head-positioners - (was Apple Floppy Drives (was: More Apple Pimpers))

From: Don Maslin <donm_at_cts.com>
Date: Thu Nov 8 13:31:42 2001

On Thu, 8 Nov 2001, Richard Erlacher wrote:

> That spiral cam was an attempt to reduce price and mass, I suppose. Like the
> stone wheel, I imagine it was better than SOME of the other options available at
> the time, in one respect or another.
>
> I don't remember at all (go figure!) what options there were at the time, short
> of the lead-screw that was used on 8" drives, for moving the heads. I've got a
> few pictures of Siemens mini-drives (5-1/4") that use lead screws, but I don't
> remember other vendors using them. Did Shugart make a minifloppy with a lead
> screw? The old BASF drives that I've cussed from time to time for their
> fragility at the door latch used that spiral cam arrangement. It was
> interesting, and, if you worked at it, you could foul it up, since it was
> readily accessible. Every other scheme I remember from that period used a
> tendon drive, as did the DS 8" drives, other than Siemens'. What do you
> remember?
>
> Dick
>

Aside from the abortive spiral cam, about all that I recall in the full
height 5.25" drives was the `capstan/split-band' scheme used by Tandon
and many others then and later. Lead-screw types became more common in
the half height drives, I believe, and some survive even today in the
3.5" half height drives.
                                                 - don
________O/_______
        O\
Received on Thu Nov 08 2001 - 13:31:42 GMT