HUGE Magnet VS Copper Sphere - Defying Gravity- Will a Neodymium Magnet Float Inside?

I recently made this seventeen pound copper  tube to experiment with Lenz’s Law using this terrifyingly powerful neodymium magnet. It's fascinating to watch the magnet seemingly defy gravity while it  floats to the bottom of the tube, This happens because as the magnet moves,  it creates electric currents in the copper, which in turn create magnetic fields  that oppose the magnet's motion. This invisible resistance slows the fall, making  it look like the magnet is defying gravity.

What's even more fascinating is that when  I place the magnet in the tube and spin it, the magnet stays suspended in the center. This got me thinking, will a spherical magnet  float in the center of a copper sphere? Well in today's video we’re going to find out but first I need to make a copper  sphere that we can actually see into I wasn't sure how I was going  to design something like that until I noticed one of my dogs favorite toys.

Here's what I designed. It's as close  I could get to a sphere while still being able to see the magnet through it. This  actually called a truncated Icosahedron but that's a mouthful so for my sanity  I’ll just refer to it as a sphere.

I started by 3D printing it in PLA plastic. I’ll use these 3D prints to make  a mold out of ceramic shell. It came off of the printer looking  pretty good but I still needed to spend some time cleaning it up  to get it ready for casting.

Next I’ll attach some sprues. These are  what I’ll pour the metal into and they're really large because  they'll also act as risers, supplying the castings with molten  metal as they solidify and shrink. Here's the ceramic slurry that I use. 

Over the course of about a week I’ll dip the models into the slurry a total of nine  times in order to build up a thick shell. In between each layer I’ll coat them with fused silica sand. This helps thicken the  shells and also adds some strength.

Making complex shapes like these  is where casting in ceramic shell really shines. There's no way  I could make these any other way and having a machine shop make  them would be incredibly expensive. Next it's into the kiln to burn away the plastic  and turn the shells into a strong ceramic.

I don't just burn away all of the plastic though, once the temperature is high enough for  it to liquify I remove most of it, and then return the shells to the kiln  and fire them at 1600° Fahrenheit. Here’s all the copper I’ll be  melting. This is nine pounds or about four kilograms.

It’s mostly copper  pipe with some wire thrown in there also. It’ll take about an hour to melt this amount. Copper is always fun to melt because it  creates these really cool looking green flames when I add fresh pieces to the crucible.

Once the copper is hot enough to pour  into the shells. I’ll quickly remove the shells from the kiln while  they’re still extremely hot, place them on some sand to catch any  spills and then pour in the metal. It’s always amazing to me that for all the  prep work and time that I put into thinking about how to do this, figuring out how  to execute it properly without fumbling around or making any mistakes it only takes a few seconds or so to cast these and then they're done, Its out of my hands.

I’ve done this hundreds of times by now,  but I still get a little rush of adrenaline every time I pour a casting and I  think that’s mainly because of how much work has led up to this point and I just want everything  to go right and fortunately most of the time it does. Now I just have to wait for them to completely cool overnight before I can  begin removing the shells. I'll have to use my sandblaster to carefully  remove the shell because I can't risk trying to break it off since copper is so soft.

I could  end up deforming the castings in the process. This is actually really satisfying.  Instead of just slowly blasting the whole thing away, I try to cut large pieces off.

To give you some idea, each shell  took about thirty minutes to remove. These castings turned out super nice looking.  You can see these booger looking things here which are caused by air bubbles as  I dipped the models into the slurry, these are easy to remove with a chisel and  besides that they're just about perfect.

Now I’m drilling a hole in the center while I  have something to hold onto in the vise. It'll make it easier to file in the pentagonal shapes  later on. You’ll see what I mean in a minute.

I wonder what I could use these for? Any Ideas? It's important that the pentagonal  holes are filed straight and precise, as I'll be 3D printing plugs  to fit perfectly into them.

These plugs will serve as the points  where I’ll be able to spin the sphere, so the fit needs to be exact for  smooth and balanced rotation. The last step is to polish each facet and  this little belt grinder really made it easy. I'm using a Scotch-Brite like belt, which can  polish each facet in just a few seconds.

Since it's solid copper, though, it heats up quickly,  so I have to cool it down in between each one. Well here it is. I think this turned  out incredibly cool looking.

Honestly, even if I had made it just to have something  interesting to look at, I’d still be happy. Okay, let's find out if it actually works. Here are the plugs that I’ll press into those  holes I filed in.

Hopefully they'll stay put. The magnet I’m using is a two inch  N52 Neodymium magnet. It's the most powerful grade you can buy as far as I know.

To hold the sphere together I printed  some clips which should do the trick. And I also made a stand for everything to sit on. Okay so I’ve resisted actually  spinning this thing up until this moment so hopefully something cool happens.

Oh yeah it is, it's actually  floating right there, look! There, now it's kind of  falling but, at the right speed Right there! Yep Ah that’s so cool!

I wonder if I can get a better angle  on this, so you can see what I mean. Okay, so I changed up the lighting  a little bit and obviously it's a different angle so hopefully  you can see what I’m seeing. Yeah it is actually floating there!

It's just about getting the right speed. Right there. Yep Totally just floating there.

That's awesome! Ah man that's so cool! Let's try a drill.

So I think when I do it really  really fast centripetal force is just forcing it over to one side, I think. So obviously this is working but its  difficult to get it at a consistent speed. And also this plug isnt fitting there really  well I think its kinda worked itself loose so.

I’m going to need to re-print this and then uhm  in the future maybe I’ll hook it up to a motor, that'll make it a lot more consistent. So clearly it works but the effect isn't  quite as dramatic as I was hoping. There may be some ways I can improve on it  so let me know if you have any ideas.

Besides levitating a magnet, there are a lot of  other things that can be done with this thing. By using another magnet about a foot  away I can rotate the whole sphere. It's hard to show on camera just how strange it is to manipulate the magnet in here. 

It's almost like it's underwater. Let me know if you can think of some experiments  I should try and I’ll make a compilation video. If you would like to follow along with the  progress of my projects and help to support the channel then consider joining  my patreon for patreon only content.

I hope you enjoyed this video and  if you did then let me know in the comments give the video a thumbs up  and subscribe for future projects.