Just about all of us have a few old hard drives in our junk box. There are a myriad of projects out there to put them to work in new and interesting ways. One of those ways is to turn your hard drive into a solenoid motor of sorts. (YouTube link) This isn’t a new hack, videos of it have been kicking around the internet for years. [black1985vette] gives a pretty good explanation of how he’s done it. He used a piece of brass as a connecting rod between the drive head and a pin mounted off-center to the platter hub. One of the platter mounting screws provides the perfect place to set the pin. A bent safety-pin rubs the center of the hub, which is partially insulated with tape. When the pin contacts the hub, the drive head is energized, pushing the whole assembly around. The mass of the platters acts as a flywheel, carrying the motor the rest of the way around.
[Pulverrostmannen] performed a similar mod, though he used a micro switch to time the drive head. Rather than a brass connecting rod, [Pulverrostmannen] used a spare head. With a simple transistor circuit acting as a speed control, his hard drive motor revved up to around 1560 RPM, which is pretty respectable for a bunch of junk parts.
So next time you’re stuck in on cold rainy weekend, pull out some of those old drives and get hacking! Click past the break to several of these projects in action.