Fixing 8" disk hubs - test-drb@ccmp.vtda.org

2 Mar 2006

Hi
 Also, make sure that the disk isn't being clamped
too tightly by the disk envelope. I've seen this
happen a number of times by disk that were stored
tightly in a bunch of disk.
 Things usually work OK if I manually rotate the disk
in the envelope a few times but I've had to remove
the disk from the envelope in a couple cases.
Dwight

...
 From: ard at p850ug1.demon.co.uk

 All:

             I'm restoring an IMSAI system which has an Icom "Frugal
Floppy"
 system setup (8" FD-400 drives). I've been getting CRC errors since I got it
 running a few weeks ago, so I decided to run it with the cover off to try to
 see what's going on. Tonight I noticed that the floppy disk itself wasn't
 spinning. The hub engages when the door closes but it must be *just* missing
 contacting the diskette by *this* much.

             What kind of tricks are people using to improve the contact
 between the floppy disk and the spindle hub? I remember they made "hub
 protectors" for 5.25" disks - is there something similar? Other ideas? 
I think you're going about it in the wrong way. If the disks are not 
obviously physically damaged (and you don't mention that they are), the 
drive should grip them. If it doesn't, the fault is with the drive, not 
with the disks. And I never believe in 'curing the symptoms'

For some reason your drive is not clamping the disk properly. Maybe 
there's a spring that's not providing enough tension. Maybe a mechanical 
latch is not alighned properly and the clamp is not held down far enough. 
I would start looking at something like that.

-tony 