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This PowerPoint is based on the DRAFT rules for Mousetrap Vehicle The rules may have changed. The rules and parameters in the 2013 Rules Manual is the final say. 2

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??? SO WANNA WIN??? Design your vehicle to…. Design your vehicle to…. GO FAST (More so this year!!!) GO FAST (More so this year!!!) GO STRAIGHT GO STRAIGHT GO A PRECISE DISTANCE GO A PRECISE DISTANCE ….AND DO IT ALL CONSISTENTLY!!! ….AND DO IT ALL CONSISTENTLY!!! 3

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!!! 4 (THIS CAR IS LEGAL FOR THE YEAR 2013!!!)

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. 5 ALL to be explained as we go along!!!

CONSTRUCTION PARAMETERS 6

snap 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. 7

All of the vehicles 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 cant be added to increase its PE. 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. 8

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 tracks 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. 9

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. 10

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. 11

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. 12

The competition will be on a smooth, level, and hard, low-friction surface. 1 Tape will be used to define the tracks 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. 13

Starting Line 0.5 m Line Target Point Target Point Distance m (1.0 m inc): Regionals m (0.5 m inc): States m (0.1 m inc): Nats 8.5 m Line Start Point Caution: This diagram is NOT in proportion. The track width is only 0.75 m wide for the 1 st 8.5 m. Timed Distance

The Competition 15

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. 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. 16

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. 17

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. The team may not push their vehicle nor will they be allowed to constrain the vehicle during release. 18

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, including the Measurement point (caution*). 19

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. 20

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. LOW SCORE shall determine the winner. 21

1 st Tie Breaker The better non-scored run. 2 nd Tie Breaker Faster time on the scored run. 22

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. 23

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 measurement point passes the 0.5 m line, (with a score of 5000) If any part of the vehicle leaves the 0.75 m track before the measurement point crosses the 8.50 m line If the vehicle starts moving before the ES is ready (with a score of 5000) If the team picks up the vehicle before it can be measured (with a score of 5000) Umm….any other Run Violation!!! 24

25 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….

vehicle! 26

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 27

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? 28

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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 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) 31

Wheels # - 3 wheeled v. 4 wheeled Type – Rubber, balsa, plastic (DVDs), 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 32

For a very basic kit, go to He also has a book: 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. 33

Div B Rules 2012 File on CD of pics of almost all of the National Mousetrap Vehicles Non SO

Div. C 2011: Rules where the vehicle had to reverse and come back. Uses one mousetrap each way: Uses both mousetraps simultaneously

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