Final Rules, draft 1
(October 9, 2007)
ME72: Engineering Design Laboratory
FIRE and FLY
Contest Description and Rules
Twenty-third Annual
Engineering Design Competition
1.
Introduction
The contest this year involves the construction of:
(1)
a projectile or flying
device that will rise from a ground-level launcher, fly over a rope hurdle and
then glide or be projected as far as possible over clear ground. This device
must carry a 50 gram payload (likely to consist of a stack of metal washers).
Each team will be provided with at least one such payload.
(2)
a ground-level
launcher device that will help propel the flying/projectile device on its way.
The final contest will take place at
As described in more detail below, each team will have the potential ability to
control their flying/projectile device during the launching and air-borne
periods via a standard hobbyist remote control system. A fixed number of servo motors, battery packs,
and a radio control receiver will be provided to each team so that they can be
engineered into their design solution.
During the each heat of the contest, at least one team member must be
initially positioned within a 3m x 3m box surrounding the launch area. The second team member can be initially
positioned at any location north of the rope hurdle, and between the lateral
contest boundaries. After the launch, both team members may move as may be
needed to monitor and control their device.
However, at no time can a team member, or any other person, have contact
with either the launching or flying components of their system until the
payload has come to rest. Moreover, no
team member or other person may interfere with the movement or activities of
their human competitors during the setup, launch, and flight periods. No device shall interfere with the launching
of a competitor’s device, but once both competing flying/projectile devices are
launched, your device may interfere with your competitor’s flight, as long as
there is no intent to cause structural damage to the competitor’s apparatus
(both flying and fixed components).
2.
Energy and Actuation Sources
Every team will be provided with the same energy
sources and actuators, which will consist of
1)
Possible
potential energy at higher ground level locations within the launch area.
2)
One small
compressed CO2 cartridge. These cartridges will be provided free but it is not
permissible to inject gas into these cartridges or heat them up in a way that
would increase the energy of the compressed gas energy within. It is also not
permissible to remove material from the cartridge in order to decrease its
mass.
3)
A “small” battery
pack for the radio-controlled receiver and 4 hobbyist servo-motors (two “small”
and two “medium” sized hobbyist servo-motors).
4)
A large battery
pack and two D.C. servomotors that are compatible with the battery pack. Students will have a choice of two different
motors sizes (one “small” and one “large”).
Neither the large battery pack nor the D.C. servomotors can leave the
launch area from the time when the
launching sequence is started until the time when the payload comes to rest.
5)
Energy stored in
a spring-like device made from a limited and prescribed amount of standard
contest materials (see below), and with upper limits on how much energy can be
stored in these materials prior to the launching period.
6)
Note: it IS possible to use a propeller, or any
device that can be construed as a propeller, on the flying/projectile device,
with the constraint that the propeller is power only be stored mechanical
energy.
Each team will be have access to a standard model-airplane
radio-controller with 6 channels of control that can be used to remotely
control the motions of the hobbyist servos and the D.C. servo motors if desired
(through the use of an optional D.C. motor controller board). These radios and
receivers cannot be modified in any way; they must be used in the format as
they are provided to you. Similarly, the
battery packs provided can not be chemically or thermally altered.
3.
Launching
- Prior to each
launch, the design team will be permitted a maximum set up time of 45
seconds (beginning with the instructors’ start command) to place their
device(s) within their launching zone.
The launching zone will consist of a simple flat slab including
eight ¼-20 tapped holes (see Figure 1).
Contestants may choose to (but are not required to) use these
mounting holes to fasten and stabilize their device during the launching
period.
- Two launching
pads will be available for each heat of the competition. They will be placed 3 meters apart,
symmetrically located about the midline of the competition zone. We are choosing to go with head-to-head
heat competitions so that the effects of weather on device performance are
minimized.
- During the 45
second setup period, any of the provided actuators and battery packs can
not be used to store energy in the device.
Energy can be stored in the passive mechanical storage devices
during this period (as part of the set-up process), as long as the amount
of energy does not exceed the guidelines described elsewhere.
- At the end of
the 45 second placement period, the total design system must be statically
stable, prior to launch activation.
