Mousetrap Vehicle 10

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Mousetrap Vehicle 10

• Bro. Nigel Pratt
• bronigel_at_kellenberg.org

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Years ago.

• This is basically what you wanted to do
  (1986-1995)
• http//www.youtube.com/watch?vHqc9uexNL64
• The rules were very similar to what we have had
  with Wheeled Vehicle and Battery Buggy in the
  past.
• BUT THIS YEAR EXCITING CHANGES ARE IN STORE!!!

3
Goal

• Teams will build a Mousetrap powered vehicle
  to travel 7 m down a track AND BACK as quickly as
  it can and end up as close to the point where it
  started as possible! Low score WINS!

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Parameters

• Only one or two unmodified snap mousetraps (bases
  must be lt 6 x 12 cm) may be used as energy
  sources.
• Unmodified means that all the original parts of
  the mousetrap(s) remain in place.
• Things may be added to the mousetrap(s), but not
  removed.
• They could be single spring or multiple spring
  mousetraps.

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Parameters (contd)

• 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.
• All of the vehicles kinetic energy must
  originate from the mousetrap(s).
• Conversion of the mechanical energy of the
  mousetrap(s) spring is permissible, but any
  additional energy sources must be at their lowest
  states at the beginning of the run.

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Parameters (contd)

• The vehicle must have a clearly marked fixed
  pointed object on the exterior of the vehicle
  that extends down to 1.0 cm of the tracks
  surface. This fixed point will be used as the
  reference point on the vehicle for all distance
  measurements.

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Parameters (contd)

• The vehicles wheel base is the distance measured
  parallel to the direction of travel between the
  center of rotation of the front and rear axles,
  and it must be between 30.0 and 34.0 cm.
• The vehicles width is the distance measured
  perpendicular to the direction of travel between
  the outermost side of the left and right wheel of
  the vehicles widest axle, and it may not exceed
  25.0 cm.

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Parameters (contD)

• Sighting devices which do not use electricity are
  permitted. All sighting devices must be
  permanently attached in a fixed position and
  travel with the vehicle.
• No part of the vehicle, other than the wheels,
  may contact the floor or tape defining the track
  at any time.

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The track

• The competition will be on a straight and level
  lane with a relatively smooth, hard, low-friction
  surface.
• Three quarter or one inch tape will be used to
  define the tracks starting line, and lines at
  3.5 m, 7.0 m and 8.0 m from the starting line.

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The track (Contd)

• The same tape will be used to define the 1.50
  meter lane side boundaries from the starting line
  to the 8 m line.
• The center of the start line will be indicated
  with an arrow drawn in ink pointing toward the
  inside tape, The 7 m line will be likewise
  marked.
• The distance between the two arrows will measure
  exactly 7.0 m.

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The track (contd)

• Additional space must be provided in all 4
  directions of the lane to allow for the vehicle
  over-running the track.
• At the National Tournament, there will be 0.50
  meters of additional space outside the lane side
  boundary and there will be 2.00 meters of
  additional space beyond the starting line and the
  8 m line.

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The track (contd)

• Every 0.50 meters of additional space beyond the
  8 m line will be marked with tape.
• The additional space requirements for Regional
  and State tournaments will depend on the
  availability of the venue.
• Realize that ALL levels of competition SHOULD
  have a similar set up.

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The competition

• The students can chose to start their vehicle
  anywhere along the starting line with the
  designated fixed pointer directly above the
  starting line.
• A target may be placed at the 7 m finish line to
  aid in aligning the vehicle, but must be removed
  before starting each run.

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The competition (contd)

• The vehicle must be able to remain at the
  starting position without being touched until the
  trigger is released using a pencil, pen, dowel,
  or similar device.
• which is not a part of and does not travel with
  the vehicle
• It is considered a run if the vehicle moves any
  distance after the trigger has been released.
• So if it doesnt move, its not a considered a
  run.

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The competition (contd)

• The students may not push the vehicle nor will
  they be allowed to constrain the vehicle during
  release.
• The fixed pointer of the vehicle is to cross the
  7 meter line (but NOT the 8 m line) and return as
  closely as possible to the center of the starting
  line as quickly as possible in order to receive
  the best score!!!!

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The competition (contd)

• Reversing and stopping mechanisms must work
  automatically. The vehicle may not be tethered
  or remotely controlled in any way to guide it,
  reverse it, or make it stop. Recoil in NOT
  reversing.
• So, you cant do this.
• http//www.youtube.com/watch?vVO_k9Hkz_oU

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The competition (contd)

• Teams will have 10 minutes of Event Time in which
  to get two runs started.
• 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 10
  minute period has elapsed, it will be allowed to
  run to completion.

