.

Figure 1: Solid Beam Axle

Table 2: Suspension Concept Selection Grading Chart. Selection Constraints Cost: Due to our budget, cost was a factor in deciding what parts we are able to purchase for our suspension so it played a significant role in our selection process. Durability: The durability of the design is taking into consideration a low level maintenance requirement and rider safety. Tool Availability: The tools available create a limit to the type of in house manufacturing the team is capable of performing; in addition, the type of materials the team can work with is based on the tools service quality. Portability: The vehicle suspension must allow the vehicle to be transported in vehicles and pass through facility entrance and exits pathways. Knowledge: The limited knowledge of using certain tools, working with composites, and various metals played a factor when selecting the complexity of vehicle suspension design. Skills: Not all members have adequate skills to use power/ air tools and build a complex suspension system. Time: Testing the vehicle and using campus facilities and equipment was limited to department hours, so team members had to worked within a strict work schedule.

Human Powered Vehicle Challenge 2011 6  Complexity: A suspension design with minimal components requires a smaller inventory of replacement parts and tools. Camber: Most sports cars have between 4 to 6 degrees negative camber to ensure better handling while cornering at high speeds (Hammill, 58), so the team selected 5 degrees fixed static negative camber for a wider track width and handling during cornering. Steering Design

Research was done on various types of steering system found in both trucks and cars. The most widely used steering systems used are rack and pinion, and pitman arm steering. These two types have multiple sub designs such as worm and sector as well as cam and lever. These variations are stable but heavy for use on a human powered vehicle. The turn ratio is affected by the system used for steering, and each design has its advantages and disadvantages. Our toe angle will be adjustable due to the competition needs. Since we will be competing in the drag as well as endurance events we will need to adjust our toe so we can have zero degrees toe on our drag race. Zero degree toe allows the vehicle to move strait ahead without causing any resistance while driving strait ahead. During the Endurance event we will need to adjust our wheels with toe in for strait line stability (Puhn 75). An Ackermann angle formula was used to find the single chosen corner radius (Staniforth 65).

 Figure 2. Comparison of front wheels with negative and zero toe

  Figure 4: Wheel with no scrub radius

Figure 3: Hub-to-Hub Wheelbase The effect of scrub radius is to provide a turning moment, which attempts to turn the wheel away from the central position when the vehicle is in motion. The amount of scrub affects the twisting forces exerted on the steering, so less or zero scrub radius will eliminate the effecting forces. Vehicles with zero scrub radiuses will not need power steering. Camber and knuckle design are key features in determining the scrub radius, if both are kept to a minimum or zero, handling, control, and steering can be improved (Adams 46). Elander 2.0 will have zero scrub radius because the king pin inclination will intersect at the center of the contact patch from the tire and the road. See figure 8.

Human Powered Vehicle Challenge 2011 7  

The ride height will be 4 inches from ground level because A.S.M.E. regulations require that the vehicle must have 2.5 inches of ground clearance. The extra 1.5 inches will be added as a safety of factor. The center of gravity (CG) changes depending on the roll center (rider height) of the vehicle, the Elander 2.0 vehicle have 4 inches of ground clearance, which translates to 4 inches roll center height. The distance between the roll center (RC) and center of gravity correlates with the roll angle, the smaller the distance between CG and RC reduces the roll angle. Roll angle causes the tire to lose contact patch traction, because the tire moves from an optimum position at a perpendicular position from the ground to a slightly tilt from the road causing a smaller contact patch with the surface of the ground (Adams 33).

Figure 5: Vehicle ride height with 4 in. of ground clearance. “The roll center height is a useful concept because it defines the moment arm - the distance from roll center to center of gravity - acting to overturn the car.” (Dixon, Tyres, Suspension and Handling). The roll center for the new design will be 4 inches from the ground because the ride height will cross the centerline, which is the chassis. A tire has its maximum traction when it rolls perpendicular to the road surface; a smaller roll angle will result in smaller positive camber, “so car will corner faster if the roll angle is kept small” (Adams). “Reducing the distance between the roll center height and the center of gravity height will reduce the roll angle” (Adams 51).

 Table 3: Morphological Chart of Steering Functions and Means. Steering Systems Selection Various combinations of steering components using a morphological chart determined the steering selection of our steering system. The two main types of steering were rack and pinion steering and pitman arm steering, which could be used with various combinations. Some constraints limit the team to some variations of the steering, which were taken into account when selecting between pitman arm and rack and pinion. After using the morphological chart the selections were graded using a 1-5 scale with 5 being the greatest value to complete the selection. The constraints that limited us to our design were the same as those for the suspension selection.

Human Powered Vehicle Challenge 2011 8  

 Table 4 Steering Concept Selection Grading Chart

After viewing our constraints and various steering system combinations, a grading chart

prioritized according to the teams overall objectives and goals was created. The team decided to select pitman arm steering with dual hand controls. Dual hand controls will add to the overall aesthetics of the new vehicle, while also removing the obstructed over seat steering from the 2010 vehicle that larger riders had interference with when their knees came in contact with the handle bars. The wheelbase of the new vehicle will be shorter than the 2010 HPVC vehicle, to minimize flexing forces in the chassis as well as tighten up our turn radius.

Figure 6: Above the seat steering.

2.22  Chassis  Design  and  Material  Selection   Objective: To research the different materials that can be used to construct a vehicle chassis. Research should include but not be limited to types of metals, manufacturing cost, chassis durability, ability to repair the chassis, and portability of chassis. The selection of each component should be done in a nonbiased method and with the overall team goals and objectives in mind.

