Inside a Hard Drive: an interesting video

[Farid]

I just saw this and I thought it was cool enough to warrant a thread:

http://youtube.com/watch?v=9eMWG3fwiEU

Since many of you are wondering...
- It was an old 3.2 GB Hard Drive, so I dont mind if it blows up
- The deleted folder had tons of files in it
- The copy paste was performed aith a folder that had tons of files one it

 

[digitalwanderer]

Very cool, thanks Vy.

 

[Bludd]

I thought the platters would start oxidizing as soon as they were exposed to air.

Cool nevertheless.

Edit: Dunno where I got the oxidizing idea from but I just read the Wikipedia entry for harddisk drives and it says there's air inside the casing.

Damn, I have believed for many years that harddisk platters couldn't be exposed to air.

 

[Simon F]

I just saw this related one . Given recent experiences with a Maxtor I thought it amusing.

 

[Simon F]

Damn, I have believed for many years that harddisk platters couldn't be exposed to air.

No, I believe it is mainly dust particles (or, IIRC, even worse, cigarette smoke). I remember being told an analogy that the relationship of the disk head and platter is something like a 747 flying a centimetre off the ground and a dust particle would be a large boulder in its path.

 

[_xxx_]

That's because of dust, not air.

 

[Bludd]

But I have no idea where I have the idea of oxidization from. I thought the drives contained some kind of protected enviroment of some gas other than air..

 

[Neeyik]

Hard drives aren't sealed units anyway - so the platters are always exposed to air.

 

[Bludd]

Yes, I realize that now.

 

[pascal]

Hard drives aren't sealed units anyway - so the platters are always exposed to air.

IIRC:
- HD are sealed but with clean air inside. The air is needed because the nowdays heads literally fly close to the surface.
- The air is compressed below the head. What you dont want is this big dust particle.
- In fact there is an start/stop airport inside of the HD (special track ?).
- and the entire HD surface is covered by a thin and hard material (diamond like carbon ?).

 

[Neeyik]

Hard drives aren't contained with a 100% air-tight, sealed unit - it would be impossible to regulate the air pressure within them otherwise.

 

[zsouthboy]

Many HDDs are full of fluid now, aren't they?

Or, at least the word "fluid bearing" appears in their specs.

Or, I am retarded (I can't think of any good reason to slow down things by filling it with fluid)

 

[Powderkeg]

Many HDDs are full of fluid now, aren't they?

Or, at least the word "fluid bearing" appears in their specs.

Or, I am retarded (I can't think of any good reason to slow down things by filling it with fluid)

LOL.

A fluid bearing is like a ball bearing.

It doesn't mean the whole hard drive is full of fluid. It means a tiny amount of pressurized fluid replaces the ball bearings in the motor which reduces friction and wear.

Old fashioned Ball Bearing:

Fluid Bearing:

 

[pascal]

Hard drives aren't contained with a 100% air-tight, sealed unit - it would be impossible to regulate the air pressure within them otherwise.

You are right!

Found this in the wiki: http://en.wikipedia.org/wiki/Hard_disk

Hard drives have a mostly sealed enclosure that protects the drive internals from dust, condensation, and other sources of contamination. The hard disk's read-write heads fly on an air bearing which is a cushion of air only nanometers above the disk surface. The disk surface and the drive's internal environment must therefore be kept immaculate to prevent damage from fingerprints, hair, dust, smoke particles and such, given the sub-microscopic gap between the heads and disk.

The hard disk's spindle system relies on air pressure inside the drive to support the heads at their proper flying height while the disk is in motion. A hard disk drive requires a certain range of air pressures in order to operate properly. The connection to the external environment and pressure occur through a small hole in the enclosure (about 1/2 mm in diameter), usually with a carbon filter on the inside (the breather filter, see below). If the air pressure is too low, there will not be enough lift for the flying head, the head will not be at the proper height, and there is a risk of head crashes and data loss. Specially manufactured sealed and pressurized drives are needed for reliable high-altitude operation, above about 10,000 feet (3,000 m). This does not apply to pressurized enclosures, like an airplane pressurized cabin. Modern drives include temperature sensors and adjust their operation to the operating environment.

It is mostly sealed but with an small hole with carbon filter inside !

 

[PeterAce]

More open HDD fun :

http://www.videosift.com/story.php?id=14782

 

[Skrying]

More open HDD fun :

http://www.videosift.com/story.php?id=14782

Would have been so much more awesome if a data transfer or some such had been running and that happened. Talk about data loss......... giggle.

 

[t0y]

I saw this posted on slashdot sometime ago and I was pretty impressed:
http://www.afrotechmods.com/cheap/hdspeakers/hdspeakers.htm

It's a 3-way speaker system made out of hard disks.

WARNING: Cheesy porn music ahead!

 

[mbfree]

Fluid Bearing

Powderkeg,
I was wondering whether you could help me out. I am looking for information on Fluid Bearings, specifically those used in HDDs. I have an application that is a small size- low load -high speed and was thinking of using a fluid bearing. Do you have any idea where I can get hold of one for testing purposes.
Your help would be much appreciated.

Thanks,

mbfree

 

[Ty]

Yes, I realize that now.

And I *think* HDs actually rely on the air being there to act as a buffer or cushion between the heads and the platters.

Edit - Pascal beat me to it.

 

[rado354]

Nice one, thank you!