G K t E i P j t

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.