Junkyard Challenge

“It’s a Snap”

CeAnn Chalkerchalker@ix.netcom.com

Dennis Papeshpapeshdr@holyangels.cc

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Object

Competitors will construct a device, partially on-site, to solve a creative

engineering challenge using only the materials and tools that will fit

in a “junk box” of specified dimensions.

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Materials - General

All materials and tools must be brought in a “junk box” with a lid with outside dimensions no greater than 40 cm x 40 cm x 60 cm when closed.

Competitors are allowed to construct their own box, made from any material, or use a box that is within the specified dimensions. The box may be used as a part of the device.

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Materials – General, cont’d

With all materials in the box, the lid must fit all the way on the box and close completely.

The box must be measured, contents checked for safety, and impounded before the event begins.

Teams that impound a box but fail to attempt construction of a device during competition will be considered a ‘No Show’.

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Materials - Required

Four unmodified mechanical ‘snap trap’ mousetraps (labeled 1, 2, 3, 4, for intended order of tripping), 1 standard unmodified golf ball, and ANZI 87+ safety spectacles with side shields.

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Materials - Prohibited

Acids bases, flammable liquids or powders, razor blades, rat traps, all forms of glue, power tools, modified batteries, batteries exceeding 6 V, and other potentially dangerous objects.Mouse traps hurt enough when they catch your

fingers. Trust me on that. Any prohibited or dangerous materials will be

confiscated at impound.6

Materials - Other

Teams must impound any other materials and tools needed to construct their device.

Parts of the device may be glued together before teams arrive at the tournament site, but gluing on-site is prohibited.

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Materials – Other, cont’d

Batteries may be used; however, they must be unmodified and may not exceed 6 Volts in any circuit.

All materials and tools must fit within the closed box as described in 2.b.

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Competition – Start Task

Teams will drop a standard unmodified golf ball into the device at its central point. Team name on ball is permitted.

The team must define the central point of the device. If central point is covered, perhaps a circle of

known dimension could be placed around it.

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Competition – Start Task

If the device covers the central point, mousetrap locations will be marked by the event supervisor and measured after the device operates.

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Competition – Task Completion

• The device must trip all 4 unmodified mousetraps within 1 minute.

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Competition – Additional Requirements

All devices will be assembled where space allows. (The floor is preferable.)

The mousetraps must be placed 90 degrees apart in a compass arrangement of North, South, East, and West. The Event Supervisor will probably arbitrarily

designate a direction to be North.

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Competition

The mousetraps must be unmodified.Unmodified means that all the original parts of the

mousetrap(s) remain in place and are fully functioning.

Precautions must be taken to ensure that mousetraps, tripping mechanisms, and other parts of the device do not become an unshielded projectile or other hazard to spectators or other devices around them.

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Competition – Distance Requirements

The distance between the closest point on each mousetrap and the central point of the device in each direction will range from 30.0 to 60.0 cm straight line distance.Students must be prepared to make the

adjustments to meet the required distances.

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Distance Requirements, cont’dThe exact distance (in 5.0 cm intervals at

Regionals; 1.0 cm intervals at State and National) will be chosen by the event supervisor and will not be announced until all devices have been impounded.

At Regionals and States, all 4 distances will be the same.

At National, each of the 4 distances may be different.

Mousetraps may be oriented in any direction.15

Competition, cont’d

Only competitors and event supervisors will be allowed in the event area during competition.

Once teams enter the event area to compete, they will not receive outside assistance, materials, or communication. Teams violating this rule may be disqualified.

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Competition, cont’d

If a team member leaves the event area before finishing, they may not return except as allowed by the event supervisor.

Construction begins and ends at the direction of the event supervisor.

Each team will receive 30 minutes to set up their device and only materials and tools impounded may be used.

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Competition, cont’d

Once construction begins, all team members in the competition area are required to wear ANSI Z87+ safety goggles with side shields at all times.

Teams without proper eye protection will not be allowed to compete.

