What’s in a… Hard Disk Drive?

A Heap of Hard Drives. And a Bear.

A Heap of Hard Drives. And a Bear.

Sustainability apparently means mending and re-purposing but that is so easily confused with collecting stuff that “may be useful one day”. There are many things in my attic and on my workbench that fall into this category – some have been waiting for their day a very long time.

Over the course of a decade, the Snail and I have used a few computers, all of which have finally given up the ghost in one way or another (often due to excessive demands of new operating systems/internet browsers). The problem is that, while our local recycling centre takes all electronic items for recycling, the hard disk drives (HDDs for short) from our machines may still contain information that could be useful to someone. There are stories of people having their bank accounts hacked after giving up their PCs for recycling, because the drives have not been erased to anything like the required standard (for example, this BBC story from 2006).

So, I thought it would be fun to take one apart, show you what’s inside before destroying the data permanently. Auguste decided he would ‘help’.

Auguste gets to work

Auguste gets to work

A Bear Hard Drive

A Bear Hard Drive

Basically, an HDD is a miniature record player where the record is made of the same sort of stuff as a cassette tape (sort of – it can be “written” to using a magnetic field). The arm thing in the picture is the same as the stylus on a record player – only this is more akin to a cassette tape head. It allows data from anywhere on the disk to be accessed more quickly than, say, a corresponding tape. If you have ever used a cassette player, you’ll know the inevitability of having to fast-forward through the entire tape to reach the track you want to hear (only for the player to then “eat” the tape. The joys of that technology!).

Taking one apart means undoing a gazillion screws, then failing to remove the motor because it is held in by magic or something. That is after Auguste has turned the disk itself into a merry-go-round (or carousel, if you prefer). Basically, you end up with: a metal case (with integral motor), which is possibly useful but definitely recyclable; a controller circuit board that may have useful electronics components on but can be recycled (I think they are melted down and the gold and other metals recovered); a strong neodymium magnet which might be fun to play with; a silicon glass or aluminium disk which I assume is recyclable but could be used as a mirror or bird-scarer (whatever, it should probably be thoroughly destroyed to make sure the data really is unreadable); and a read/write head that looks cool and has no discernible use.

And how long has this piece of kit been around? The first one was introduced in 1956 and was the size of a baby elephant – it actually did weigh about a ton. But Humans being Humans, we made them* better, smaller, cheaper until now when they are all but forgotten about bits of magic that make the World work. That first drive could hold 5 million bytes (5 Megabyte) – the machine I have on my desk and I am using now has a hard disk drive that can hold 1 Terabyte – 200,000 times more data but weighing a mere 500g. (For a brief history of drives, read this article.)

All in my head - the Read/Write Head

All in my head – the Read/Write Head

The read/write head and control mechanism contains magnets made of a rare earth metal called neodymium** – so rare, in fact, we’re running out. Actually, this particular metal isn’t that rare, it’s just uneconomic to mine it although that is changing as demand for the products that use it – wind turbines, headphones, and HDDs – grow. Of course, until quite recently, no one thought about recycling this and all the other metal contained in old HDDs. Indeed, the U.S. Environmental Protection Agency reported that in 2009, 2.37 million tons of electronics were discarded, but only 25 percent of that was recycled. That’s an awful lot of neodymium to waste.

HDDs will eventually be replaced – by Solid State Drives, which have no moving parts (so no merry-go-round to play with then, Auguste) and are, basically, a large block of memory like the memory cards you use for your digital camera. Sure, they are great, robust and use less power but you can’t take them apart and re-use the bits. Probably.

Now, how to remove the motor?

Now, how to remove the motor?

A bear and a drill. What could possibly go wrong?

A bear and a drill. What could possibly go wrong?


* HDDs, not elephants. Some so-called Humans just seem to want to mindlessly kill them, and other animals, for no reason at all.

** Neodymium makes the strongest magnets – watch this YouTube clip of people who should presumably be working, wearing lab coats and pretending to do science. And you know it is fun, because it tells you not to try it at home.

Categories: computers, recycling, Sustainable Stuff | Tags: , , | 7 Comments

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7 thoughts on “What’s in a… Hard Disk Drive?

  1. Multi-talented Auguste! Dizzy too when I got home – clearly I should not leave the two of you alone.

    Liked by 1 person

  2. I learned a lot! I’m not sure if I will remember any of it – I suspect my science brain is about the same size as Auguste’s! But I will remember what happens when two giant magnets smash together – that was impressive! What I don’t know is how they got them to meet rather than repel each other…….. perhaps that is a whole other blog post.

    Liked by 1 person

  3. Interesting Mr Snail. I always thought that hard disk drives were populated by very small imps. I was assured this was so by the Discworld book series. I am now having to renegotiate all of my prior conceptions about electrical items and am very suspicious of them now. Imps I could handle, re-readable content? My big brother senses are tingling!

    Liked by 1 person

  4. Pingback: What’s in a… Kindle e-reader? | writinghouse

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