MagLev C

[retired1]

Take a look at the fine print. The top of the motor can not be any higher than the top of the rail. This is going to limit your prop size and it will be tiny props if you mount them side by side. Tandem, front to rear will work, but the rear prop will have to be a pusher prop rather than a tractor or a tiny prop.
I would like to see the definition of a ducted fan prop. There are ducted fans on airplanes that do not have a ring on the outside of the blades. The tolerances and the duct shape as well as the prop pitch are critical for optimum use. The half duct that you can buy is rather sloppy in clearances.

[_HenryHscioly_]

I just read through the rules, but I dont see a part that limits the motor to be lowerthan the top of the rail
which letter /section is it in?

[retired1]

3.f.
Note that this is a bit of a conflict with3.b. , which appears to be talking about the prop, which is impossible considering a max of 5.0 cm wall. Prop max dia would be in the ball park of 9.+ .

[wlsguy]

Take a look at the fine print. The top of the motor can not be any higher than the top of the rail. This is going to limit your prop size and it will be tiny props if you mount them side by side. Tandem, front to rear will work, but the rear prop will have to be a pusher prop rather than a tractor or a tiny prop.
I would like to see the definition of a ducted fan prop. There are ducted fans on airplanes that do not have a ring on the outside of the blades. The tolerances and the duct shape as well as the prop pitch are critical for optimum use. The half duct that you can buy is rather sloppy in clearances.

I think the requirement is the entire vehicle (except the propellers) must be within the track width.
The vertical planes should extend upward to the ceiling so I don't believe the height of the vehicle is limited.
Now, had they said "horizonal" plane, it would limit the height.

[retired1]

3.b. says that the max height is 20 cm. Eventually, they will open up the FAQ section and we can get an official interpretation.

You probably are correct about the vertical plane defining width. Which really opens up this event. If the motor is mounted on a pylon, you could use a large prop.

[Flavorflav]

I think it's pretty clear that the vertical plane of the side rails defines the width, not the height, which as you say is already set by 3.b. Vertical is not really an ambiguous term. Note also that 3.1 specifies the maximum width of ducted motor/propeller combinations, not ducted propellers. I envision this as applying only to ducted fans purchased with the motor in place, and so would not apply to a prop with a cowling to which you attached your own motor. I could be wrong, though - might be worth a clarification.

[twototwenty]

What is the rule regarding full magnetic levitation like? Is it similar to what was discussed on last year's thread, which was that when the car was pushed down while on the track, it would come back up?

[Flavorflav]

Rule 3.l actually just says "pushed down." Whether or not that implies "come back up" would be supervisor's discretion, I guess. I assume most would want to see some rebound, but the rule does not actually require it.

[_HenryHscioly_]

if the poles of a magnet or both facing the same direction, can two of them stick side by side?
if not, are the magnets along one side of the track not right next to each other?

http://www.pitsco.com/store/detail.aspx ... &l=&bhcp=1
has anyone used these?
Would the hole in the magnet make the levitation be not as stable?

And lastly, about how much clearance is there if 4 of these magnets are used on a ~300g vehicle?

[JBoyd-NY]

The poles of the ceramic magnets are on the face of the magnet - one side is North, the opposite side is South. You can place the magnets against each other to form the magnetic track.

The shortest vehicle allowed is 15 cm. Each magnet is 1" (or 2.54 cm) long, so two magnets on each side of the vehicle would take up just over 5 cm, leaving more than 9 cm of clearance, front to back.

The narrowest track you are allowed to build is 2" wide. Each magnet is .75" wide. Again, putting 4 magnets on the vehicle (two on each side) results in .75" per magnet, or 1.5" for both magnets, leaving .5" of clearance between them.

If you are asking how high the vehicle would float if it was ~300 grams, that depends on the magnets on the track and the magnets on the vehicle - you'll just have to try them out to see. My experience is that the ceramic magnets provide more lift than the magnetic strip, so if you are building your own track and can afford them, I'd go with the ceramic magnets (if you buy the package of 100, you will have enough magnets for a 4' track with the four magnets left over for your vehicle). If the 4 magnets aren't enough to levitate your vehicle, you can purchase more from Radio Shack in smaller quantities (more expensive per magnet, but cheaper than purchasing an entire bag from Pitsco). Or (if you have the money), Kelvin has the same magnets in a bag of 250 for $36.95, which you can purchase instead of the bag of 100 and that will give you plenty. If your vehicle is the shortest allowed (15 cm) you can place 5 magnets per side (total of 10 magnets on the vehicle) with room left over.

And yes, I've seen many tracks that use the ceramic magnets rather than the magnetic strip, and they work fine.