2. Abstract
This project concerns the design, construction, and testing of a gravity
powered vehicle. The design of the vehicle allows it to harness the power
of gravity in order to propel itself forward. It requires no motor and does
not produce emissions. However, no practical uses have been found for
this type of vehicle.
3. Introduction: Reciprocating Internal
Combustion Engines
Numerous methods are currently in use in the automotive industry that
enable society to move about in a timely manner. The modern
reciprocating internal combustion engine, created by Siegfried Marcus, has
been perfected over the course of more than 100 years and was first
available in 1864. Although 21st century technology has improved Marcus’
design, these engines still produce emissions that contribute to air
pollution and are the leading cause of smog in large cities. Despite this,
vehicles powered by these engines are the preferred method of
transportation around the world. They mostly provide efficiency,
convenience, and reliability when it comes to long distance travel.
4. Introduction: Modern Electric Motor
Another type of engine making its way into the market is the electric motor.
The development of the electric motor was underway as early as the 1800s.
However, the modern electric motor wasn’t created and put to use until 1838,
when the German-speaking Prussian Moritz Jacobi developed such motor and
used it to power a boat with 14 people on board across a wide river. Although
a handful of car manufacturers are in the electric car business, Tesla Motors is
the leading company developing and manufacturing electric cars in the
automobile industry. Although electric cars produce no exhaust gases
themselves, they are limited to a certain range of distance per charge. They are
also generally more expensive to buy and maintain than regular internal
combustion engine vehicles. Recently however, Tesla Motors announced the
Model 3 priced at around $35,000, which would make it affordable for the
average American consumer.
5. Introduction: Gravity powered car
Aside from these two sources of power, there really are no other practical
sources to move a car from point A to point B. Many alternative ways of
propelling vehicles have been proposed but none of them have made it into
production. This project, however, will consist of a very peculiar method of
moving a car. Gravity is a force that is all around us and is constant. This force
can be exploited to actually launch a vehicle into forward motion. Very
lightweight materials were used to construct the body and wheels of the car. A
pulley system was rigged in order to efficiently transfer the force of the falling
weight to the axle of the car. The axle of the car turns the wheels forward,
moving the entire vehicle. The vehicle is of course limited to the height of the
beams used to secure the pulley system. This particular model will only travel a
few feet. The procedure of the design and construction of the gravity powered
car follows.
6. Design
A simple design was procured in order to maximize understanding of the
working principle of the gravity powered car. A two pulley system was
devised in order to distribute the weight properly. A relatively normal
height for the vertical beams was chosen to allow some travel of the
vehicle. The following is a visual representation of the design of the car.
7. Procedure
Typically, a gravity powered vehicle would be required to weigh no more
than 10 ounces. In light of this, I strived to acquire lightweight materials in
order to keep the weight of the car down. This is because ideally, you want
the weight attached to the string to actually rotate the rear axle of the car.
I tried to find the parts for the project in various stores including arts and
crafts stores and home supply stores to no avail. For my EGR 188 class at
AWC, I am required to build a hydraulic arm and the required materials
were supplied to us. These materials were perfect for the gravity powered
car and were also lightweight. After getting permission from the
Engineering Department to use them, I set out to figure out the best way
to build it.
8. Procedure Continued
I sat down and made some rough sketches of what I wanted the car to look
like, but also making sure the moving parts would work appropriately. Once I
was satisfied with the design, I started working on building the car. Two plates
with holes in them were used to set up the frame of the car. I used round
basswood sticks to fasten them together about 5 inches apart. The bottom
basswood sticks would serve as the axles for the wheels. The wheels
themselves were rather big, around 5 inches in diameter. Because the plates
with holes had corner holes with grooves and lands, I used a reamer to get rid
of the lands so that the axles would spin freely on their axis of rotation. The
top of the car was also secured with basswood sticks, but this time the grooves
and lands were left in place in order to tighten the grip. After this, 4 12 inch
strips with holes in them were attached to the frame of the car with basswood
pieces; 2 on each side. These two vertical beams would serve as the mounts for
the pulley system.
9. Procedure Continued
The pulley system itself was comprised of two small pulleys that were
originally sold for screen doors. Small screws were used to attach them to
small square connectors that themselves would attach to the basswood
sticks. Once I installed the pulley system to the vertical beams, I had to
figure out how to angle both pulleys because if they were placed a certain
way they weren’t going to properly move the string going over them. But
once I got the right angle, I was able to string the axle and over the
pulleys, and they moved the string freely with no problems what so ever.
After attaching the pulley system, I tested the car by using the right
amount of string and attaching a pair of pliers to the other end of the
string where it would fall down. The test was successful; the car started
moving forward once the pair of pliers started going down due to gravity.
10. References
Carter, Tim. “Small Gravity Powered Model Cars – Speed Tips.” Ask the
Builder. Ask the Builder, n.d. Web. May 2nd 2016.
Doppelbauer, Martin. “The invention of the electric motor 1800-1854.”
Karlsruhe Institute of Technology. Elektrotechnisches Institut, Sep 25 2014.
Web. May 2nd 2016.