Completing the 2009-2010 HPV challenge, the team discussed how they could improve the vehicle performance. The team had the option of designing a completely new vehicle or designing a new vehicle with similar dimension to the existing vehicle and while taking alternative designs to components or designs that failed to perform during the 2010 HPVC. The team meeting discussed the benefits of building a new vehicle without taking into consideration the current vehicle (Elander 1), but time and resources the new vehicle would require both time and financially was not an option the team had. If the team decided to improve the functionality of the current vehicle, then the materials and cost could be minimize; in addition, the team would have an existing vehicle to test, and make improvements on. Deciding to keep the same vehicle design, the team could focus their attention to making improvements to the structure rigidity, wheel length, track width, RPS, and crank bottom bracket. Because the team overall goal is to place top ten, Elander 1 prove to be functional vehicle that could help the team reach their goal. Instead of designing a new vehicle the team would focus their research in the current vehicle chassis and look at ways it could improve on it.

Human Powered Vehicle Challenge 2011 9  Selection of Vehicle Chassis Design

The chassis team completed a morphological chart with three different chassis configurations

to include backbone, monocoque, and ladder frame. The morphological charts allowed the team to create a single set of functions and means and piece them to each individual chassis design creating a list of multiple vehicle configurations. The chassis design of monocoque provides the stiffest chassis according to Fred Puhn How to Make Your Car Handle, but the construction of a one-piece enclosed vehicle requires both equipment and skills the team does not posses. Also, the ladder frame and backbone chassis offer both the best design in simplicity and manufacturing skills, but the ladder frame offers poor torsion stiffness when compared to a backbone (Adams, 92).

Table 5: Rolling Huskies team discussion on weather to improve the existing vehicle design or create a completely new design.

Table 6. Sample of the Morphological Chart listing the functions and means for the Backbone chassis design. Ranking Goals Using A Pair wise Chart

A Pair wise chart illustrating the goals set by the chassis team, which is considered the client.

The chart is read by matching a column to a row; for instance, the Portability row is matched with the

Human Powered Vehicle Challenge 2011 10  column of Durability and ranked according to what the team has established as part of their team goals and objectives. Giving the chart simplicity, a score of 1 or 0 is used for ranking. In the case with the Portability row and Durability column the zero ranking indicates Durability is considered having a higher value then Portability; likewise, if Portability had been considered a greater value a 1 would have been placed instead of a 0. The process of ranking is continued until each cell has a ranking. The last column shows the total score for each row and according the Pairwise chart both Durability and Cost is considered to have the greatest value. Convenience scored a 0, for a 0 only means it ranked the least important; nerveless, it’s still considered important or else it wouldn’t have made it to the chart (Dym, Little and Elizabeth 61). Selection Constraints In order for the chassis team to have a good understanding of what they where responsible for they created a list of goals that would help them through the decision making process. Cost: The vehicle will be manufactured with the minimal expense in mind. Materials purchased will be appropriated and consumed in a method that provides the least waste. Durability: The selection of components and materials will include a robust designed to prevent the likelihood of experiencing vehicle down time due to faulty or low quality design, parts, or marksmanship. Repairable: Exotic materials or components that carry a high value or waiting period for delivery should be reconsidered. A more practical approach will be the selection of components that are accessible through local distributors. Furthermore, vehicle design should take into consideration the flexibility of repairs during breakdown outside a shop environment. Manufacturing Process: The vehicle manufacturing process is limited to basic hand/ power tools, for the team tools consist of one drill bench, band saw, simple ratchet/ wrench set, and various hand saws, chisels, and screw drivers, so the design of the chassis needs to be robust but at the same time simple enough to disassemble and repair/ replace. The team access to a metal active gas (MIG) welder through the automotive department requires an advance notice before the team can access that equipment or facility. Portability: The vehicle should lend itself when being transported to different locations. Research should be place on the location the vehicle will be stored, carried, and used. Convenience: When the decision of selecting two or more chassis components or between two different materials, the team should consider what is most convenient for the team considering cost, durability, repairable, manufacturing process, and portability.

Table 7: Ranking team goals using Pairwise Chart (Clive L. Dym, Engineering Design A Project-Based Introduction). Selection of Chassis Material and Research

Human Powered Vehicle Challenge 2011 11   A modified version of the Pairwise Chart was used in Fig. 12 for the selection of the chassis material. The ranking was set for 5 different metals and raked in the same manner they where ranked in Fig. 11. The metal was placed in the rows and goals placed in the columns. A 0 or 1 ranked each metal, so 0 indicates the metal does not meet the sub-team goal and a 1 indicates the metal meets the sub-team goal. The team first conducted research of each metal to get a better understanding of the metal properties, corrosion resistance, and weld ability. Tabulating the score on the last column the team discovered aluminum to be the preferred metal alloy for the construction of the vehicle chassis. Aluminum

According to Metals and How to Weld Them by T.B. Jefferson 6061 aluminum alloy is the most widely used for its high tensile strengths and workability. 6061 alloy is most widely used in architecture, furniture, and automotive applications, for it has a high tensile strength even after losing up to 1/3 of its strength in the heat affected zone when welding (Jefferson 70). Magnesium

Magnesium is a metal alloy similar to aluminum in color with a density 2/3 of aluminum and ¼ of steel, which makes it the lightest metal available to the commercial public (Jefferson 71). Also, magnesium is a relatively soft metal unless it is mixed with other alloys such as aluminum and zinc; furthermore, magnesium can be welded in similar manners as aluminum but it cannot be welded to different metals because of its brittle inner-metallic properties; in addition, when welding magnesium to another piece of magnesium it must be of the same properties or else corrosion can develop in the welded area (Jefferson 71). Titanium

