Old hard drives can no longer be considered as the matter of non biodegradable wastes that were only seen as a matter of pollution for the environment, as it needed complex methodologies for recycling. Hardware hackers and IT experts have devised some very cool products that can be made out from those old dead hard drives. The components of a hard drive includes a set of several magnetic hard disks (made of concentric rings comprising magnetic dots for memorizing data), magnetic read-write heads, a drive motor to spin the head, and a lot of circuitry of wires. These components and features have been utilized to make some very cool products among which top five products include, hard drive speakers, hard drive clocks, hard drive laser oscilloscope, hard drive generator and hard drive grinder or a sander as described below.
1. Hard drive speakers
Hard drive speakers are devised on the fact that a normal speaker is made to work by moving a coil inside the magnetic field that creates oscillations and resonance followed by magnification of sound, while as same features like movable coils are present in the movable magnetic field inside a hard drive that makes magnetic heads to move to the desired locations from track to track. The same fact can be used to create a magnified sound from such hard disks by providing amplified audio signals at desired frequencies in those moving coils which in turn oscillate or move inside magnetic fields of magnetic tapes. So more the hard disks and more different the sizes, much better speakers can be made. Capable hard disk speakers have been made by Afrotech by keeping three different sizes in series from small to bigger ones.
2. Hard drive laser oscilloscope
Hard disk laser oscilloscope is also made on the same model used in hard disk speakers in which addition of laser and two mirror mounts is done over the edge of the hard drive body and at center of round tape, laser is mounted over the read-write heads, which emits laser beams while read write heads move, laser beams fall on the first mirror at edges which reflects them on to the second mirror located at center of magnetic platter, thereby a visual oscillating effect of laser beams can be witnessed while sound plays and makes a visualization of a music on output mirror. Successful projects on this product have been done by Allen Parekh.
3. Hard drive clocks
Hard drive clock is an analogue type clock with hands or clock arms made of red (hour hand), blue (minute hand) and purple (second hand, made together from red and blue LEDs on illumination) beams of light. Six red and six blue LEDs are installed around the plate for this purpose; they illuminate the slot cuts at the upper drive and white paper on the center drive. The whole process is executed by a programmed microcontroller, PIC16F628 for operating the clock. This program is a set of instructions recorded on the same hard drive or burnt on a portion of it. There are also three microswitches to adjust the clock timers.
4. Hard drive generators
Hard disks possess the worlds most rare neodymium magnets which are known to possess strong magnetic fields, so this capability is utilized in making windmill power generators by separating magnets from hard drives, neodymium magnets have four diagonally located poles(north-north; south-south) with similar poles across diagonals, hence they are cut into two pieces to create normal north and south poles in each piece, which are then stacked to form twice the strong magnetic fields to generate around 100 Watts of power as compared to 2 Watts by a Stepper wind generator.
5. Hard drive grinder or sander
Hard drive discs have a powerful potential of rotation around their axis when connected to a power supply, this ability has been utilized in making cool orbital disk sanders. All you have to do is to remove the disc coverings and other board units from the drive, expose the disc surface and after that apply some glue on the disc surface, cut a round piece from some sand paper according to disc size and then fix that piece of sand paper on it. Once the hard drive is given power supply, it rotates fast and gives shape to a cool sander that can then be used to clean the surfaces of any kind of metallic or non metallic tools. You can even polish and fasten the knives with the aid of such sanders.