MOUSETRAP VEHICLE B ‘13
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WARNING!
This PowerPoint is based on the
DRAFT rules for Mousetrap Vehicle
2013. The rules may have
changed. The rules and
parameters in the 2013 Rules
Manual is the final say.
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THIS YEAR….
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Finished mousetrap build (non SO)
The rules ARE similar to ones in the past and yet different in a UNIQUE sort of way.
SO WANNA WIN???
 Design your vehicle to….
 GO FAST (More so this year!!!)
 GO STRAIGHT
 GO A PRECISE DISTANCE
 ….AND DO IT ALL CONSISTENTLY!!!
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GOAL…..
As in the past, travel a selected distance as fast
as possible, go straight as an arrow and stop
on a dime….or more precisely a Target Point!!!
(THIS CAR IS LEGAL FOR THE YEAR 2013!!!)
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DIFFERENCES FROM LAST YEAR!
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One or TWO mousetraps.
Vehicle dimensions changed.
NO prediction time so NO predicted time score.
NO Center Line Bonus
Finish as close as you can to a Target Point instead of
a Target Line. Harder!
Run time is NOT started at the beginning nor ended at
the END!!!
Vehicle must be built to carry an object supplied by
the Event Supervisor.
ALL to be
explained as
we go
along!!!
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CONSTRUCTION
PARAMETERS
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PARAMETERS

Up to TWO unmodified snap
mousetraps (base must be < 6 x 12 cm) may
be used as THE energy source.
Unmodified means that all the original parts of the
mousetrap remain in place.
 Things may be added to the mousetraps, but not
removed. Careful, see rules!!!
 They could be single spring or multiple spring
mousetraps.
 Holes (up to 4) may be made in their bases, but
only for attachment purposes.
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PARAMETERS

All of the vehicle’s kinetic energy must originate
from the mousetrap.
Conversion of the mechanical energy of the
mousetrap spring to any other type of energy except
kinetic energy to drive the vehicle down the track is
NOT permitted.
 Things can’t be added to increase its PE.
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All parts of the vehicle must move as a whole,
i.e. no anchors, tie downs, tethers, launching
ramps, or other separate pieces are allowed.
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PARAMETERS
The vehicle must have the all important
“Measurement point”. It must be a bent paper
clip whose endpoint extends down to be within
1.0 cm of the track’s surface.
 It must extend beyond ANY other point of the
vehicle with the exception of the extension bar.
 This point will be used as the reference point
on the vehicle for distance measurements.
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PARAMETERS
The ENTIRE vehicle must be no longer than
80.0 cm long and 30.0 wide in ready to start
mode.
 After it begins its run…
 It can exceed 80.0 cm in total length.
 It cannot exceed the 30.0 cm width at any
time.
 It cannot exceed 90.0 cm high at any time.
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PARAMETERS
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It must be started with a trigger that can be
activated by using an unsharpened #2 pencil (to
be supplied by the ES). The action must be up or
down. (Obvious hint: Down is much better!)
Besides the wheels, only the drive string is
permitted to contact the floor at any time.
Sighting devices which do not use electricity are
permitted. All sighting devices can be removed
from the vehicle before it does its runs.
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PARAMETERS (THE REALLY NEW STUFF)

The vehicle MUST have built-into it a fixed location
which will accommodate a ¼” x 1.0 m wood dowel
(mass between 10 and 25 g) which will be supplied by
the Event Supervisor. This dowel will extend at least
1.00 m from the floor and be used to facilitate the
timing. The location can be anywhere along the body
of the vehicle.

The ES will NOT supply any material to help attach the dowel.
Vehicles unable to accommodate the supplied dowel will be
allowed to run but will be placed in Tier 3.
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THE TRACK
The competition will be on a smooth, level, and
hard, low-friction surface.
 1” Tape will be used to define the track’s
sidelines, Starting line, and the 0.5 and 8.5 m
lines.
 The Target Point will be on a 1” x approximately
5.0 cm piece of tape.
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THE TRACK
Timed Distance
Target Point
Start Point
Starting Line
Caution: This
diagram is NOT in
proportion. The
track width is only
0.75 m wide for
the 1st 8.5 m.
0.5 m Line
Target Point Distance
9 - 12 m (1.0 m inc): Regionals
9 - 12 m (0.5 m inc): States
9 - 12 m (0.1 m inc): Nats
8.5 m Line
The
Competition
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THE COMPETITION
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The vehicle must be impounded at the start of the
competition.
Teams will have 8 minutes of Event Time in which to
get two runs started. This includes aligning the
vehicle and attaching the dowel.
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The Event Time will begin when the Event Supervisor
finishes his instructions to the students.
Time needed for the Supervisor to take measurements after
the first run will NOT be part of the Event Time.
If the second run has started before the 8 minute period
has elapsed, it will be allowed to run to completion.
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THE COMPETITION
The Measurement Point must be on the Start
point at the beginning of the run.
 A target may be placed on the track to aid in
aligning the vehicle, but must be removed
before starting each run.
 The vehicle must be able to remain at the
starting position without being touched until
the trigger is released using the supplied
pencil.
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THE COMPETITION
It is considered a run if the vehicle moves any
distance after the trigger has been released.
So if it doesn’t move, it’s not a considered a
run.
 The team may not push their vehicle nor will
they be allowed to constrain the vehicle during
release.
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THE COMPETITION
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Teams may not follow their vehicle down the
track.
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They must wait until called by the Event Supervisor
to observe their finish distance and pick up their
vehicle.
At this point, the Event Time will resume.