Titanium weight is about half of steel and it’s high corrosion resistance make it an ideal metal in marine and chemical processing environments; in addition, titanium is also used in aviation and engine components (Jefferson 348). Titanium when mixed with other alloy like aluminum, chromium, manganese, or zirconium can change its properties giving it a high strength to weight ratio and resistance to corrosion at temperatures above 800; in addition, when welded correctly, titanium can have high tensile strengths reaching as high as 200 psi (Jefferson 348). Welding titanium requires great skill as the preferred method is Tungsten Inert Gas (TIG); furthermore, titanium must be kept protected with shielding with an inert gas until it cools down below 800 F while at the same time back-up bars (bars used beneath the weld providing a supply of inert gas) must be used, and welds should be started and stopped with an amperage-varying control unit to prevent burn through when starting a weld and provide continuous flow of inert gas after welding (Jefferson 351). Molybdenum

Molybdenum alloy has better high temperature strengths above 1700 F than any other non-alloy metal; also, molybdenum can be welding using a TIG, metal inert gas (MIG), or arc welding but not as reliable as TIG or MIG (Jefferson 358). Alloys with properties better than regular carbon steel are sometimes pieced at a higher price but their higher tensile strength and ability to use less material to achieve the same properties of other non alloy steels sometimes have a lower cost (Jefferson 55). Rolled Carbon Steel

Rolled carbon steel also referred to mild steel is the simplest steel to weld, for no special tools or techniques is required besides basic welding equipment and technique; for example, rolled steel can be welded by the method of TIG, MIG, arc welding, or brazing (Jefferson 49). Low carbon steels have good ductility, are easy to machine, formed and some can be easily heat treated (Jefferson 51).

Human Powered Vehicle Challenge 2011 12  

Table 8: Pair wise Chart with different metal alloys As a result of our selection process, Aluminum 6061 was chosen as the vehicle’s material as indicated in fig. 14 (Aluminum scored 6 points). Even so, the team further conducted a more detailed selection process for the size and shape of aluminum tubing to choose. After testing different tubing using 3-point tests and conducting SolidWorks Finite Element Analysis, a point system was devised to rank tubing performance from a set of functions:

Stress Strength: In order to decide, the tube must be able to pass two important tests. These are similar to the ASME HPVC RPS requirements. In this case, the tube must have a deformation of less than 2 inches when a load of 300 lbs is applied from the top. Available tubes that had a stress values lower than their stress yields were the only ones considered. Also in consideration is shear stress, which causes fishtailing when turning. The stress function awards from 5 points for the tubes with the lowest stress experience to 1 point to the tubes whose stress values neared their stress yields.

Cross-Sectional Area: Deflection is the amount the tube bends when a force is applied. The same conditions as the stress function are considered, except it also considers the cross-sectional area. Increasing cross-sectional area decreases deflection, which is a property of the available tubes that can be scored. The scoring is 1 to 5, from smallest cross-sectional area to highest cross-sectional area. Weight and Wall Thickness: One of the team’s goals is to build a vehicle that weighs less than the previous 2010 vehicle. Since the biggest contributor of the vehicle’s weight was its steel tubing (especially from the chassis, which is the largest component). The common materials available for bicycle tubing are 10xx steel, aluminum, chromoly steel, composite, and titanium (D. G. Wilson, Bicycling Science 379-380).

Another factor for tubing is the wall thickness, since thicker tubes increase the weight of the vehicle. The problem is finding out which wall thickness is capable of handling the load and at what point does the thickness becomes excessive. In the 3 point stress test deflection formula, ! = !"!

!"!"

(where P is the force and L is the length) the second moment of inertia contains the variables that determine the shape of the tubes, such as diameter (D) and thickness (t). Setting all the variables except for thickness as constants makes deflection a function of t (with a domain of 0 <t<D/2 because D/2 would make the tube into a rod) shows the graph pictured in Figure 1. Around the -1 slope region is where the thickness would deflect as little as solid rod would. Solving for !!

!! = -1 provides the optimal thickness, which was used to

determine whether if the tube excessively thick or too thin. Tubes whose thickness matched the optimal thickness were awarded 5 points, 4-1 points if tubes became excessively thick, and 0 points for tubes that are too thin.

Figure 7: δ vs. t graph showing where δ begins to settle at approximately t = 0.2.

Human Powered Vehicle Challenge 2011 13  Welding and Costs: Other factors included cost and weldability. Prior to individually scoring the available tubes, cost eliminated the options chromoly, composite, and titanium due to the team’s budget. 5 points were awarded to the cheapest material, 1 point for the more expensive materials. Weldability was also a factor, especially if aluminum is chosen. Extra precaution must be taken when welding thin aluminum tubes because it can affect the tensile strength of tube. Welding points are awarded from 1-5, taking into consideration of welding ease and the effects of welding on the material.

Function Ranking and Selections per Component Each component ranked the functions to suit specific needs. The needs of the chassis are different from the needs of the suspension. For instance, the suspension should not rank weight as high as chassis since it is a less massive component. The chassis and suspension sub-teams ranked the following functions as shown in Figure 3. The top three tubes were considered and were chosen based on the ability to attach the components together. The tubes chosen have the cells highlighted in green in Figure 4. The aluminum material is AISI 6061-T6 and 1020 steel was also evaluated.

