Hard disk motor

Hi all, i need a motor with a high rotational accuracy, so i 've think to re-use a motor of a hard disk.

Here are some questions:

  1. considering the smallest rotation permitted with a motor of this type, which is the corrisponding rotating angle?
  2. where can i find some tutorial/guide/or any other information on how to write a software to control an hard diks motor ?

Any help will be appreciated.
Best regards,
Andrea

Hard disc motors dont have rotational accuracy as they are controlled to spin at a fixed rate that is not tied to rotation precision, the precision is gathered from the data on the disc to mark sector start and end. They are also driven by electronics on the main board that run 3 wires to switch the drive magnets on & off that is under the drives chipset control only (you instruct the chipset to shut the spindle motor down etc).

If you are after rotations to a specific degree then you need a steppermotor with a gearbox, depending on what gearbox you have depends on how small each step will be.

Do ypu have any information about Voice Coil Motor present into hard disk ? May be this be helpful ?

Best regards,
Andrea

You probably should do a little bit more research into how hard disks work, modern hard disks use a closed feedback loop to vary input to the voice coil motor. The controller reads servo information from the platters. That information tells the controller that the heads are, and the controller uses that to determine how to vary input to the voice coil to make the head move to where it wants them. It’s useless without the closed feedback loop and it only moves a few degrees back and forth anyway.