As usual, click any photo to bring up a larger version.
This isn't exactly woodworking...
Magnets are cool, and fun, and they are also very useful around the house and around the shop. Rare-earth magnets, are in particular very powerful despite their small size, and useful in many projects. For instance, I have magnets in my featherboards. I use magnets when changing my DC bag to help hold things in place. We use magnets to hold notes to the door, and so on and so on...
What you may not know, is that computer hard drives (aka: hard disks, or HDs) contain two powerful magnets.
Virtually everyone has a computer these days. Actually, most of us are on our third (or fourth or..) computer by this point. If you're like me, your old computer is probably still stashed away in the basement, since you kept it "just for a bit" after getting the new computer, and you've never gotten around to tossing it.
But before you take it off to your electronic-waste recycler, how about you first have some fun and retrieve the magnets from the disks.
This photo essay is about how to disassemble a typical HD in order to extract the magnets. I will also show how to make a simple magnetic hook out of the result.
I am fortunate in that I work at a university and have access to a whole bunch of old HD's that are being scrapped and tossed into the recycling bin. These are 10+ year old units, either too old, too broken, or too small for continued use.
This is the top side of the HD. This is what we need to remove to access the innards. As you can see there are several torx screws holding it closed.
This is the one tool that you may need to buy.
You will need a screwdriver with the correct size (it's quit small) torx bit on the end. I have access to a multi-tool, which has many sizes of torx tips. Even so, I need the smallest tip in order to be able to loosen those screws.
Hopefully on your drive you won't have to get sou forceful, if you can manage to remove all the screws.
On the left are the highly-reflect platters. If you can get those out, they make interesting little mirrors. Above (and below) the platters are the read/write heads on an arm which moves in and out. This is how your data gets onto and off of the hard drive. In the bottom right of the photo is the top magnet. Below it is located a thin copper coil, which is attached to the read/write arm. That is how the arm moves, by sending voltages through the coil, which interacts with the magnetic field. Below that is the lower magnet.
(And that concludes the small geeky tech lecture.)
The lower magnet is on the right. These always have some form of bent "legs" (for lack of a better term) sticking up. This makes them a bit harder to work with, if you want to incorporate this magnet into another project. Oh well, that's what hacksaws and grinders are good at removing!
I did notice that the magnet like this could easily scratch or mark the surface. I would recommend covering the magnet, perhaps with some plastic tape or some high-friction plastic (Available from Lee Valley) to cover the magnet and protect the surface. I would also consider routing out a recess to sink the magnet flush, or even fractionally below, the surface of the wood where it is mounted.
Here are a couple more photos of that simple project:
This web page has focused just on extracting the magnets. What to do with the magnets is for another day. You could just leave them bare and use them, or mount them on wood as I did, or come up with some other use. I'll be thinking of different ways I can use these around the home and shop.
Thanks for reading!