Moreover, at the end of this 45 second placement period, each
contest entry must fit within an imaginary rectangular box that is 80cm x
80cm at the base, and 2m in height.
- Each system
must have a launching mechanism that can be simply activated by the press
of a switch, or an analogous device.
A switch will be provided in the contest material list. Prior to
activation of the launching switch, the launcher and the flying device
must all be static and must be contained within the imaginary box
described above.
- The launch
sequence may take up to 15 seconds.
Starting from the instant at which the launch switch is depressed
or activated, the contestants (or any other person) may have no further physical
contact with their device, except for purposes of dismantling their device
and removing it from the launch area.
However, internal mechanisms within the launching system may carry
out predesigned tasks, and remote control of the launching system and
flying/projectile component via the radio controller system and servo
motors is allowed during the launching period. Additionally, the battery
packs and motors can be used to store additional energy into either the
launching or flying mechanisms. However, if no portion of the design
system has left the imaginary box by the end of the 15 second period, then
that contest entry will be assigned a zero travel distance, and a loss in that
particular heat of the competition.
- No external electrical
connection to the launcher or to the on-off switch will be permitted. The switch may only be connected to the
battery packs, servo motors, and controllers provided to each team.
- After
launching, the launching subsystem (and all of its parts which are clearly
not part of the flying/projectile component) must come to rest within a
circle of radius 130cm whose center is the center of the imaginary box
described above.
- After the end
of the launching period, all parts of the system must be removed from the
launching zone within 45 seconds.
Figure 1: Geometry
of the launching plate (not drawn to scale).
Each hole will be tapped to receive ¼ -20 threaded bolts.
4.
Landing
As described above, the goal is to have the
flying/projectile device reach the farthest southerly configuration. Once the payload first touches the ground,
the payload will be allotted a 5 second settling period. That is, the payload can continue to roll,
bounce, etc. for a period of up to 5 seconds.
The total payload distance will be judged by the its location at the end
of this 5 second period, or when the payload comes to rest (in the opinion of
one or more of the contest judges)—whichever comes first.
During the 5 second settling period, the
flying/projectile system can not deploy or use external wheels, legs, or tracks
to further the movement of the payload.
5.
Evaluation
An overall winner will be determined in a
double elimination tournament. This is just like a single elimination
tournament, except a team must lose twice (instead of once) to be eliminated
from the competition. The double elimination format is chosen so as to
eliminate, as much as is humanly possible, the effects of transient weather
conditions (e.g., gusts), on overall contest performance. Your device must be robust enough to survive
repeated launches and landings.
Pairing of teams to compete will be chosen
randomly at the start of each round of the tournament. The team selected first
in the random draw will go first in every contest. In each contest pairing, the
team whose payload comes to rest furthest south, according to the rules
described above, will be declared the winner. Again, recall that a flying/projectile
device that lands outside of the proscribed boundaries will have its southerly progress
marked at the point where the device first crosses the boundary. Each boundary
will be staffed by a line judge who will determine this point of exit. In all cases (particularly those requiring
judgment) the judges will decide the winner.
6.
Individual Work
While you will be working in teams of two, it
is expected that each individual will design and fabricate a significant
portion of each functional device. It is acknowledged that interaction between
teams in the class is highly beneficial. To that end, any conversations,
calculations, analyses, ideas and tests may be shared among the teams, but the
device design and fabrication must be an individual team effort. Note that this
collaboration policy does not extend to replicating others’ ideas. Occasionally
two teams will arrive independently at very similar solutions. Sometimes one team will see a great idea in another
team’s device, and finding no superior alternative, will want to incorporate
it. This duplication is permissible, however, not encouraged. In the past, some competitors have maintained
a high level of secrecy around their device, and blindly copying an idea or
strategy may be risky. In many respects,
you should treat this design project as similar to an ordinary homework set. It is permissible to collaborate with your
classmates and seek the advice of the instructor, TA’s, M.E. Shop staff, other
class participants, and other students.
However, the final product must be your own work. At the end of the
term, for grading purposes, you should indicate, where possible, the boundary
of the functional devices that you designed and fabricated, and in particular
to distinguish it from the parts of the device that your teammate designed and
fabricated. Furthermore, it is vital to document both your own work and the
contributions of others to your ideas by detailing the process of ideation,
design, and fabrication in your design notebook. If you are concerned about the acceptable
limits to collaboration, discuss the situation with the instructor(s). Do your own work, and as always, it is best
if you use your own ideas and concepts.