Table 9: Function rankings by component Function Chassis Suspension Stress 33% 33% Weight 26% 14% Cost 6% 14% Difference in optimal thickness

8% 0%

Weldability 20% 14% Cross Sectional Area 7% 25%

Table 10: Top 3 tubes for chassis and suspension Rank Chassis Suspension First Al 1.5"×1.5", 0.188" (3.80) Al 2" Dia., 0.125" (3.67) Second Al 1.5"×2", 0.125" (3.74) Al 3"×3", 0.188" (3.52) Third Al 2"×2", 0.125" (3.74) Al 3"×3", 0.125" (3.74)

Material x×y (for rectangular) or diameter, wall thickness and (points)

Tube Selection for RPS The tube selection for the rollover protection system is a 1.25” diameter circular aluminum tubing with wall thickness of 0.125”. The deflection on a three point test would be 0.767” at 600 lbs. with a bar length of 24”. This deflection is less than the ASME RPS limit of 2”. The reason why this tube was chosen instead that of the tubing highlighted in the above tabel was because the tube bender available can only bend tubes of diameter 1.25” maximum. The RPS design requires the tubes to be bent and since the 1.25” diameter tube passes the ASME HPVC RPS requirements, then this tube was chose under the needs of the RPS design. It was quickly identified that because the team is to use a smaller diameter tube, the current RPS design must be reinforced with additional members to provide a greater factor of safety.

Human Powered Vehicle Challenge 2011 14  

2.23  Hardware  and  Fasteners   Objective To have a better understanding of the tools and hardware commonly found on bicycles. Knowing which tools are used to perform maintenance on bicycle, the team can limit the inventory of tools while performing maintenance and repairs on their HPV. Also, limiting the number of tools necessary to work on the vehicle will directly result in controlled inventory of hardware. Elander 1 was built using both standard and metric hardware almost doubling the amount of tools the team needed to keep in inventory and transport when performing field-testing, maintenance, and repairs. Research of Bolts, Washers, and Grade Selection

Bicycles may seem simple to understand and use, but it consists of different methods and requirements when building or fixing them. Fasteners are “complex mechanically-engineered hardware” (Potter). Luckily, most bicycles contain the same fasteners and same tools will be used when building them. Most of the fasteners that are used on a bike are metric but there may be instances when standard fasteners are used. Socket head cap screws, machine screws, nuts and washers of different sizes are used as bike components.

Standard socket head cap screws of grades 8 and 7 are mainly used in a bike because the higher the grade the stronger its force. According to David. M Potter’s calculations, a 0.250-inch diameter of grade 8 socket head cap screw gives a shear capability of 4468 lbs; yet a grade 5 gives a shear capability of 3683 lbs. Overall, screws hold items stronger than nails. Acorn nuts cover exposed threads, M16, will also be used to hold the fasteners and components together. Metric washers, sizes 2mm-4.9mm will be a good choice of fasteners for thick screws or bolts. Allen keys are mainly used to unattached most of the fasteners that are being used in the bicycle.

Bicycle hardware is important to understand, so the team can carry the right tools necessary to repair the HPV while at the same time not reducing or preventing the purchase of tools that are not required. The research of tools, screws, and bolts used on road, mountain, and cross cycle bikes continues to be an ongoing research.

2.24  Seat  Reference  Point  and  Bottom  Bracket  (Biomechanics)   Objective To research the position of the HPV bottom bracket and seat reference point while taking into consideration of the medium of the tallest and shortest rider height measured from the heel of the feet to the hip. Seat Reference Point (SRP) and Bottom Bracket (BB) When determining the desired functionality and purpose of the vehicle, the designing of the seat position is crucial. The team gathered the height of every member by measuring his or her height from the heel to their hip as described by David Wilson in Bicycling Science Third Edition the performance of a cyclist will increase by 7 percent when the saddle height is position 40-50 mm above the riders height; in addition, when the saddle is not adjusted correctly the rider can experience up to an 80% reduction in performance (Wilson, 88). Table 11 shows the measurements of each team member’s height. In addition, the height from the shortest and tallest riders was used to calculate the medium height to generate distance from the seat reference point (SRP) to the bottom bracket (BB). Bicycle Science states that the SRP and BB angle can be determined by establishing a linear line between the SRP and BB. The seat is then tilted backwards enough to create a 15˚

Human Powered Vehicle Challenge 2011 15  difference. For instance, a rider was seated on a road bike with the saddle height adjusted 45 mm. above his height (heel of foot to hip) and a full 360˚ revolution of the crank was completed measuring the degrees rider’s knee bent. The same test was conducted on a total of three different bikes ranging from upright seating position to semi recumbent seating position. The 15 degrees were subtracted from the average 45˚ and the final result was an angle of 30˚. Calculating the SRP and BB was accomplished through the application of trigonometric functions and a special right triangle.

Table 11: Measurement of riders height from heel to hip

Figure 8: Special right triangle used to calculate seat reference poin the bottom bracket.(cm)

Figure 9: The medium of the shortest and tallest rider was used to calculate shortest, midpoint, and furthest position of the BB in relation to the SRP (measurements in cm). If the SRP is kept at a fixed point, and the BB adjustable following the linear path created between the two points the SRP angle of 30˚ will remain constant; whereas, BB being a fixed point and the SRP becoming adjustable will cause the SRP angle to very, for the linear line created with the SRP and BB will not remain constant. Having a fixed SRP and an angle of 30˚ provides the greatest power according to Bicycle Science; therefore, the team has opted to have a fixed SRP and an adjustable BB that moves while maintain a constant SRP angle of 30˚.

Human Powered Vehicle Challenge 2011 16  

2.25  Drive  Train,  Innovation,  and  Energy  Storage  Device  Objective

The vehicle will have the best combination of gear ratio to achieve a fast take off from 0 mph, acceleration to pass other vehicles, and achieve a minimum cruise speed of 25 mph (11.2 m/s) Drive Train Selections

Goal Drive Vehicle

Save Energy

Racing

Sustain Heavy Loads

Uphill Climbing

Total

Drive Vehicle ----- 1 1 1 1 4 Save Energy 0 ----- 0 0 0 0

Racing 0 1 ----- 1 1 3 Sustain

heavy load 0 1 0 ----- 1

2 Uphill

Climbing 0 1 0 1 ----- 2

Table 12: A Pair Wise chart is created to display various goals considered and to prioritize the functions of a drive train.