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Competition, cont’d

Teams should notify event supervisors when ready to operate their device if construction is completed before the 30 minute time limit elapses. To ease time crunches, teams finished building

early may be allowed to demonstrate their device before others have completed their construction.

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Competition, cont’dFollowing construction and prior to operating the

device, the event supervisor will ask the team to explain device operation.

Teams will be allowed to make last minute adjustments (setting mousetraps, etc.) immediately prior to operating the device.

Event Supervisor will give a 3, 2, 1 countdown to start the device and timing will begin.

Timing will stop when the intended fourth mousetrap is tripped or when 1 minute is reached.

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Competition, cont’d

Actions occurring after 1 minute will not be scored.

If at any time during construction or operation, the device or actions of the competitors is deemed to be unsafe by the event supervisor, teams may either be warned to make adjustments or may be immediately disqualified.

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Scoring 100 pts for being ready to run within 30 minutes 33 pts for staying within box dimensions with lid closed 22 pts for having all required materials and mousetraps

labeled 58 pts for successful Start Task 60 pts for successful Task Completion 2 points for each second of operation to task completion

Up to 60 seconds 42 pts if device operates for at least 5 seconds before the first

mousetrap trip 35 pts for each mousetrap that is tripped by the device

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Scoring, cont’d 25 pts if North trap is tripped first 50 pts if South trap is tripped second 75 pts if West trap is tripped third 100 pts if East trap is tripped fourth

Order of trips must be plainly obvious

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Scoring - Penalties

Any action that is a direct result of a touch CANNOT earn points (e.g. a mousetrap that is tripped as a direct result of a touch cannot earn points for being tripped, the order of the trip, or for task completion).This may bring up some discussions concerning

“direct result” of a touch.

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Penalties, cont’d

• 18 points each time the device is touched.• 8 points for each whole centimeter each

mousetrap is off from the defined distance.

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Tie Breakers

Ties will be broken as follows: 1. Fewest penalty points 2. Longest time of operation 3. Shortest setup time

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Some ideasA simple trigger

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IdeasMechanical – electrical switch

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IdeasNot recommended – as is

Too easy to malfunction

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Ideas

Holes in both stirrers are 5 cm apart – easy to adjust length

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IdeasRemove all unused items

Wing nuts save a lot of time

Try to keep the same size bolts and nuts

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Ideas

With a metal ball – a simple electrical contact switch

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IdeasA simple electrical contact switch – in this case, when paper clip is pulled, wires drop free and break the circuit, shutting off the motor

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IdeasGolf ball down PVC into cup.

Cup descends, pulling string which goes through pulley at top to lift lever.

Lever descends, snapping trap.

String on trap pulls string on pulley leading to releasing blue marble.

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IdeasSnapping mousetrap in lower right (out of view) pulls string, releasing blue marble.

Marble rolls down and snaps trap with metal rod, flipping it over to hit lever.

Lever rises to pull string on third mouse trap.

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IdeasMarble down ramp, triggering mousetrap.

Arm on trap swings to hit lever.

Lever rises and pulls string through pulley to snap 3rd trap.

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IdeasString on 3rd trap releases golf ball.

Golf ball rolls down ramp, springing last mousetrap.

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Ideas

Golf ball dropped down center of tower. Nut knocked off lever. Lever knocks dominos down, tripping mousetrap. String on mousetrap releases trap door at top of cup tunnel, releasing marble to trip trap.

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Ideas

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Ideas

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Ideas

Final progression to move mousetrap farther from center.

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Ideas

Golf ball slowly rolls down ramp and activates a lever, the top of which snaps first trap.

Bottom of lever releases a marble to roll down and snap second trap.

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Ideas

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Long, low incline ramp can be used as a time delay.

Ideas

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Ramp support and lever set up.

IdeasGolf ball hits bottom of lever, swinging top of lever forward to strike mousetrap.

Bottom of lever swings opposite direction to release marble.

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Ideas

Bottom of lever swings to hit marble, sending it down PVC pipe to ramp to hit mousetrap.

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