Students may take any measurements and make
any adjustments to their vehicle, including the
Measurement point (caution*).
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THE COMPETITION
Measurements made by the Event Supervisor
are the only ones that will be used as the
official distances.
 Teams who wish to file an appeal must leave
their vehicle with the Event Supervisor.
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SCORING
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The RUN SCORE will be the sum of the
Distance Score + Time Score.
Distance Score = Measurement Point to Target
Point in centimeters (to nearest 0.1 cm). This is a
point to point measure.
 Time Score = Run Time x 5

 The
Run time is the time in seconds it takes to go from
the 0.5 m line to the 8.5 m line (to 0.01 s)
 ES are encouraged to use photogate systems, hence the
reason for the dowels.
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LOW SCORE shall determine the winner.
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SCORING
1st Tie Breaker
 The better non-scored run.
 2nd Tie Breaker
 Faster time on the scored run.
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SCORING – TIERS
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There will be 4 tiers of scoring
1: A clean run.
 2: Any run which has a run violation.
 3: Any run which has a construction or a run and
construction violation.
 4: If the device cannot complete any runs.
(Participation points only): If the vehicle never
moves during the 8 minute Event time.
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SCORING – RUN VIOLATIONS (TIER 2)
If the vehicle starts moving in the wrong
direction (with a score of 5000)
 If the vehicle disrupts the photogate timing
system
 If the vehicle is inadvertently started (with a
score of 5000)
 If the vehicle passes the 0.5 m line but its
measurement point stops before the 8.50 m
line
 If the vehicle moves but stops before its
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SCORING – TIER 3
Any vehicle too big
 Any vehicle that cannot hold the ¼” dowel
 Any vehicle that has the wrong size mousetraps
 Any vehicle that has modified the mousetraps
beyond that which is allowed by the Rules.
 Etc….
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vehicle!”
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SO HOW DO YOU MAKE A GOOD ONE?
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So for a basic construction:
 MAKE Magazine mousetrap (non S0)
Things to consider and discuss
 Dimensions of the vehicle
Keep in mind: KINETIC ENERGY
Mass, friction, efficiency of energy transfer
Experienced coach Wisdom re: rulers
Experienced coach Wisdom re: axles
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 Energy
Transfer: How will you transfer the energy of
the spring to the axle for maximum speed?
 Torque
issues are very important here – Axle thickness
The thicker the axle, the faster the vehicle, but….
 Thin axle gives you more distance, but….
 Axle to wheel ratio important

 Do
you want to have the energy delivered very fast to the
wheels and use momentum to travel down the course or
should the energy be applied at a constant (but slow)
rate to the wheels?
 Since you want speed for the 0.5 m to 8.5 m distance
only, can you design a vehicle that uses one mousetrap
to start it, then kicks in the other mousetrap (like
NITRO!!!) for the speed section?
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Squeeze out EVERY microJoule you can….
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 Mousetraps
– Check different manufacturers (Victors,
Tomcat, Bonide, D-con, Snap E, Clean Catch, etc…) for
Spring Constant – which has more energy to deliver??

Suggestion: Design the vehicle for quick mousetrap
replacement. Velcro, wire ties, etc….
 String
issues
 entanglement, “free string” getting caught in the
axles/wheels
 Type – String that stretches or doesn’t
 Release mechanism – the string needs to go free!!!
 Length of drive arm – short v. long

Long drive arm problem…..
 Please,

please forgive us for the following…
Geek Dad Mousetrap - corny but good hints (non SO)
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 Wheels
#
- 3 wheeled v. 4 wheeled
 Type – Rubber, balsa,
plastic (DVD’s), etc…
 Diameter – Should both
axles have the same size
wheels? GO….Medium!!!!
 Thick v. Thin – need to stop quickly, so…
 Braking
 Use
the string to act as brake
 Use the wing nut/axle brake
 SO Nut and Axle Demo
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
For a very basic kit, go to http://www.docfizzix.com/
 He also has a book:
http://www.docfizzix.com/how_work.htm
 Watch
out for…..
 Aim:
As the competition gets more intense, the difference
of just a few cm will drastically affect the results. Use a
non- electronic sighting device and a target and/or
alignment guide on the floor.
 SPEED. SPEED. SPEED. SPEED.
 Build cleanly and solidly!!!
 PRACTICE. PRACTICE. PRACTICE.
 Know the quirks of your vehicle.
 Find out what type of surface the competition will be on.
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SOME GOOD MOUSTRAP VIDEOS…
Div B Rules 2012
 File on CD of pics of almost all of the National
Mousetrap Vehicles.
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http://www.youtube.com/watch?v=QaiINzcf3dE&feature=related
http://www.youtube.com/watch?v=gVgIo2rQcVE&feature=related
http://www.youtube.com/watch?v=Hq3thqpkASM
http://www.youtube.com/watch?v=OW8-m17V4gY
Non SO
http://www.youtube.com/watch?feature=endscreen&NR=1&v=SzicVkpj28A
http://www.youtube.com/watch?feature=endscreen&NR=1&v=83b3zgqTzz
4
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SOME GOOD MOUSTRAP VIDEOS…
Div. C 2011: Rules where the vehicle had to reverse and
come back.
 Uses one mousetrap each way:
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http://www.youtube.com/watch?v=sIqMcze4034
Uses both mousetraps simultaneously
 http://www.youtube.com/watch?v=lkgQYco0-5g
 http://www.youtube.com/watch?v=IA1JPcdBkHE
 http://www.youtube.com/watch?v=q1Rr1vZLSvg
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