Table 12 shows that the most important function of a drive train is to drive the vehicle. The next objective of having a drive train is to race in competitions, namely drag races, which requires high level of acceleration as well as maintainable top speed. An innovative flywheel and clutch system was also studied to help the vehicle increase its speed. This system will be described in a later section.

Function Means Drive Type chain Shaft Direct Belt Power Type crank Ratchet Pull Rims spoke Solid Gears sprockets Table 13: Morphological Chart for Drive Train Component Selection

After completing the morph chart, the following combination of means was found to be the best

suited: a chain drive, crank, sprockets and a spoke rim. The reasons are that this combination is widely available, easy to maintain, and is affordable. Gear Ratio and Speed

Through experiments an average cruising cadence was found to be 1 rev/ second, which

translates to 60rpmCrank. Utilizing this fact a formula can be derived to calculate the vehicle speed as function of crank rpm and each gear ratio (Wilson 99) (Serway): Mphvehicle = ((rpmCrank/Gear Ratio)*Circumference Tire*60min)/63360Inches/mile Using this formula a chart and graph were generated:

Human Powered Vehicle Challenge 2011 17  

 Figure 10: Speed vs. Crank Rpm Table 14: Speed vs. Crank rpm data

Table 15: Vehicle speed Vs. RPM Data

Figure 11: Another graph was generated using the same formula, this time fixing the value of the 8th gear. From this graph the vehicle speed can be determined from the crank rpm. An ideal maximum speed of 25 would therefore take 88.5 crank revolutions per minute (RPM). The FlyClutch system (innovative energy storage device) Functions

• To reduce lag in start of a race due to weigh and strength of the HPV rider. • To increase accelerations when the HPV is coming out of a turn. • To relieve physical strains while cruising with the HPV.

At the start of the race, there is an initial lag due to the overcoming of friction. Therefore on regular bicycles the effort required to initiate pedaling is larger than once the bicycle is in motion. The purpose of the flywheel is to alleviate this larger effort. The flywheel operates in the following manner: before the start of the race the rider will disengage the clutch and begin pedaling which will rotate the flywheel. This will store moments of inertia. At green light the rider will continue to pedal while engaging the clutch, this will accelerate the vehicle at a higher rate than without the FlyClutch system. Using the same procedure the rider can accelerate out of a turn at a faster rate than without the system. Also the extra weight and rotational forces will provide a smoother cruise at long distance. Under 2011 ASME HPVC general rules and competition paragraph d, it states that no energy storage is permitted prior to each event and that energy storage must be generated while the vehicle is in motion; therefore, the use of the FlyClutch will be limited to use after the utility endurance has started.

Human Powered Vehicle Challenge 2011 18   The FlyClutch system consists of a one way gear on the flywheel that allows the flywheel to spin freely when the rider stops pedaling. The clutch basket will be attached to the flywheel and the clutch hub will be connected to the driveshaft. The driveshaft is connected directly to the rear wheel with a chain. A push rod and a separator will mediate between the two systems. It disengages the clutch when the clutch lever that is mounted on the handle bar is pulled. This system is designed to be a stand-alone component. It can be attached to any HPV that has room to accommodate it. The only requirement is it must be aligned with the rear wheel either above or in front of it. In case of system failure, removal of the entire system will allow the rest of the vehicle to function normally without the extra weight. All that is required is removal of the clutch lever from the handlebar as well as replacement of the drive chain.

Table 16:FlyClutch morphological chart Figure 12: Conceptual design

2.26  House  of  Quality     Objective The House of Quality is designed to convert abstract concepts into technical requirements. Before the team creates any abstract concepts, the team had to keep their objectives in mind for the design of the vehicle fairing. The vehicle fairing will provide a location to place a team name ASME and sponsorship logo while reducing drag coefficient and protecting the rider from rain and debris. Based on the team objectives, the team asked the questions and ranked them by their importance The importance of the ranks will come into play after creating the actual fairing, for it will be used to see if the team meets the requirements created at the beginning of the project.

Table 17: Customer Questions Table 18: Questions to Technical

Human Powered Vehicle Challenge 2011 19  

The next step on the House of Quality is to convert the questions into technical needs. To do so, the team had a meeting to create the technical needs to the corresponding questions in Table 18.

Based on the scoring system in the book Project Management for business, engineering, and technology: principles and practice, the team had a meeting to create how each technical needs and questions relate to each other according our survey legend (Table 19) If the relationship is strong, then the corresponding score will be matched with “O”. If the relationship has somewhat of a relationship, then the score will be “X”. If the relationship is weak, then the score is “:::”. Lastly, when there is no relationship between the question and the technical need, then the area will be left blank (Fig 5). The line that is cutting across the graph represents the cancellation of the strong relationship because the technical need originates from the corresponding questions.

Table 19: Question-to-Technical Relationship          Table 20: Survey Legend   Raw Score & Technical Ranking

Each symbol in the relationship represents a value of 1 (Weak relationship), 3, and 9 (Strong relationship). By accumulating all the points, the team can judge which technical need requires more attention and priority by ranking the points from highest to lowest (Table 21). A repeated score will have repeated ranks.

Table 21: Raw Score and Technical Ranking

Correlation Matrix – Technical-to-Technical

The Correlation Matrix (Located above the House of Quality) shows how each technical need affect each other. By using the legend that the team created, the team created a chart (table 22) showing the technical relationships.

