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-About half of your score in this event comes from the car. It must move down a track on fans. It must magnetically levitate (pemanent, non-rare earth magnets) on the track.

Sled-The car must pull a sled that has a weight of anywhere from 50 to 200 grams in various icrements, depending on the level of competition (The smaller increments are used at the higher levels).



This is the method of sled attachment. The sled must be 4 inches long. It then must have a string that attaches to the car that is at most 3\4 inches long.

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 7" in length, while not being below 4" in length.

Mass of Car-The mass of the car may be anything over 200 grams, though I don't recommend any mass higher than 300 grams.

Power-The car must have one or two 9 volt batteries powering motor(s) and propeller(s). They cannot power anything else. Yes, this means you can't have electro-magnets. Also it must have the batteries wired in parallel, not series, which is still only 9 volts, if you use multiple batteries. It shouldn't take a Shock Value person to figure this paragraph out.

Eye Screw-The car must have an eyescrew with at least 1/8 of an inch free attached to the car.

Magnets-See above.

Height-No requirements that I know of.

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.

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 same goes for the sled. It is an eight foot long track.

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. To do this, you will need to build a test sled to carry weight. It doesn't need to be anything special; just make sure it runs down the track without dragging on the sides or bouncing around. Once you have your sled, you can test your car, timing it multiple times while pulling various weights, using weight inrements relative to the level of competition that you are preparing for.

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 reaally 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
Run Score-The team that goes the fastest gets 100 points. Other teams get their points by this formula: The team's fastest time on the data sheets/the teams fastest time, then multiplied by 100.

Prediction-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-These add up to create the total score.

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!