7. Additional Clarifications of the
Contest Rules
7.1.
Safety:
(a) Any device which is judged to have the
potential to cause injury to any participant or spectator will be disqualified.
(b) It is mandatory that safety glasses be worn
at all times while competing and testing. This requirement will be relaxed
during the final tournament. It is, of
course, also mandatory that safety glasses be worn at all times while in the
M.E. Shop.
7.2.
Energy Sources:
The energy used by each contestant’s device is
limited to the following:
(a) Electrical power
supplied by a “small” and a “large” battery pack that is provided to each
design team. Students will have access to an ample number of battery chargers
throughout the course and during the contest.
However, design teams may choose to purchase additional battery packs if
so desired in order to ensure maximum charge during the contest. But no more than one small and one large
battery pack may be used at any one time in the system design and deployment.
Additionally, batteries will be provided during the testing and contest period
for the hand-held radio control modules. The battery packs may not be modified
in any way at any time (mechanically, chemically, thermally, electrically,
etc.); they must be stored and operated at ambient temperature. Used radio
control module batteries must be recycled when depleted of electrical energy. A
container for this purpose will be available in the M.E. Shop.
(b) There will be limits
on the spring energy stored by deforming any element or elements in the
prescribed material list, including the springs and rubber bands. The limit of
the spring energy that can be stored in the launcher will be 20.0 joules
(approximately the amount of spring energy stored by deforming six (6) medium
sized rubber bands; the material in which this energy is stored must remain in
the launcher throughout the duration of a contest round. The limit on the spring energy that can be
stored in the flying device will be 10.0 joules (approximately the amount of
spring energy stored by deforming three (3) medium sized rubber bands). Testing
and analysis that demonstrates conclusively that these limits have been met
must be included in your design notebook, and approval of your analysis must be
indicated by the signature of the instructor.
(d) The energy contained in a single CO2
cartridge supplied by the course instructors.
Replacement cartridges
will be available. The first replacement cartridge will be supplied upon
request. All subsequent replacement cartridges will only be provided at the
time a used cartridge is turned in. Each contestant will be limited to a
maximum of eight (8) cartridges.
Additional cartridges can be purchased by each team if desired, but at
no time can a team’s contest entry contain more than one cartridge. Additionally, contestants using the CO2 must
convince the course instructors that the deployment of the cartridge does not
have the potential to harm other contestants, spectators, or judges.
7.3.
Contest Materials:
Each contestant’s device(s) must be constructed
entirely from materials supplied in the contest materials list (which can be
found in a separate on the course website). No other materials (either from the M.E. Shop,
or elsewhere) can be used or substituted, with exceptions described immediately
below. In addition to the standard
material list each contestant may also use:
(a) A maximum of 113.4
grams [4.0 ounces] (dry cured mass) of RTV silicone casting compound. This
casting compound is supplied in bulk. See the Staff in the M.E. Shop if you
wish to cast one or more parts out of silicone. The intended purpose of this
casting compound is for sealing, however, it may be used for molding
components.
(b) A maximum of 3 meters
[118.1 inches] of 2.38 mm [3/32 inch] diameter “Orange-Go” belt material may be
used. The M.E. Shop staff can show you how to join the ends of a segment of
this material into a continuous belt. The intended purpose of the “Orange-Go”
is for power transmission as a belt, however, it may find other
(non-decorative) purposes.
(c) Glues and epoxies that
are used only for bonding. A total of 2 ounces of glue or epoxy may be used (in
combination with other materials on the approved contest material list) to
create a composite material, with glue as the matrix.
(d) Paint or Shellac may be used to
insulate strands of wire, if desired.
Similarly, up to one meter of black electrical tape may also be used for
purposes of electrical insulation. Such
tape may not be used for structural purposes.
(e) Light machine oil,
mineral oil, or vegetable oil (depending on the competitor’s preference) can be
used SPARINGLY to lubricate moving parts.
