Re: motors from floppy drives

hi David,

thanks for sharing your look at motors from drives. i gave up too easliy
looking at these readily available small motors. i will also dig into
the MFM Seagate motor source, since this form factor can be very useful.

-ron

On Thu, 13 May 1999, DAFcnc wrote:

---snip---
> the ones I'm using are from older halfheight 5.25" 1.2meg drives, Teac
> and other makes. The motors are stock 'Japan Servo Co' NEMA 17 size,
> running off 12v via various driver chips, inc ULM2003 and BA12004.
>
> definitely 200 step per rev Ron, I have them on the bench, and
> outputting 200 steps makes the motor go round once.
>
> older 5.25" drive for 360kb disks used 100 step per rev
>
> newer drives that use lead screws to drive the head mech are 10 to 48
> step per rev types. the ones in 3.5" drive are 10 step per rev (the
> ones I've tested).
>
> note that some of the leadscrew types have no front bearing in the
> motor housing, and so cannot be used once removed from the frame that
> supports the far end of the leadscrew.
>
> now we come to harddrives. 0lder MFM drives (the ones with 2 data
> cables) used stepper motors for the heads. Some of them are quite
> big in diameter, but flat, (seagate) and others are smaller (about an
> inch across) than NEMA 17 but the usual square shape, and give 200
> steps per rev. I have one of these at home with the end of the shaft
> toothed to directdrive the mechanism.
---snip---