STEMM
Report
Systems
Engineering II
Remote
Controlled Land Sailor
Introduction:
The Remote
Controlled Land Sailor’s only practical purpose in this day and age is for
competitive purposes and as a recreational pastime to hobbyists. That said, the land sailor has a very
specific environment where the model is intended for use, primarily flat
surfaces with hard ground and moderate winds.
In terms of functionality, consumers are attracted to specific land
sailors based on performance, which includes speed and maneuverability as well
as the aesthetics. With the basic requirements
of consumers in mind, the final model land sailor was designed to complete
timed courses to demonstrate the maneuverability and speed in the final testing
stages. As of now, the land sailor’s
designs are completed, seen in Figure 1. As described in the Rationale, this model has a “T” shaped frame with one wheel in the
front and two in the back. Steering is
controlled by the single front wheel hooked up to a servo. The servo is part of an electrical system
that consists of two other servos that control the sail, a battery, and a four
extension receiver. The frame is made
from balsa wood with metal support sidings around the mast placement. Full descriptions on the parts, as well as
materials, supplies, and tools can be seen in the Developmental Work section. All
specifications in terms of the size of the chassis adhere to the International
Radio Controlled Surface Sailing Association regulations.
Relation to Systems
Engineering:
Because the concept of land sailing,
not to mention sailing in general is not new, this design counts as an
innovation. The current design in itself
resembles designs that others have been done by others in the past for their
land sailors. However, the final land
sailor model for this group will be unique compared to the other designs that precede
it, hopefully allowing the model to complete the final tests successfully in
the future.
The engineering that tied in with
this design the most is structural. The
location of parts as well as the design of crucial parts, such as frame and
steering, will determine the outcome of this model’s functionality and ability
to complete the specifications.
Additionally, the materials and supplies that make up each part will
also affect how the final design functions.
When manufacturing the model, building
will most nearly ties into prefabrication.
In this method, a single person with knowledge on the building process
gathers materials that they cannot produce themselves and assembles them to
make the final product. In this
scenario, many of the parts are pre-assembled, such as the wheels, ball
bearings, servos, receivers, batteries, and sheet metal. All the manufacturer has to do is shape the
materials and supplies into parts (see Plan
of Procedures) and then assemble the parts into a final product as
directed. This could also involve the
English system of manufacturing, as the materials that need to be duplicated
may not be the same shape or size as the original. This problem with non-interchangeable
parts is normal when construction is done by hand.
Being that this project is to design
and build the chassis of a remote controlled land sailor, this project falls into
the engineering and electronics categories.
Engineering was an important topic to keep in mind when working on the alternate solutions and the CAD models.
As stated before, the placement and composition of each part have major effects
on the functionality of the design. This information was important to keep in mind
when choosing the shape of each design, material of each part, and the
placement of pre-fabricated parts. Part
placement can be seen in Figure 2. Additionally, engineering also relates to
the types of electronic components chosen.
When choosing servos,
one has to think about how much force is needed to do the task the servo has to
do. For example, a servo needed to pull
a winch is not the same as a servo needed to swing the boom of a mast or operate
the steering of a model going at high speeds.
Just as before, part choice is crucial
to achieving the planned functionality of a design. In terms of electronics, part choice depended
on the amount power needed to operate and the amount of force the component needs
to exert. These factors influence the
type of battery needed as well as what specialized servos are needed for their
specific job. This can be seen in the
wire diagram in Figure 3.
Science Concepts:
This project’s design was influence
by several science concepts in the early design phases. One of the deciding factors when comparing
this design to others in the Rationale
section was the mast placement and the effects on mobility. Being that the mast is such a huge structure,
the concept of the center of gravity and balance, the principles of which are
accredited to Sir Isaac Newton, played a
part in choosing the design. Because maneuverability
is one of the final tests, turning has to be quick and stable to reduce time
loss while the final design runs through a timed course. To accomplish this, the design must have a
relatively spread out frame with the sail location ranging from the middle to
front area of the central beam. A poor
example of this can be seen in one of the early designs in Figure 4. The current design
has a wheel span of approximately 27.7 inches in width to 36.6 inches in length
is sufficient in holding the mast upright in the testing phases. An
orthographic view of the land sailor can be seen in Figure 5. The ability of the
servos to turn the steering also relates to the concepts of torque as stated by
Archimedes. Rather than use standard
servos provided by the school, more powerful Futaba S3305 High-Torque Standard
Servo with Metal Gears will be used.
Standard servos might not be able to handle the strain of moving at high
speeds, and even if they can hold the steering column still, turning would be
near impossible, if sloppy.
Integrated
Technology:
Possibly one of
the greatest impacts that technology has had on this design process is the
compactness that each individual electric component has. With the specs of each electronic part
provided by the manufacturers, their relative combined weight is miniscule
compared to the total design. This decrease
of weight and size will have positive effects on the end performance of the
land sailor. A close up of the battery
and receiver can be seen in figure 6. Additionally, the availability of other
designs on the internet has given a wider range of solutions that can be found
to compare to the current design.
Learning from mistakes and successes of others can be beneficial in the
designing of your own solution. In other
words, a large group of opinions can help designer pick desirable traits and
turn away bad ideas.
Mathematical Computations:
Not many mathematical
principles had to be taken into account during the designing of this project. However, conversions had to be done between the
imperial system to the metric system.
Because the groups went by the class 2 IRCSSA standards, we had to stay within
the parameters of .75 meters wide by 1 meter long by 1.5 meters tall. AutoCAD uses imperial units, so these
measurements had to be run through an online length calculator to find an applicable
measurement. In reality, the lengths in
meters can be multiplied by 3.28084 (feet per meter) and by 12 (inches per foot)
to get the end values. Since only width
and length are relevant to the chassis, the measurements from end to end can be
seen in Figure 5. Other than that,
simple subtraction and addition were used when matching up parts in the CAD
views.
Conclusion:
The Remote Controlled Land Sailor
is a structural based project that takes concepts from engineering and
electrical work in the design. The final
model will be built using primarily the prefabrication method with a small
English system of manufacturing addition.
While the electric components and the wheels are factory-made, the frame,
steering system, and support system will be constructed from materials and
supplies. The parts will then be joined
together to form the final model, a “T” shaped land sailor with a single front
wheel servo controlled turning system.
This design will help prevent flipping, while the shape also allows for
easy mobility and maneuverability. The concepts
of balance and the center of gravity were used in creating this design element
during the initial creation of the model.
Math was useful in measuring my design in the 3D renderings, while
technologically the relatively lightweight and small components will not
detract the designs overall performance.
In the end, the Remote Controlled Land Sailor in the final form will be
able to fulfill all of the listed specifications and function as intended by
the designer.
