If you want to join in here, I'll kick off with the 3.5" drives. Handfuls of bust ones can be had for free at any PC repair shop if you ask nicely...
- 1 or 2 really strong neodymium magnets
- three phase motor with ultra smooth bearings
- controller ASIC for motor + all required components (leave the controller board intact and cut the pair of traces from the CPU and inject your own PWM signal)
- .1" pitch headers (good for AVR or PIC ISP connections)
- SPI eeprom, usually about 1 or 2Mb
- A 3.3V 3 terminal voltage regulator
- Molex style 4-pole power connector
- big chunk of light alloy (maybe good for a heatsink or for metal casting if you've got your own foundry)
- 1 or more shiny aluminium disks
- SMT capacitors, especially high value MLCs and tantalums (get a multimeter with capacitance function if you want to know the values though)
