MagLev C

[twototwenty]

We will all have to wait a couple more days till we get the rules to see what is and is not legal.
Having flown gas powered model airplanes a few years, I think that you are significantly overstating the problem. The electric motor spins at a fairly high RPM but is not terribly strong, so when it hits the pillow at the end of the run, it will either stop turning or be trapped enough to turn it off - if - you have a switch or a quick disconnect in the power line.
If you are concerned with your personal safety, you might want to go to Kelvin.com and buy one of their safety props, assuming that it is of legal size.

Actually, safety was something of an issue. My team ordered special propellors that are highly effiecient, but very sharp, and this combined with a powerful motor connected to a powerful lithium polymer battery was no small hazard.

[retired1]

Safety should always be a concern. a remote on/off switch, electronic, is not required. A welders glove or a thick oven mitt would protect the hand. Our teams will go with a simple micro switch that is not close to the prop(s) and could be manipulated with a new pencil. KISS principle.

[iwonder]

While actuating a microswitch with a pencil is a very simple idea, I'd be careful about pushing the maglev into the track before you start it. When you remove the pencil chances are the maglev will bounce around for a little bit while it starts moving, this could effect time scores. it might be simpler to run a string around the back of the device and simply let go of the string. It'd add a little drag as the string pulls out of the vehicle(i.e. if you looped it around a screw on the vehicle) but I think that would be negligible, and it still allows you to keep hands/fingers away from the prop while starting. Personally, I'll probably have a switch mounted up front to stop the device at the end, and will hold the end of the maglev before launch(I'm a little more daring, I guess). Of course, there'll be a power switch at the back, but not a switch you have to continuously hold.

[twototwenty]

Well, my guess is the rules with regulate how you release your vehicle; in the past, you have had to hold a pencil in front of it and removing it when the ES says go...anyway, the release isn't the tricky part; it's the turning the motor off that is, because some cars flip over at the end of the track, or are bouncing around, especially with powerful motors, and getting to the switch has caused problems in the past.

[JBoyd-NY]

The maximum length of the track used for testing is 95.0 cm, which is roughly 3 feet 1.5 inches. If you build your own track, it must be 4 feet or longer. There's a really simple way to stop the vehicle to make it easy to turn off the motor, and it works if you have a purchased track that is 8 feet long or if you build your own track and make it 5 feet long. Just change the polarity of the track magnets beyond the 4 foot mark. When the vehicle passes the 4 foot mark (which would be the finish line if the event supervisor uses the maximum length for the test track), the vehicle will encounter the opposite polarity magnets and, instead of being levitated, it will be attracted to the magnets and come to a stop. Once the vehicle is setting on the track and is completely stopped, you can hit the switch to turn off the motor. This method of stopping the vehicle has been used in the New York State B Division competition in previous years with no problems.

[_HenryHscioly_]

the vehicle only needs to travel 95cm??!
That is so much shorter than 209.5cm
I am guessing I wont be using a hand timer for this event since the run times are so short; how do you time the vehicle?photogates?

[twototwenty]

Photogates are ideal, yes, but you cannot count on the Event Supervisor having them, especially at lower levels of competitions...I don't have my rules yet, so I don't know what provisions have been made for this, but hopefully there will be multiple people timing in a way similar to what was encouraged for helicopter last year if photogates are not avaiable.

As far as stopping the vehicle, an even simpler way than having the track magnets reverse polarity at a certain point is have a piece of metal at the end of the trackthat the car is attracted to and gets stuck on.

[iwonder]

I'm fairly new to the event, but I was wondering if competitive teams generally worry about drag on the vehicles? Do these travel fast enough for it to matter, or is it generally fine as long as it's not unreasonable?

[twototwenty]

I'm fairly new to the event, but I was wondering if competitive teams generally worry about drag on the vehicles? Do these travel fast enough for it to matter, or is it generally fine as long as it's not unreasonable?

For NY state last year, aprt from the test, it seemed like it was a matter of who had the best battery/motor/propellor materials...however, from what the event supervisors who are on here have hinted at, the rules now disallow some of these fancy setups...I personally can't really answer this question yet, because I don't have my rules, but depending on how they've changed, finesse like that may play a much larger role than it did last year.

[DeathTriangleCoach]

I was on the committee re-doing the rules this year. The current version of the rules is absolutely nothing like any previous version. It's never been run as it is now. Similar in idea, yes, but it was re-written after the Coaches Clinic this year. Don't waste too much time speculating much until the rule manuals are available (which, per Nationals office, will not be until next week now...the C manuals didn't get printed until this past Monday, so they need to get packaged and sent to the respective states, then mailed out again. If on schedule, probably not going to see them until Monday or Tuesday at the earliest). The track is down to a 4 foot one now. Weight minimum on the vehicle, no carts anymore. Prediction time (like in Gravity Vehicle recently) is included. No ICs. Voltages and types of fan/motor are rewritten. So...be patient, all, be patient!