So you have an old hard drive that can't store information any better then an oven stores fruit? I assume you've replaced it with a new one but what to do with the old one. It can't perform it's most basic function, to store data, so you cant well use it, why not take it apart and see how it works? This instructable was performed on a Western Digital Caviar WD2500 but doesn't differ much on any other brand or model. I have not tried this on a sata hard drive but it can't be too much different, and SSD's are like a 3 piece design. This is my first instructable and I hope you find it useful.
Sorry for the poor quality pictures but my camera is a piece of crap, it's kinda self explanatory though. For my own safety I must say this instructable is a one way operation, only do this if you intend on destroying all saved data because it will not be recovered and I cannot be held responsible for your loss.
*Update* I would like to thank WestFW for contributing better pictures that in most cases replaced the old ones. It's not the same model but like I stated earlier they're all mostly the same.
Step 1: Plan of Attack
First of all you'll need some tools. I used a T-8 for the majority of the screws and a T-7 on the platters but this can very by company. I also used a flathead screwdriver to help remove the cover and magnets. Remember throughout this instructable, if a part isn't coming out, you probably missed a screw.
It's best to remove the chip on the bottom and undo any screws under the board to make future steps easier. There's normally only 5-7 screws holding the board on and it can be lifted pretty easily.
Step 2: Lifting the Hood
Now we get to see the real nitty gritty of the hard drive. This is most commonly where screws are hidden because of warranty voiding things. You'll want to feel around on the label and cut open any spot that feel "open" to you and you'll most likely be surprised by a screw. This is where you'll probably need the screwdriver most to pry open the cover because it can be on there pretty snug.
Step 3: Removing the Magnets
Now we're at the best part, the uber magnets. Normally held in by 3 screws, they're hard to get out without damaging anything. What I found works well is after you undo the screws you hold down on one of the screw holes while prying up the other with the screwdriver. After a little prying the top magnet should snap onto the screwdriver and can be lifted out. Next you'll want to take out the actuator, the thing that reads the disks, by unscrewing it's cable from the case, moving the actuator away from the disks and lift. The last magnet should be self explanatory.
Step 4: Removing the Platters
This is where you'll need your T-7 or T-6 but if you're anything like me yours are striped thanks too a few too many xbox controller mods. Be Careful with these screws because they are in extra snug and will strip easily if precautions aren't taken, unfortunalty I do not know these precautions so keep a power drill nearby in case you need to drill the screws out like I did.
After these screws are undone the platters should just lift out pretty easily reveling the high rpm motor. These motor typically don't use too much power but spin at 5200, 7200, 10000 and 15000 rpm's depending on the drive. If you can figure out which connections are positive and negative then you can use this motor for a variety of projects.
Step 5: What Now?
There's plenty of projects here on instructables that deal with what to do with you're old drive, it just depends on what you want/need. You can make any of many hard drive clocks here, or you could make a Tesla turbine or if you're really feeling crazy try making a rotary input device. If you plan on doing your own little project be sure to put it here on instructables and tell me about it because I have 2 hard drives taken apart and nothing to do with them.