I had been looking around the net and found the Hard Drive Laser Oscilloscope over at Hacked-Gadgets and thought about trying to make one using two hard drives to give horizontal and vertical beams. So rather than an oscilloscope it would give me some funky visuals fx.
First job was to open both hard drives, and remove all the unneeded bit, (ie. there was little plastic locks on the Read/Write Arms stopping them from moving, plus I removed platters and platter drive motor from one of the drives just to make the project a little lighter, since hot glue is not very strong)
Now I need to find out what pins on the ribbon cable connect to the Read/Write Arm Voice Coil, some people might use a multimeter for this but I find it much easier with 1.5v AA Battery and 2 bits of wire, then you can see the Arm move. Once they where located solder wires to them, then repeat on the second drive.
I took the two drive a hot glued them together, mounted a mirror on both Read/Write Arms then mounted the laser pointer. This took a few attempts to get the laser at the right height and both mirrors aligned.
This is what was projected once mirrors and laser where aligned
And that's about it, All i have to do now it connect the two pairs of wires to the multicore cable, and run it off to a stereo amp, One pair one wires from 1 drives Read/Write Arm to the left channel, and the second drives to the right channel. An alternative approach would be to get a speaker cross-over out of an old pair of speakers, and wire the bass to one drive, and treble to the other.