(f) Non-functional
decorations (such as decals and paint) can be used, and are encouraged.
Each contestant’s final device(s) must be able
to have been fabricated from the materials or parts contained in the parts
list, with the exceptions described above.
During the construction and testing of your devices, you may use more
total materials than are prescribed on the approved material list, but the
final device can not use any more material than is specified by this list.
Replacement supplies and materials are
available on a limited basis. If you damage something, or cut it up and then
want to do something different with it, see the M.E. Shop staff or one of the
TA’s. We will do our best to supply replacements, but we cannot guarantee
unlimited supplies of all materials. We also cannot guarantee that replacements
will be identical to the original. You may want to check availability of
replacements prior to conducting a risky experiment with a rare part. In particular, each team will only be
supplied with one set of hobbyist motors and radio control motors. If these devices are damaged, it is up to the
students to replace them. Sources for
these items can be found in the resources
section of the class web site.
Contestants are responsible for providing their
own glues and epoxies. Some glues and epoxies will be available in the M.E.
Shop, but to ensure an un-interrupted supply, go to a (hardware) store, and buy
your own.
The approved contest materials may be
mechanically modified in any way (disassembled, cut, machined, turned, ground,
etc.). However, they may not be altered chemically (except locally by glues,
for bonding, or paint for decoration or insulation purposes).
Soldering and brazing are permitted, though not
particularly encourage. Welding is not permitted.
7.4.
Contest Device:
(a)
Size:
i. Prior to the start of
the tournament, each team must demonstrate to the course instructors that, in
its immediate pre-launch configuration, all the devices will fit into an
imaginary 80 x 80 x 200 cm box. A
measuring device will be available in the M.E. Shop to check this constraint.
ii. At the start of the
each contest (t=0), each team’s combined devices must be positioned within the proscribed
launch area as described above.
iii. At the end of the
launch period, as described above, all parts of the launching system must come
to rest within a circle of 130 cm radius, centered on the launch pad.
(b)
Mass: Each team’s total design
must not weigh more than 7.5 kg, including the mass of the supplied actuators
and battery packs (but not including the hand-held radio control module or the
payload).
(c)
Finalized Design. After each device’s
initial flight during the final contest, no major design changes or
construction will be allowed. Crashes of the flying devices are inevitable and
repairs to these devices using materials from the approved materials list will
be permitted provided that, in the judges’ opinion, they involve no major
design changes to the initial device. However, changes to flight parameters
such as angles of incidence or rebalancing of the flying device will not only
be permitted but are encouraged. Any
such minor corrections to the device must respect the rules on size, mass, and
materials described elsewhere.
(d) Interaction
with the device. Other than radio control through the
servomotors and the radio transmitter, and through the activation of the
launching switch or device, no manipulation of, or interaction with, a device
will be allowed while it is competing (i.e., after the start of the launching
period, and up to the end of the 5 second payload settling time).
(f) Team
Number. Each team will be assigned a 2-digit integer
number to identify their team and their contest device(s). Each major component of each team’s design
must carry an identifying team number.
Note that Number 00 is reserved for the contest placebo. While not
required, teams are also encouraged to choose a team name.
7.5. Device Deployment Rules:
(a) The contest arena includes all air-space
above the ground, and within the lateral contest boundaries (as described in
more detail below).
(b) Each device must be designed to
functionally interact with nothing other than the launch area, the
air, the ground, and the remote control system.
Bouncing off buildings and other exotic strategies that deploy the
buildings, trees, or other infrastructure in the vicinity of the contest are
not allowed.
(c) At the start, before the launch switch is
activated, all portions of each team’s devices must rest entirely within that
team’s start volume, as defined by the imaginary box above.
(d) You may not interfere in any way with the
conduct of any opponent’s device during the set-up and launch period. However, you are allowed to interfere with an
opponent’s device once your device and the opponent’s flying/projectile devices
are both in the air. You may not
interact with, modify, or intentionally block the radio control signals from
the opposing teams’ transmitter. Each
team’s transmitter/receiver pair will have a different frequency to minimize
interference effects.
(e) Intentional damage to any receiver/control
module will result in disqualification. It is your responsibility to avoid damage
to the receiver/control module during the design, fabrication, testing, and
contest phases. Competitors should make efforts in the design and fabrication
of their devices to avoid placement of the receiver/control module in a
vulnerable position.
