I have been mostly working on a shelf this weekend. It is very needed because there is more than enough stuff just cluttering up the house and it is getting on my nerves.
But I also had worked on my little project involving the magnets that I have salvaged from defunct HDD a few months ago.
First I took a piece of 3 mm thick, 20 mm wide galvanized mild steel and I cut off a piece big enough so I could bend it into a U-shape in such a way that the magnets can sit inside with about 2 mm free space between the magnets and the bends. then I also cut two just 3 mm bits of the same stock. When put together as seen on the picture, you get a very strong magnet that only pulls in one direction (up). Plus the way the HDD magnets are magnetized means that this magnet now has four poles N-S-N-S. Also that the magnetic field is very strong, but has a very short reach. I tried to measure the force with which it holds a piece of steel and it was about 65 Newton, which is impressive for such a small thing cobbled together from scraps.
After this, I cut a few pieces of brass to fill the spaces as tightly as possible, and I drilled and cut an M5 thread in one arm of the U. Precision is essential here. Unfortunately, we do not get along very well and she is a mere nodding acquaintance, despite my best efforts, so everything was a bit wonky.
I have no pictures of that work because I still did not figure out exactly how my new phone works – I thought I took pictures, but apparently not.
When I had everything cut, I mixed a generous amount of quick drying epoxy and slathered it all around and glued everything together. And after the epoxy hardened enough I have ground off (manually) excessive material and I trued and polished slightly the magnetic surface.
So now I have this strong, one-directional magnet 50x20x10 mm. So far everything goes as planned, and I hope that the next step in this project will go similarly well.
voyager says
Very interesting, Charly. What is the next step in your project?
Charly says
The next step is going to try and make the magnet to switch on/off.