zero cost magnetic isolation

has anybody done a diy isolation platform using magnets ?

My idea ......

A sheet of mdf as base [10mm] drilled out to take circular magnets in a pattern of three or four ..this repeats on the upper support.
So that it floats on the lower magnets.

 

what stops it zipping off sideways?

 

Sorry to be pedantic but how are these tweaks "zero cost"? Low cost , possibly, but "zero cost", not IMO.

Anyway, carry on...

 

oh its a play on zerogain name ... as you know theres no such thing as a free lunch....

projected costs.. £5 worth of magnets £2 worth of mdf some odds and sods ..total £15 ish

So a from my point of view £15 magnetic isolation platform does not have quite the same ring ... but if theres a problem feel free to change the title..

thats exactly my concern ......

so you could encapsulate the magnets in a frictionless tube to stop lateral movement ?

 

There are a few ways to work around Earnshaws Theorem, low friction tubes isn't one of them.

 

May i suggest:
http://www.emagnetsuk.com/index.asp?function=DISPLAYCAT&catid=1

They do almost any shape, size etc. Even spheres.

I have been thinking about a decent way to do this myself for a while now. I might get the CAD program out over the weekend and have a fiddle.

 

Well thanks for that positive and enlightening answer.....not

what do you suggest ?

 

looks like the same people I've ordered from of ebay ...well same pics anyway ...

I've ordered disc with holes so I can make a mechanical attachment [and also reuse them if the ideas don't work]

 

Indeed, its not like diamagnetic levitation, rotational stabilisation, translational halbach arrays, high frequency oscillating electromagnetic fields etc. are really possible in a home hifi environment for cheap.

My idea uses http://www.emagnetsuk.com/index.asp?function=DISPLAYCAT&catid=47 magnets with holes in the middle, so a nylon rod (self lubricating) or something similar could be used through the middle to stop lateral movement.


edit: you responded as i responded, i think we have answered each other!

 

...er, I presume Earnshaws Theoremsays soemthing about cd players slipping off magnetic isolation platforms?

Might I ask what the solution IS to this? (if its not a trade secret?)









David

 

the relaxa 1 works well ..... I heard one at effem and wonder how hard it would be to build something similar..

the relax use guide rails to prevent sideways slipage .....

 

Zanash - I played with this a while ago (and consequently have a pile of twelve 1" diameter neodymium magnets that are lethally strong and have to be kept out of range of sharp objects). I never got around to completing it, but the basic principle is sound... it's the "frictionless" tube that might be problematic.

There's a couple of further ideas I had that could be interesting to play with:

1) use a metal encapsulation tube - something non-magnetic like aluminium. Despite it's non-magnetic nature, it still has mobile electrons and thus you will set up eddy currents in it when the rack moves - the eddy currents convert the energy to heat, giving you some damping

2) Lubrication - you could use grease or something to get the whole thing moving smoothly, but it could dry out, etc. You could use something altogether more interesting - ferrofluid. The sort that is used in speaker drive units is typically ferrous particles suspended in PolyAlphaOlefin. PAO is the basis for class 4 synthetic motor oils (note that most of what you can buy in the shops is not true class 4 or class 5, but rather class 3 hydro-cracked mineral based, which can still be sold as "synthetic". Even Mobil 1 is only class 3) and as you might imagine is thus rather slippery. The advantage to using the ferrofluid is that it will obviously adhere very nicely to the magnet, giving it essentially a frictionless coating.

 

www.gadgetshop.com

Glasto is on the telly.

 

Is a quick sketch of what i had in mind for a single shelf.

Using something like end grain balsa with an oak veneer to match the cones. For a rack i am thinking of having wooden sides with the magnets attached down the sides horizontally, similar to mana racks. But instead of spikes you have the magnets with the rod running through them and the shelves sitting down through the rods.

 

Thats neat ...how did you do the pics ?

my idea ....

fix ring magnets at bass of rod ....moving magnet set to oppose the others. Lateral movement limited by rod up the center....top plate sits on three or four magnet sets.

Isaac ....interesting

 

Sounds like useful stuff for all kinds of things. Where would one get hold of this stuff?

 

I just did a quick sketch in photoshop. I have ordered some magnets, different sizes and so on to try them out. I will make some up over the next few weeks and report back on any sort of success / failure. I will just mount the magnets on the cones without recessing them for testing. Find the best sizes etc for weights and then recess when i know what does and doesn't work.

 

Couldn't you use opposing magnets on the outsides too, to keep the platform centred?

 

I've tied that in the past ....with limited success...its like trying to balance a ball bearing on top of a cone ...the magnetic forces want to push the other magnet one way or the other..

With luck I should have a prototype built soon ....

the relaxa platform [effem's] is an interesting unit the top platform is held in place by a rail and wheel system set at right angles....this allows transmission of vibration [confirmed with the use of a stethescope..] this system removes a large portion of hi freq vibration but allows lower freqs almost unhindered to enter the top plate.

sap who made the relaxa series seem to have disappeared....they made at least three different units having magnetic levitation using slightly different modes of operation.

Effem's relaxa 1 made a large difference to the sound of cdp transports placed on it ...which got me thinking about a diy version on my long trek home.

ah ....then imported it as as a jpeg ?

 

Any downsides to using magnets?

I'd also thought about using magnets in this way, but was far too lazy to try to make anything in practice. Good luck; please let us know how it goes.

As a question to the group and not as a challenge to anyone, are there potentially any problems with using these new super-powerful magnets near Hi-Fi equipment? I'd be a bit nervous having one anywhere near a transformer and wonder whether they could influence inductors. I stress I've no idea whether the fields involved would be sufficiently strong to cause problems, but other forum members may be better informed.