External HDD enclosure PPL, question...

I have abn IcyBox but it probably applies to all external cases.

When I come to powering down/disconnect etc, i hate having to flick that switch at the back of the case. Not because its hard to reach or anything. But it doesn't seem like a healthy way to shut off the drive. I can clearly hear the quiet clunk as power is cut and the drive comes to a halt with some small scrath-like noises :(

Is this acceptable?

That noise is fine, it is the heads returning to their rest position. It happens on all drives but in computers the noise is usually drowned out by fans that are spinning down.

As long as you're not writing to the drive it's fine.

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Originally Posted by Timmy!!!

That noise is fine, it is the heads returning to their rest position. It happens on all drives but in computers the noise is usually drowned out by fans that are spinning down.

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Ah, ok

Thats good then, i swap the drives out of my enclosure quite often so i didnt like what i was hearing

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Originally Posted by Timmy!!!

That noise is fine, it is the heads returning to their rest position. It happens on all drives but in computers the noise is usually drowned out by fans that are spinning down.

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Wait, how do the heads return to their rest poisition without any power?

Heads move using electromagnets, I presume that when the power is turned off there is a magnet that pulls the heads to the correct position. The magnet could be an electromagnet that slowly looses its magnetism so it has enough power to pull the head over, or it could simply be a magnet.

Magnets around hard drives is usually considered a very bad idea :confused:

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Originally Posted by Marcos

Magnets around hard drives is usually considered a very bad idea :confused:

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They have flaming strong magnets inside them. You have the servo arm, one side hangs over the drive, the other side has a wire coil which sits between two of said flaming strong magnets. Changing the current through the coil positions the the arm in the right location. Presumably when there's no current there, the magnets force the arm to the parked position... and that's how it works :)

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Originally Posted by Marcos

Wait, how do the heads return to their rest poisition without any power?

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Using a good old fashioned spring! :)

EDIT> See here.
(May also explain why IBM drives make funny noises!)

While there are alternatives to using a spring, I'll bet none of them are as reliable.

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Originally Posted by rajagra

Using a good old fashioned spring! :)

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I suppose there are cogs in there too somewhere? :lol:

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Originally Posted by rajagra

Using a good old fashioned spring! :)

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Don't be silly, they use a rubber band!!!

Also mirrors and fishing wire.

Just uh wondering....how are the mirrors gonna help? Or do they reflect the pulling force of the rubber bands and fishing wire onto the heads?