Table 22: Correlation Matrix

Human Powered Vehicle Challenge 2011 20  

Technical Requirement Target

In this phase, the team created concrete numbers to use for creating the fairing. The first step was to create a lower specific limit (LSL) and an upper specific limit (USL). By creating a LSL and a USL, the team had a range to work within. Keeping with the technical ranking and the Correlation Matrix in mind, the team was able to create a technical target requirement which help gave an actual value for creating the fairing. (Fig 9)

*Calculation was too complex due to missing data. The actual fairing is required to finish calculation for air displacement

2.27  Robust  Design  Objective

The vehicle fairing will provide a location to place a team name ASME and sponsorship logo while reducing drag coefficient and protecting the rider from rain and debris.

Based on the team objective, the implementation of robustness design to the vehicle was done by adding a fairing, which helps by minimizing environmental variables (I.E. Drag, protections from the weather elements and debris) that could affect the vehicle or riders performance.

Applying the design and Manufacturing Method For the fairing, the design team used an organizer known as the House of Quality. The House of Quality helped the team with creating a design range to work with. Once the first draft is completed, the House of Quality is discussed with the manufacturing sub-teams to help validate whether the design can be created or not. If it cannot be created, the manufacturing team discusses what changed need to be made with the fairing design team. The process is repeated until no further changes are needed.

The team also used the parallel design and manufacturing method for the fairing of our vehicle. The design team had to find out the coefficient of drag, envelope space, and selection of material. To find coefficient of drag, the design team used SolidWorks to create multiple shapes and test how each are affected by airflow. The data is then collected with 0.2 being lowest drag and 1.2 being the

*  

Table 23: Results  

Human Powered Vehicle Challenge 2011 21  highest drag values. Using the House of Quality, the manufacturing team calculated that it is possible to create a fairing with a drag of 0.2. For envelope space, the design team had to use ergonomics by calculating the average height and width of our team member and using our data from our previous vehicle. With the data accumulated, our design team created a lowest possible length of 78 inches and a highest possible length of 96 inches. With the House of Quality, the manufacturing team calculated that the fairing should be 84 inches by length. With Selection of Material, we had a choice between carbon fiber to aluminum. Based on our cost analysis from manufacturing, the team decided upon fiber glass which was light enough to ride comfortably and strong enough to withstand some impact. 3.0 Material Analysis

3.1  Rollover  Protection  System  (RPS)  FEA     The rollover protection system was designed using aluminum 6061-T6 alloy tubing, weighing a total of 7.5 lbs. To protect riders from injury during a rollover accident, a roll over bar (RPS) that meets the safety specifications set forth by ASME will be implemented into the vehicle. The roll bar must be high enough to clear the tallest rider’s helmet (at least 39” in height) and strong enough to endure a 300 lb. side load, a 600 lb. top load directed 12° from vertical, and rigid enough to deflect no more than 2” in any direction (ASME). Protecting the rider’s sides, the roll bar also has to be constructed beyond the rider’s widest point at the shoulders (in our case the widest rider is 20” wide at the shoulders). The side and top load cases are presumably set by ASME in order to simulate:

1) a complete rolling accident situation (600 lb.) and

2) an impact with the floor during a side fall or a possible collision with another vehicle (300lbs)

In conjunction with the 3-point flexural testing of materials and hand calculations, Finite Element Analysis (FEA) SolidWorks simulation was performed to determine the performance of proposed RPS designs given the rollover conditions. To achieve a more accurate and complete study of the RPS design in terms of stress and deformations, FEA analysis was primarily used to make an RPS design choice. An ideal RPS design was put into the software for analysis following the following criteria:

1) The simulated RPS design would not be re-enforced (without bracing) and would stand alone as pictured above

2) The only fixed points in the isolated system would be its bottom point (simulating the RPS welded only to the chassis bottom)

Human Powered Vehicle Challenge 2011 22  

The justifications behind these restrictions are that the team’s design process is on-going and so a final RPS design is in the works. The point of the simulation was to mainly test whether the selected aluminum tubing would perform accordingly to the requirements set fourth by ASME given a simplest level of RPS design. After that point, the team could move on to improving the preliminary design to increase the factor of safety by providing additional structural bracing supports in the final RPS design.

The final results from the Finite Element Analysis show a maximum deflection of 0.52 inches for the

300 lb. side load and maximum deflection of 0.62 inches for the 600 lb. case. The analysis also

showed a 2.3 factor of safety for the design and so it is projected to perform well in case of a vehicle

accident. In addition, FEA also provided demonstration that the stresses involved in both load cases

Figure 13: RPS 300 lb. side load deflection  

Figure 14: Deflection: A 600 lb. top load at 12˚ from vertical, simulating a complete rollover incident  

Human Powered Vehicle Challenge 2011 23  would not be enough to permanently deform the RPS aluminum frame and therefore causing

permanent damage to the vehicle during a collision.

Further reinforcing the design’s safety analysis, the 3-point flexural bending predictions on 1 ft.

length sections of aluminum tubing suggests a factor of safety of 3.6 in case a section of the RPS

tubing is impacted by an object in such a way that the situation mimics a 3-point flexural situation.

These results gave the team confidence that the material choice and basic RPS design would

perform accordingly to the requirements set fourth by ASME.

