Magnets

blacklionboy

hi all
I am doing a project and we are looking to make floating wheels using magnet.

Now i need your help.
What is the lightest, magnetic material?

I mean really light as in 2grams/cm^3

Many Thanks!
Sean

mawk

http://www.lmt.uab.es/docs/docs/papers/2003/2003APL82_4307.pdf

lab in Barcelona invented these, ferro magnets mixed with aerogels. ranging from 0.14 to 0.22 g/cm^3.

thats preeeety light. also transparent which is interesting.


pdf above explains about them, http://www.uab.es/ there is the lab's address. id say contact them about procurement

blacklionboy

Thanks!!

Darren1o1

Try have a look at the technology behind the maglev. Also some interesting stuff with magnetics include magneto rheological fluids and electro rheological fluids. Depending on how detailed you get you could build some pretty decent FEA models relatively easily. Have a look out for FEMM, it is a pretty decent 2D FEA package for magnetic applications.

mawk

as a different solution, why not use some electro magnets and just make a nice strong magnetic field as opposed to using very light natural magnets? gotta be easier, or at least cheaper

blacklionboy

wont the battery weigh too much though?

mawk

well depends on how heavy the floating object is, how high it needs to float and for how long. button cells could give a high-ish voltage, just not for a long time.

why not use a permanent natural rare earth magnet for the floater and a repulsive electromagnet for the frame. then you dont need to life the weight on the battery

OR;

put a north charge on a high plate and a south charge on a low plate and make the wheel out of anything ferrous. the two magnet sides can pull it and push it respectively and make it float between the two plates. but that would probably take a proximity sensor and a micro controller to adjust the magnets. itd be cool though..

Wazdakka

Might be a bit late but I only just saw this..

Could be of some help
Dirt cheap, very strong magnets, just scroll down a bit on the page..
http://www.dealextreme.com/search.dx/search.magnet