Ferro-fluid, active bearing, floating spindle

[redrabbit]

I don't know if this has been discussed before.

...or what it might be properly called ?

At my work, we have some ferro fluid (liquid iron).
When a magnet is placed near this fluid, the fluid will "attract" to it, forming a ball of this liquid. If I squeezed it, it felt like an eyeball...kinda freaky.
To get the fluid off the magnet, you would squeeze it hard, but not all the fluid can be removed.

This is the point where I had an idea, because when I put the magnet (still with some fluid on it) on to the flat table top, it would glide and spin very easily.....it was "floating" on the thin layer of the ferro fluid.

I thought about the applications for a turntable spindle, or tonearm pivot. It would need to be sealed some how, this stuff is messy.

Is this not a new idea?

=RR=

[Shaun]

New idea or not, I like the way you think.

...but I'm not very comfortable with you knowing what a squeezed eyeball feels like

[harwoodspark]

I once had a similar idea. I was going to float the platter on mercury instead. Over here in the UK we still have some lighthouses whose old lamp assemblies float on mercury. The lamps are extremely heavy yet can be rotated by hand easily. Your idea is very interesting. Si.

[sq225917]

good luck with encapsulating that mercury,and the vapour...

[harwoodspark]

Originally posted by sq225917
good luck with encapsulating that mercury,and the vapour...

I knew someone would say that! That's why I haven't taken the idea any further. Mercury vapour is highly toxic and not ideally suited to a domestic environment. I've been keeping an eye out for an alternative but nothing seems to fit the bill. I wonder if this ferrofluid may have possibilities?

[Illusus]

http://www.unitednuclear.com/magnets.htm

Scroll down 3/4 of the page to the magnet fluid.... there is a paragraph about a 'frictionless' bearing.

[oshifis]

A few sentences later "an almost frictionless bearing" is stated. I suppose there is some internal friction between the particles.

[Werner]

Originally posted by harwoodspark
I was going to float the platter on mercury instead.

There was a French turntable in the late seventies doing exactly that.

[Illusus]

Originally posted by oshifis
A few sentences later "an almost frictionless bearing" is stated. I suppose there is some internal friction between the particles.

Of course.

[harwoodspark]

Well I've just done a Google search and found that French tt.It was built by Jaques Marteau in the late 80's. The platter weighed 25 kg and there was no centre spindle. It relied on an ingenious belt drive that contacted the platter in four places and automatically kept the platter central. It states further on that he was inspired by the lantern used in lighthouses that floated on mercury! I saw a program on the tv about lighthouses and that's what put the idea in my head. Someone once said that there is nothing new under the sun. I guess he's right!