G K t Engineering Go-Kart E i i P Project j t {Team off 13 students {Electric, Plug in, Go-Kart Project {Team deadline for completed project: March 31,2010 O Overview i {Objectives {The Team {Research {Survey Information Obj ti Objectives {Build {B ild an electric l t i go-kart k t that th t can plug right into a 120 V AC current outlet {Have the ability to go 30 Mph {Have the vehicle safe to drive {Designed to fit a 6ft 6in 300 pound p person {Fundraise to earn $2,500 to aid in the completion of the go-kart Th Team The T Top: Amanda, Eric, Jarred, Cory, Domeniko, Dan Bottom: Ale, Ryan, Anthony, Colin, John R Research h {Batteries and charging systems {Motors {Motor Controllers {Frames/suspension {Safety features B tt i and Batteries d charging h i systems t {We are looking at z 48 volt batteries to reduce the current draw. draw z 40-50 Ah capacity for approximately an hour or more battery life based off a 2 horsepower motor. z An approximated 3 hour charging time. Battery Study for Different Storage Options Closer study, comparing the lifecycle cost of Sealed Lead Acid Batteries and the lifecycle cost of LiFePO4 Batteries, B tt Battery Analysis A l i {We had narrowed down our choices to between Sealed Lead Acid and Lithium Iron Batteries. Batteries {Currently, the best battery option is the Sealed Lead Acid battery, battery and we are researching the various prices. prices M t Motors {Used calculators to get an estimated motor power requirement {1 Hp=746 W {The values we used in the calculators l l we estimated i d to b be higher than the real life values. Calculator Estimate of Power Requirements at 5-45 MPH Source: http://ecomodder.com/forum/tool-aero-rollingresistance.php?Weight=700&WeightUnits=lbs&CRR=.01&Cd=.30 &FrontalArea=10&FrontalAreaUnits=ft^2&FuelWh=33557&IceEffi ciency .75&DrivetrainEfficiency .95&ParasiticOverhead 0&rho ciency=.75&DrivetrainEfficiency=.95&ParasiticOverhead=0&rho= 1.22&FromToStep=5-120-5 M t Analysis Motor A l i {From that data we find f a 2 HP Motor would be sufficient to maintain our speed at 30MPH {We are currently contacting local companies to find a second opinion on our motor need. {Additional analysis was done using: {http://buggies.builtforfun.co.uk/Calc ulator/analyse metric php ulator/analyse-metric.php Additi Additional lA Analysis l i { To T determine d t i power required i d for f acceleration we preformed our own calculations: P = τ *ω τ = F *l F = m * a = 318kg * .894m s 2 (0 − 30mph _ in _ 15s ) = 284.5 N 30 Mi 5280 ft 12in 1 _ rotation 2πrad 92.4rad * * * * = s Hr Mi ft 2 * π * 5.7in(r ) rotation τ = 284.5 N * .145m(5.7in _ radius _ tire) = 41.3Nm 92.4rad P = 41.3 Nm * = 3816 watts s ω= F Frame and d Suspension S i {Materials in consideration for f the frame: z Stainless St i l St Steell {Strong and durable {Resistant to wear z Aluminum {Inexpensive p {Lightweight {Possible Suspension Ideas: z Independent rear-suspension S f t Safety {Will include: z Seatbelt z Kill switch i h {Under consideration: z Roll ll cage z Airbags z Speed limiter S Survey Information I f ti {Population size: 36 {Ages 16-18 {Wanted some potential customer opinion to influence our design { Needed to know what was most important to customers. { Cost C t cutting tti iin lleastt iimportant t t areas S Survey Information I f ti Continued C ti d {Average height: 5ft 8in {80% wanted go kart to be close to the h ground d – 4 inch h clearance l {70% wanted brake and gas pedal on single l side, d as opposed d to separated. {65% believes b li suspension i is i ffairly i l important (7+ on a 10 point scale) In Conclusion In Conclusion { { Our objective O b is to construct an electric, l plug-in go-kart that can go 30 mph and carry an 6ft 6in person. person We are currently researching many different aspects p of the g go-kart,, such as batteries, motors, and safety features.