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Pushing the Limits of Efficiency: Electric racers try for 50 mph with one horsepower!
Greenpower competitor 2004 There is a lot to learn from the information on this page. If it doesn't answer your questions, e-mail Greenpower anytime on helpline@greenpower.co.uk TECHNICAL
AND PRACTICAL TIPS FOR YOUR 24 VOLT RACE CAR When
designing and building your car there are a number of important points to
consider. To start with get your design team together and go through the
items listed and discuss them. Decide the basic direction you wish to go
in, and why. When you have finished you will be able to start going
through them in detail and commence the full design of the vehicle. Watch
how various design decisions affect each other. Do not be afraid to seek
help from a Science and Engineering Ambassador or your Contact at your
local Technical College. Greenpower are happy to assist if needed. Get
your Formula
24 regulations handy and refer to them at all times. Don’t read
them after you have fixed your design! Appoint a ‘Marketing Team’ to
put together a presentation package of what you are going to do and get
out there and find some sponsors for your car. Some teams have raised
thousands of pounds for their project! First
of all it is a 6-hour race. You are supplied with a 240 watt, 24 volt d.c.
electric motor that runs naturally at 2000 rpm. You will also have four
12-volt batteries, 2 on the car and 2 spares. (Unless you opt for the
lighter 028 type in which case you will have 6 batteries in all, 2 on the
car and four off).
Motor:
Examine
the curves. Discuss what they mean. What happens if the motor runs at less
than 2000 rpm. What happens when you are accelerating? How can you get the
most out of this small but willing motor?
Batteries:
Look
at the capacity. Can you predict how long they should last, or could last?
Can you work out the best tactics for changing batteries?
Wheels:
Large,
small, wide, narrow, soft, hard, treaded or smooth tyres, heavy or
light??? All questions; how do you work out the answers?
Drive:
How
do you get the power onto the road? What drive should you use? What do
other vehicles use? How can you use gears? Do you need gears?
Speed:
What
maximum speed should you go for? Why? What are the advantages and
disadvantages of speed?
Weight:
Heavy
and strong, light and nimble? Materials? Chassis design? Drivers? How
important?
Shape:
Does
it matter? If it does, what is best?
Steering:
What
ways can you steer? What is steering geometry? Why does it matter?
Brakes:
What
options are there? What is out there to use? What is electrical braking?
Is it a proposition for us?
Controls:
How
will you control the motor? What switching to use? What do you need to
control?
Bodywork:
Think of materials, finish, access, strength. Will it last the race? Other
points for consideration and discussion: Freewheeling,
good or bad, a virtue or a handicap? Suspension,
is it just for a comfy ride? Spares
– How long will parts last, what spares should you have and how much
will they cost? What
sort of racetrack are you designing for, does it matter? Remember
– you can use standard, proven bits and pieces from bicycles, prams,
lawnmowers, trolleys, pedal cars, ‘wheely-bins’, or whatever. However
proprietary electric driven vehicle parts cannot be used. Full
‘Go-cart’ chassis and other assemblies are outlawed. Remember
there are prizes for ‘originality of design’ and ‘appearance’ but
the car must be both practical and safe. All bodywork must be strongly
attached and comply with the regulations. Every vehicle must have numbers
one both sides and at the front of the car. These must be at least 250 x
250 mm. in a contrasting colour. Remember:
Before the race your vehicle may be inspected by race officials for
compliance with Formula
24 regulations,
safety, and durability. This is a confidential visit and no information on
your design will be relayed to other competitors. However, the officials
might suggest modifications or improvements if they consider that the car
needs them to be safe, or strong enough to last the race distance. Remember:
On race day it will be too late to finish off any last minute details.
There will be, however, usually be a central repair facility for use by
all competitors should they meet with some disaster during practise or in
the race. This service will be on a ‘first come first served’ basis
and speed of repair will obviously depend on the nature of the breakage
and the number of cars in the queue. Some thought should therefore be
given to what ‘first-aid’ equipment you should bring with you to keep
your vehicle moving while waiting your turn. (The vehicle itself need not
actually be in the queue). Remember:
Cars in the race will get up to speeds in excess of 25 mph and care must
be taken to ensure that your driver is safe. All drivers must have had
adequate practise before race day, particularly with respect to
controlling the cars in, braking, cornering, and emergency avoidance of
obstacles. A full safety bulletin will be sent out four weeks before heats
to ensure that all drivers are totally familiar with procedures. On race
days there will be a pre-race drivers briefing when all questions will be
answered and any last minute instructions issued.
AND FINALLY - Learn
from what you are doing. If things go wrong, don’t panic. Think about it
and go about it in another way. Look at other cars. Watch the old
Greenpower videos. Engineering is always an ongoing process of development
and, once you have a base to work from, you can only get better. Do not
try to achieve too much too quickly. A
quiet car is an efficient car – GOOD.
LINKS: New - Scrutineering Check List (see if your car will pass) NEW - Design Profiles of top 2004 cars Fracmo
Motor Performance Graph Simple
Wiring Diagrams
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Email: info@greenpower.co.uk Latest
News: -
Important Information for those who have Read the Telegraph articles on previous UK events
More International Electrathon info at: www.electrathonnewengland.org & www.electrathonamerica.org
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