7.6. Contest
Arena:
(a) The final contest will take place in the Court of
Man. The launchers can be placed at any location within a defined launch area,
which will be close to the front of Beckman Auditorium. The rope hurdle will be
strung between the Beckman Behavioral Biology building and Baxter Hall. It will
not be horizontal but will sag such that its minimum elevation of 5 meters will
occur near the mid-point between the two buildings. The rope hurdle will be placed 30 meters
south from the launch area. The rope
will be oriented in as nearly an east-west direction as is possible.
(b) Boundary lines that are approximately north/south will
be marked on each side of the Court of Man and will extend into the space
between Dabney Hall and the Parsons-Gates building. Note that the boundary
lines may not necessarily be “straight” at all locations. The boundaries are implied to extend vertically
upward from these lines placed on the ground. As stated earlier, the final
resting place that will determine the winner of each contest will be the southerly
location of the payload, provided it comes to rest inside the boundary lines.
If the payload ends up outside one of the boundary lines then the final resting
place will be the location where the payload first crosses the boundary, as
judged by the line judge responsible for that boundary. Additional points (in the form of a 50 meter distance
added to a team’s flight distance) will be awarded to entries that land in a
circle of 2m radius placed in front of Parson’s Gates.
(c) Prior to the final contest, participants
are encouraged to use the Court of Man for their practice flights. However no
overhead rope, no launch area, and no boundary lines will necessarily be
provided prior to the contest day for such practices.
(d) Any intentional damage to Caltech buildings,
grounds, or other infrastructure, other than that within the launch area, will
result in disqualification.
7.7.
Time:
(a) During the tournament, contestants will be
called up “On-Deck” while the preceding flight is taking place and should be
prepared to begin their set-up period of 45 seconds as soon as the preceding
flight is concluded and the preceding contestants clear the launching zone of
their entry.
(b) Exceeding the 45 second set-up time will
result in a loss in that round for the offending team.
(c) After the end of the set-up time, no action
of a team’s device(s) is permitted prior to the initiation of the launch switch. I.e., during the setup time, it is not
permissible for motors to be working to store energy. Only those movements of the team’s mechanisms
that are needed to place the devices in the launch region, and to bring the
devices to rest by the end of the 45 second set-up period are allowed.
(d) During the 15 second launch period, which
must be initiated by an electrical switch or analogously simple mechanism, any
movement of the mechanism (as long as it is unaided by direct human contact) is
allowed. The flying/projectile portion
of the device must leave the launch region by the end of the 15 seconds. If no portion of the contestant’s device(s)
leaves the launch region after 15 seconds, a flight distance of zero meters and
a loss will be assigned to the team for that round of the competition.
(e) A maximum pick-up time of 45 seconds will
be allowed for removing all of your device(s) from the arena after a flight.
7.8.
Tournament:
(a) Teams will compete in a double-elimination
tournament to determine the wining team.
(b) Teams will be chosen at random (during the
tournament) to compete against each other in each round.
(c) If,
after any flight in which the flying device fails to fly over the suspended rope,
the payload within the flying device does not end up outside the launch area, that
effort will be counted as a loss irrespective of the performance of the
competitor.
(d) If the flying device of neither team
manages to fly over the suspended rope then the team whose flying device ends
up furthest south will be declared the winner (the rules pertaining to devices
that end up outside the north-south boundaries will be as described previously)
provided the payload of that device ends up outside the launch area.
(e) If only one of the two flying/projectile
devices manages to fly over the suspended rope, then that team will be declared
the winner irrespective of the location of its final resting place.
(f) During a contest, if your team gets a bye,
or your opponent(s) do not show, your team must be prepared to compete against
a placebo device.
8.
Weather
Since the outdoor contest will be held in
March, there is a possibility that rain may cause disruption of the event. It
is likely that we will proceed with the contest in the event of light or
occasional rain showers. Otherwise the
event may be moved to the gym which is available on that afternoon. However,
some of the parameters of the contest may have to be changed to fit within the
confines of the gym. Alternatively, the
contest may be postponed.