MagLev C

[darkwinters]

Just out of curiosity, has anyone here actually had successful results with the kelvin strips?

We got them, just to sorta see what they'd be like, and just from some preliminary running magnets-against-magnets, I'm not entirely confident that, once we actually build the cart, the strips will be able to support it if it's not pretty light.

Thoughts?

I used kelvin strips last year to support 2.5kg. Though I didn't use kelvin strips for the vehicle, I choose to use ceramic magnets (square with round holes) for the vehicle.

Just wondering, how many magnets did that take?

[Jdogg]

Just wondering, how many magnets did that take?

Not that many. Maybe around 300g of magnets on the car? I mean it's totally doable and can be done for very cheap. I know the square magnets we used came in a pack of 100 from kelvin and we had enough to make several cars.
Though that was our state vehicle last year and that car only got around a 5500 score at states. Our national car used a different track and different set up of magnets and brought our score up to 8400 at like .83m. That was with last years scoring though. Speed and weight don't matter as much and it's all about getting a 2kg car to be consistent.

[twototwenty]

Just wondering, how many magnets did that take?

Not that many. Maybe around 300g of magnets on the car? I mean it's totally doable and can be done for very cheap. I know the square magnets we used came in a pack of 100 from kelvin and we had enough to make several cars.
Though that was our state vehicle last year and that car only got around a 5500 score at states. Our national car used a different track and different set up of magnets and brought our score up to 8400 at like .83m. That was with last years scoring though. Speed and weight don't matter as much and it's all about getting a 2kg car to be consistent.

Actually, weight is still very important, up to the 2 kg limit. And I have to ask, how did you manage to get the kelvin stips to levitate that much weight? (When you say kelvin strips, I am presuming that you mean the magnet strips that come on the standard kelvin tracks). That is what I have used for the past two years, and I haven't been able to levitate more that 1 kg with them - I had always assumed that the teams levitating 2+ kg had made their own tracks with stronger magnets.

[Jdogg]

Actually, weight is still very important, up to the 2 kg limit. And I have to ask, how did you manage to get the kelvin stips to levitate that much weight? (When you say kelvin strips, I am presuming that you mean the magnet strips that come on the standard kelvin tracks). That is what I have used for the past two years, and I haven't been able to levitate more that 1 kg with them - I had always assumed that the teams levitating 2+ kg had made their own tracks with stronger magnets.

Yes I'm referring to the standard magnetic tape that comes with the kelvin track. I just stacked magnets on top of each other last year, using a lot of magnets on the car.

[darkwinters]

In the rules specifying the propeller shielding: do they want us to build/use something akin to the mesh around a household fan?

Or do they just want us to obstruct your ability to touch the fan from the side, but leave the front/back of the fan exposed?

[Phys1cs]

darkwinters,

We were told it had to be completely shielded by not having the dowel touch the prop in any angle. This would be a full-on shield so nothing could be touched. A lot of duct fans have side casings so those you would just need something on the front and back of the duct. If you have one of the free propellers without a casing around it, the two things I have seen people do have been to either make a duct fan type case around their car (it also helps funnel air flow) and then put a mesh on the front/back, or to just make an entire shield out of mesh, and find a way to keep it on your car.

https://www.google.com/url?sa=i&rct=j&q ... 1080242718
this is one of many duct fans, but one I have seen a lot of people using

[Flavorflav]

this is one of many duct fans, but one I have seen a lot of people using

I hope not. It has a brushless motor.

[GeoChamp96]

this is one of many duct fans, but one I have seen a lot of people using

I hope not. It has a brushless motor.

You can just order the duct without the brushless motor and buy a brushed one. That's what my team did. Just make sure the shaft diameter of the motor you select matches that of the fan. Otherwise, you're in for a lot of machining... My partner spent 4 nights (3 hours a night) with a mill and a lathe, making a little brass contraption that would allow our motor to fit inside the fan.

[iwonder]

That was our problem with ducted fans, they were all brushless...

And the fact the your partner has a lathe automatically makes it awesome

[GeoChamp96]

That was our problem with ducted fans, they were all brushless...

And the fact the your partner has a lathe automatically makes it awesome

Haha, yeah. Although that's the only time we've used it. It's expensive, and her dad is quite fond of it.