Bro. Nigel Prattbronigel@kellenberg.org

Dennis Papeshpapeshdr@holyangels.cc

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Teams will design, build, and test a vehicle which uses one or two single-spring mousetraps as their sole source of energy for propulsion.

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This is basically what you wanted to do (1986-1995) http://www.youtube.com/watch?v=Hqc9uexNL64

The rules were very similar to what we have had with Wheeled Vehicle and Battery Buggy in the past.

BUT THIS YEAR – EXCITING BUT THIS YEAR – EXCITING CHANGES ARE IN STORE!!!CHANGES ARE IN STORE!!!

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Only one or two unmodified single-spring mousetraps (not rat traps) 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. Mousetrap bases less than 6.0 cm x 12.0

cm

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All parts of the vehicle must move as a whole, i.e. no anchors, tie downs, launching ramps, or other separate pieces are allowed. If any piece falls off during a run, it is considered

a Competiton Violation. All of the vehicle’s 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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Reversing and stopping mechanism must work automatically.

The vehicle may not be tethered or controlled in any way to guide it, reverse it, or make it stop.

Recoil is NOT considered reversing.

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The vehicle must have a fixed, pointed object on the perimeter of the chassis of the vehicle that extends to within 1.0 cm of the track’s surface. Toothpick, pin, small nail Must be easily accessible to event supervisor

without lifting or moving vehicle The tip of this fixed, pointed object nearest the

track surface will be used as the reference point on the vehicle for all distance measurements.

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The vehicle’s 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 vehicle’s maximum wheel width is the distance measured perpendicular to the direction of travel between the outermost side of the left and right wheels and it may not exceed 25.0 cm.

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Sighting devices which do not use electricity are permitted.

Sighting devices do not have to be permanently attached and may be removed before the vehicle runs.

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 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 track’s starting line, a line 7.00 meters from the starting line (the “7 meter line”), and a line 8.00 meters from the starting line (the “8 meter line”)

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The same tape will be used to define the 1.50 meter lane side boundaries from the starting line to the 8 meter line.

The center of the start line will be indicated with an arrow drawn in ink pointing toward the inside tape, The 7 meter line will be likewise marked.

The distance between the two arrows will measure exactly 7.00 meters.

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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 meter line.

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Every 0.5 meters of additional space beyond the 8 meter 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 students can chose to start their vehicle anywhere along the starting line with the designated fixed point directly above the starting line.

A target may be placed at the finish line to aid in aligning the vehicle, but must be removed before starting each run.

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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 doesn’t move. It’s not considered a run.

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The students may not push the vehicle nor will they be allowed to constrain the vehicle during release.

The fixed point of the vehicle is to cross the 7 meter line and return to the center of the starting line as quickly as possible in order to receive the maximum score.

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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. So, you can’t do this….

http://www.youtube.com/watch?v=VO_k9Hkz_oU

Teams will have 10 minutes of Event Time in which to get two runs started.

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The Event Time will begin when the students are allowed to place their vehicle on the starting line.

Teams will have 10 minutes of Event time in which to get 2 runs started.

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If the second run has started before the 10 minute period has elapsed, it will be allowed to run to completion.

Time used by the Event Supervisor for measuring will not count toward the 10 minute Event Time.

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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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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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The Run Score shall be the sum of the Distance Score + Lane Bonus + Over-run penalty + Time Score.

Negative scores are possible. Low score shall be the winner.

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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 point.

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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 both directions.

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If the fixed point of the vehicle crosses the 8 meter line, an Over-run 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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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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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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Outlined in Section 5 (The Competition)

Will result in being ranked in Tier 3

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Construction Violations are outlined in Section 2 (Construction Parameters)

Will result in being ranked in Tier 4

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Teams will be ranked in four tiers using the single run that will give them the best overall place where: 1st Tier: A run with no violations and

reverses its direction of travel 2nd Tier: A run with no violations but does

not reverse its direction of travel 3rd Tier: A run with Competition Violations 4th Tier: A run with Construction Violations or

both Competition and Construction Violations

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1st Tie Breaker Distance Score of the counted run.

2nd Tie Breaker The vehicle’s other run score.

If the device cannot start at least one run within the 10 minute period, or has two failed runs, the team will receive participation point(s) only.

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At State competition, the run took 15.8 seconds. The fixed point crossed the 8.5 meter line, but not the 9 meter line, and ended up with its fixed point 18.6 cm from the center of the starting line. It stayed within the lane the entire run. No violations.

Time Score 31.6 points (15.8 sec = 15/8 sec x 2 pt/1 sec)

Over-run Penalty 100.0 points (50 passed 7.5 m + 50 passed 8.0 m)Distance Score 18.6 pointsLane Bonus -20.0 pointsRun Score 130.2 points (31.6 + 100 + 18.6 – 20)

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So for a basic construction: http://www.youtube.com/watch?v=OOobN0bUxqs

&feature=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 (DVD’s), 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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String issues entanglement, “free string” getting caught

in the axles/wheels Type – String that stretches or doesn’t

Length of drive arm – short v. long Please, please forgive us for the following…

http://www.youtube.com/watch?v=wZDSfRe5opo How will you make it reverse???

Let’s take a brainstorming session…..