MagLev C

[mp727]

My maglev car is not working. It looks like it is getting stuck to the track and I tried fixing it by putting tape on the side rails of the track, but it seems like it isn't working. I don't know what else i can do. Also my car doesn't weigh a lot either, so i dont really know what the problem is. I have a state competition in 4 days and I need to do something about it. Can someone please help me!

[FawnOnyx]

My maglev car is not working. It looks like it is getting stuck to the track and I tried fixing it by putting tape on the side rails of the track, but it seems like it isn't working. I don't know what else i can do. Also my car doesn't weigh a lot either, so i dont really know what the problem is. I have a state competition in 4 days and I need to do something about it. Can someone please help me!

Some things you can check for:
Are your car magnets spaced wide enough so they're centered directly over the track magnets?
Is the car just barely narrower than the track width?
Is the center of gravity low?
Sometimes higher side walls on the car may help.

I was in a really similar position last year before our state so don't panic, be patient, try those things and hopefully it'll work out! (It did for me)

[Stingray355]

Join the club only about half of the vehicles at our State competition were able to make a complete pass. Ours weighs very close to 2 kilos and I don't know if your lighter weight device is as sensitive to these same factors as ours but I can tell you where we found improvements. A key challenge this year is eliminating all sources of friction/drag (unless your design uses that to slow it down to run the designated time) The only parts of our device that actually makes contact with the track are two very small flanged roller bearings and the contact area is very small and has little friction. Note both are on the same side of the vehicle and the other side simply floats and never contacts the track, if it did there are two more flanged roller bearings that would be the contact points.
For us the need to have the track level was key to being able to run the longer times and also to run with any consistency. Our vehicle sees low or high points as a "hill or valley" and will react accordingly. We found that a good carpenters level is not precise enough and used it just to get it close. A more accurate indicator was the vehicle, we put it on the track without power of course and gently bumped it in both directions at all points on the track. Any deviations from level will show up in the behavior of the vehicle. This only takes a few moments and will allow the vehicle to run to its calibration.

Do this along with the suggestions made by FawnOnyx and I agree you will get it sorted out and be ready for the big competition. Good luck.

[jharmn]

On rule 2J, about the vehicle needing to operate in either direction: is this in reference to using the event-provided track, or is this relevant with bringing your own track as well (we have our own track)? With weight balance and prop torque change, this is a tricky issue that I don't want us to waste time tuning if it's not a real concern. Are we going to have to run the vehicle in both directions in order to get valid runs? This isn't entirely clear from the rules. We didn't do this event for regionals, and I haven't seen it conducted before, and wasn't sure about how this aspect works.

[Schrodingerscat]

On rule 2J, about the vehicle needing to operate in either direction: is this in reference to using the event-provided track, or is this relevant with bringing your own track as well (we have our own track)? With weight balance and prop torque change, this is a tricky issue that I don't want us to waste time tuning if it's not a real concern. Are we going to have to run the vehicle in both directions in order to get valid runs? This isn't entirely clear from the rules. We didn't do this event for regionals, and I haven't seen it conducted before, and wasn't sure about how this aspect works.

(Standard disclaimer: This is not the place for rule clarifications, any opinions expressed have no official standing)

My understanding is that at least the primary intent of 3.J is for photogate systems that cannot easily be reversed. Thus the event supervisor can require students to always enter and leave the photogate in one direction; however, it also says that you can rotate the track so your vehicle always moves one direction down the track.

[blakinator8]

Does anyone have the ideal time / winning scores for the vehicles from nats?

[sciolycoach]

Here is the information on Maglev from the National Tournament this past Saturday:

Ideal Time: 5.0 seconds (this was picked at random by a student in the first time block from a stack of cards)

There were 24 / 58 teams (2 NS) that had a time score of at least 20.0 points with a max time score of 24.90.

Heaviest Mass: 1999 g

There were 21 / 58 cars that had a mass of at least 1800.0 g that made at least one successful run

I was particularly impressed by the variety of methods students used to slow down their cars. I personally saw at least three very different, yet highly successful, methods for slowing down their car. Of course (as is described on here), I saw rheostats, but I also saw spring-loaded switches for turning the motor on and off, and I saw some teams put barriers over their fan guard to restrict air flow, and that worked well for some too.

We had 51 / 58 teams successfully get at least one completed run, which was outstanding to see. This event has come a long ways in the four years I have seen it (2 years as a trial event) and thank you to all of you who put tremendous time and effort into the event. The level of student enthusiasm I have seen for this event has increased every year and it has been a lot of fun to watch the development over the years.

I was particularly impressed to see some cars, including some from teams who medaled at nationals, that were not expensive to build coupled with inexpensive tracks. While there are always some teams that will throw a lot of money at the problem to find a solution, I think one of the best performing cars actually used one 9V battery and the car was built using commonly-available (and inexpensive) supplies, however, the kids obviously knew how to adjust their car and did well.

Congratulations to everybody who competed at UCF on Saturday and have a fun and hopefully restful off-season. Good luck in the events you do next year (or college if you are graduating).

Andy Hamm
Maglev National Event Supervisor
UW 2011, UCF 2012, WSU 2013, UCF 2014