3.2  Vehicle  Fairing  and  Fluid  Flow  Analysis   This year, the team a new analysis technique to study the effects of different fairing designs on

the proposed vehicle. A fairing fluid flow simulation analysis aided in the fairing design selection and

in identifying which design would help the team meet the goal of achieving an average cruise speed

of 25 mph. A number of fairing designs were sketched and the most practical were analyzed using

SolidWorks fluid flow simulation analysis. The analysis mainly focused on exploring the software and

the design approach used in designing a fairing for a vehicle. An improvement from last year’s design

process (which did not include a fairing study), this year the team was able to come up with a few

designs, create a mold for a more realistic rendering, and test designs using computational fluid

dynamics (CFD) simulation. Thus the main goals for this analysis were as follows:

1) Use CFD to find the coefficient of drag of three different fairing designs

2) Judge which of the designs would be most able to help the team reach its speed goal

In the simulation, the air flow velocity was set to 30 mph at 20˚C and the coefficient of drag was

obtained from the software. The chart below shows the progression in fairing design. Each

successive design simulation showed improvements in the coefficient of drag. With a CD of 0.066,

the latest fairing design showed low back turbulence and maximum wind velocity throughout the

fairing; indicating that the fluid does not cause too much drag on the fairing.

Even so, team discussions about implementing the final fairing design on the vehicle are

ongoing. The biggest issue in these discussions is the duration of construction of the fairing design.

Facing Low familiarity and inexperience with composite material construction methods, the team

hopes to fully implement a complete fairing design for next year while partial designs for this year’s

competition are in the works.

Human Powered Vehicle Challenge 2011 24  

Fairing Description

Average Value of Coefficient of

Drag (CD)

Design

Fairing 1

Very Simple tube design. High drag, and high coefficient of drag

0.69

Fairing 2

Improved design with smooth front and

narrow back end with a top opening

0.28

Fairing 3

Modification of fairing #2, closed top

provided an excellent CD streamlined body

0.066

Table 24: Solidworks renderings of some fairing prototypes along with their coefficient of drag

4.0  Material  Testing  

Background – The Tubing of the 2010 Vehicle The 2010 East Los Angeles College Vehicle was fairly heavy. The Elander by itself weighed about

67 lbs., most of which came from the steel tubing. The reason why the 2010 team chose steel tubing was due to the high factor of safety that steel provides. For first time builders, the factor of safety should be high to insure that the product is less likely to fail (Beer, Mechanics of Materials 44). Because of steel’s high Young’s modulus, tensile yield, and shear modulus, the tubing provided a high factor of safety. The trade off was its high weight, which required more power from the driver to move the vehicle. Much of the 2010 team members were freshmen, so it was necessity to have a high factor of safety.

FLOW  

Human Powered Vehicle Challenge 2011 25   To understand the effects of a load force, a several candidate tubes for this year’s vehicle were experimentally tested. The test was a three point stress test of rectangular steel tubes and circular steel tubes. The manual three point stress test machine applied a force on the center of the tube and reported the amount of force until the tube went beyond the elastic region. The objectives of these physical tests were to first establish the validity of using the stress and deflection equations on other types of tubes not physically tested, and to also give the team so raw data to test whether or not AISI 1060 steel tubes of 1 ft in length would perform accordingly to ASME’s RPS deflection requirements. These tests also served to help aid the tube selection process by comparing both the 3-point test on SolidWorks FEA simulation and the actual physical test results.

Only selections of data points are shown in the table where the highest values of force correspond to the points were the tubes began showing permanent deformation (plastic region). Only the 1"×1½" tube produced sufficient data points to calculate young’s modulus (Eexp = 2×107 psi, compare to the theoretical value for AISI 1060 Steel of 2.97x107). None of the tubes bent more than 2” while the tubing was still in the elastic region of material strength.

Table 25: Raw data of the 3-point testing

0  10000  20000  30000  40000  50000  60000  70000  

0   0.002   0.004   0.006   0.008   0.01  

Stress,  psi  

Strain  

1"×1.5"  Steel  Stress-­‐Strain  Diagram  

y  =  2E+07x  -­‐  5332.1  R²  =  0.9527  

0  

10000  

20000  

30000  

40000  

5E-­‐05   0.00055  0.00105  0.00155  0.00205  0.00255  

Stress,  psi  

Strain  

1"×1.5"  Steel  Stress  -­‐Strain    (linear  portion)  

Tube Force (lbs)

Experimental Deflection δexp (in)

Stress σ (psi)

Strain ε

1"×1" 200 0.03 9033 0.00130 300 0.03 13549 0.00130 1100 0.09 49679 0.00357 1200 0.12 54195 0.00487 1"×1½" 200 0.01 1048 0.00049 300 0.01 1572 0.00049 1100 0.03 5762 0.00157 1200 0.03 6286 0.00167 2100 0.07 11001 0.00441 2200 0.09 11525 0.00588 1"diameter 100 0.05 13751 0.00087 200 0.08 27502 0.00145 300 0.11 41253 0.00203 400 0.19 55004 0.00347 ¾"diameter 100 0.09 19310 0.00149 200 0.30 38620 0.00498

Figure 15: Results of the experimental 3-point tests on various steel tubes

Human Powered Vehicle Challenge 2011 26  

Figure 16 the 3-point test setup of the 1”x1½” 1060 Steel tube. A ruler was placed at the middle of the bar to measure its vertical deflection.

The results of the testing showed that the smaller-dimension tubes deflected much quicker than that of the larger dimension. It became clear that if the stresses of a tube exceed the yield stress, then the tube should not be considered. Also, circular tubes must not have a small diameter (less than 1.5”). Both 1” and ¾" diameter circular tubes left the elastic region at around 300 lbs. The rectangular tube performed well, despite having a modulus of elasticity less than the literature value of 1020 steel of 2.97×107 psi (MatWeb). Additional confirmation

of these results came from the 3-point FEA simulation, which showed a reasonable correlation with the physical

test results.

