let's try this again... how do you build a floppy disk? - test-drb@ccmp.vtda.org

17 Feb 2013

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On Sat, Feb 16, 2013 8:44 PM PST Chuck Guzis wrote:

...
 On 02/16/2013 07:51 PM, Chris Tofu wrote:

 start with a disk...

 Then what? smear on some rust? is it sprayed on? once you get the
 chemistry correct it doesn't sound like the application portion
 should be that challenging. is there an adhesive applied first?
 Afterwards? Where's that Jeri lady. Get her on this LOL 
Well, no, you don't start with a disk.  That would be silly.

You start with a very wide blanket-on-a-roll of substrate.  You mix the binder and oxide
together in a thick paste and spread them on the sheet.  I suspect that the thickness of
the coating is regulated by a "doctor blade" setup.  The coating is cured and
then round disks are punched--the result is called a "cookie" for obvious
reasons.  It's then verified and inserted into the jacketing medium, sealed and
packaged. 
 Not so fast bucko. Got to flip the blankee over and coat that side.

...
 The oxide coating on a 5.25" DD floppy is not much
different from that of VHS videotape.  I suspect that the demise of floppy manufacturing
to more a case of video- and audiotape dying off. 
 I would think what put the kybosh on both were advances in optical media, which became a
solution for computer storage earlier then video.

 Both useful.posts though. Anyone think this can't be done? Is choice of substrate
that critical? Question in my mind is how to control the thickness. This is why I had
thought spraying would be appropriate. Maybe it is.