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Hello everyone! I've just joined dakkadakka pretty much for the express purpose of asking this question, or rather posing this scenario.

I had this idea to magnetize the bottoms and bases of my flying necrons (destroyers, arks, barges- though that might be tougher- etc.) so they actually float off the table without the use of those dorky and quite easily broken stems. I was wondering if this is totally new and i'm doing something groundbreaking (which I doubt) or if someone has done (or attempted) a similar thing. Any advice is welcome!

It would be difficult and tedious to accomplish and would need powerful magnets to repel each other more than a half inch or so.

Plus you'd have to have some method of keeping the model tethered in place so the magnets could do their thing such as putting the whole thing in a clear acrylic tube which would defeat the goal of making them look like they're floating.

Oh I'm not saying it won't be tedious
I have it mostly figured out, actually. I was planning on tying the model down with some thin-gauge fishing wire to make sure it doesn't float away from its base, and I'd probably attach the wire with green stuff or something. As for the strength of the magnets, I'm using neodymium, a rare earth magnet, so I'm hoping strength won't be an issue
Thanks for the reply though~

You need an electromagnet or something to do this. Using 2 permanent magnets is inherently unstable and the model will just fall over. You don't have to worry about it floating away from the base, it'll just topple over.

You can buy magnetic levitation devices and I've seen one display model that used it as well. My coworker has a magnetically levitating globe sitting on his desk.

From wikipedia:
"Earnshaw's theorem proves that using only ferromagnetic or paramagnetic materials it is impossible to stably levitate against gravity, but servomechanisms, the use of diamagnetic materials, superconduction, or systems involving eddy currents permit this to occur."

https://www.google.com/search?q=magnetic+levitation+globe&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-USfficial&client=firefox-a#q=magnetic+levitation+globe&hl=en&safe=off&client=firefox-a&hs=qNd&rls=org.mozilla:en-USfficial&source=univ&tbm=shop&tbo=u&sa=X&ei=IgRdUYXPBufh4AP4moDgCg&ved=0CGQQsxg&bav=on.2,or.r_qf.&bvm=bv.44770516,d.dmg&fp=b51ed0fb2796a404&biw=946&bih=921

https://www.dwarvenforge.com/forum?func=view&catid=3&id=46195

http://en.wikipedia.org/wiki/Magnetic_levitation

Agreed, the harder part would be keeping the model balanced so that it doesn't slide laterally and just flop to the ground.

The main problem is if the model rotates even slightly (which the fishing wire can't stop) then the torque progressively increases, causing it to rotate even further, causing the torque to increase even further, causing it to rotate further until eventually it has rotated far enough that the magnet no longer holds it up and it'll just topple. This will all happen in the space of about half a second, it's called being "statically unstable", where even the tiniest microscopic misalignment will cause a force that will increase misalignment until it collapses.

Fishing wires can't stop this rotation unless they constrain the model in rotation, which would mean you'd need something above the model as well with a fishing wire leading up to it and another wire leading down to the base. Either that or you'd need 3+ horizontal wires tethering it horizontally. None of those options is terribly neat and if you were doing to that extreme, you might as well just let the fishing wires themselves take the weight of the model and forgo the magnets entirely.

This is a cool idea, it might be possible, just think out of the box (two magnet points, two wires sperated about 6" apart, might prevent the rotation issues).

however, this might be incredibly annoying to do, and might not work. Kudos to you for trying it however.

Me, to deal with the problem of broken stems? Get 1/4" acrylic rod, put magnets on them - thats what i use for my crons.

davethepak wrote:
This is a cool idea, it might be possible, just think out of the box (two magnet points, two wires sperated about 6" apart, might prevent the rotation issues)

I've seen this thread at least half a dozen times, and people always try to think outside the box. I invite you to try it, but it simply cannot be done. Any system stabilized enough to stop the alignment from disintegrating is no longer relying on levitation but rather the wires.

''The reason for this is that magnetic fields are not flat, like a shelf, but are rounded, like a ball. In addition, there is no friction between the two rounded fields that might help keep the magnets balanced in place. ''

I would start by investigating any and all floating magnetic devices, the significance of the statement above is simply attempting to magnetise to a normal base without something to stabalise it will as others have said, fly off.

Quick look over google told me that devices like the 'floating bed' actually have thin wire attached to the ground to stabalise the constuction. I believe this is possible but would need precise and clever magnetic engineering.

 Nem wrote:
''The reason for this is that magnetic fields are not flat, like a shelf, but are rounded, like a ball. In addition, there is no friction between the two rounded fields that might help keep the magnets balanced in place. ''

I would start by investigating any and all floating magnetic devices, the significance of the statement above is simply attempting to magnetise to a normal base without something to stabalise it will as others have said, fly off.

Quick look over google told me that devices like the 'floating bed' actually have thin wire attached to the ground to stabalise the constuction. I believe this is possible but would need precise and clever magnetic engineering.

I googled magnetic floating bed and all I found was one that...

" To make sure that the bed doesn’t float away should it become windy (or “interesting,” wink wink), it’s tethered to the walls by four cables."

So that basically conforms to what I was saying earlier, you need 3+ wires horizontally aligned or 2 wires vertically (one above and one below) to constrain any rotation. OR, you need something with an electric circuit and a feedback loop, like all the magnetic levitating desk toys you can buy.

So it can be done, don't get me wrong, it just can't be done with fishing wire to the base being the only stabilising factor. It's all about the rotation of the model, two magnets at a distance are unstable in rotation, a fishing wire to the base cannot prevent rotation, even half a dozen fishing wires to the base can't prevent rotation because fishing wire can only take tensile loads and is incapable of taking compressive loads (ie. fishing wire can be pulled apart and will resist, but if you push it together it just goes slack and doesn't resist, any rotation will cause some or all of the wires to go slack, allowing the thing to rotate further until it topples).

If you want to make it work, I think the best thing to do in practical terms is you really have to buy a maglev device like one of those desk things and hope you can get one small enough, but then it becomes impractical for gaming because you need a power chord running to the model at all times and as soon as the power cuts, the model will topple. There are devices where if the power goes, the model tends to just fall down rather than toppling, but those are the ones with the magnets positioned above the model, like this...

http://www.ultimateglobes.com/4-Magnetic-Levitating-Antique-p/sn891094.htm?gclid=CJ2Dot2asbYCFcud4Aod4XAAbw&gdftrk=gdfV2697_a_7c819_a_7c9359_a_7cSN891094

If the power goes out, the globe should (I believe) just fall on to the bottom of the base instead of flying away or toppling over.

Thanks for everyone's input. It seems as though my idea is much more mathematically impossible than I originally thought
Especially since most kits or devices are for magnetic propulsion, like maglev trains, and I need STATIC magnetic levitation, which now seems only possible with diamagnetism, which of course isn't available to common folk
Oh well. It was a good idea, and I may still pursue it in the future just for a laugh

If you drill a hole through the middle of the model and put a guiding rod through that should hold it in place. It'll be pretty obvious, but it's the simplest solution.

 Mr Nobody wrote:
If you drill a hole through the middle of the model and put a guiding rod through that should hold it in place. It'll be pretty obvious, but it's the simplest solution.

are you referring to magnets still?

I've seen it done but for a showcase model only.
The problem is when you come to move the model - it will just flip due to the forces involved.


Automatically Appended Next Post:
Found the link:
http://www.dakkadakka.com/dakkaforum/posts/list/481010.page