How would I make a magnet/electromagnet strong enough to lift a drum?

  1. My friend came to me today with an interesting problem. He wants to make some sort of magnet that will make the school band's drumline's snare drums, in essence, levitate. This is for a big school event and he wants to do something special this year. Is it possible to make such a magnet? If so, can it be made with a 4'x4' piece of sheet metal? Thanks ahead of time, SeaCrane1
     
  2. jcsd
  3. mgb_phys

    mgb_phys 8,952
    Science Advisor
    Homework Helper

    Levitate is tricky - there is a famous law that says you can't do this with a simple magnet, it's unstable.

    Those levitating globe toys use a computer and a set of varying magnetic coils to keep the globe in the centre. It's difficult to do over a larger area and the base has to be much larger than the thing you are levitating
     
  4. Which is why the metal plates would be approximately 3.5 times the diameter of the snare drums. The drums are about 13" in diameter, 9" tall, and weigh between 10-14 lbs. If the magnet would truly be unstable, then some support could be added. All I really want to know is if a magnet could be made to lift the drum.
     
  5. how does one put a electro-magnet to the mains, keeping in mind that i have built a Graetz bridge?
     
  6. sophiecentaur

    sophiecentaur 13,399
    Science Advisor
    Gold Member

    Lifting a steel object once an electromagnet is actually in contact is very easy. To work over a gap of as little as a cm is hard and, as has been mentioned, unstable.
    If you want to produce Levitation then use a few thin wires which will achieve the illusion and be more reliable. With the right lighting, it will be fine. It's what all illusonists use and they should know what's best.

    Steer clear of 'the mains', my friend, until you really know what you are doing. The diode bridge rectifier is the least of your concerns.
     
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