MagLev

{{EventLinksBox }}
 * active=yes
 * type=Physics
 * cat=Build
 * 2010thread=2010 (CoT)
 * 2011thread=2011 (Trial)
 * 2012thread=2012 (Trial}
 * 2013thread=2013
 * C Champion=Ward Melville High School (Trial)

General
MagLev is a Division C event for 2013.

Originally called Car of Tomorrow, this event has been run as a trial in New York and Wisconsin. It was run as a Division B trial event at the 2011 National Tournament and as a Division C trial event at the 2012 National Tournament. In 2012, New York ran the event as a Division C trial under the full name Magnetic Levitation.

The official rules for the 2012 New York trial event can be found here.

Basics
Car-Compeditors are required to build a vehicle. It must move down a track on fans. It must magnetically levitate (pemanent, non-rare earth magnets) on the track.

Prediction-With any given distance between 50.0 and 95.0 cm, in 1 cm increments, the compeditor must predict run time of the vehicle.

Test-The other significant portion of this event is the test. The test counts for about half of the overall score. It covers a broad range of topics within the general field of magnetism from the physics related to magnets and magnetic fields, to modern practical applications of magnets (such as maglev vehicles).

Parts
Propellers-These should be modified to have a 45 degree angle from the motor. You also want long, straight, and large (surface area wise) propellers to get the highest performance. Remember, the larger the diameter, the better the propulsion (to an extent, of course).

Motors-You want mostly high speed motors. They have to push air to move a car almost frictionlessly. High torque therefore is not as necessary as other events like Battery Buggy.

Chassis Base-This part needs to be light enough to not weigh back the motor, yet strong enough to withstand countless impacts, vibrations, and motor kickback.

Chassis Tower-This part must be secured to the base in order for it to not fall off. It holds up the motor. It must withstand perpendicular pressure from the fans. It also must be low. It needs a low center of gravity so the car doesn't tip. But you don't want it too low, or else it will scrape the track.

Magnets-Very possibly one of the most important parts of the car. It must have magnets in order to float. They must be permanent (not electro) magnets, and not rare earth magnets. For magnet placement, see Miscellaneous:Track.

Requirements/Qualifications/Parameters
Length-The car may not exceed 22 cm in length, while not being below 15 cm in length.

Mass of Car-The mass of the car must be over 250 grams, though I don't recommend any mass higher than 300 grams.

Power-The car may have a battery no greater than 9 volts, or multiple batteries connected together that do not exceede a total of 9 volts, used to power motor(s) and propeller(s). They cannot power anything else. Yes, this means you can't have electro-magnets.

Dowel-The car must have an dowel measuring 30 cm long with a 1/8" diameter attatched vertically to the vehicle. It must be attatched within 5 cm of the front of the vehicle. The dowel is counted in the total mass.

Magnets-See above.

Height-Less than 20 cm tall, excluding the dowel, when non-levitated.

Width-Oviously, the car must fit inside the track. However, it improtant to build your car so that there is a small amount of "wiggle room" so that there is minimal drag between the car and the track. Futhermore, all of these tracks are unfortunately not the exact same size; the rules allow that the width may be 2mm more or less than the "official" track dimensions. Therefore, it is strongly recommended that car is built to have adjustable width, and this, if applied, is a very major part of the construction process. The only true specification given is no part of the vehicle, with the exception of the propellers, can extend outside the track at any given time.

Track-The track consists of two metal sides and a metal bottom. It has two magnet strips in the corners of the track. It looks like this:





The car therefore must have magnets at its edges so that it can levitate on the track. The track must be longer than 4', with a mark at 4'. The inside width is between 2" and 3", and the top railing between 2 cm and 5 cm.

Start of the Track-The car should be started from a point on the track marked (the rules say exactly where). It is easiest to start the fans and then have a pencil or something of that manner blocking it from moving. Then you should release the pencil just before starting the timer.

Target-The car should have a pillow or block of wood (that falls over, keeping the car from tipping) that is at the end that cushions the impact. The timer should stop as soon as this target is reached.

Competition Preparation
A very major part of the scoring for this event is the run time prediction, which, depending on the level of the competition, can very easily be placement-determining. Now, the Mag Lev tracks can be somewhat expensive, so make sure to try to find one you can use before you buy your own. Many school technology classes have them, so it is not impossible that your school might already have a track. If you can't get access to one, you should then go ahead and buy one if you can, because they really are a necessity for this event.

Anyway, the first thing to do is to adjust your car so that it runs down the track as fast as it can. To run well, the car needs to be balanced. This is accomplished by adding weight where needed, and by not overcrowding the device. One way to overcrowd is to have more than one motor arranged side-by-side. When this happens, if the device is slightly off weight, it may capsize and break. If your car is touching the edges of the track, it will need to be lubricated. You will need to experiment for yourself which lubricant is right for you.

Once you have your car running smoothly and swiftly down the track, it is time to actuallt test and time it. Test your vehicle running down the track, timing the vehicle, so you can begin to gather data so you can make accurate predictions. It may be benificial to derive a formula you can use to predict run time.

Make sure to record all of the data you collect. The rules require that you have both a graph and a table, and it is beneficial to your score to have the data on these match, but besides this, you really do need the data for the competition anyway because, as stated before, the run time prediction can be a determining part of your overall score.

Pre-competition
Impound-You will need to impound your car. It must fit the parameters (see above). You should also impound any tools/materials you might need for any repairs to your car, as some accidentsmay inevitably occur accross the course of your two runs. In addition, your graphs and tables must be impounded.

Score
Vehicle Score-The total vehicle mass divided by the run time. Run Score-The run score is the team's best vehicle score divided by the highest vehicle score at the competition, multiplied by 50. Time Score-Prediction plays a big role in this event. Much more so than any other event. It has a complicated formula. Check the rules at the link above.

Graph-Competitors will hand in a table with the data on it and a graph that matches the table. These will be scored as follows: 5 points for:

a.a complete table b.a graph c.the graph matches the table d.the labels are correct: team name and number, title, x and y axis titles, and x and y axis increments

Final Score-The run score, time score and exam score added together, minus all penalties. The best possible final score is 110, and the high score wins.

Run Preparation
It is important to make sure that you have all required materials. Remember to bring several new batteries, a backup propeller, tape, super glue, a copy of the rules, and any other tools or parts that are needed specifically for your vehicle.

During The Run
Check before the run to ensure the polarity of your magnets are correct. Ask any questions or clarify anything you need to know before running. Just remember, in this event, the MagLev track is only eight feet long, so the reaction time of the supervisor/timer will have a huge effect on time. However, if the timer is a bit late for every competing team, it will solely come down to the speed of your vehicle, so test it and make sure it can move very fast.

The Test
The test itself is about 20 minutes long. Depending on how large the competition is, you will take it right before or right after you test your car, or, if it is a large competition, you may have to pause your test to test your car.

Good luck!