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The competition (contd)

• Teams may not follow their vehicle down the
  track.
• 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.

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The competition (contd)

• 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

• The Run Score shall be the sum of the Distance
  Score Lane Bonus Overrun penalty Time
  Score.
• Negative scores are possible.
• LOW SCORE shall be the winner.

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Scoring distance score

• For vehicles that reach 7 m AND reverse, the
  Distance Score shall be the distance measured in
  centimeters (to 0.1 cm) from the center of the
  starting tape to the tip of the fixed pointer.
• Penalties
• Reverse, but lt 7 m and gt 3.5 m add 1000 pts.
• Reverse, but lt 3.5 m add 2000 pts.
• Do NOT reverse, Tier 2, Distance Score Absolute
  value of 700 distance from center of the
  starting line to the fixed pointer.

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Scoring lane bonus

• There shall be a -20 point Lane Bonus awarded to
  any vehicle whose fixed point remains inside the
  tape defining the 1.50 meter lane between the
  starting line and the 8 meter line while
  traveling in both directions.

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Scoring overrun penalty

• If the fixed point of the vehicle crosses the 8
  meter line, an Overrun penalty shall be assessed
  as follows
• 50 points shall be added for crossing the 8 meter
  line
• An additional 50 points shall be added for each
  additional half-meter of travel.

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Scoring time score

• The Time Score shall be the time of each run in
  seconds measured in 0.01 seconds.
• The time of the run starts when the vehicle
  begins movement.
• If the vehicle does not reverse within 3 seconds
  after coming to a stop, the total run time will
  be the time of motion plus the three seconds.
• If the vehicle reverses direction, the run time
  will stop when ALL motion ceases.

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Scoring time Score (contd)

• At Regional competitions, the Time Score shall be
  added as 1 point for every second.
• At State competitions, the Time Score shall be
  added as 2 points for every second.
• At National competition, the Time Score will be
  added as 4 points for every second.

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Scoring Run violations

• If the vehicle starts moving in the wrong
  direction, it is considered a failed run.
• If the vehicle is inadvertently started, it is
  considered a failed run
• Any other violation of the Competition parameters
  (not wearing goggles, etc.) will result in Tier 3
  placement.

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Scoring construction violations

• Construction Violations will result in a Tier 4
  placement.
• Examples include no fixed pointer, no triggering
  device, not the correct dimensions, etc
• If the device cannot start one run or has 2
  failed runs, the team will receive
  participation points.

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Scoring - tiers

• Teams will be ranked in six (or more) tiers using
  the single run that will give them the best
  overall place where
• 1st Tier Reverses
• 2nd Tier Doesnt reverse.
• 3rd Tier Competition Violation
• 4th Tier Construction or Competition and
  Construction Violations
• Participation points

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Scoring (contd)

• 1st Tie Breaker
• The team with the lower Distance Score of the
  counted run.
• 2nd Tie Breaker
• The 2nd Run Score

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Scoring example

• At a State competition, the run took 15.80
  seconds. It crossed both the 7 and 8.5 meter
  marks, but not the 9 meter mark, and ended up
  with its fixed point 18.6 cm from the starting
  line. It stayed within the lane for the entire
  run.
• Time Score 31.6 points (15.80 sec x 2
  pt/1 sec)
• Over-run Penalty 100.0 points (50 passed 8.0 m
  50 passed 8.5 m)
• Distance Score 18.6 points
• Lane Bonus -20.0 points
• Run Score 130.2 points (31.6 100 18.6
  20)

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So how do you make a good one?

• So for a basic construction
• http//www.youtube.com/watch?vOOobN0bUxqsfeature
  fvw
• 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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• Wheels
• - 3 wheeled v. 4 wheeled
• Type Rubber, balsa, plastic (DVDs), etc
• Diameter Should both axles have the same size
  wheels?
• Energy Transfer How will you transfer the energy
  of the spring to the axle for maximum speed?
• Directly v. Indirect (spring, rubber band)
• Torque issues are very important here Axle
  thickness
• 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?

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Squeeze out EVERY mJ you can.
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(No Transcript)
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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 doesnt
• Length of drive arm short v. long
• Please, please forgive us for the following
• http//www.youtube.com/watch?vwZDSfRe5opo
• How will you make it reverse???
• Lets take a brainstorming session..

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• Ideas
• A
• A
• A
• A
• A
• A
• A
• A
• A
• A

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• Ideas
• Each mousetrap drives each way.
• Two mousetraps drive ½ way then back
• Use the string to act as brake
• Use the wing nut/axle brake
• http//www.youtube.com/watch?vRJwFtkFSuJM