RPS testing has not been conducted, although the test methods have been designed. The design previously mentioned has been manufactured and it will be tested to validate the FEA simulation results. These basic tests have already been identified:

1) Drop test: Drop the RPS from a certain height that produces a final velocity of about 30 mph, while loosely fastened to a guide wire in order to control the drop orientation. This test will simulate the impact resulting from a collision. Material fracture and tube bending performance will be analyzed.

2) Compression testing using the 3-point test machine: The whole RPS will be put under the loads specified by ASME to validate the FEA and 3-point tubing test results.

Collision Safety The vehicle will also contain a safety harness to complement the safety provided by the RPS. Without a safety belt, an RPS would do little to protect the rider from harm as they would be flown off the vehicle towards the environment in the event of a rollover incident. The design calls for using last year’s vehicle’s commercially available, SFI 16.1 safety approved, 4-point Sabelt safety harness. This harness is specifically designed for racing in vehicles and therefore provides ideal rider safety in event of an accident.

Figure 16 : 3-Point Testing Setup

Figure 17: 300lbs 3-point testing simulating a backbone the stresses on a backbone chassis design  

Human Powered Vehicle Challenge 2011 27  Appendix:  Cost  Analysis  

 

Human Powered Vehicle Challenge 2011 28  References  [1] ASME, 2011, “Rules for the 2011 Human Powered Vehicle Challenge,” New York [2] Adams, H., 1992, Chassis Engineering, Penguin Group, New York. [3] Hammill, D., 2008, The Sports Car and Kit Car suspension and Brad Brakes High-Performance [4] Puhn, F. 1981, How to Make Your Car Handle, Berkley Publishing Group, New York New. [5] Dixon, J.C., 1991, Suspension and Handling, Cambridge University Press. [6] Dym, C.L., Patrick, L., Elizabeth J. O., 2009, Engineering Design: A Project-Based Introduction, 3rd edition. Wiley, Hoboken, N.J: Wiley. [7] Jefferson, T.B., 1962, Metals and How to Weld Them, James F. Lincoln Arc Welding Foundation, Cleveland, OH. [8] Wilson, D. G. 2004 Bicycling Science Third Edition, MIT Press Cambridge, Mass, pp. 88 [9] “Grade 5 vs. Grade 8 Fasteners.” Rockcrwoler.com. rockcrowler, Potter, David M. n.d. [10] Serway, R. A. and John W. J., 2007, Physics for Scientist and Engineers 7th Edition. Volume 1 Thomson, Belmont. [11] Beer, F. P., 2009, Pure Bending Mechanics of Materials, New York [12] “MatWeb.” matweb.com matweb n.p. n.d. [ ] Aird, F., 2006, Fiberglass & Other Composite Materials: A Guide to High Performance Non-Metallic Materials for Race Cars, Street Rods, Body Shops, Boats, and Aircraft New York: HP Books, New York. [ ] Dietzsch, C., 2010, “Finding Your Front and Rear Roll Center,” OneDirt.com., 30 Sep. 2010., Web 8 Apr 2011. [] Dym, C. L., 2009, Engineering Design A Project-Base Introduction Third Edition, Wiley & Sons Inc. [] Dixon, J.C., 1991, Suspension Geometry and Computation, John Wiley and Sons Ltd. Manual, Veloce Publishing Ltd. [ ] Jazar, R.N. 2008, Vehicle Dynamics, Springer Science + Business, New York, New York Media, LLC. [ ] Kalapkjian, S., 2008, Manufacturing Process for Engineering Materials. Prentice Hall, Upper Saddle River, NJ. [ ] “McMaster-Carr.” mcmaster.com mcmaster n.p. n.d. [] Nicholas, J. M. and Herman, S., 2008, Project Management for Business, Engineers, and Technology: Principles and Practice, Elsevier Inc. [ ] “Robust Systems and Strategy.” robuststrategy.com robuststrategy n.p. n.d. [ ] Wanberg, J. 2009, Composite Materials: Fabrication Handbook, Wolfgang Stillwater, Minn [ ] “Wheels & Tires: Wheel alignment fundamentals.” cdxetextbook.com cdxetextbook n.p. n.d. [ ] Wysk, R.A., Niebel, B.W., Cohen, P.H., and Simpson, T.W., 2000, Manufacturing Process: Integrated Product and Process Design, McGraw Hill, New York.

 

Vehicle Description Form  

Human Powered Vehicle Challenge 2011                   (HPVC Form 6)

 East Event Host: Rose‐Hulman Institute of Technology, Indianapolis, IN.   Apr 29‐May 1, 2011 West Event Host: Montana State University, Bozeman, MT.  May 13‐15 

http://www.asme.org/hpv 

***    This is a required document for all teams.  Please incorporate it into your Design Report   *** 

***                

 Please Observe Your Due Dates 

Vehicle Description 

Competition Location:      

School name:                   

Vehicle name:                  

Vehicle number     

 

Vehicle type      Unrestricted    Speed_______ 

   

Vehicle configuration 

    Upright      Semi‐recumbent       

    Prone      Other (specify)        

  Frame material                

  Fairing material(s)               

  Number of wheels     

  Vehicle Dimensions (please use inches, pounds) 

      Length      Width     

      Height        Wheelbase    

  Weight Distribution  Front      Rear      Total     

  Wheel Size  Front      Rear     

  Frontal area     

  Steering  Front      Rear     

  Braking    Front      Rear      Both     

  Estimated Cd      

Vehicle history (e.g., has it competed before?  where?  when?)________________________    

   

   

   

   

EAST March 28, 2011

WEST April 11, 2011