3.5" floppy failure mode? Hub not attched to media.

[Chuck Guzis]

On 02/27/2015 11:40 AM, Eric Smith wrote:
> On Fri, Feb 27, 2015 at 10:05 AM, Chuck Guzis <cclist at sydex.com> wrote:
>> On 5.25" Drivetec floppies, the cylinder density is
>> double that--192 tpi.
>>
>> Now consider the hub-clamp mechanism of a 5.25" drive.  I suspect that with
>> a bit of care, one can probably get things right most of the time.
>
> And the only way Drivetec was able to get that to work was by using an
> embedded servo for closed-loop positioning.

I'm not sure that the "fine" stepper was used other than to bring the 
head initially on-track.  That is, I'm not at all sure that it 
compensated for any eccentricity.

--Chuck