[Coco] Cleaning old 5.25" floppy drives

[Gene Heskett]

Jim Cox wrote:
> I have rescued a few 5.25" floppy drives and would like to use them for 
> working with the CoCo and other projects. Most are 1.2M drives, but 
> there are a few 360K drives.
> 
> What is the best way to clean these?  I of course will be dusting them 
> with canned air, but how should I clean the heads?  What else should I 
> look out for?
> 
> -Jim Cox
> http://www.miba51.com/
> 
Long sherwood medical q-tips, and paint thinner alcohol in quarts from 
your local ACE HDWE etc.  There are places that should be cleaned other 
than the heads which should be the first point of attack.  Next is the 
track rods the head carriage slides on, which will need any crud removed 
and a drop of light oil applied.  Then if the stepper drive is one with 
the thin steel straps running around a pulley on the motor, make sure 
the pulley and the straps are clean because a wee bit of dust there can 
result in missed tracking on the inner tracks, or even in erratic 
location of track zero when the controller attempts to zero the head.

Those drives, both 3.5 and 5 inch, that use a spiral drive groove in a 
long shaft to move the head from a small motor at the back of the drive, 
will need to have that groove cleaned up down to bare metal, and the 
wire that engages that groove also cleaned, then given a drop of light 
oil.  Except in Amiga's, wear there isn't usually a problem, but the 
amiga's usually managed to destroy their floppies in a couple of years 
because they did a seek to zero and a read of the disk every few seconds 
just to see if there was a disk in the drive.  Bad dog, no bisquit IMO.

Belt drive disk hubs might need the belt replaced too.  Those will 
usually have a strobe pattern pasted on them so you can check the speed 
with a florescent lamp.

Lastly, some of the rosettes that clamp the disk to the drive hub can 
take a 'set', which has 2 effects.  The first one is poor centering 
because thats how they normally bend in their old age, and secondarily, 
  the pressure from the clamp spring may be reduced, both from aging of 
the spring, and the collapsing plastic of the rosette that enters the 
hole in the disk and both centers it and exerts (we hope, it can be a 
huge problem with 8" drives) enough clamping pressure to rotate the disk 
at the correct speed.

-- 
Cheers, Gene