06-10-2012, 11:28 AM
Mechanical Engineering with a Remote Control Car
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Abstract
The goal of this project was to design and
build a remote controlled car. The idea was
to first design the car on paper, including the
parts, their locations, and their overall
purposes. Using our own previous
knowledge of cars in general combined with
the teachings of ProEngineer, computer
software specifically designed for threedimensional
CAD drawings, it was possible
to research different aspects of cars and
create as well as buy the various parts
compatible for an R/C car. We were
motivated by our passion for engineering
and the overall satisfaction of driving our
end product.
Using the ProEngineer software, we were
able to design and replicate the components
of our very own miniature car. Using
nothing but two sets of calipers, we were
able to get dimensions for each part of the
car and replicate the pieces into the program.
Calipers are measuring tools which can
make precise distance measurements down
to a thousandth of a millimeter. Using our
intricate drawings on the program, we used a
“3-D Printer” to convert our 2-D drawings
into 3-D plastic parts.
Introduction
A remote controlled car is a car that uses
radio frequencies as a source of control. The
first R/C model was a Ferrari 250LM built
in a 1:12 scale. This model was then
followed by the company’s (El-Gi) next R/C
Ferrari P4 built in a 1:10 scale. R/C cars
started off reasonably primitive back then,
having the bare minimum of parts and being
shaped as dune buggies, then later evolving
into monster trucks [5].
It wasn’t until the mid 1980s that the United
States got actively involved in the remote
controlled car industry and the structures
became more and more involved. They went
from just a simple motor and axes, to a fully
functional miniature car. Manufacturers
began to give them complex systems
including ball bearings, transmissions, shock
absorbers, and disc brakes. The
transformation happened rather rapidly and
is still evolving today.
Background Information/Related Work
The first few days were devoted to
mastering the basics of a single, vital
program. “Pro-Engineer,” as it was called,
would be used primarily to execute the
CAD and CAM functions. Rapid
prototyping is an additive fabrication
technology used for building physical
models and prototype parts from 3D
computer-aided design (CAD) and medical
scan data.
Unlike CNC machines tools, which are
subtractive in nature, these systems join
together liquid, powder, and sheet materials
to form complex parts. Layer by layer, they
fabricate plastic, wood, ceramic, and metal
objects based on thin horizontal cross
sections taken from a computer model [3]. A
rapid prototyping machine reads the data
from the CAD drawing and lays down a
liquid material layer by layer until the threedimensional
model is completed.
Modeling Parts with Pro-Engineer
After we had a general idea of what we
wanted the car to look like we began to
work on Pro-Engineer. We spent the most
part of the first week learning how to use
Pro-E to create parts and assemblies. Some
of us were quick learners, mastering the
program within the first few days, while
others struggled.
The first things that were modeled on
Pro-Engineer were the cases for all of the
electronic parts that were needed to run the
car (Figure 2). Cases were made for the
battery, speed controller, and the transmitter.
Each of these cases were required to fit their
respected part snuggly within them and they
also needed to have holes at the bottom to
fasten them to the piece of acrylic that was
being used as a base. These cases were also
made with walls with a thickness no less
than 3mm to withstand vibration and other
impacts that the car will have to endure
during use.
Future Work
After the final design was complete, the
group realized that there were improvements
that could have been made to the project in
the future. The steering system of the car
and the addition of a suspension system
were two areas in which future projects
could have been worked on for
improvement. Rear differential and better
tires could also be added by future groups in
order to improve the project, making the car
more efficient.
The steering system presented many
problems. Initial steering designs were
unstable and complicated. These designs
consisted of many small parts, with equally
as many hinges and connections to the base.
Furthermore, final designs for the steering
system were too basic. Though these designs
functioned properly, they consisted of
merely basic parts, hinges, and connections.
The final designs only allowed for a turning
radius that was sufficient only to make wide
angle turns. In a future project the steering
system should contain fewer parts, yet still
allow for a smaller turning radius in order to
turn more efficiently.
Conclusions
Throughout each phase of the project,
various obstacles were encountered and
overcome. Overall, though things did not go
as planned, we accomplished our main goal
and sub-objectives. Dissection of an alreadyfunctional
R/C car enabled us to learn more
about the important functions that each piece
contributed to the car. Using calipers, we
then proceeded to take accurate
measurements with which we used to recreate
accurate replicas of the parts in Pro-
Engineer.