harddisk and floppy drive motors

[philipsi]

hello again. i have dismantled the 3.5" floppy disk drive because i want to use the small motor inside.but i dont know what the motor is. it has 4 wires and a long shaft.can u show me a way to control it?

and what is actually the motor using inside a harddisk?

 

[crust]

The floppy motor sounds like a stepper motor -- though I would have expected 5 wires. In any case, here is a typical circuit for a 5 wire stepper.

**broken link removed**

 

[philipsi]

but my floppy has 4 wires motor.i wonder how to control it.it is connected to PCD using ribbon cable.if anyone knows, plz tell me.
harddisk also has same motor? i need it zoc the commercial steper motor (in my place) are very big and heavy

 

[Exo]

Yes, harddisk and diskdrive use stepper motors. If it has only 4 wires then maybe casing (metal) is 5'th connection

 

[philipsi]

i have two motors from the disk drive but i dont know the specifications of the motor.
just like Exo said,if the metal is the fifth wire,then how should i connect it?the ribbon cable has no color and i dont know how to connect it.can u teach me? and i also dunno how to determine the resolution of the stepper motors..it is not written at the casing of the motors.....

 

[Nigel Goodwin]

i have two motors from the disk drive but i dont know the specifications of the motor.
just like Exo said,if the metal is the fifth wire,then how should i connect it?the ribbon cable has no color and i dont know how to connect it.can u teach me? and i also dunno how to determine the resolution of the stepper motors..it is not written at the casing of the motors.....

Try turning it slowly with your fingers, if it's a stepper motor you will feel the steps as it goes round. Usually a floppy drive will have a stepper for the head movement and a DC motor for spinning the disk - the DC motor is normally brushless, and requires specific control to run (usually fed from a IC designed for the job).

 

[Exo]

The DC motor used to spin the disk is usually useless outside the diskdrive because the PCB itself is used as 'coil' (square shaped pcb tracks under the rotor power it). for 3.5" drives anyway

 

[philipsi]

i have found a url which may be useful.

**broken link removed**

wondering why the stepper motor would not work if the shaft is not supported at the end.

 

[panic mode]

4-wire stepper motor is normal.
check this out
https://www.applied-motion.com/support/wiring.php

 

[isaacj]

hello again. i have dismantled the 3.5" floppy disk drive because i want to use the small motor inside.but i dont know what the motor is. it has 4 wires and a long shaft.can u show me a way to control it?

and what is actually the motor using inside a harddisk?

It's a bi-polar stepper motor. The shaft is moved through each step by changing the polarity of the field in the coils from positive to negative and back again one coil at a time.

 

[isaacj]

The top of pinic mode's link has a good diagram.

 

[Agent 009]

You should maybe check the voltage and current rating of the motors.