We have observed that in general, cars with some flexibility have better track holding
characteristics than stiff cars. Obviously 3 wheel cars will always have all wheels on the
track.
It is not mandatory that a separate chassis is used, a well designed and constructed body
can perform the same functions as a separate chassis and in our modern motorcars does
just this.
5 Motor
The regulations allow the use of any motor or motors. Generally, permanent magnet
brush type direct current (DC) motors are used as they are common, readily available and
well suited to this application.
Inexpensive motors can be used successfully to power a car but in general their
performance is inferior to the high quality motors used in the most competitive cars.
For example a “TOY” motor can require about 0.30 Amps to just run without driving a
load. This is equivalent to about 50% of the maximum current available from a typical
cars solar panel in full sun light. The high quality high efficiency motors typically
require only about 0.020 Amps to just run. This is only equivalent to about 3.5% of the
maximum current available from a typical cars solar panel in full sun light.
Most cars use the FAULHABER 2232 6 Volt motor (FAULHABER motors are
distributed in Melbourne by Erntec Australia – see Buying Guide on Web site). Another
commonly used high quality motor is MAXON which also offers a large range of motors
which just like the Faulhaber are expensive. (Maxon motors are available from Maxon
Motor Australia in Sydney http://www.maxonmotor.com.au))
CAUTION: When using Faulhaber motors never exceed the manufacturers limit of
20 Newton (2kg.) end load on the shaft or motor destruction is probable.
Consequently I strongly advise never to push gears onto the motor shaft. If you
intend to use push on gears seriously consider the use of tooling to support the shaft.
The following is a general overview of the characteristics of small Permanent Magnet DC
Motors.
POWER:
· The motor has a nominal output power stated by the manufacturer.
· More power can be obtained from the same motor simply by increasing the
supply voltage.
· Note that running a motor above its nominal power will reduce its life.
RPM :
· As a general rule, RPM is proportional to voltage, double the voltage and the
RPM will double.